2 * GENerational Conservative Garbage Collector for SBCL x86
6 * This software is part of the SBCL system. See the README file for
9 * This software is derived from the CMU CL system, which was
10 * written at Carnegie Mellon University and released into the
11 * public domain. The software is in the public domain and is
12 * provided with absolutely no warranty. See the COPYING and CREDITS
13 * files for more information.
17 * For a review of garbage collection techniques (e.g. generational
18 * GC) and terminology (e.g. "scavenging") see Paul R. Wilson,
19 * "Uniprocessor Garbage Collection Techniques". As of 20000618, this
20 * had been accepted for _ACM Computing Surveys_ and was available
21 * as a PostScript preprint through
22 * <http://www.cs.utexas.edu/users/oops/papers.html>
24 * <ftp://ftp.cs.utexas.edu/pub/garbage/bigsurv.ps>.
34 #include "interrupt.h"
41 /* a function defined externally in assembly language, called from
43 void do_pending_interrupt(void);
49 /* the number of actual generations. (The number of 'struct
50 * generation' objects is one more than this, because one object
51 * serves as scratch when GC'ing.) */
52 #define NUM_GENERATIONS 6
54 /* Should we use page protection to help avoid the scavenging of pages
55 * that don't have pointers to younger generations? */
56 boolean enable_page_protection = 1;
58 /* Should we unmap a page and re-mmap it to have it zero filled? */
59 #if defined(__FreeBSD__) || defined(__OpenBSD__)
60 /* comment from cmucl-2.4.8: This can waste a lot of swap on FreeBSD
61 * so don't unmap there.
63 * The CMU CL comment didn't specify a version, but was probably an
64 * old version of FreeBSD (pre-4.0), so this might no longer be true.
65 * OTOH, if it is true, this behavior might exist on OpenBSD too, so
66 * for now we don't unmap there either. -- WHN 2001-04-07 */
67 boolean gencgc_unmap_zero = 0;
69 boolean gencgc_unmap_zero = 1;
72 /* the minimum size (in bytes) for a large object*/
73 unsigned large_object_size = 4 * 4096;
79 #define gc_abort() lose("GC invariant lost, file \"%s\", line %d", \
82 /* FIXME: In CMU CL, this was "#if 0" with no explanation. Find out
83 * how much it costs to make it "#if 1". If it's not too expensive,
86 #define gc_assert(ex) do { \
87 if (!(ex)) gc_abort(); \
93 /* the verbosity level. All non-error messages are disabled at level 0;
94 * and only a few rare messages are printed at level 1. */
95 unsigned gencgc_verbose = (QSHOW ? 1 : 0);
97 /* FIXME: At some point enable the various error-checking things below
98 * and see what they say. */
100 /* We hunt for pointers to old-space, when GCing generations >= verify_gen.
101 * Set verify_gens to NUM_GENERATIONS to disable this kind of check. */
102 int verify_gens = NUM_GENERATIONS;
104 /* Should we do a pre-scan verify of generation 0 before it's GCed? */
105 boolean pre_verify_gen_0 = 0;
107 /* Should we check for bad pointers after gc_free_heap is called
108 * from Lisp PURIFY? */
109 boolean verify_after_free_heap = 0;
111 /* Should we print a note when code objects are found in the dynamic space
112 * during a heap verify? */
113 boolean verify_dynamic_code_check = 0;
115 /* Should we check code objects for fixup errors after they are transported? */
116 boolean check_code_fixups = 0;
118 /* Should we check that newly allocated regions are zero filled? */
119 boolean gencgc_zero_check = 0;
121 /* Should we check that the free space is zero filled? */
122 boolean gencgc_enable_verify_zero_fill = 0;
124 /* Should we check that free pages are zero filled during gc_free_heap
125 * called after Lisp PURIFY? */
126 boolean gencgc_zero_check_during_free_heap = 0;
129 * GC structures and variables
132 /* the total bytes allocated. These are seen by Lisp DYNAMIC-USAGE. */
133 unsigned long bytes_allocated = 0;
134 static unsigned long auto_gc_trigger = 0;
136 /* the source and destination generations. These are set before a GC starts
138 static int from_space;
139 static int new_space;
141 /* FIXME: It would be nice to use this symbolic constant instead of
142 * bare 4096 almost everywhere. We could also use an assertion that
143 * it's equal to getpagesize(). */
144 #define PAGE_BYTES 4096
146 /* An array of page structures is statically allocated.
147 * This helps quickly map between an address its page structure.
148 * NUM_PAGES is set from the size of the dynamic space. */
149 struct page page_table[NUM_PAGES];
151 /* To map addresses to page structures the address of the first page
153 static void *heap_base = NULL;
155 /* Calculate the start address for the given page number. */
157 page_address(int page_num)
159 return (heap_base + (page_num * 4096));
162 /* Find the page index within the page_table for the given
163 * address. Return -1 on failure. */
165 find_page_index(void *addr)
167 int index = addr-heap_base;
170 index = ((unsigned int)index)/4096;
171 if (index < NUM_PAGES)
178 /* a structure to hold the state of a generation */
181 /* the first page that gc_alloc() checks on its next call */
182 int alloc_start_page;
184 /* the first page that gc_alloc_unboxed() checks on its next call */
185 int alloc_unboxed_start_page;
187 /* the first page that gc_alloc_large (boxed) considers on its next
188 * call. (Although it always allocates after the boxed_region.) */
189 int alloc_large_start_page;
191 /* the first page that gc_alloc_large (unboxed) considers on its
192 * next call. (Although it always allocates after the
193 * current_unboxed_region.) */
194 int alloc_large_unboxed_start_page;
196 /* the bytes allocated to this generation */
199 /* the number of bytes at which to trigger a GC */
202 /* to calculate a new level for gc_trigger */
203 int bytes_consed_between_gc;
205 /* the number of GCs since the last raise */
208 /* the average age after which a GC will raise objects to the
212 /* the cumulative sum of the bytes allocated to this generation. It is
213 * cleared after a GC on this generations, and update before new
214 * objects are added from a GC of a younger generation. Dividing by
215 * the bytes_allocated will give the average age of the memory in
216 * this generation since its last GC. */
217 int cum_sum_bytes_allocated;
219 /* a minimum average memory age before a GC will occur helps
220 * prevent a GC when a large number of new live objects have been
221 * added, in which case a GC could be a waste of time */
222 double min_av_mem_age;
225 /* an array of generation structures. There needs to be one more
226 * generation structure than actual generations as the oldest
227 * generation is temporarily raised then lowered. */
228 static struct generation generations[NUM_GENERATIONS+1];
230 /* the oldest generation that is will currently be GCed by default.
231 * Valid values are: 0, 1, ... (NUM_GENERATIONS-1)
233 * The default of (NUM_GENERATIONS-1) enables GC on all generations.
235 * Setting this to 0 effectively disables the generational nature of
236 * the GC. In some applications generational GC may not be useful
237 * because there are no long-lived objects.
239 * An intermediate value could be handy after moving long-lived data
240 * into an older generation so an unnecessary GC of this long-lived
241 * data can be avoided. */
242 unsigned int gencgc_oldest_gen_to_gc = NUM_GENERATIONS-1;
244 /* The maximum free page in the heap is maintained and used to update
245 * ALLOCATION_POINTER which is used by the room function to limit its
246 * search of the heap. XX Gencgc obviously needs to be better
247 * integrated with the Lisp code. */
248 static int last_free_page;
249 static int last_used_page = 0;
252 * miscellaneous heap functions
255 /* Count the number of pages which are write-protected within the
256 * given generation. */
258 count_write_protect_generation_pages(int generation)
263 for (i = 0; i < last_free_page; i++)
264 if ((page_table[i].allocated != FREE_PAGE)
265 && (page_table[i].gen == generation)
266 && (page_table[i].write_protected == 1))
271 /* Count the number of pages within the given generation. */
273 count_generation_pages(int generation)
278 for (i = 0; i < last_free_page; i++)
279 if ((page_table[i].allocated != 0)
280 && (page_table[i].gen == generation))
285 /* Count the number of dont_move pages. */
287 count_dont_move_pages(void)
291 for (i = 0; i < last_free_page; i++) {
292 if ((page_table[i].allocated != 0) && (page_table[i].dont_move != 0)) {
299 /* Work through the pages and add up the number of bytes used for the
300 * given generation. */
302 count_generation_bytes_allocated (int gen)
306 for (i = 0; i < last_free_page; i++) {
307 if ((page_table[i].allocated != 0) && (page_table[i].gen == gen))
308 result += page_table[i].bytes_used;
313 /* Return the average age of the memory in a generation. */
315 gen_av_mem_age(int gen)
317 if (generations[gen].bytes_allocated == 0)
321 ((double)generations[gen].cum_sum_bytes_allocated)
322 / ((double)generations[gen].bytes_allocated);
325 /* The verbose argument controls how much to print: 0 for normal
326 * level of detail; 1 for debugging. */
328 print_generation_stats(int verbose) /* FIXME: should take FILE argument */
333 /* This code uses the FP instructions which may be set up for Lisp
334 * so they need to be saved and reset for C. */
337 /* number of generations to print */
339 gens = NUM_GENERATIONS+1;
341 gens = NUM_GENERATIONS;
343 /* Print the heap stats. */
345 " Generation Boxed Unboxed LB LUB Alloc Waste Trig WP GCs Mem-age\n");
347 for (i = 0; i < gens; i++) {
351 int large_boxed_cnt = 0;
352 int large_unboxed_cnt = 0;
354 for (j = 0; j < last_free_page; j++)
355 if (page_table[j].gen == i) {
357 /* Count the number of boxed pages within the given
359 if (page_table[j].allocated == BOXED_PAGE) {
360 if (page_table[j].large_object)
366 /* Count the number of unboxed pages within the given
368 if (page_table[j].allocated == UNBOXED_PAGE) {
369 if (page_table[j].large_object)
376 gc_assert(generations[i].bytes_allocated
377 == count_generation_bytes_allocated(i));
379 " %8d: %5d %5d %5d %5d %8d %5d %8d %4d %3d %7.4f\n",
381 boxed_cnt, unboxed_cnt, large_boxed_cnt, large_unboxed_cnt,
382 generations[i].bytes_allocated,
383 (count_generation_pages(i)*4096
384 - generations[i].bytes_allocated),
385 generations[i].gc_trigger,
386 count_write_protect_generation_pages(i),
387 generations[i].num_gc,
390 fprintf(stderr," Total bytes allocated=%ld\n", bytes_allocated);
392 fpu_restore(fpu_state);
396 * allocation routines
400 * To support quick and inline allocation, regions of memory can be
401 * allocated and then allocated from with just a free pointer and a
402 * check against an end address.
404 * Since objects can be allocated to spaces with different properties
405 * e.g. boxed/unboxed, generation, ages; there may need to be many
406 * allocation regions.
408 * Each allocation region may be start within a partly used page. Many
409 * features of memory use are noted on a page wise basis, e.g. the
410 * generation; so if a region starts within an existing allocated page
411 * it must be consistent with this page.
413 * During the scavenging of the newspace, objects will be transported
414 * into an allocation region, and pointers updated to point to this
415 * allocation region. It is possible that these pointers will be
416 * scavenged again before the allocation region is closed, e.g. due to
417 * trans_list which jumps all over the place to cleanup the list. It
418 * is important to be able to determine properties of all objects
419 * pointed to when scavenging, e.g to detect pointers to the oldspace.
420 * Thus it's important that the allocation regions have the correct
421 * properties set when allocated, and not just set when closed. The
422 * region allocation routines return regions with the specified
423 * properties, and grab all the pages, setting their properties
424 * appropriately, except that the amount used is not known.
426 * These regions are used to support quicker allocation using just a
427 * free pointer. The actual space used by the region is not reflected
428 * in the pages tables until it is closed. It can't be scavenged until
431 * When finished with the region it should be closed, which will
432 * update the page tables for the actual space used returning unused
433 * space. Further it may be noted in the new regions which is
434 * necessary when scavenging the newspace.
436 * Large objects may be allocated directly without an allocation
437 * region, the page tables are updated immediately.
439 * Unboxed objects don't contain pointers to other objects and so
440 * don't need scavenging. Further they can't contain pointers to
441 * younger generations so WP is not needed. By allocating pages to
442 * unboxed objects the whole page never needs scavenging or
443 * write-protecting. */
445 /* We are only using two regions at present. Both are for the current
446 * newspace generation. */
447 struct alloc_region boxed_region;
448 struct alloc_region unboxed_region;
450 /* XX hack. Current Lisp code uses the following. Need copying in/out. */
451 void *current_region_free_pointer;
452 void *current_region_end_addr;
454 /* The generation currently being allocated to. */
455 static int gc_alloc_generation;
457 /* Find a new region with room for at least the given number of bytes.
459 * It starts looking at the current generation's alloc_start_page. So
460 * may pick up from the previous region if there is enough space. This
461 * keeps the allocation contiguous when scavenging the newspace.
463 * The alloc_region should have been closed by a call to
464 * gc_alloc_update_page_tables(), and will thus be in an empty state.
466 * To assist the scavenging functions write-protected pages are not
467 * used. Free pages should not be write-protected.
469 * It is critical to the conservative GC that the start of regions be
470 * known. To help achieve this only small regions are allocated at a
473 * During scavenging, pointers may be found to within the current
474 * region and the page generation must be set so that pointers to the
475 * from space can be recognized. Therefore the generation of pages in
476 * the region are set to gc_alloc_generation. To prevent another
477 * allocation call using the same pages, all the pages in the region
478 * are allocated, although they will initially be empty.
481 gc_alloc_new_region(int nbytes, int unboxed, struct alloc_region *alloc_region)
493 "/alloc_new_region for %d bytes from gen %d\n",
494 nbytes, gc_alloc_generation));
497 /* Check that the region is in a reset state. */
498 gc_assert((alloc_region->first_page == 0)
499 && (alloc_region->last_page == -1)
500 && (alloc_region->free_pointer == alloc_region->end_addr));
504 generations[gc_alloc_generation].alloc_unboxed_start_page;
507 generations[gc_alloc_generation].alloc_start_page;
510 /* Search for a contiguous free region of at least nbytes with the
511 * given properties: boxed/unboxed, generation. */
513 first_page = restart_page;
515 /* First search for a page with at least 32 bytes free, which is
516 * not write-protected, and which is not marked dont_move.
518 * FIXME: This looks extremely similar, perhaps identical, to
519 * code in gc_alloc_large(). It should be shared somehow. */
520 while ((first_page < NUM_PAGES)
521 && (page_table[first_page].allocated != FREE_PAGE) /* not free page */
523 (page_table[first_page].allocated != UNBOXED_PAGE))
525 (page_table[first_page].allocated != BOXED_PAGE))
526 || (page_table[first_page].large_object != 0)
527 || (page_table[first_page].gen != gc_alloc_generation)
528 || (page_table[first_page].bytes_used >= (4096-32))
529 || (page_table[first_page].write_protected != 0)
530 || (page_table[first_page].dont_move != 0)))
532 /* Check for a failure. */
533 if (first_page >= NUM_PAGES) {
535 "Argh! gc_alloc_new_region failed on first_page, nbytes=%d.\n",
537 print_generation_stats(1);
541 gc_assert(page_table[first_page].write_protected == 0);
545 "/first_page=%d bytes_used=%d\n",
546 first_page, page_table[first_page].bytes_used));
549 /* Now search forward to calculate the available region size. It
550 * tries to keeps going until nbytes are found and the number of
551 * pages is greater than some level. This helps keep down the
552 * number of pages in a region. */
553 last_page = first_page;
554 bytes_found = 4096 - page_table[first_page].bytes_used;
556 while (((bytes_found < nbytes) || (num_pages < 2))
557 && (last_page < (NUM_PAGES-1))
558 && (page_table[last_page+1].allocated == FREE_PAGE)) {
562 gc_assert(page_table[last_page].write_protected == 0);
565 region_size = (4096 - page_table[first_page].bytes_used)
566 + 4096*(last_page-first_page);
568 gc_assert(bytes_found == region_size);
572 "/last_page=%d bytes_found=%d num_pages=%d\n",
573 last_page, bytes_found, num_pages));
576 restart_page = last_page + 1;
577 } while ((restart_page < NUM_PAGES) && (bytes_found < nbytes));
579 /* Check for a failure. */
580 if ((restart_page >= NUM_PAGES) && (bytes_found < nbytes)) {
582 "Argh! gc_alloc_new_region() failed on restart_page, nbytes=%d.\n",
584 print_generation_stats(1);
590 "/gc_alloc_new_region() gen %d: %d bytes: pages %d to %d: addr=%x\n",
595 page_address(first_page)));
598 /* Set up the alloc_region. */
599 alloc_region->first_page = first_page;
600 alloc_region->last_page = last_page;
601 alloc_region->start_addr = page_table[first_page].bytes_used
602 + page_address(first_page);
603 alloc_region->free_pointer = alloc_region->start_addr;
604 alloc_region->end_addr = alloc_region->start_addr + bytes_found;
606 if (gencgc_zero_check) {
608 for (p = (int *)alloc_region->start_addr;
609 p < (int *)alloc_region->end_addr; p++) {
611 /* KLUDGE: It would be nice to use %lx and explicit casts
612 * (long) in code like this, so that it is less likely to
613 * break randomly when running on a machine with different
614 * word sizes. -- WHN 19991129 */
615 lose("The new region at %x is not zero.", p);
620 /* Set up the pages. */
622 /* The first page may have already been in use. */
623 if (page_table[first_page].bytes_used == 0) {
625 page_table[first_page].allocated = UNBOXED_PAGE;
627 page_table[first_page].allocated = BOXED_PAGE;
628 page_table[first_page].gen = gc_alloc_generation;
629 page_table[first_page].large_object = 0;
630 page_table[first_page].first_object_offset = 0;
634 gc_assert(page_table[first_page].allocated == UNBOXED_PAGE);
636 gc_assert(page_table[first_page].allocated == BOXED_PAGE);
637 gc_assert(page_table[first_page].gen == gc_alloc_generation);
638 gc_assert(page_table[first_page].large_object == 0);
640 for (i = first_page+1; i <= last_page; i++) {
642 page_table[i].allocated = UNBOXED_PAGE;
644 page_table[i].allocated = BOXED_PAGE;
645 page_table[i].gen = gc_alloc_generation;
646 page_table[i].large_object = 0;
647 /* This may not be necessary for unboxed regions (think it was
649 page_table[i].first_object_offset =
650 alloc_region->start_addr - page_address(i);
653 /* Bump up last_free_page. */
654 if (last_page+1 > last_free_page) {
655 last_free_page = last_page+1;
656 SetSymbolValue(ALLOCATION_POINTER,
657 (lispobj)(((char *)heap_base) + last_free_page*4096));
658 if (last_page+1 > last_used_page)
659 last_used_page = last_page+1;
663 /* If the record_new_objects flag is 2 then all new regions created
666 * If it's 1 then then it is only recorded if the first page of the
667 * current region is <= new_areas_ignore_page. This helps avoid
668 * unnecessary recording when doing full scavenge pass.
670 * The new_object structure holds the page, byte offset, and size of
671 * new regions of objects. Each new area is placed in the array of
672 * these structures pointer to by new_areas. new_areas_index holds the
673 * offset into new_areas.
675 * If new_area overflows NUM_NEW_AREAS then it stops adding them. The
676 * later code must detect this and handle it, probably by doing a full
677 * scavenge of a generation. */
678 #define NUM_NEW_AREAS 512
679 static int record_new_objects = 0;
680 static int new_areas_ignore_page;
686 static struct new_area (*new_areas)[];
687 static int new_areas_index;
690 /* Add a new area to new_areas. */
692 add_new_area(int first_page, int offset, int size)
694 unsigned new_area_start,c;
697 /* Ignore if full. */
698 if (new_areas_index >= NUM_NEW_AREAS)
701 switch (record_new_objects) {
705 if (first_page > new_areas_ignore_page)
714 new_area_start = 4096*first_page + offset;
716 /* Search backwards for a prior area that this follows from. If
717 found this will save adding a new area. */
718 for (i = new_areas_index-1, c = 0; (i >= 0) && (c < 8); i--, c++) {
720 4096*((*new_areas)[i].page)
721 + (*new_areas)[i].offset
722 + (*new_areas)[i].size;
724 "/add_new_area S1 %d %d %d %d\n",
725 i, c, new_area_start, area_end));*/
726 if (new_area_start == area_end) {
728 "/adding to [%d] %d %d %d with %d %d %d:\n",
730 (*new_areas)[i].page,
731 (*new_areas)[i].offset,
732 (*new_areas)[i].size,
736 (*new_areas)[i].size += size;
740 /*FSHOW((stderr, "/add_new_area S1 %d %d %d\n", i, c, new_area_start));*/
742 (*new_areas)[new_areas_index].page = first_page;
743 (*new_areas)[new_areas_index].offset = offset;
744 (*new_areas)[new_areas_index].size = size;
746 "/new_area %d page %d offset %d size %d\n",
747 new_areas_index, first_page, offset, size));*/
750 /* Note the max new_areas used. */
751 if (new_areas_index > max_new_areas)
752 max_new_areas = new_areas_index;
755 /* Update the tables for the alloc_region. The region maybe added to
758 * When done the alloc_region is set up so that the next quick alloc
759 * will fail safely and thus a new region will be allocated. Further
760 * it is safe to try to re-update the page table of this reset
763 gc_alloc_update_page_tables(int unboxed, struct alloc_region *alloc_region)
769 int orig_first_page_bytes_used;
775 "/gc_alloc_update_page_tables() to gen %d:\n",
776 gc_alloc_generation));
779 first_page = alloc_region->first_page;
781 /* Catch an unused alloc_region. */
782 if ((first_page == 0) && (alloc_region->last_page == -1))
785 next_page = first_page+1;
787 /* Skip if no bytes were allocated. */
788 if (alloc_region->free_pointer != alloc_region->start_addr) {
789 orig_first_page_bytes_used = page_table[first_page].bytes_used;
791 gc_assert(alloc_region->start_addr == (page_address(first_page) + page_table[first_page].bytes_used));
793 /* All the pages used need to be updated */
795 /* Update the first page. */
797 /* If the page was free then set up the gen, and
798 * first_object_offset. */
799 if (page_table[first_page].bytes_used == 0)
800 gc_assert(page_table[first_page].first_object_offset == 0);
803 gc_assert(page_table[first_page].allocated == UNBOXED_PAGE);
805 gc_assert(page_table[first_page].allocated == BOXED_PAGE);
806 gc_assert(page_table[first_page].gen == gc_alloc_generation);
807 gc_assert(page_table[first_page].large_object == 0);
811 /* Calculate the number of bytes used in this page. This is not
812 * always the number of new bytes, unless it was free. */
814 if ((bytes_used = (alloc_region->free_pointer - page_address(first_page)))>4096) {
818 page_table[first_page].bytes_used = bytes_used;
819 byte_cnt += bytes_used;
822 /* All the rest of the pages should be free. We need to set their
823 * first_object_offset pointer to the start of the region, and set
827 gc_assert(page_table[next_page].allocated == UNBOXED_PAGE);
829 gc_assert(page_table[next_page].allocated == BOXED_PAGE);
830 gc_assert(page_table[next_page].bytes_used == 0);
831 gc_assert(page_table[next_page].gen == gc_alloc_generation);
832 gc_assert(page_table[next_page].large_object == 0);
834 gc_assert(page_table[next_page].first_object_offset ==
835 alloc_region->start_addr - page_address(next_page));
837 /* Calculate the number of bytes used in this page. */
839 if ((bytes_used = (alloc_region->free_pointer
840 - page_address(next_page)))>4096) {
844 page_table[next_page].bytes_used = bytes_used;
845 byte_cnt += bytes_used;
850 region_size = alloc_region->free_pointer - alloc_region->start_addr;
851 bytes_allocated += region_size;
852 generations[gc_alloc_generation].bytes_allocated += region_size;
854 gc_assert((byte_cnt- orig_first_page_bytes_used) == region_size);
856 /* Set the generations alloc restart page to the last page of
859 generations[gc_alloc_generation].alloc_unboxed_start_page =
862 generations[gc_alloc_generation].alloc_start_page = next_page-1;
864 /* Add the region to the new_areas if requested. */
866 add_new_area(first_page,orig_first_page_bytes_used, region_size);
870 "/gc_alloc_update_page_tables update %d bytes to gen %d\n",
872 gc_alloc_generation));
875 /* There are no bytes allocated. Unallocate the first_page if
876 * there are 0 bytes_used. */
877 if (page_table[first_page].bytes_used == 0)
878 page_table[first_page].allocated = FREE_PAGE;
881 /* Unallocate any unused pages. */
882 while (next_page <= alloc_region->last_page) {
883 gc_assert(page_table[next_page].bytes_used == 0);
884 page_table[next_page].allocated = FREE_PAGE;
888 /* Reset the alloc_region. */
889 alloc_region->first_page = 0;
890 alloc_region->last_page = -1;
891 alloc_region->start_addr = page_address(0);
892 alloc_region->free_pointer = page_address(0);
893 alloc_region->end_addr = page_address(0);
896 static inline void *gc_quick_alloc(int nbytes);
898 /* Allocate a possibly large object. */
900 gc_alloc_large(int nbytes, int unboxed, struct alloc_region *alloc_region)
908 int orig_first_page_bytes_used;
913 int large = (nbytes >= large_object_size);
917 FSHOW((stderr, "/alloc_large %d\n", nbytes));
922 "/gc_alloc_large() for %d bytes from gen %d\n",
923 nbytes, gc_alloc_generation));
926 /* If the object is small, and there is room in the current region
927 then allocation it in the current region. */
929 && ((alloc_region->end_addr-alloc_region->free_pointer) >= nbytes))
930 return gc_quick_alloc(nbytes);
932 /* Search for a contiguous free region of at least nbytes. If it's a
933 large object then align it on a page boundary by searching for a
936 /* To allow the allocation of small objects without the danger of
937 using a page in the current boxed region, the search starts after
938 the current boxed free region. XX could probably keep a page
939 index ahead of the current region and bumped up here to save a
940 lot of re-scanning. */
943 generations[gc_alloc_generation].alloc_large_unboxed_start_page;
945 restart_page = generations[gc_alloc_generation].alloc_large_start_page;
947 if (restart_page <= alloc_region->last_page) {
948 restart_page = alloc_region->last_page+1;
952 first_page = restart_page;
955 while ((first_page < NUM_PAGES)
956 && (page_table[first_page].allocated != FREE_PAGE))
959 /* FIXME: This looks extremely similar, perhaps identical,
960 * to code in gc_alloc_new_region(). It should be shared
962 while ((first_page < NUM_PAGES)
963 && (page_table[first_page].allocated != FREE_PAGE)
965 (page_table[first_page].allocated != UNBOXED_PAGE))
967 (page_table[first_page].allocated != BOXED_PAGE))
968 || (page_table[first_page].large_object != 0)
969 || (page_table[first_page].gen != gc_alloc_generation)
970 || (page_table[first_page].bytes_used >= (4096-32))
971 || (page_table[first_page].write_protected != 0)
972 || (page_table[first_page].dont_move != 0)))
975 if (first_page >= NUM_PAGES) {
977 "Argh! gc_alloc_large failed (first_page), nbytes=%d.\n",
979 print_generation_stats(1);
983 gc_assert(page_table[first_page].write_protected == 0);
987 "/first_page=%d bytes_used=%d\n",
988 first_page, page_table[first_page].bytes_used));
991 last_page = first_page;
992 bytes_found = 4096 - page_table[first_page].bytes_used;
994 while ((bytes_found < nbytes)
995 && (last_page < (NUM_PAGES-1))
996 && (page_table[last_page+1].allocated == FREE_PAGE)) {
1000 gc_assert(page_table[last_page].write_protected == 0);
1003 region_size = (4096 - page_table[first_page].bytes_used)
1004 + 4096*(last_page-first_page);
1006 gc_assert(bytes_found == region_size);
1010 "/last_page=%d bytes_found=%d num_pages=%d\n",
1011 last_page, bytes_found, num_pages));
1014 restart_page = last_page + 1;
1015 } while ((restart_page < NUM_PAGES) && (bytes_found < nbytes));
1017 /* Check for a failure */
1018 if ((restart_page >= NUM_PAGES) && (bytes_found < nbytes)) {
1020 "Argh! gc_alloc_large failed (restart_page), nbytes=%d.\n",
1022 print_generation_stats(1);
1029 "/gc_alloc_large() gen %d: %d of %d bytes: from pages %d to %d: addr=%x\n",
1030 gc_alloc_generation,
1035 page_address(first_page)));
1038 gc_assert(first_page > alloc_region->last_page);
1040 generations[gc_alloc_generation].alloc_large_unboxed_start_page =
1043 generations[gc_alloc_generation].alloc_large_start_page = last_page;
1045 /* Set up the pages. */
1046 orig_first_page_bytes_used = page_table[first_page].bytes_used;
1048 /* If the first page was free then set up the gen, and
1049 * first_object_offset. */
1050 if (page_table[first_page].bytes_used == 0) {
1052 page_table[first_page].allocated = UNBOXED_PAGE;
1054 page_table[first_page].allocated = BOXED_PAGE;
1055 page_table[first_page].gen = gc_alloc_generation;
1056 page_table[first_page].first_object_offset = 0;
1057 page_table[first_page].large_object = large;
1061 gc_assert(page_table[first_page].allocated == UNBOXED_PAGE);
1063 gc_assert(page_table[first_page].allocated == BOXED_PAGE);
1064 gc_assert(page_table[first_page].gen == gc_alloc_generation);
1065 gc_assert(page_table[first_page].large_object == large);
1069 /* Calc. the number of bytes used in this page. This is not
1070 * always the number of new bytes, unless it was free. */
1072 if ((bytes_used = nbytes+orig_first_page_bytes_used) > 4096) {
1076 page_table[first_page].bytes_used = bytes_used;
1077 byte_cnt += bytes_used;
1079 next_page = first_page+1;
1081 /* All the rest of the pages should be free. We need to set their
1082 * first_object_offset pointer to the start of the region, and
1083 * set the bytes_used. */
1085 gc_assert(page_table[next_page].allocated == FREE_PAGE);
1086 gc_assert(page_table[next_page].bytes_used == 0);
1088 page_table[next_page].allocated = UNBOXED_PAGE;
1090 page_table[next_page].allocated = BOXED_PAGE;
1091 page_table[next_page].gen = gc_alloc_generation;
1092 page_table[next_page].large_object = large;
1094 page_table[next_page].first_object_offset =
1095 orig_first_page_bytes_used - 4096*(next_page-first_page);
1097 /* Calculate the number of bytes used in this page. */
1099 if ((bytes_used=(nbytes+orig_first_page_bytes_used)-byte_cnt) > 4096) {
1103 page_table[next_page].bytes_used = bytes_used;
1104 byte_cnt += bytes_used;
1109 gc_assert((byte_cnt-orig_first_page_bytes_used) == nbytes);
1111 bytes_allocated += nbytes;
1112 generations[gc_alloc_generation].bytes_allocated += nbytes;
1114 /* Add the region to the new_areas if requested. */
1116 add_new_area(first_page,orig_first_page_bytes_used,nbytes);
1118 /* Bump up last_free_page */
1119 if (last_page+1 > last_free_page) {
1120 last_free_page = last_page+1;
1121 SetSymbolValue(ALLOCATION_POINTER,
1122 (lispobj)(((char *)heap_base) + last_free_page*4096));
1123 if (last_page+1 > last_used_page)
1124 last_used_page = last_page+1;
1127 return((void *)(page_address(first_page)+orig_first_page_bytes_used));
1130 /* Allocate bytes from the boxed_region. First checks whether there is
1131 * room. If not then call gc_alloc_new_region() to find a new region
1132 * with enough space. Return a pointer to the start of the region. */
1134 gc_alloc(int nbytes)
1136 void *new_free_pointer;
1138 /* FSHOW((stderr, "/gc_alloc %d\n", nbytes)); */
1140 /* Check whether there is room in the current alloc region. */
1141 new_free_pointer = boxed_region.free_pointer + nbytes;
1143 if (new_free_pointer <= boxed_region.end_addr) {
1144 /* If so then allocate from the current alloc region. */
1145 void *new_obj = boxed_region.free_pointer;
1146 boxed_region.free_pointer = new_free_pointer;
1148 /* Check whether the alloc region is almost empty. */
1149 if ((boxed_region.end_addr - boxed_region.free_pointer) <= 32) {
1150 /* If so finished with the current region. */
1151 gc_alloc_update_page_tables(0, &boxed_region);
1152 /* Set up a new region. */
1153 gc_alloc_new_region(32, 0, &boxed_region);
1155 return((void *)new_obj);
1158 /* Else not enough free space in the current region. */
1160 /* If there some room left in the current region, enough to be worth
1161 * saving, then allocate a large object. */
1162 /* FIXME: "32" should be a named parameter. */
1163 if ((boxed_region.end_addr-boxed_region.free_pointer) > 32)
1164 return gc_alloc_large(nbytes, 0, &boxed_region);
1166 /* Else find a new region. */
1168 /* Finished with the current region. */
1169 gc_alloc_update_page_tables(0, &boxed_region);
1171 /* Set up a new region. */
1172 gc_alloc_new_region(nbytes, 0, &boxed_region);
1174 /* Should now be enough room. */
1176 /* Check whether there is room in the current region. */
1177 new_free_pointer = boxed_region.free_pointer + nbytes;
1179 if (new_free_pointer <= boxed_region.end_addr) {
1180 /* If so then allocate from the current region. */
1181 void *new_obj = boxed_region.free_pointer;
1182 boxed_region.free_pointer = new_free_pointer;
1184 /* Check whether the current region is almost empty. */
1185 if ((boxed_region.end_addr - boxed_region.free_pointer) <= 32) {
1186 /* If so find, finished with the current region. */
1187 gc_alloc_update_page_tables(0, &boxed_region);
1189 /* Set up a new region. */
1190 gc_alloc_new_region(32, 0, &boxed_region);
1193 return((void *)new_obj);
1196 /* shouldn't happen */
1198 return((void *) NIL); /* dummy value: return something ... */
1201 /* Allocate space from the boxed_region. If there is not enough free
1202 * space then call gc_alloc to do the job. A pointer to the start of
1203 * the region is returned. */
1204 static inline void *
1205 gc_quick_alloc(int nbytes)
1207 void *new_free_pointer;
1209 /* Check whether there is room in the current region. */
1210 new_free_pointer = boxed_region.free_pointer + nbytes;
1212 if (new_free_pointer <= boxed_region.end_addr) {
1213 /* Allocate from the current region. */
1214 void *new_obj = boxed_region.free_pointer;
1215 boxed_region.free_pointer = new_free_pointer;
1216 return((void *)new_obj);
1218 /* Let full gc_alloc() handle it. */
1219 return gc_alloc(nbytes);
1223 /* Allocate space for the boxed object. If it is a large object then
1224 * do a large alloc else allocate from the current region. If there is
1225 * not enough free space then call gc_alloc() to do the job. A pointer
1226 * to the start of the region is returned. */
1227 static inline void *
1228 gc_quick_alloc_large(int nbytes)
1230 void *new_free_pointer;
1232 if (nbytes >= large_object_size)
1233 return gc_alloc_large(nbytes, 0, &boxed_region);
1235 /* Check whether there is room in the current region. */
1236 new_free_pointer = boxed_region.free_pointer + nbytes;
1238 if (new_free_pointer <= boxed_region.end_addr) {
1239 /* If so then allocate from the current region. */
1240 void *new_obj = boxed_region.free_pointer;
1241 boxed_region.free_pointer = new_free_pointer;
1242 return((void *)new_obj);
1244 /* Let full gc_alloc() handle it. */
1245 return gc_alloc(nbytes);
1250 gc_alloc_unboxed(int nbytes)
1252 void *new_free_pointer;
1255 FSHOW((stderr, "/gc_alloc_unboxed() %d\n", nbytes));
1258 /* Check whether there is room in the current region. */
1259 new_free_pointer = unboxed_region.free_pointer + nbytes;
1261 if (new_free_pointer <= unboxed_region.end_addr) {
1262 /* If so then allocate from the current region. */
1263 void *new_obj = unboxed_region.free_pointer;
1264 unboxed_region.free_pointer = new_free_pointer;
1266 /* Check whether the current region is almost empty. */
1267 if ((unboxed_region.end_addr - unboxed_region.free_pointer) <= 32) {
1268 /* If so finished with the current region. */
1269 gc_alloc_update_page_tables(1, &unboxed_region);
1271 /* Set up a new region. */
1272 gc_alloc_new_region(32, 1, &unboxed_region);
1275 return((void *)new_obj);
1278 /* Else not enough free space in the current region. */
1280 /* If there is a bit of room left in the current region then
1281 allocate a large object. */
1282 if ((unboxed_region.end_addr-unboxed_region.free_pointer) > 32)
1283 return gc_alloc_large(nbytes,1,&unboxed_region);
1285 /* Else find a new region. */
1287 /* Finished with the current region. */
1288 gc_alloc_update_page_tables(1, &unboxed_region);
1290 /* Set up a new region. */
1291 gc_alloc_new_region(nbytes, 1, &unboxed_region);
1293 /* (There should now be enough room.) */
1295 /* Check whether there is room in the current region. */
1296 new_free_pointer = unboxed_region.free_pointer + nbytes;
1298 if (new_free_pointer <= unboxed_region.end_addr) {
1299 /* If so then allocate from the current region. */
1300 void *new_obj = unboxed_region.free_pointer;
1301 unboxed_region.free_pointer = new_free_pointer;
1303 /* Check whether the current region is almost empty. */
1304 if ((unboxed_region.end_addr - unboxed_region.free_pointer) <= 32) {
1305 /* If so find, finished with the current region. */
1306 gc_alloc_update_page_tables(1, &unboxed_region);
1308 /* Set up a new region. */
1309 gc_alloc_new_region(32, 1, &unboxed_region);
1312 return((void *)new_obj);
1315 /* shouldn't happen? */
1317 return((void *) NIL); /* dummy value: return something ... */
1320 static inline void *
1321 gc_quick_alloc_unboxed(int nbytes)
1323 void *new_free_pointer;
1325 /* Check whether there is room in the current region. */
1326 new_free_pointer = unboxed_region.free_pointer + nbytes;
1328 if (new_free_pointer <= unboxed_region.end_addr) {
1329 /* If so then allocate from the current region. */
1330 void *new_obj = unboxed_region.free_pointer;
1331 unboxed_region.free_pointer = new_free_pointer;
1333 return((void *)new_obj);
1335 /* Let general gc_alloc_unboxed() handle it. */
1336 return gc_alloc_unboxed(nbytes);
1340 /* Allocate space for the object. If it is a large object then do a
1341 * large alloc else allocate from the current region. If there is not
1342 * enough free space then call general gc_alloc_unboxed() to do the job.
1344 * A pointer to the start of the region is returned. */
1345 static inline void *
1346 gc_quick_alloc_large_unboxed(int nbytes)
1348 void *new_free_pointer;
1350 if (nbytes >= large_object_size)
1351 return gc_alloc_large(nbytes,1,&unboxed_region);
1353 /* Check whether there is room in the current region. */
1354 new_free_pointer = unboxed_region.free_pointer + nbytes;
1355 if (new_free_pointer <= unboxed_region.end_addr) {
1356 /* Allocate from the current region. */
1357 void *new_obj = unboxed_region.free_pointer;
1358 unboxed_region.free_pointer = new_free_pointer;
1359 return((void *)new_obj);
1361 /* Let full gc_alloc() handle it. */
1362 return gc_alloc_unboxed(nbytes);
1367 * scavenging/transporting routines derived from gc.c in CMU CL ca. 18b
1370 static int (*scavtab[256])(lispobj *where, lispobj object);
1371 static lispobj (*transother[256])(lispobj object);
1372 static int (*sizetab[256])(lispobj *where);
1374 static struct weak_pointer *weak_pointers;
1376 #define CEILING(x,y) (((x) + ((y) - 1)) & (~((y) - 1)))
1382 static inline boolean
1383 from_space_p(lispobj obj)
1385 int page_index=(void*)obj - heap_base;
1386 return ((page_index >= 0)
1387 && ((page_index = ((unsigned int)page_index)/4096) < NUM_PAGES)
1388 && (page_table[page_index].gen == from_space));
1391 static inline boolean
1392 new_space_p(lispobj obj)
1394 int page_index = (void*)obj - heap_base;
1395 return ((page_index >= 0)
1396 && ((page_index = ((unsigned int)page_index)/4096) < NUM_PAGES)
1397 && (page_table[page_index].gen == new_space));
1404 /* to copy a boxed object */
1405 static inline lispobj
1406 copy_object(lispobj object, int nwords)
1410 lispobj *source, *dest;
1412 gc_assert(is_lisp_pointer(object));
1413 gc_assert(from_space_p(object));
1414 gc_assert((nwords & 0x01) == 0);
1416 /* Get tag of object. */
1417 tag = lowtag_of(object);
1419 /* Allocate space. */
1420 new = gc_quick_alloc(nwords*4);
1423 source = (lispobj *) native_pointer(object);
1425 /* Copy the object. */
1426 while (nwords > 0) {
1427 dest[0] = source[0];
1428 dest[1] = source[1];
1434 /* Return Lisp pointer of new object. */
1435 return ((lispobj) new) | tag;
1438 /* to copy a large boxed object. If the object is in a large object
1439 * region then it is simply promoted, else it is copied. If it's large
1440 * enough then it's copied to a large object region.
1442 * Vectors may have shrunk. If the object is not copied the space
1443 * needs to be reclaimed, and the page_tables corrected. */
1445 copy_large_object(lispobj object, int nwords)
1449 lispobj *source, *dest;
1452 gc_assert(is_lisp_pointer(object));
1453 gc_assert(from_space_p(object));
1454 gc_assert((nwords & 0x01) == 0);
1456 if ((nwords > 1024*1024) && gencgc_verbose) {
1457 FSHOW((stderr, "/copy_large_object: %d bytes\n", nwords*4));
1460 /* Check whether it's a large object. */
1461 first_page = find_page_index((void *)object);
1462 gc_assert(first_page >= 0);
1464 if (page_table[first_page].large_object) {
1466 /* Promote the object. */
1468 int remaining_bytes;
1473 /* Note: Any page write-protection must be removed, else a
1474 * later scavenge_newspace may incorrectly not scavenge these
1475 * pages. This would not be necessary if they are added to the
1476 * new areas, but let's do it for them all (they'll probably
1477 * be written anyway?). */
1479 gc_assert(page_table[first_page].first_object_offset == 0);
1481 next_page = first_page;
1482 remaining_bytes = nwords*4;
1483 while (remaining_bytes > 4096) {
1484 gc_assert(page_table[next_page].gen == from_space);
1485 gc_assert(page_table[next_page].allocated == BOXED_PAGE);
1486 gc_assert(page_table[next_page].large_object);
1487 gc_assert(page_table[next_page].first_object_offset==
1488 -4096*(next_page-first_page));
1489 gc_assert(page_table[next_page].bytes_used == 4096);
1491 page_table[next_page].gen = new_space;
1493 /* Remove any write-protection. We should be able to rely
1494 * on the write-protect flag to avoid redundant calls. */
1495 if (page_table[next_page].write_protected) {
1496 os_protect(page_address(next_page), 4096, OS_VM_PROT_ALL);
1497 page_table[next_page].write_protected = 0;
1499 remaining_bytes -= 4096;
1503 /* Now only one page remains, but the object may have shrunk
1504 * so there may be more unused pages which will be freed. */
1506 /* The object may have shrunk but shouldn't have grown. */
1507 gc_assert(page_table[next_page].bytes_used >= remaining_bytes);
1509 page_table[next_page].gen = new_space;
1510 gc_assert(page_table[next_page].allocated = BOXED_PAGE);
1512 /* Adjust the bytes_used. */
1513 old_bytes_used = page_table[next_page].bytes_used;
1514 page_table[next_page].bytes_used = remaining_bytes;
1516 bytes_freed = old_bytes_used - remaining_bytes;
1518 /* Free any remaining pages; needs care. */
1520 while ((old_bytes_used == 4096) &&
1521 (page_table[next_page].gen == from_space) &&
1522 (page_table[next_page].allocated == BOXED_PAGE) &&
1523 page_table[next_page].large_object &&
1524 (page_table[next_page].first_object_offset ==
1525 -(next_page - first_page)*4096)) {
1526 /* Checks out OK, free the page. Don't need to both zeroing
1527 * pages as this should have been done before shrinking the
1528 * object. These pages shouldn't be write-protected as they
1529 * should be zero filled. */
1530 gc_assert(page_table[next_page].write_protected == 0);
1532 old_bytes_used = page_table[next_page].bytes_used;
1533 page_table[next_page].allocated = FREE_PAGE;
1534 page_table[next_page].bytes_used = 0;
1535 bytes_freed += old_bytes_used;
1539 if ((bytes_freed > 0) && gencgc_verbose)
1540 FSHOW((stderr, "/copy_large_boxed bytes_freed=%d\n", bytes_freed));
1542 generations[from_space].bytes_allocated -= 4*nwords + bytes_freed;
1543 generations[new_space].bytes_allocated += 4*nwords;
1544 bytes_allocated -= bytes_freed;
1546 /* Add the region to the new_areas if requested. */
1547 add_new_area(first_page,0,nwords*4);
1551 /* Get tag of object. */
1552 tag = lowtag_of(object);
1554 /* Allocate space. */
1555 new = gc_quick_alloc_large(nwords*4);
1558 source = (lispobj *) native_pointer(object);
1560 /* Copy the object. */
1561 while (nwords > 0) {
1562 dest[0] = source[0];
1563 dest[1] = source[1];
1569 /* Return Lisp pointer of new object. */
1570 return ((lispobj) new) | tag;
1574 /* to copy unboxed objects */
1575 static inline lispobj
1576 copy_unboxed_object(lispobj object, int nwords)
1580 lispobj *source, *dest;
1582 gc_assert(is_lisp_pointer(object));
1583 gc_assert(from_space_p(object));
1584 gc_assert((nwords & 0x01) == 0);
1586 /* Get tag of object. */
1587 tag = lowtag_of(object);
1589 /* Allocate space. */
1590 new = gc_quick_alloc_unboxed(nwords*4);
1593 source = (lispobj *) native_pointer(object);
1595 /* Copy the object. */
1596 while (nwords > 0) {
1597 dest[0] = source[0];
1598 dest[1] = source[1];
1604 /* Return Lisp pointer of new object. */
1605 return ((lispobj) new) | tag;
1608 /* to copy large unboxed objects
1610 * If the object is in a large object region then it is simply
1611 * promoted, else it is copied. If it's large enough then it's copied
1612 * to a large object region.
1614 * Bignums and vectors may have shrunk. If the object is not copied
1615 * the space needs to be reclaimed, and the page_tables corrected.
1617 * KLUDGE: There's a lot of cut-and-paste duplication between this
1618 * function and copy_large_object(..). -- WHN 20000619 */
1620 copy_large_unboxed_object(lispobj object, int nwords)
1624 lispobj *source, *dest;
1627 gc_assert(is_lisp_pointer(object));
1628 gc_assert(from_space_p(object));
1629 gc_assert((nwords & 0x01) == 0);
1631 if ((nwords > 1024*1024) && gencgc_verbose)
1632 FSHOW((stderr, "/copy_large_unboxed_object: %d bytes\n", nwords*4));
1634 /* Check whether it's a large object. */
1635 first_page = find_page_index((void *)object);
1636 gc_assert(first_page >= 0);
1638 if (page_table[first_page].large_object) {
1639 /* Promote the object. Note: Unboxed objects may have been
1640 * allocated to a BOXED region so it may be necessary to
1641 * change the region to UNBOXED. */
1642 int remaining_bytes;
1647 gc_assert(page_table[first_page].first_object_offset == 0);
1649 next_page = first_page;
1650 remaining_bytes = nwords*4;
1651 while (remaining_bytes > 4096) {
1652 gc_assert(page_table[next_page].gen == from_space);
1653 gc_assert((page_table[next_page].allocated == UNBOXED_PAGE)
1654 || (page_table[next_page].allocated == BOXED_PAGE));
1655 gc_assert(page_table[next_page].large_object);
1656 gc_assert(page_table[next_page].first_object_offset==
1657 -4096*(next_page-first_page));
1658 gc_assert(page_table[next_page].bytes_used == 4096);
1660 page_table[next_page].gen = new_space;
1661 page_table[next_page].allocated = UNBOXED_PAGE;
1662 remaining_bytes -= 4096;
1666 /* Now only one page remains, but the object may have shrunk so
1667 * there may be more unused pages which will be freed. */
1669 /* Object may have shrunk but shouldn't have grown - check. */
1670 gc_assert(page_table[next_page].bytes_used >= remaining_bytes);
1672 page_table[next_page].gen = new_space;
1673 page_table[next_page].allocated = UNBOXED_PAGE;
1675 /* Adjust the bytes_used. */
1676 old_bytes_used = page_table[next_page].bytes_used;
1677 page_table[next_page].bytes_used = remaining_bytes;
1679 bytes_freed = old_bytes_used - remaining_bytes;
1681 /* Free any remaining pages; needs care. */
1683 while ((old_bytes_used == 4096) &&
1684 (page_table[next_page].gen == from_space) &&
1685 ((page_table[next_page].allocated == UNBOXED_PAGE)
1686 || (page_table[next_page].allocated == BOXED_PAGE)) &&
1687 page_table[next_page].large_object &&
1688 (page_table[next_page].first_object_offset ==
1689 -(next_page - first_page)*4096)) {
1690 /* Checks out OK, free the page. Don't need to both zeroing
1691 * pages as this should have been done before shrinking the
1692 * object. These pages shouldn't be write-protected, even if
1693 * boxed they should be zero filled. */
1694 gc_assert(page_table[next_page].write_protected == 0);
1696 old_bytes_used = page_table[next_page].bytes_used;
1697 page_table[next_page].allocated = FREE_PAGE;
1698 page_table[next_page].bytes_used = 0;
1699 bytes_freed += old_bytes_used;
1703 if ((bytes_freed > 0) && gencgc_verbose)
1705 "/copy_large_unboxed bytes_freed=%d\n",
1708 generations[from_space].bytes_allocated -= 4*nwords + bytes_freed;
1709 generations[new_space].bytes_allocated += 4*nwords;
1710 bytes_allocated -= bytes_freed;
1715 /* Get tag of object. */
1716 tag = lowtag_of(object);
1718 /* Allocate space. */
1719 new = gc_quick_alloc_large_unboxed(nwords*4);
1722 source = (lispobj *) native_pointer(object);
1724 /* Copy the object. */
1725 while (nwords > 0) {
1726 dest[0] = source[0];
1727 dest[1] = source[1];
1733 /* Return Lisp pointer of new object. */
1734 return ((lispobj) new) | tag;
1742 /* FIXME: Most calls end up going to some trouble to compute an
1743 * 'n_words' value for this function. The system might be a little
1744 * simpler if this function used an 'end' parameter instead. */
1746 scavenge(lispobj *start, long n_words)
1748 lispobj *end = start + n_words;
1749 lispobj *object_ptr;
1750 int n_words_scavenged;
1752 for (object_ptr = start;
1754 object_ptr += n_words_scavenged) {
1756 lispobj object = *object_ptr;
1758 gc_assert(object != 0x01); /* not a forwarding pointer */
1760 if (is_lisp_pointer(object)) {
1761 if (from_space_p(object)) {
1762 /* It currently points to old space. Check for a
1763 * forwarding pointer. */
1764 lispobj *ptr = (lispobj *)native_pointer(object);
1765 lispobj first_word = *ptr;
1766 if (first_word == 0x01) {
1767 /* Yes, there's a forwarding pointer. */
1768 *object_ptr = ptr[1];
1769 n_words_scavenged = 1;
1771 /* Scavenge that pointer. */
1773 (scavtab[widetag_of(object)])(object_ptr, object);
1776 /* It points somewhere other than oldspace. Leave it
1778 n_words_scavenged = 1;
1780 } else if ((object & 3) == 0) {
1781 /* It's a fixnum: really easy.. */
1782 n_words_scavenged = 1;
1784 /* It's some sort of header object or another. */
1786 (scavtab[widetag_of(object)])(object_ptr, object);
1789 gc_assert(object_ptr == end);
1793 * code and code-related objects
1796 /* FIXME: (1) Shouldn't this be defined in sbcl.h? */
1797 #define FUN_RAW_ADDR_OFFSET (6*sizeof(lispobj) - FUN_POINTER_LOWTAG)
1799 static lispobj trans_fun_header(lispobj object);
1800 static lispobj trans_boxed(lispobj object);
1803 scav_fun_pointer(lispobj *where, lispobj object)
1805 lispobj *first_pointer;
1808 gc_assert(is_lisp_pointer(object));
1810 /* Object is a pointer into from space - no a FP. */
1811 first_pointer = (lispobj *) native_pointer(object);
1813 /* must transport object -- object may point to either a function
1814 * header, a closure function header, or to a closure header. */
1816 switch (widetag_of(*first_pointer)) {
1817 case SIMPLE_FUN_HEADER_WIDETAG:
1818 case CLOSURE_FUN_HEADER_WIDETAG:
1819 copy = trans_fun_header(object);
1822 copy = trans_boxed(object);
1826 if (copy != object) {
1827 /* Set forwarding pointer */
1828 first_pointer[0] = 0x01;
1829 first_pointer[1] = copy;
1832 gc_assert(is_lisp_pointer(copy));
1833 gc_assert(!from_space_p(copy));
1840 /* Scan a x86 compiled code object, looking for possible fixups that
1841 * have been missed after a move.
1843 * Two types of fixups are needed:
1844 * 1. Absolute fixups to within the code object.
1845 * 2. Relative fixups to outside the code object.
1847 * Currently only absolute fixups to the constant vector, or to the
1848 * code area are checked. */
1850 sniff_code_object(struct code *code, unsigned displacement)
1852 int nheader_words, ncode_words, nwords;
1854 void *constants_start_addr, *constants_end_addr;
1855 void *code_start_addr, *code_end_addr;
1856 int fixup_found = 0;
1858 if (!check_code_fixups)
1861 ncode_words = fixnum_value(code->code_size);
1862 nheader_words = HeaderValue(*(lispobj *)code);
1863 nwords = ncode_words + nheader_words;
1865 constants_start_addr = (void *)code + 5*4;
1866 constants_end_addr = (void *)code + nheader_words*4;
1867 code_start_addr = (void *)code + nheader_words*4;
1868 code_end_addr = (void *)code + nwords*4;
1870 /* Work through the unboxed code. */
1871 for (p = code_start_addr; p < code_end_addr; p++) {
1872 void *data = *(void **)p;
1873 unsigned d1 = *((unsigned char *)p - 1);
1874 unsigned d2 = *((unsigned char *)p - 2);
1875 unsigned d3 = *((unsigned char *)p - 3);
1876 unsigned d4 = *((unsigned char *)p - 4);
1878 unsigned d5 = *((unsigned char *)p - 5);
1879 unsigned d6 = *((unsigned char *)p - 6);
1882 /* Check for code references. */
1883 /* Check for a 32 bit word that looks like an absolute
1884 reference to within the code adea of the code object. */
1885 if ((data >= (code_start_addr-displacement))
1886 && (data < (code_end_addr-displacement))) {
1887 /* function header */
1889 && (((unsigned)p - 4 - 4*HeaderValue(*((unsigned *)p-1))) == (unsigned)code)) {
1890 /* Skip the function header */
1894 /* the case of PUSH imm32 */
1898 "/code ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1899 p, d6, d5, d4, d3, d2, d1, data));
1900 FSHOW((stderr, "/PUSH $0x%.8x\n", data));
1902 /* the case of MOV [reg-8],imm32 */
1904 && (d2==0x40 || d2==0x41 || d2==0x42 || d2==0x43
1905 || d2==0x45 || d2==0x46 || d2==0x47)
1909 "/code ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1910 p, d6, d5, d4, d3, d2, d1, data));
1911 FSHOW((stderr, "/MOV [reg-8],$0x%.8x\n", data));
1913 /* the case of LEA reg,[disp32] */
1914 if ((d2 == 0x8d) && ((d1 & 0xc7) == 5)) {
1917 "/code ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1918 p, d6, d5, d4, d3, d2, d1, data));
1919 FSHOW((stderr,"/LEA reg,[$0x%.8x]\n", data));
1923 /* Check for constant references. */
1924 /* Check for a 32 bit word that looks like an absolute
1925 reference to within the constant vector. Constant references
1927 if ((data >= (constants_start_addr-displacement))
1928 && (data < (constants_end_addr-displacement))
1929 && (((unsigned)data & 0x3) == 0)) {
1934 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1935 p, d6, d5, d4, d3, d2, d1, data));
1936 FSHOW((stderr,"/MOV eax,0x%.8x\n", data));
1939 /* the case of MOV m32,EAX */
1943 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1944 p, d6, d5, d4, d3, d2, d1, data));
1945 FSHOW((stderr, "/MOV 0x%.8x,eax\n", data));
1948 /* the case of CMP m32,imm32 */
1949 if ((d1 == 0x3d) && (d2 == 0x81)) {
1952 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1953 p, d6, d5, d4, d3, d2, d1, data));
1955 FSHOW((stderr, "/CMP 0x%.8x,immed32\n", data));
1958 /* Check for a mod=00, r/m=101 byte. */
1959 if ((d1 & 0xc7) == 5) {
1964 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1965 p, d6, d5, d4, d3, d2, d1, data));
1966 FSHOW((stderr,"/CMP 0x%.8x,reg\n", data));
1968 /* the case of CMP reg32,m32 */
1972 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1973 p, d6, d5, d4, d3, d2, d1, data));
1974 FSHOW((stderr, "/CMP reg32,0x%.8x\n", data));
1976 /* the case of MOV m32,reg32 */
1980 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1981 p, d6, d5, d4, d3, d2, d1, data));
1982 FSHOW((stderr, "/MOV 0x%.8x,reg32\n", data));
1984 /* the case of MOV reg32,m32 */
1988 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1989 p, d6, d5, d4, d3, d2, d1, data));
1990 FSHOW((stderr, "/MOV reg32,0x%.8x\n", data));
1992 /* the case of LEA reg32,m32 */
1996 "abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1997 p, d6, d5, d4, d3, d2, d1, data));
1998 FSHOW((stderr, "/LEA reg32,0x%.8x\n", data));
2004 /* If anything was found, print some information on the code
2008 "/compiled code object at %x: header words = %d, code words = %d\n",
2009 code, nheader_words, ncode_words));
2011 "/const start = %x, end = %x\n",
2012 constants_start_addr, constants_end_addr));
2014 "/code start = %x, end = %x\n",
2015 code_start_addr, code_end_addr));
2020 apply_code_fixups(struct code *old_code, struct code *new_code)
2022 int nheader_words, ncode_words, nwords;
2023 void *constants_start_addr, *constants_end_addr;
2024 void *code_start_addr, *code_end_addr;
2025 lispobj fixups = NIL;
2026 unsigned displacement = (unsigned)new_code - (unsigned)old_code;
2027 struct vector *fixups_vector;
2029 ncode_words = fixnum_value(new_code->code_size);
2030 nheader_words = HeaderValue(*(lispobj *)new_code);
2031 nwords = ncode_words + nheader_words;
2033 "/compiled code object at %x: header words = %d, code words = %d\n",
2034 new_code, nheader_words, ncode_words)); */
2035 constants_start_addr = (void *)new_code + 5*4;
2036 constants_end_addr = (void *)new_code + nheader_words*4;
2037 code_start_addr = (void *)new_code + nheader_words*4;
2038 code_end_addr = (void *)new_code + nwords*4;
2041 "/const start = %x, end = %x\n",
2042 constants_start_addr,constants_end_addr));
2044 "/code start = %x; end = %x\n",
2045 code_start_addr,code_end_addr));
2048 /* The first constant should be a pointer to the fixups for this
2049 code objects. Check. */
2050 fixups = new_code->constants[0];
2052 /* It will be 0 or the unbound-marker if there are no fixups, and
2053 * will be an other pointer if it is valid. */
2054 if ((fixups == 0) || (fixups == UNBOUND_MARKER_WIDETAG) ||
2055 !is_lisp_pointer(fixups)) {
2056 /* Check for possible errors. */
2057 if (check_code_fixups)
2058 sniff_code_object(new_code, displacement);
2060 /*fprintf(stderr,"Fixups for code object not found!?\n");
2061 fprintf(stderr,"*** Compiled code object at %x: header_words=%d code_words=%d .\n",
2062 new_code, nheader_words, ncode_words);
2063 fprintf(stderr,"*** Const. start = %x; end= %x; Code start = %x; end = %x\n",
2064 constants_start_addr,constants_end_addr,
2065 code_start_addr,code_end_addr);*/
2069 fixups_vector = (struct vector *)native_pointer(fixups);
2071 /* Could be pointing to a forwarding pointer. */
2072 if (is_lisp_pointer(fixups) &&
2073 (find_page_index((void*)fixups_vector) != -1) &&
2074 (fixups_vector->header == 0x01)) {
2075 /* If so, then follow it. */
2076 /*SHOW("following pointer to a forwarding pointer");*/
2077 fixups_vector = (struct vector *)native_pointer((lispobj)fixups_vector->length);
2080 /*SHOW("got fixups");*/
2082 if (widetag_of(fixups_vector->header) ==
2083 SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG) {
2084 /* Got the fixups for the code block. Now work through the vector,
2085 and apply a fixup at each address. */
2086 int length = fixnum_value(fixups_vector->length);
2088 for (i = 0; i < length; i++) {
2089 unsigned offset = fixups_vector->data[i];
2090 /* Now check the current value of offset. */
2091 unsigned old_value =
2092 *(unsigned *)((unsigned)code_start_addr + offset);
2094 /* If it's within the old_code object then it must be an
2095 * absolute fixup (relative ones are not saved) */
2096 if ((old_value >= (unsigned)old_code)
2097 && (old_value < ((unsigned)old_code + nwords*4)))
2098 /* So add the dispacement. */
2099 *(unsigned *)((unsigned)code_start_addr + offset) =
2100 old_value + displacement;
2102 /* It is outside the old code object so it must be a
2103 * relative fixup (absolute fixups are not saved). So
2104 * subtract the displacement. */
2105 *(unsigned *)((unsigned)code_start_addr + offset) =
2106 old_value - displacement;
2110 /* Check for possible errors. */
2111 if (check_code_fixups) {
2112 sniff_code_object(new_code,displacement);
2116 static struct code *
2117 trans_code(struct code *code)
2119 struct code *new_code;
2120 lispobj l_code, l_new_code;
2121 int nheader_words, ncode_words, nwords;
2122 unsigned long displacement;
2123 lispobj fheaderl, *prev_pointer;
2126 "\n/transporting code object located at 0x%08x\n",
2127 (unsigned long) code)); */
2129 /* If object has already been transported, just return pointer. */
2130 if (*((lispobj *)code) == 0x01)
2131 return (struct code*)(((lispobj *)code)[1]);
2133 gc_assert(widetag_of(code->header) == CODE_HEADER_WIDETAG);
2135 /* Prepare to transport the code vector. */
2136 l_code = (lispobj) code | OTHER_POINTER_LOWTAG;
2138 ncode_words = fixnum_value(code->code_size);
2139 nheader_words = HeaderValue(code->header);
2140 nwords = ncode_words + nheader_words;
2141 nwords = CEILING(nwords, 2);
2143 l_new_code = copy_large_object(l_code, nwords);
2144 new_code = (struct code *) native_pointer(l_new_code);
2146 /* may not have been moved.. */
2147 if (new_code == code)
2150 displacement = l_new_code - l_code;
2154 "/old code object at 0x%08x, new code object at 0x%08x\n",
2155 (unsigned long) code,
2156 (unsigned long) new_code));
2157 FSHOW((stderr, "/Code object is %d words long.\n", nwords));
2160 /* Set forwarding pointer. */
2161 ((lispobj *)code)[0] = 0x01;
2162 ((lispobj *)code)[1] = l_new_code;
2164 /* Set forwarding pointers for all the function headers in the
2165 * code object. Also fix all self pointers. */
2167 fheaderl = code->entry_points;
2168 prev_pointer = &new_code->entry_points;
2170 while (fheaderl != NIL) {
2171 struct simple_fun *fheaderp, *nfheaderp;
2174 fheaderp = (struct simple_fun *) native_pointer(fheaderl);
2175 gc_assert(widetag_of(fheaderp->header) == SIMPLE_FUN_HEADER_WIDETAG);
2177 /* Calculate the new function pointer and the new */
2178 /* function header. */
2179 nfheaderl = fheaderl + displacement;
2180 nfheaderp = (struct simple_fun *) native_pointer(nfheaderl);
2182 /* Set forwarding pointer. */
2183 ((lispobj *)fheaderp)[0] = 0x01;
2184 ((lispobj *)fheaderp)[1] = nfheaderl;
2186 /* Fix self pointer. */
2187 nfheaderp->self = nfheaderl + FUN_RAW_ADDR_OFFSET;
2189 *prev_pointer = nfheaderl;
2191 fheaderl = fheaderp->next;
2192 prev_pointer = &nfheaderp->next;
2195 /* sniff_code_object(new_code,displacement);*/
2196 apply_code_fixups(code,new_code);
2202 scav_code_header(lispobj *where, lispobj object)
2205 int n_header_words, n_code_words, n_words;
2206 lispobj entry_point; /* tagged pointer to entry point */
2207 struct simple_fun *function_ptr; /* untagged pointer to entry point */
2209 code = (struct code *) where;
2210 n_code_words = fixnum_value(code->code_size);
2211 n_header_words = HeaderValue(object);
2212 n_words = n_code_words + n_header_words;
2213 n_words = CEILING(n_words, 2);
2215 /* Scavenge the boxed section of the code data block. */
2216 scavenge(where + 1, n_header_words - 1);
2218 /* Scavenge the boxed section of each function object in the */
2219 /* code data block. */
2220 for (entry_point = code->entry_points;
2222 entry_point = function_ptr->next) {
2224 gc_assert(is_lisp_pointer(entry_point));
2226 function_ptr = (struct simple_fun *) native_pointer(entry_point);
2227 gc_assert(widetag_of(function_ptr->header) == SIMPLE_FUN_HEADER_WIDETAG);
2229 scavenge(&function_ptr->name, 1);
2230 scavenge(&function_ptr->arglist, 1);
2231 scavenge(&function_ptr->type, 1);
2238 trans_code_header(lispobj object)
2242 ncode = trans_code((struct code *) native_pointer(object));
2243 return (lispobj) ncode | OTHER_POINTER_LOWTAG;
2247 size_code_header(lispobj *where)
2250 int nheader_words, ncode_words, nwords;
2252 code = (struct code *) where;
2254 ncode_words = fixnum_value(code->code_size);
2255 nheader_words = HeaderValue(code->header);
2256 nwords = ncode_words + nheader_words;
2257 nwords = CEILING(nwords, 2);
2263 scav_return_pc_header(lispobj *where, lispobj object)
2265 lose("attempted to scavenge a return PC header where=0x%08x object=0x%08x",
2266 (unsigned long) where,
2267 (unsigned long) object);
2268 return 0; /* bogus return value to satisfy static type checking */
2272 trans_return_pc_header(lispobj object)
2274 struct simple_fun *return_pc;
2275 unsigned long offset;
2276 struct code *code, *ncode;
2278 SHOW("/trans_return_pc_header: Will this work?");
2280 return_pc = (struct simple_fun *) native_pointer(object);
2281 offset = HeaderValue(return_pc->header) * 4;
2283 /* Transport the whole code object. */
2284 code = (struct code *) ((unsigned long) return_pc - offset);
2285 ncode = trans_code(code);
2287 return ((lispobj) ncode + offset) | OTHER_POINTER_LOWTAG;
2290 /* On the 386, closures hold a pointer to the raw address instead of the
2291 * function object. */
2294 scav_closure_header(lispobj *where, lispobj object)
2296 struct closure *closure;
2299 closure = (struct closure *)where;
2300 fun = closure->fun - FUN_RAW_ADDR_OFFSET;
2302 /* The function may have moved so update the raw address. But
2303 * don't write unnecessarily. */
2304 if (closure->fun != fun + FUN_RAW_ADDR_OFFSET)
2305 closure->fun = fun + FUN_RAW_ADDR_OFFSET;
2312 scav_fun_header(lispobj *where, lispobj object)
2314 lose("attempted to scavenge a function header where=0x%08x object=0x%08x",
2315 (unsigned long) where,
2316 (unsigned long) object);
2317 return 0; /* bogus return value to satisfy static type checking */
2321 trans_fun_header(lispobj object)
2323 struct simple_fun *fheader;
2324 unsigned long offset;
2325 struct code *code, *ncode;
2327 fheader = (struct simple_fun *) native_pointer(object);
2328 offset = HeaderValue(fheader->header) * 4;
2330 /* Transport the whole code object. */
2331 code = (struct code *) ((unsigned long) fheader - offset);
2332 ncode = trans_code(code);
2334 return ((lispobj) ncode + offset) | FUN_POINTER_LOWTAG;
2342 scav_instance_pointer(lispobj *where, lispobj object)
2344 lispobj copy, *first_pointer;
2346 /* Object is a pointer into from space - not a FP. */
2347 copy = trans_boxed(object);
2349 gc_assert(copy != object);
2351 first_pointer = (lispobj *) native_pointer(object);
2353 /* Set forwarding pointer. */
2354 first_pointer[0] = 0x01;
2355 first_pointer[1] = copy;
2365 static lispobj trans_list(lispobj object);
2368 scav_list_pointer(lispobj *where, lispobj object)
2370 lispobj first, *first_pointer;
2372 gc_assert(is_lisp_pointer(object));
2374 /* Object is a pointer into from space - not FP. */
2376 first = trans_list(object);
2377 gc_assert(first != object);
2379 first_pointer = (lispobj *) native_pointer(object);
2381 /* Set forwarding pointer */
2382 first_pointer[0] = 0x01;
2383 first_pointer[1] = first;
2385 gc_assert(is_lisp_pointer(first));
2386 gc_assert(!from_space_p(first));
2392 trans_list(lispobj object)
2394 lispobj new_list_pointer;
2395 struct cons *cons, *new_cons;
2398 gc_assert(from_space_p(object));
2400 cons = (struct cons *) native_pointer(object);
2402 /* Copy 'object'. */
2403 new_cons = (struct cons *) gc_quick_alloc(sizeof(struct cons));
2404 new_cons->car = cons->car;
2405 new_cons->cdr = cons->cdr; /* updated later */
2406 new_list_pointer = (lispobj)new_cons | lowtag_of(object);
2408 /* Grab the cdr before it is clobbered. */
2411 /* Set forwarding pointer (clobbers start of list). */
2413 cons->cdr = new_list_pointer;
2415 /* Try to linearize the list in the cdr direction to help reduce
2419 struct cons *cdr_cons, *new_cdr_cons;
2421 if (lowtag_of(cdr) != LIST_POINTER_LOWTAG || !from_space_p(cdr)
2422 || (*((lispobj *)native_pointer(cdr)) == 0x01))
2425 cdr_cons = (struct cons *) native_pointer(cdr);
2428 new_cdr_cons = (struct cons*) gc_quick_alloc(sizeof(struct cons));
2429 new_cdr_cons->car = cdr_cons->car;
2430 new_cdr_cons->cdr = cdr_cons->cdr;
2431 new_cdr = (lispobj)new_cdr_cons | lowtag_of(cdr);
2433 /* Grab the cdr before it is clobbered. */
2434 cdr = cdr_cons->cdr;
2436 /* Set forwarding pointer. */
2437 cdr_cons->car = 0x01;
2438 cdr_cons->cdr = new_cdr;
2440 /* Update the cdr of the last cons copied into new space to
2441 * keep the newspace scavenge from having to do it. */
2442 new_cons->cdr = new_cdr;
2444 new_cons = new_cdr_cons;
2447 return new_list_pointer;
2452 * scavenging and transporting other pointers
2456 scav_other_pointer(lispobj *where, lispobj object)
2458 lispobj first, *first_pointer;
2460 gc_assert(is_lisp_pointer(object));
2462 /* Object is a pointer into from space - not FP. */
2463 first_pointer = (lispobj *) native_pointer(object);
2465 first = (transother[widetag_of(*first_pointer)])(object);
2467 if (first != object) {
2468 /* Set forwarding pointer. */
2469 first_pointer[0] = 0x01;
2470 first_pointer[1] = first;
2474 gc_assert(is_lisp_pointer(first));
2475 gc_assert(!from_space_p(first));
2481 * immediate, boxed, and unboxed objects
2485 size_pointer(lispobj *where)
2491 scav_immediate(lispobj *where, lispobj object)
2497 trans_immediate(lispobj object)
2499 lose("trying to transport an immediate");
2500 return NIL; /* bogus return value to satisfy static type checking */
2504 size_immediate(lispobj *where)
2511 scav_boxed(lispobj *where, lispobj object)
2517 trans_boxed(lispobj object)
2520 unsigned long length;
2522 gc_assert(is_lisp_pointer(object));
2524 header = *((lispobj *) native_pointer(object));
2525 length = HeaderValue(header) + 1;
2526 length = CEILING(length, 2);
2528 return copy_object(object, length);
2532 trans_boxed_large(lispobj object)
2535 unsigned long length;
2537 gc_assert(is_lisp_pointer(object));
2539 header = *((lispobj *) native_pointer(object));
2540 length = HeaderValue(header) + 1;
2541 length = CEILING(length, 2);
2543 return copy_large_object(object, length);
2547 size_boxed(lispobj *where)
2550 unsigned long length;
2553 length = HeaderValue(header) + 1;
2554 length = CEILING(length, 2);
2560 scav_fdefn(lispobj *where, lispobj object)
2562 struct fdefn *fdefn;
2564 fdefn = (struct fdefn *)where;
2566 /* FSHOW((stderr, "scav_fdefn, function = %p, raw_addr = %p\n",
2567 fdefn->fun, fdefn->raw_addr)); */
2569 if ((char *)(fdefn->fun + FUN_RAW_ADDR_OFFSET) == fdefn->raw_addr) {
2570 scavenge(where + 1, sizeof(struct fdefn)/sizeof(lispobj) - 1);
2572 /* Don't write unnecessarily. */
2573 if (fdefn->raw_addr != (char *)(fdefn->fun + FUN_RAW_ADDR_OFFSET))
2574 fdefn->raw_addr = (char *)(fdefn->fun + FUN_RAW_ADDR_OFFSET);
2576 return sizeof(struct fdefn) / sizeof(lispobj);
2583 scav_unboxed(lispobj *where, lispobj object)
2585 unsigned long length;
2587 length = HeaderValue(object) + 1;
2588 length = CEILING(length, 2);
2594 trans_unboxed(lispobj object)
2597 unsigned long length;
2600 gc_assert(is_lisp_pointer(object));
2602 header = *((lispobj *) native_pointer(object));
2603 length = HeaderValue(header) + 1;
2604 length = CEILING(length, 2);
2606 return copy_unboxed_object(object, length);
2610 trans_unboxed_large(lispobj object)
2613 unsigned long length;
2616 gc_assert(is_lisp_pointer(object));
2618 header = *((lispobj *) native_pointer(object));
2619 length = HeaderValue(header) + 1;
2620 length = CEILING(length, 2);
2622 return copy_large_unboxed_object(object, length);
2626 size_unboxed(lispobj *where)
2629 unsigned long length;
2632 length = HeaderValue(header) + 1;
2633 length = CEILING(length, 2);
2639 * vector-like objects
2642 #define NWORDS(x,y) (CEILING((x),(y)) / (y))
2645 scav_string(lispobj *where, lispobj object)
2647 struct vector *vector;
2650 /* NOTE: Strings contain one more byte of data than the length */
2651 /* slot indicates. */
2653 vector = (struct vector *) where;
2654 length = fixnum_value(vector->length) + 1;
2655 nwords = CEILING(NWORDS(length, 4) + 2, 2);
2661 trans_string(lispobj object)
2663 struct vector *vector;
2666 gc_assert(is_lisp_pointer(object));
2668 /* NOTE: A string contains one more byte of data (a terminating
2669 * '\0' to help when interfacing with C functions) than indicated
2670 * by the length slot. */
2672 vector = (struct vector *) native_pointer(object);
2673 length = fixnum_value(vector->length) + 1;
2674 nwords = CEILING(NWORDS(length, 4) + 2, 2);
2676 return copy_large_unboxed_object(object, nwords);
2680 size_string(lispobj *where)
2682 struct vector *vector;
2685 /* NOTE: A string contains one more byte of data (a terminating
2686 * '\0' to help when interfacing with C functions) than indicated
2687 * by the length slot. */
2689 vector = (struct vector *) where;
2690 length = fixnum_value(vector->length) + 1;
2691 nwords = CEILING(NWORDS(length, 4) + 2, 2);
2696 /* FIXME: What does this mean? */
2697 int gencgc_hash = 1;
2700 scav_vector(lispobj *where, lispobj object)
2702 unsigned int kv_length;
2704 unsigned int length = 0; /* (0 = dummy to stop GCC warning) */
2705 lispobj *hash_table;
2706 lispobj empty_symbol;
2707 unsigned int *index_vector = NULL; /* (NULL = dummy to stop GCC warning) */
2708 unsigned int *next_vector = NULL; /* (NULL = dummy to stop GCC warning) */
2709 unsigned int *hash_vector = NULL; /* (NULL = dummy to stop GCC warning) */
2711 unsigned next_vector_length = 0;
2713 /* FIXME: A comment explaining this would be nice. It looks as
2714 * though SB-VM:VECTOR-VALID-HASHING-SUBTYPE is set for EQ-based
2715 * hash tables in the Lisp HASH-TABLE code, and nowhere else. */
2716 if (HeaderValue(object) != subtype_VectorValidHashing)
2720 /* This is set for backward compatibility. FIXME: Do we need
2723 (subtype_VectorMustRehash<<N_WIDETAG_BITS) | SIMPLE_VECTOR_WIDETAG;
2727 kv_length = fixnum_value(where[1]);
2728 kv_vector = where + 2; /* Skip the header and length. */
2729 /*FSHOW((stderr,"/kv_length = %d\n", kv_length));*/
2731 /* Scavenge element 0, which may be a hash-table structure. */
2732 scavenge(where+2, 1);
2733 if (!is_lisp_pointer(where[2])) {
2734 lose("no pointer at %x in hash table", where[2]);
2736 hash_table = (lispobj *)native_pointer(where[2]);
2737 /*FSHOW((stderr,"/hash_table = %x\n", hash_table));*/
2738 if (widetag_of(hash_table[0]) != INSTANCE_HEADER_WIDETAG) {
2739 lose("hash table not instance (%x at %x)", hash_table[0], hash_table);
2742 /* Scavenge element 1, which should be some internal symbol that
2743 * the hash table code reserves for marking empty slots. */
2744 scavenge(where+3, 1);
2745 if (!is_lisp_pointer(where[3])) {
2746 lose("not empty-hash-table-slot symbol pointer: %x", where[3]);
2748 empty_symbol = where[3];
2749 /* fprintf(stderr,"* empty_symbol = %x\n", empty_symbol);*/
2750 if (widetag_of(*(lispobj *)native_pointer(empty_symbol)) !=
2751 SYMBOL_HEADER_WIDETAG) {
2752 lose("not a symbol where empty-hash-table-slot symbol expected: %x",
2753 *(lispobj *)native_pointer(empty_symbol));
2756 /* Scavenge hash table, which will fix the positions of the other
2757 * needed objects. */
2758 scavenge(hash_table, 16);
2760 /* Cross-check the kv_vector. */
2761 if (where != (lispobj *)native_pointer(hash_table[9])) {
2762 lose("hash_table table!=this table %x", hash_table[9]);
2766 weak_p_obj = hash_table[10];
2770 lispobj index_vector_obj = hash_table[13];
2772 if (is_lisp_pointer(index_vector_obj) &&
2773 (widetag_of(*(lispobj *)native_pointer(index_vector_obj)) ==
2774 SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG)) {
2775 index_vector = ((unsigned int *)native_pointer(index_vector_obj)) + 2;
2776 /*FSHOW((stderr, "/index_vector = %x\n",index_vector));*/
2777 length = fixnum_value(((unsigned int *)native_pointer(index_vector_obj))[1]);
2778 /*FSHOW((stderr, "/length = %d\n", length));*/
2780 lose("invalid index_vector %x", index_vector_obj);
2786 lispobj next_vector_obj = hash_table[14];
2788 if (is_lisp_pointer(next_vector_obj) &&
2789 (widetag_of(*(lispobj *)native_pointer(next_vector_obj)) ==
2790 SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG)) {
2791 next_vector = ((unsigned int *)native_pointer(next_vector_obj)) + 2;
2792 /*FSHOW((stderr, "/next_vector = %x\n", next_vector));*/
2793 next_vector_length = fixnum_value(((unsigned int *)native_pointer(next_vector_obj))[1]);
2794 /*FSHOW((stderr, "/next_vector_length = %d\n", next_vector_length));*/
2796 lose("invalid next_vector %x", next_vector_obj);
2800 /* maybe hash vector */
2802 /* FIXME: This bare "15" offset should become a symbolic
2803 * expression of some sort. And all the other bare offsets
2804 * too. And the bare "16" in scavenge(hash_table, 16). And
2805 * probably other stuff too. Ugh.. */
2806 lispobj hash_vector_obj = hash_table[15];
2808 if (is_lisp_pointer(hash_vector_obj) &&
2809 (widetag_of(*(lispobj *)native_pointer(hash_vector_obj))
2810 == SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG)) {
2811 hash_vector = ((unsigned int *)native_pointer(hash_vector_obj)) + 2;
2812 /*FSHOW((stderr, "/hash_vector = %x\n", hash_vector));*/
2813 gc_assert(fixnum_value(((unsigned int *)native_pointer(hash_vector_obj))[1])
2814 == next_vector_length);
2817 /*FSHOW((stderr, "/no hash_vector: %x\n", hash_vector_obj));*/
2821 /* These lengths could be different as the index_vector can be a
2822 * different length from the others, a larger index_vector could help
2823 * reduce collisions. */
2824 gc_assert(next_vector_length*2 == kv_length);
2826 /* now all set up.. */
2828 /* Work through the KV vector. */
2831 for (i = 1; i < next_vector_length; i++) {
2832 lispobj old_key = kv_vector[2*i];
2833 unsigned int old_index = (old_key & 0x1fffffff)%length;
2835 /* Scavenge the key and value. */
2836 scavenge(&kv_vector[2*i],2);
2838 /* Check whether the key has moved and is EQ based. */
2840 lispobj new_key = kv_vector[2*i];
2841 unsigned int new_index = (new_key & 0x1fffffff)%length;
2843 if ((old_index != new_index) &&
2844 ((!hash_vector) || (hash_vector[i] == 0x80000000)) &&
2845 ((new_key != empty_symbol) ||
2846 (kv_vector[2*i] != empty_symbol))) {
2849 "* EQ key %d moved from %x to %x; index %d to %d\n",
2850 i, old_key, new_key, old_index, new_index));*/
2852 if (index_vector[old_index] != 0) {
2853 /*FSHOW((stderr, "/P1 %d\n", index_vector[old_index]));*/
2855 /* Unlink the key from the old_index chain. */
2856 if (index_vector[old_index] == i) {
2857 /*FSHOW((stderr, "/P2a %d\n", next_vector[i]));*/
2858 index_vector[old_index] = next_vector[i];
2859 /* Link it into the needing rehash chain. */
2860 next_vector[i] = fixnum_value(hash_table[11]);
2861 hash_table[11] = make_fixnum(i);
2864 unsigned prior = index_vector[old_index];
2865 unsigned next = next_vector[prior];
2867 /*FSHOW((stderr, "/P3a %d %d\n", prior, next));*/
2870 /*FSHOW((stderr, "/P3b %d %d\n", prior, next));*/
2873 next_vector[prior] = next_vector[next];
2874 /* Link it into the needing rehash
2877 fixnum_value(hash_table[11]);
2878 hash_table[11] = make_fixnum(next);
2883 next = next_vector[next];
2891 return (CEILING(kv_length + 2, 2));
2895 trans_vector(lispobj object)
2897 struct vector *vector;
2900 gc_assert(is_lisp_pointer(object));
2902 vector = (struct vector *) native_pointer(object);
2904 length = fixnum_value(vector->length);
2905 nwords = CEILING(length + 2, 2);
2907 return copy_large_object(object, nwords);
2911 size_vector(lispobj *where)
2913 struct vector *vector;
2916 vector = (struct vector *) where;
2917 length = fixnum_value(vector->length);
2918 nwords = CEILING(length + 2, 2);
2925 scav_vector_bit(lispobj *where, lispobj object)
2927 struct vector *vector;
2930 vector = (struct vector *) where;
2931 length = fixnum_value(vector->length);
2932 nwords = CEILING(NWORDS(length, 32) + 2, 2);
2938 trans_vector_bit(lispobj object)
2940 struct vector *vector;
2943 gc_assert(is_lisp_pointer(object));
2945 vector = (struct vector *) native_pointer(object);
2946 length = fixnum_value(vector->length);
2947 nwords = CEILING(NWORDS(length, 32) + 2, 2);
2949 return copy_large_unboxed_object(object, nwords);
2953 size_vector_bit(lispobj *where)
2955 struct vector *vector;
2958 vector = (struct vector *) where;
2959 length = fixnum_value(vector->length);
2960 nwords = CEILING(NWORDS(length, 32) + 2, 2);
2967 scav_vector_unsigned_byte_2(lispobj *where, lispobj object)
2969 struct vector *vector;
2972 vector = (struct vector *) where;
2973 length = fixnum_value(vector->length);
2974 nwords = CEILING(NWORDS(length, 16) + 2, 2);
2980 trans_vector_unsigned_byte_2(lispobj object)
2982 struct vector *vector;
2985 gc_assert(is_lisp_pointer(object));
2987 vector = (struct vector *) native_pointer(object);
2988 length = fixnum_value(vector->length);
2989 nwords = CEILING(NWORDS(length, 16) + 2, 2);
2991 return copy_large_unboxed_object(object, nwords);
2995 size_vector_unsigned_byte_2(lispobj *where)
2997 struct vector *vector;
3000 vector = (struct vector *) where;
3001 length = fixnum_value(vector->length);
3002 nwords = CEILING(NWORDS(length, 16) + 2, 2);
3009 scav_vector_unsigned_byte_4(lispobj *where, lispobj object)
3011 struct vector *vector;
3014 vector = (struct vector *) where;
3015 length = fixnum_value(vector->length);
3016 nwords = CEILING(NWORDS(length, 8) + 2, 2);
3022 trans_vector_unsigned_byte_4(lispobj object)
3024 struct vector *vector;
3027 gc_assert(is_lisp_pointer(object));
3029 vector = (struct vector *) native_pointer(object);
3030 length = fixnum_value(vector->length);
3031 nwords = CEILING(NWORDS(length, 8) + 2, 2);
3033 return copy_large_unboxed_object(object, nwords);
3037 size_vector_unsigned_byte_4(lispobj *where)
3039 struct vector *vector;
3042 vector = (struct vector *) where;
3043 length = fixnum_value(vector->length);
3044 nwords = CEILING(NWORDS(length, 8) + 2, 2);
3050 scav_vector_unsigned_byte_8(lispobj *where, lispobj object)
3052 struct vector *vector;
3055 vector = (struct vector *) where;
3056 length = fixnum_value(vector->length);
3057 nwords = CEILING(NWORDS(length, 4) + 2, 2);
3063 trans_vector_unsigned_byte_8(lispobj object)
3065 struct vector *vector;
3068 gc_assert(is_lisp_pointer(object));
3070 vector = (struct vector *) native_pointer(object);
3071 length = fixnum_value(vector->length);
3072 nwords = CEILING(NWORDS(length, 4) + 2, 2);
3074 return copy_large_unboxed_object(object, nwords);
3078 size_vector_unsigned_byte_8(lispobj *where)
3080 struct vector *vector;
3083 vector = (struct vector *) where;
3084 length = fixnum_value(vector->length);
3085 nwords = CEILING(NWORDS(length, 4) + 2, 2);
3092 scav_vector_unsigned_byte_16(lispobj *where, lispobj object)
3094 struct vector *vector;
3097 vector = (struct vector *) where;
3098 length = fixnum_value(vector->length);
3099 nwords = CEILING(NWORDS(length, 2) + 2, 2);
3105 trans_vector_unsigned_byte_16(lispobj object)
3107 struct vector *vector;
3110 gc_assert(is_lisp_pointer(object));
3112 vector = (struct vector *) native_pointer(object);
3113 length = fixnum_value(vector->length);
3114 nwords = CEILING(NWORDS(length, 2) + 2, 2);
3116 return copy_large_unboxed_object(object, nwords);
3120 size_vector_unsigned_byte_16(lispobj *where)
3122 struct vector *vector;
3125 vector = (struct vector *) where;
3126 length = fixnum_value(vector->length);
3127 nwords = CEILING(NWORDS(length, 2) + 2, 2);
3133 scav_vector_unsigned_byte_32(lispobj *where, lispobj object)
3135 struct vector *vector;
3138 vector = (struct vector *) where;
3139 length = fixnum_value(vector->length);
3140 nwords = CEILING(length + 2, 2);
3146 trans_vector_unsigned_byte_32(lispobj object)
3148 struct vector *vector;
3151 gc_assert(is_lisp_pointer(object));
3153 vector = (struct vector *) native_pointer(object);
3154 length = fixnum_value(vector->length);
3155 nwords = CEILING(length + 2, 2);
3157 return copy_large_unboxed_object(object, nwords);
3161 size_vector_unsigned_byte_32(lispobj *where)
3163 struct vector *vector;
3166 vector = (struct vector *) where;
3167 length = fixnum_value(vector->length);
3168 nwords = CEILING(length + 2, 2);
3174 scav_vector_single_float(lispobj *where, lispobj object)
3176 struct vector *vector;
3179 vector = (struct vector *) where;
3180 length = fixnum_value(vector->length);
3181 nwords = CEILING(length + 2, 2);
3187 trans_vector_single_float(lispobj object)
3189 struct vector *vector;
3192 gc_assert(is_lisp_pointer(object));
3194 vector = (struct vector *) native_pointer(object);
3195 length = fixnum_value(vector->length);
3196 nwords = CEILING(length + 2, 2);
3198 return copy_large_unboxed_object(object, nwords);
3202 size_vector_single_float(lispobj *where)
3204 struct vector *vector;
3207 vector = (struct vector *) where;
3208 length = fixnum_value(vector->length);
3209 nwords = CEILING(length + 2, 2);
3215 scav_vector_double_float(lispobj *where, lispobj object)
3217 struct vector *vector;
3220 vector = (struct vector *) where;
3221 length = fixnum_value(vector->length);
3222 nwords = CEILING(length * 2 + 2, 2);
3228 trans_vector_double_float(lispobj object)
3230 struct vector *vector;
3233 gc_assert(is_lisp_pointer(object));
3235 vector = (struct vector *) native_pointer(object);
3236 length = fixnum_value(vector->length);
3237 nwords = CEILING(length * 2 + 2, 2);
3239 return copy_large_unboxed_object(object, nwords);
3243 size_vector_double_float(lispobj *where)
3245 struct vector *vector;
3248 vector = (struct vector *) where;
3249 length = fixnum_value(vector->length);
3250 nwords = CEILING(length * 2 + 2, 2);
3255 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
3257 scav_vector_long_float(lispobj *where, lispobj object)
3259 struct vector *vector;
3262 vector = (struct vector *) where;
3263 length = fixnum_value(vector->length);
3264 nwords = CEILING(length * 3 + 2, 2);
3270 trans_vector_long_float(lispobj object)
3272 struct vector *vector;
3275 gc_assert(is_lisp_pointer(object));
3277 vector = (struct vector *) native_pointer(object);
3278 length = fixnum_value(vector->length);
3279 nwords = CEILING(length * 3 + 2, 2);
3281 return copy_large_unboxed_object(object, nwords);
3285 size_vector_long_float(lispobj *where)
3287 struct vector *vector;
3290 vector = (struct vector *) where;
3291 length = fixnum_value(vector->length);
3292 nwords = CEILING(length * 3 + 2, 2);
3299 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
3301 scav_vector_complex_single_float(lispobj *where, lispobj object)
3303 struct vector *vector;
3306 vector = (struct vector *) where;
3307 length = fixnum_value(vector->length);
3308 nwords = CEILING(length * 2 + 2, 2);
3314 trans_vector_complex_single_float(lispobj object)
3316 struct vector *vector;
3319 gc_assert(is_lisp_pointer(object));
3321 vector = (struct vector *) native_pointer(object);
3322 length = fixnum_value(vector->length);
3323 nwords = CEILING(length * 2 + 2, 2);
3325 return copy_large_unboxed_object(object, nwords);
3329 size_vector_complex_single_float(lispobj *where)
3331 struct vector *vector;
3334 vector = (struct vector *) where;
3335 length = fixnum_value(vector->length);
3336 nwords = CEILING(length * 2 + 2, 2);
3342 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
3344 scav_vector_complex_double_float(lispobj *where, lispobj object)
3346 struct vector *vector;
3349 vector = (struct vector *) where;
3350 length = fixnum_value(vector->length);
3351 nwords = CEILING(length * 4 + 2, 2);
3357 trans_vector_complex_double_float(lispobj object)
3359 struct vector *vector;
3362 gc_assert(is_lisp_pointer(object));
3364 vector = (struct vector *) native_pointer(object);
3365 length = fixnum_value(vector->length);
3366 nwords = CEILING(length * 4 + 2, 2);
3368 return copy_large_unboxed_object(object, nwords);
3372 size_vector_complex_double_float(lispobj *where)
3374 struct vector *vector;
3377 vector = (struct vector *) where;
3378 length = fixnum_value(vector->length);
3379 nwords = CEILING(length * 4 + 2, 2);
3386 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
3388 scav_vector_complex_long_float(lispobj *where, lispobj object)
3390 struct vector *vector;
3393 vector = (struct vector *) where;
3394 length = fixnum_value(vector->length);
3395 nwords = CEILING(length * 6 + 2, 2);
3401 trans_vector_complex_long_float(lispobj object)
3403 struct vector *vector;
3406 gc_assert(is_lisp_pointer(object));
3408 vector = (struct vector *) native_pointer(object);
3409 length = fixnum_value(vector->length);
3410 nwords = CEILING(length * 6 + 2, 2);
3412 return copy_large_unboxed_object(object, nwords);
3416 size_vector_complex_long_float(lispobj *where)
3418 struct vector *vector;
3421 vector = (struct vector *) where;
3422 length = fixnum_value(vector->length);
3423 nwords = CEILING(length * 6 + 2, 2);
3434 /* XX This is a hack adapted from cgc.c. These don't work too well with the
3435 * gencgc as a list of the weak pointers is maintained within the
3436 * objects which causes writes to the pages. A limited attempt is made
3437 * to avoid unnecessary writes, but this needs a re-think. */
3439 #define WEAK_POINTER_NWORDS \
3440 CEILING((sizeof(struct weak_pointer) / sizeof(lispobj)), 2)
3443 scav_weak_pointer(lispobj *where, lispobj object)
3445 struct weak_pointer *wp = weak_pointers;
3446 /* Push the weak pointer onto the list of weak pointers.
3447 * Do I have to watch for duplicates? Originally this was
3448 * part of trans_weak_pointer but that didn't work in the
3449 * case where the WP was in a promoted region.
3452 /* Check whether it's already in the list. */
3453 while (wp != NULL) {
3454 if (wp == (struct weak_pointer*)where) {
3460 /* Add it to the start of the list. */
3461 wp = (struct weak_pointer*)where;
3462 if (wp->next != weak_pointers) {
3463 wp->next = weak_pointers;
3465 /*SHOW("avoided write to weak pointer");*/
3470 /* Do not let GC scavenge the value slot of the weak pointer.
3471 * (That is why it is a weak pointer.) */
3473 return WEAK_POINTER_NWORDS;
3477 trans_weak_pointer(lispobj object)
3480 /* struct weak_pointer *wp; */
3482 gc_assert(is_lisp_pointer(object));
3484 #if defined(DEBUG_WEAK)
3485 FSHOW((stderr, "Transporting weak pointer from 0x%08x\n", object));
3488 /* Need to remember where all the weak pointers are that have */
3489 /* been transported so they can be fixed up in a post-GC pass. */
3491 copy = copy_object(object, WEAK_POINTER_NWORDS);
3492 /* wp = (struct weak_pointer *) native_pointer(copy);*/
3495 /* Push the weak pointer onto the list of weak pointers. */
3496 /* wp->next = weak_pointers;
3497 * weak_pointers = wp;*/
3503 size_weak_pointer(lispobj *where)
3505 return WEAK_POINTER_NWORDS;
3508 void scan_weak_pointers(void)
3510 struct weak_pointer *wp;
3511 for (wp = weak_pointers; wp != NULL; wp = wp->next) {
3512 lispobj value = wp->value;
3513 lispobj *first_pointer;
3515 first_pointer = (lispobj *)native_pointer(value);
3517 if (is_lisp_pointer(value) && from_space_p(value)) {
3518 /* Now, we need to check whether the object has been forwarded. If
3519 * it has been, the weak pointer is still good and needs to be
3520 * updated. Otherwise, the weak pointer needs to be nil'ed
3522 if (first_pointer[0] == 0x01) {
3523 wp->value = first_pointer[1];
3538 scav_lose(lispobj *where, lispobj object)
3540 lose("no scavenge function for object 0x%08x (widetag 0x%x)",
3541 (unsigned long)object,
3542 widetag_of(*(lispobj*)native_pointer(object)));
3543 return 0; /* bogus return value to satisfy static type checking */
3547 trans_lose(lispobj object)
3549 lose("no transport function for object 0x%08x (widetag 0x%x)",
3550 (unsigned long)object,
3551 widetag_of(*(lispobj*)native_pointer(object)));
3552 return NIL; /* bogus return value to satisfy static type checking */
3556 size_lose(lispobj *where)
3558 lose("no size function for object at 0x%08x (widetag 0x%x)",
3559 (unsigned long)where,
3561 return 1; /* bogus return value to satisfy static type checking */
3565 gc_init_tables(void)
3569 /* Set default value in all slots of scavenge table. */
3570 for (i = 0; i < 256; i++) { /* FIXME: bare constant length, ick! */
3571 scavtab[i] = scav_lose;
3574 /* For each type which can be selected by the lowtag alone, set
3575 * multiple entries in our widetag scavenge table (one for each
3576 * possible value of the high bits).
3578 * FIXME: bare constant 32 and 3 here, ick! */
3579 for (i = 0; i < 32; i++) {
3580 scavtab[EVEN_FIXNUM_LOWTAG|(i<<3)] = scav_immediate;
3581 scavtab[FUN_POINTER_LOWTAG|(i<<3)] = scav_fun_pointer;
3582 /* skipping OTHER_IMMEDIATE_0_LOWTAG */
3583 scavtab[LIST_POINTER_LOWTAG|(i<<3)] = scav_list_pointer;
3584 scavtab[ODD_FIXNUM_LOWTAG|(i<<3)] = scav_immediate;
3585 scavtab[INSTANCE_POINTER_LOWTAG|(i<<3)] = scav_instance_pointer;
3586 /* skipping OTHER_IMMEDIATE_1_LOWTAG */
3587 scavtab[OTHER_POINTER_LOWTAG|(i<<3)] = scav_other_pointer;
3590 /* Other-pointer types (those selected by all eight bits of the
3591 * tag) get one entry each in the scavenge table. */
3592 scavtab[BIGNUM_WIDETAG] = scav_unboxed;
3593 scavtab[RATIO_WIDETAG] = scav_boxed;
3594 scavtab[SINGLE_FLOAT_WIDETAG] = scav_unboxed;
3595 scavtab[DOUBLE_FLOAT_WIDETAG] = scav_unboxed;
3596 #ifdef LONG_FLOAT_WIDETAG
3597 scavtab[LONG_FLOAT_WIDETAG] = scav_unboxed;
3599 scavtab[COMPLEX_WIDETAG] = scav_boxed;
3600 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
3601 scavtab[COMPLEX_SINGLE_FLOAT_WIDETAG] = scav_unboxed;
3603 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
3604 scavtab[COMPLEX_DOUBLE_FLOAT_WIDETAG] = scav_unboxed;
3606 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
3607 scavtab[COMPLEX_LONG_FLOAT_WIDETAG] = scav_unboxed;
3609 scavtab[SIMPLE_ARRAY_WIDETAG] = scav_boxed;
3610 scavtab[SIMPLE_STRING_WIDETAG] = scav_string;
3611 scavtab[SIMPLE_BIT_VECTOR_WIDETAG] = scav_vector_bit;
3612 scavtab[SIMPLE_VECTOR_WIDETAG] = scav_vector;
3613 scavtab[SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG] =
3614 scav_vector_unsigned_byte_2;
3615 scavtab[SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG] =
3616 scav_vector_unsigned_byte_4;
3617 scavtab[SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG] =
3618 scav_vector_unsigned_byte_8;
3619 scavtab[SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG] =
3620 scav_vector_unsigned_byte_16;
3621 scavtab[SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG] =
3622 scav_vector_unsigned_byte_32;
3623 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
3624 scavtab[SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG] = scav_vector_unsigned_byte_8;
3626 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
3627 scavtab[SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG] =
3628 scav_vector_unsigned_byte_16;
3630 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
3631 scavtab[SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG] =
3632 scav_vector_unsigned_byte_32;
3634 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
3635 scavtab[SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG] =
3636 scav_vector_unsigned_byte_32;
3638 scavtab[SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG] = scav_vector_single_float;
3639 scavtab[SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG] = scav_vector_double_float;
3640 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
3641 scavtab[SIMPLE_ARRAY_LONG_FLOAT_WIDETAG] = scav_vector_long_float;
3643 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
3644 scavtab[SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG] =
3645 scav_vector_complex_single_float;
3647 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
3648 scavtab[SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG] =
3649 scav_vector_complex_double_float;
3651 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
3652 scavtab[SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG] =
3653 scav_vector_complex_long_float;
3655 scavtab[COMPLEX_STRING_WIDETAG] = scav_boxed;
3656 scavtab[COMPLEX_BIT_VECTOR_WIDETAG] = scav_boxed;
3657 scavtab[COMPLEX_VECTOR_WIDETAG] = scav_boxed;
3658 scavtab[COMPLEX_ARRAY_WIDETAG] = scav_boxed;
3659 scavtab[CODE_HEADER_WIDETAG] = scav_code_header;
3660 /*scavtab[SIMPLE_FUN_HEADER_WIDETAG] = scav_fun_header;*/
3661 /*scavtab[CLOSURE_FUN_HEADER_WIDETAG] = scav_fun_header;*/
3662 /*scavtab[RETURN_PC_HEADER_WIDETAG] = scav_return_pc_header;*/
3664 scavtab[CLOSURE_HEADER_WIDETAG] = scav_closure_header;
3665 scavtab[FUNCALLABLE_INSTANCE_HEADER_WIDETAG] = scav_closure_header;
3667 scavtab[CLOSURE_HEADER_WIDETAG] = scav_boxed;
3668 scavtab[FUNCALLABLE_INSTANCE_HEADER_WIDETAG] = scav_boxed;
3670 scavtab[VALUE_CELL_HEADER_WIDETAG] = scav_boxed;
3671 scavtab[SYMBOL_HEADER_WIDETAG] = scav_boxed;
3672 scavtab[BASE_CHAR_WIDETAG] = scav_immediate;
3673 scavtab[SAP_WIDETAG] = scav_unboxed;
3674 scavtab[UNBOUND_MARKER_WIDETAG] = scav_immediate;
3675 scavtab[WEAK_POINTER_WIDETAG] = scav_weak_pointer;
3676 scavtab[INSTANCE_HEADER_WIDETAG] = scav_boxed;
3677 scavtab[FDEFN_WIDETAG] = scav_fdefn;
3679 /* transport other table, initialized same way as scavtab */
3680 for (i = 0; i < 256; i++)
3681 transother[i] = trans_lose;
3682 transother[BIGNUM_WIDETAG] = trans_unboxed;
3683 transother[RATIO_WIDETAG] = trans_boxed;
3684 transother[SINGLE_FLOAT_WIDETAG] = trans_unboxed;
3685 transother[DOUBLE_FLOAT_WIDETAG] = trans_unboxed;
3686 #ifdef LONG_FLOAT_WIDETAG
3687 transother[LONG_FLOAT_WIDETAG] = trans_unboxed;
3689 transother[COMPLEX_WIDETAG] = trans_boxed;
3690 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
3691 transother[COMPLEX_SINGLE_FLOAT_WIDETAG] = trans_unboxed;
3693 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
3694 transother[COMPLEX_DOUBLE_FLOAT_WIDETAG] = trans_unboxed;
3696 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
3697 transother[COMPLEX_LONG_FLOAT_WIDETAG] = trans_unboxed;
3699 transother[SIMPLE_ARRAY_WIDETAG] = trans_boxed_large;
3700 transother[SIMPLE_STRING_WIDETAG] = trans_string;
3701 transother[SIMPLE_BIT_VECTOR_WIDETAG] = trans_vector_bit;
3702 transother[SIMPLE_VECTOR_WIDETAG] = trans_vector;
3703 transother[SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG] =
3704 trans_vector_unsigned_byte_2;
3705 transother[SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG] =
3706 trans_vector_unsigned_byte_4;
3707 transother[SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG] =
3708 trans_vector_unsigned_byte_8;
3709 transother[SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG] =
3710 trans_vector_unsigned_byte_16;
3711 transother[SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG] =
3712 trans_vector_unsigned_byte_32;
3713 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
3714 transother[SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG] =
3715 trans_vector_unsigned_byte_8;
3717 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
3718 transother[SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG] =
3719 trans_vector_unsigned_byte_16;
3721 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
3722 transother[SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG] =
3723 trans_vector_unsigned_byte_32;
3725 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
3726 transother[SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG] =
3727 trans_vector_unsigned_byte_32;
3729 transother[SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG] =
3730 trans_vector_single_float;
3731 transother[SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG] =
3732 trans_vector_double_float;
3733 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
3734 transother[SIMPLE_ARRAY_LONG_FLOAT_WIDETAG] =
3735 trans_vector_long_float;
3737 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
3738 transother[SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG] =
3739 trans_vector_complex_single_float;
3741 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
3742 transother[SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG] =
3743 trans_vector_complex_double_float;
3745 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
3746 transother[SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG] =
3747 trans_vector_complex_long_float;
3749 transother[COMPLEX_STRING_WIDETAG] = trans_boxed;
3750 transother[COMPLEX_BIT_VECTOR_WIDETAG] = trans_boxed;
3751 transother[COMPLEX_VECTOR_WIDETAG] = trans_boxed;
3752 transother[COMPLEX_ARRAY_WIDETAG] = trans_boxed;
3753 transother[CODE_HEADER_WIDETAG] = trans_code_header;
3754 transother[SIMPLE_FUN_HEADER_WIDETAG] = trans_fun_header;
3755 transother[CLOSURE_FUN_HEADER_WIDETAG] = trans_fun_header;
3756 transother[RETURN_PC_HEADER_WIDETAG] = trans_return_pc_header;
3757 transother[CLOSURE_HEADER_WIDETAG] = trans_boxed;
3758 transother[FUNCALLABLE_INSTANCE_HEADER_WIDETAG] = trans_boxed;
3759 transother[VALUE_CELL_HEADER_WIDETAG] = trans_boxed;
3760 transother[SYMBOL_HEADER_WIDETAG] = trans_boxed;
3761 transother[BASE_CHAR_WIDETAG] = trans_immediate;
3762 transother[SAP_WIDETAG] = trans_unboxed;
3763 transother[UNBOUND_MARKER_WIDETAG] = trans_immediate;
3764 transother[WEAK_POINTER_WIDETAG] = trans_weak_pointer;
3765 transother[INSTANCE_HEADER_WIDETAG] = trans_boxed;
3766 transother[FDEFN_WIDETAG] = trans_boxed;
3768 /* size table, initialized the same way as scavtab */
3769 for (i = 0; i < 256; i++)
3770 sizetab[i] = size_lose;
3771 for (i = 0; i < 32; i++) {
3772 sizetab[EVEN_FIXNUM_LOWTAG|(i<<3)] = size_immediate;
3773 sizetab[FUN_POINTER_LOWTAG|(i<<3)] = size_pointer;
3774 /* skipping OTHER_IMMEDIATE_0_LOWTAG */
3775 sizetab[LIST_POINTER_LOWTAG|(i<<3)] = size_pointer;
3776 sizetab[ODD_FIXNUM_LOWTAG|(i<<3)] = size_immediate;
3777 sizetab[INSTANCE_POINTER_LOWTAG|(i<<3)] = size_pointer;
3778 /* skipping OTHER_IMMEDIATE_1_LOWTAG */
3779 sizetab[OTHER_POINTER_LOWTAG|(i<<3)] = size_pointer;
3781 sizetab[BIGNUM_WIDETAG] = size_unboxed;
3782 sizetab[RATIO_WIDETAG] = size_boxed;
3783 sizetab[SINGLE_FLOAT_WIDETAG] = size_unboxed;
3784 sizetab[DOUBLE_FLOAT_WIDETAG] = size_unboxed;
3785 #ifdef LONG_FLOAT_WIDETAG
3786 sizetab[LONG_FLOAT_WIDETAG] = size_unboxed;
3788 sizetab[COMPLEX_WIDETAG] = size_boxed;
3789 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
3790 sizetab[COMPLEX_SINGLE_FLOAT_WIDETAG] = size_unboxed;
3792 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
3793 sizetab[COMPLEX_DOUBLE_FLOAT_WIDETAG] = size_unboxed;
3795 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
3796 sizetab[COMPLEX_LONG_FLOAT_WIDETAG] = size_unboxed;
3798 sizetab[SIMPLE_ARRAY_WIDETAG] = size_boxed;
3799 sizetab[SIMPLE_STRING_WIDETAG] = size_string;
3800 sizetab[SIMPLE_BIT_VECTOR_WIDETAG] = size_vector_bit;
3801 sizetab[SIMPLE_VECTOR_WIDETAG] = size_vector;
3802 sizetab[SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG] =
3803 size_vector_unsigned_byte_2;
3804 sizetab[SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG] =
3805 size_vector_unsigned_byte_4;
3806 sizetab[SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG] =
3807 size_vector_unsigned_byte_8;
3808 sizetab[SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG] =
3809 size_vector_unsigned_byte_16;
3810 sizetab[SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG] =
3811 size_vector_unsigned_byte_32;
3812 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
3813 sizetab[SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG] = size_vector_unsigned_byte_8;
3815 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
3816 sizetab[SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG] =
3817 size_vector_unsigned_byte_16;
3819 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
3820 sizetab[SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG] =
3821 size_vector_unsigned_byte_32;
3823 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
3824 sizetab[SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG] =
3825 size_vector_unsigned_byte_32;
3827 sizetab[SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG] = size_vector_single_float;
3828 sizetab[SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG] = size_vector_double_float;
3829 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
3830 sizetab[SIMPLE_ARRAY_LONG_FLOAT_WIDETAG] = size_vector_long_float;
3832 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
3833 sizetab[SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG] =
3834 size_vector_complex_single_float;
3836 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
3837 sizetab[SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG] =
3838 size_vector_complex_double_float;
3840 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
3841 sizetab[SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG] =
3842 size_vector_complex_long_float;
3844 sizetab[COMPLEX_STRING_WIDETAG] = size_boxed;
3845 sizetab[COMPLEX_BIT_VECTOR_WIDETAG] = size_boxed;
3846 sizetab[COMPLEX_VECTOR_WIDETAG] = size_boxed;
3847 sizetab[COMPLEX_ARRAY_WIDETAG] = size_boxed;
3848 sizetab[CODE_HEADER_WIDETAG] = size_code_header;
3850 /* We shouldn't see these, so just lose if it happens. */
3851 sizetab[SIMPLE_FUN_HEADER_WIDETAG] = size_function_header;
3852 sizetab[CLOSURE_FUN_HEADER_WIDETAG] = size_function_header;
3853 sizetab[RETURN_PC_HEADER_WIDETAG] = size_return_pc_header;
3855 sizetab[CLOSURE_HEADER_WIDETAG] = size_boxed;
3856 sizetab[FUNCALLABLE_INSTANCE_HEADER_WIDETAG] = size_boxed;
3857 sizetab[VALUE_CELL_HEADER_WIDETAG] = size_boxed;
3858 sizetab[SYMBOL_HEADER_WIDETAG] = size_boxed;
3859 sizetab[BASE_CHAR_WIDETAG] = size_immediate;
3860 sizetab[SAP_WIDETAG] = size_unboxed;
3861 sizetab[UNBOUND_MARKER_WIDETAG] = size_immediate;
3862 sizetab[WEAK_POINTER_WIDETAG] = size_weak_pointer;
3863 sizetab[INSTANCE_HEADER_WIDETAG] = size_boxed;
3864 sizetab[FDEFN_WIDETAG] = size_boxed;
3867 /* Scan an area looking for an object which encloses the given pointer.
3868 * Return the object start on success or NULL on failure. */
3870 search_space(lispobj *start, size_t words, lispobj *pointer)
3874 lispobj thing = *start;
3876 /* If thing is an immediate then this is a cons. */
3877 if (is_lisp_pointer(thing)
3878 || ((thing & 3) == 0) /* fixnum */
3879 || (widetag_of(thing) == BASE_CHAR_WIDETAG)
3880 || (widetag_of(thing) == UNBOUND_MARKER_WIDETAG))
3883 count = (sizetab[widetag_of(thing)])(start);
3885 /* Check whether the pointer is within this object. */
3886 if ((pointer >= start) && (pointer < (start+count))) {
3888 /*FSHOW((stderr,"/found %x in %x %x\n", pointer, start, thing));*/
3892 /* Round up the count. */
3893 count = CEILING(count,2);
3902 search_read_only_space(lispobj *pointer)
3904 lispobj* start = (lispobj*)READ_ONLY_SPACE_START;
3905 lispobj* end = (lispobj*)SymbolValue(READ_ONLY_SPACE_FREE_POINTER);
3906 if ((pointer < start) || (pointer >= end))
3908 return (search_space(start, (pointer+2)-start, pointer));
3912 search_static_space(lispobj *pointer)
3914 lispobj* start = (lispobj*)STATIC_SPACE_START;
3915 lispobj* end = (lispobj*)SymbolValue(STATIC_SPACE_FREE_POINTER);
3916 if ((pointer < start) || (pointer >= end))
3918 return (search_space(start, (pointer+2)-start, pointer));
3921 /* a faster version for searching the dynamic space. This will work even
3922 * if the object is in a current allocation region. */
3924 search_dynamic_space(lispobj *pointer)
3926 int page_index = find_page_index(pointer);
3929 /* The address may be invalid, so do some checks. */
3930 if ((page_index == -1) || (page_table[page_index].allocated == FREE_PAGE))
3932 start = (lispobj *)((void *)page_address(page_index)
3933 + page_table[page_index].first_object_offset);
3934 return (search_space(start, (pointer+2)-start, pointer));
3937 /* Is there any possibility that pointer is a valid Lisp object
3938 * reference, and/or something else (e.g. subroutine call return
3939 * address) which should prevent us from moving the referred-to thing? */
3941 possibly_valid_dynamic_space_pointer(lispobj *pointer)
3943 lispobj *start_addr;
3945 /* Find the object start address. */
3946 if ((start_addr = search_dynamic_space(pointer)) == NULL) {
3950 /* We need to allow raw pointers into Code objects for return
3951 * addresses. This will also pick up pointers to functions in code
3953 if (widetag_of(*start_addr) == CODE_HEADER_WIDETAG) {
3954 /* XXX could do some further checks here */
3958 /* If it's not a return address then it needs to be a valid Lisp
3960 if (!is_lisp_pointer((lispobj)pointer)) {
3964 /* Check that the object pointed to is consistent with the pointer
3967 * FIXME: It's not safe to rely on the result from this check
3968 * before an object is initialized. Thus, if we were interrupted
3969 * just as an object had been allocated but not initialized, the
3970 * GC relying on this result could bogusly reclaim the memory.
3971 * However, we can't really afford to do without this check. So
3972 * we should make it safe somehow.
3973 * (1) Perhaps just review the code to make sure
3974 * that WITHOUT-GCING or WITHOUT-INTERRUPTS or some such
3975 * thing is wrapped around critical sections where allocated
3976 * memory type bits haven't been set.
3977 * (2) Perhaps find some other hack to protect against this, e.g.
3978 * recording the result of the last call to allocate-lisp-memory,
3979 * and returning true from this function when *pointer is
3980 * a reference to that result. */
3981 switch (lowtag_of((lispobj)pointer)) {
3982 case FUN_POINTER_LOWTAG:
3983 /* Start_addr should be the enclosing code object, or a closure
3985 switch (widetag_of(*start_addr)) {
3986 case CODE_HEADER_WIDETAG:
3987 /* This case is probably caught above. */
3989 case CLOSURE_HEADER_WIDETAG:
3990 case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
3991 if ((unsigned)pointer !=
3992 ((unsigned)start_addr+FUN_POINTER_LOWTAG)) {
3996 pointer, start_addr, *start_addr));
4004 pointer, start_addr, *start_addr));
4008 case LIST_POINTER_LOWTAG:
4009 if ((unsigned)pointer !=
4010 ((unsigned)start_addr+LIST_POINTER_LOWTAG)) {
4014 pointer, start_addr, *start_addr));
4017 /* Is it plausible cons? */
4018 if ((is_lisp_pointer(start_addr[0])
4019 || ((start_addr[0] & 3) == 0) /* fixnum */
4020 || (widetag_of(start_addr[0]) == BASE_CHAR_WIDETAG)
4021 || (widetag_of(start_addr[0]) == UNBOUND_MARKER_WIDETAG))
4022 && (is_lisp_pointer(start_addr[1])
4023 || ((start_addr[1] & 3) == 0) /* fixnum */
4024 || (widetag_of(start_addr[1]) == BASE_CHAR_WIDETAG)
4025 || (widetag_of(start_addr[1]) == UNBOUND_MARKER_WIDETAG)))
4031 pointer, start_addr, *start_addr));
4034 case INSTANCE_POINTER_LOWTAG:
4035 if ((unsigned)pointer !=
4036 ((unsigned)start_addr+INSTANCE_POINTER_LOWTAG)) {
4040 pointer, start_addr, *start_addr));
4043 if (widetag_of(start_addr[0]) != INSTANCE_HEADER_WIDETAG) {
4047 pointer, start_addr, *start_addr));
4051 case OTHER_POINTER_LOWTAG:
4052 if ((unsigned)pointer !=
4053 ((int)start_addr+OTHER_POINTER_LOWTAG)) {
4057 pointer, start_addr, *start_addr));
4060 /* Is it plausible? Not a cons. XXX should check the headers. */
4061 if (is_lisp_pointer(start_addr[0]) || ((start_addr[0] & 3) == 0)) {
4065 pointer, start_addr, *start_addr));
4068 switch (widetag_of(start_addr[0])) {
4069 case UNBOUND_MARKER_WIDETAG:
4070 case BASE_CHAR_WIDETAG:
4074 pointer, start_addr, *start_addr));
4077 /* only pointed to by function pointers? */
4078 case CLOSURE_HEADER_WIDETAG:
4079 case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
4083 pointer, start_addr, *start_addr));
4086 case INSTANCE_HEADER_WIDETAG:
4090 pointer, start_addr, *start_addr));
4093 /* the valid other immediate pointer objects */
4094 case SIMPLE_VECTOR_WIDETAG:
4096 case COMPLEX_WIDETAG:
4097 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
4098 case COMPLEX_SINGLE_FLOAT_WIDETAG:
4100 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
4101 case COMPLEX_DOUBLE_FLOAT_WIDETAG:
4103 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
4104 case COMPLEX_LONG_FLOAT_WIDETAG:
4106 case SIMPLE_ARRAY_WIDETAG:
4107 case COMPLEX_STRING_WIDETAG:
4108 case COMPLEX_BIT_VECTOR_WIDETAG:
4109 case COMPLEX_VECTOR_WIDETAG:
4110 case COMPLEX_ARRAY_WIDETAG:
4111 case VALUE_CELL_HEADER_WIDETAG:
4112 case SYMBOL_HEADER_WIDETAG:
4114 case CODE_HEADER_WIDETAG:
4115 case BIGNUM_WIDETAG:
4116 case SINGLE_FLOAT_WIDETAG:
4117 case DOUBLE_FLOAT_WIDETAG:
4118 #ifdef LONG_FLOAT_WIDETAG
4119 case LONG_FLOAT_WIDETAG:
4121 case SIMPLE_STRING_WIDETAG:
4122 case SIMPLE_BIT_VECTOR_WIDETAG:
4123 case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
4124 case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
4125 case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
4126 case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
4127 case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
4128 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
4129 case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
4131 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
4132 case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
4134 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
4135 case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
4137 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
4138 case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
4140 case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
4141 case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
4142 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
4143 case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
4145 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
4146 case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
4148 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
4149 case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
4151 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
4152 case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
4155 case WEAK_POINTER_WIDETAG:
4162 pointer, start_addr, *start_addr));
4170 pointer, start_addr, *start_addr));
4178 /* Adjust large bignum and vector objects. This will adjust the
4179 * allocated region if the size has shrunk, and move unboxed objects
4180 * into unboxed pages. The pages are not promoted here, and the
4181 * promoted region is not added to the new_regions; this is really
4182 * only designed to be called from preserve_pointer(). Shouldn't fail
4183 * if this is missed, just may delay the moving of objects to unboxed
4184 * pages, and the freeing of pages. */
4186 maybe_adjust_large_object(lispobj *where)
4191 int remaining_bytes;
4198 /* Check whether it's a vector or bignum object. */
4199 switch (widetag_of(where[0])) {
4200 case SIMPLE_VECTOR_WIDETAG:
4203 case BIGNUM_WIDETAG:
4204 case SIMPLE_STRING_WIDETAG:
4205 case SIMPLE_BIT_VECTOR_WIDETAG:
4206 case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
4207 case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
4208 case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
4209 case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
4210 case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
4211 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
4212 case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
4214 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
4215 case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
4217 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
4218 case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
4220 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
4221 case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
4223 case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
4224 case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
4225 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
4226 case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
4228 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
4229 case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
4231 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
4232 case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
4234 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
4235 case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
4237 boxed = UNBOXED_PAGE;
4243 /* Find its current size. */
4244 nwords = (sizetab[widetag_of(where[0])])(where);
4246 first_page = find_page_index((void *)where);
4247 gc_assert(first_page >= 0);
4249 /* Note: Any page write-protection must be removed, else a later
4250 * scavenge_newspace may incorrectly not scavenge these pages.
4251 * This would not be necessary if they are added to the new areas,
4252 * but lets do it for them all (they'll probably be written
4255 gc_assert(page_table[first_page].first_object_offset == 0);
4257 next_page = first_page;
4258 remaining_bytes = nwords*4;
4259 while (remaining_bytes > 4096) {
4260 gc_assert(page_table[next_page].gen == from_space);
4261 gc_assert((page_table[next_page].allocated == BOXED_PAGE)
4262 || (page_table[next_page].allocated == UNBOXED_PAGE));
4263 gc_assert(page_table[next_page].large_object);
4264 gc_assert(page_table[next_page].first_object_offset ==
4265 -4096*(next_page-first_page));
4266 gc_assert(page_table[next_page].bytes_used == 4096);
4268 page_table[next_page].allocated = boxed;
4270 /* Shouldn't be write-protected at this stage. Essential that the
4272 gc_assert(!page_table[next_page].write_protected);
4273 remaining_bytes -= 4096;
4277 /* Now only one page remains, but the object may have shrunk so
4278 * there may be more unused pages which will be freed. */
4280 /* Object may have shrunk but shouldn't have grown - check. */
4281 gc_assert(page_table[next_page].bytes_used >= remaining_bytes);
4283 page_table[next_page].allocated = boxed;
4284 gc_assert(page_table[next_page].allocated ==
4285 page_table[first_page].allocated);
4287 /* Adjust the bytes_used. */
4288 old_bytes_used = page_table[next_page].bytes_used;
4289 page_table[next_page].bytes_used = remaining_bytes;
4291 bytes_freed = old_bytes_used - remaining_bytes;
4293 /* Free any remaining pages; needs care. */
4295 while ((old_bytes_used == 4096) &&
4296 (page_table[next_page].gen == from_space) &&
4297 ((page_table[next_page].allocated == UNBOXED_PAGE)
4298 || (page_table[next_page].allocated == BOXED_PAGE)) &&
4299 page_table[next_page].large_object &&
4300 (page_table[next_page].first_object_offset ==
4301 -(next_page - first_page)*4096)) {
4302 /* It checks out OK, free the page. We don't need to both zeroing
4303 * pages as this should have been done before shrinking the
4304 * object. These pages shouldn't be write protected as they
4305 * should be zero filled. */
4306 gc_assert(page_table[next_page].write_protected == 0);
4308 old_bytes_used = page_table[next_page].bytes_used;
4309 page_table[next_page].allocated = FREE_PAGE;
4310 page_table[next_page].bytes_used = 0;
4311 bytes_freed += old_bytes_used;
4315 if ((bytes_freed > 0) && gencgc_verbose) {
4317 "/maybe_adjust_large_object() freed %d\n",
4321 generations[from_space].bytes_allocated -= bytes_freed;
4322 bytes_allocated -= bytes_freed;
4327 /* Take a possible pointer to a Lisp object and mark its page in the
4328 * page_table so that it will not be relocated during a GC.
4330 * This involves locating the page it points to, then backing up to
4331 * the first page that has its first object start at offset 0, and
4332 * then marking all pages dont_move from the first until a page that
4333 * ends by being full, or having free gen.
4335 * This ensures that objects spanning pages are not broken.
4337 * It is assumed that all the page static flags have been cleared at
4338 * the start of a GC.
4340 * It is also assumed that the current gc_alloc() region has been
4341 * flushed and the tables updated. */
4343 preserve_pointer(void *addr)
4345 int addr_page_index = find_page_index(addr);
4348 unsigned region_allocation;
4350 /* quick check 1: Address is quite likely to have been invalid. */
4351 if ((addr_page_index == -1)
4352 || (page_table[addr_page_index].allocated == FREE_PAGE)
4353 || (page_table[addr_page_index].bytes_used == 0)
4354 || (page_table[addr_page_index].gen != from_space)
4355 /* Skip if already marked dont_move. */
4356 || (page_table[addr_page_index].dont_move != 0))
4359 /* (Now that we know that addr_page_index is in range, it's
4360 * safe to index into page_table[] with it.) */
4361 region_allocation = page_table[addr_page_index].allocated;
4363 /* quick check 2: Check the offset within the page.
4365 * FIXME: The mask should have a symbolic name, and ideally should
4366 * be derived from page size instead of hardwired to 0xfff.
4367 * (Also fix other uses of 0xfff, elsewhere.) */
4368 if (((unsigned)addr & 0xfff) > page_table[addr_page_index].bytes_used)
4371 /* Filter out anything which can't be a pointer to a Lisp object
4372 * (or, as a special case which also requires dont_move, a return
4373 * address referring to something in a CodeObject). This is
4374 * expensive but important, since it vastly reduces the
4375 * probability that random garbage will be bogusly interpreter as
4376 * a pointer which prevents a page from moving. */
4377 if (!possibly_valid_dynamic_space_pointer(addr))
4380 /* Work backwards to find a page with a first_object_offset of 0.
4381 * The pages should be contiguous with all bytes used in the same
4382 * gen. Assumes the first_object_offset is negative or zero. */
4383 first_page = addr_page_index;
4384 while (page_table[first_page].first_object_offset != 0) {
4386 /* Do some checks. */
4387 gc_assert(page_table[first_page].bytes_used == 4096);
4388 gc_assert(page_table[first_page].gen == from_space);
4389 gc_assert(page_table[first_page].allocated == region_allocation);
4392 /* Adjust any large objects before promotion as they won't be
4393 * copied after promotion. */
4394 if (page_table[first_page].large_object) {
4395 maybe_adjust_large_object(page_address(first_page));
4396 /* If a large object has shrunk then addr may now point to a
4397 * free area in which case it's ignored here. Note it gets
4398 * through the valid pointer test above because the tail looks
4400 if ((page_table[addr_page_index].allocated == FREE_PAGE)
4401 || (page_table[addr_page_index].bytes_used == 0)
4402 /* Check the offset within the page. */
4403 || (((unsigned)addr & 0xfff)
4404 > page_table[addr_page_index].bytes_used)) {
4406 "weird? ignore ptr 0x%x to freed area of large object\n",
4410 /* It may have moved to unboxed pages. */
4411 region_allocation = page_table[first_page].allocated;
4414 /* Now work forward until the end of this contiguous area is found,
4415 * marking all pages as dont_move. */
4416 for (i = first_page; ;i++) {
4417 gc_assert(page_table[i].allocated == region_allocation);
4419 /* Mark the page static. */
4420 page_table[i].dont_move = 1;
4422 /* Move the page to the new_space. XX I'd rather not do this
4423 * but the GC logic is not quite able to copy with the static
4424 * pages remaining in the from space. This also requires the
4425 * generation bytes_allocated counters be updated. */
4426 page_table[i].gen = new_space;
4427 generations[new_space].bytes_allocated += page_table[i].bytes_used;
4428 generations[from_space].bytes_allocated -= page_table[i].bytes_used;
4430 /* It is essential that the pages are not write protected as
4431 * they may have pointers into the old-space which need
4432 * scavenging. They shouldn't be write protected at this
4434 gc_assert(!page_table[i].write_protected);
4436 /* Check whether this is the last page in this contiguous block.. */
4437 if ((page_table[i].bytes_used < 4096)
4438 /* ..or it is 4096 and is the last in the block */
4439 || (page_table[i+1].allocated == FREE_PAGE)
4440 || (page_table[i+1].bytes_used == 0) /* next page free */
4441 || (page_table[i+1].gen != from_space) /* diff. gen */
4442 || (page_table[i+1].first_object_offset == 0))
4446 /* Check that the page is now static. */
4447 gc_assert(page_table[addr_page_index].dont_move != 0);
4450 /* If the given page is not write-protected, then scan it for pointers
4451 * to younger generations or the top temp. generation, if no
4452 * suspicious pointers are found then the page is write-protected.
4454 * Care is taken to check for pointers to the current gc_alloc()
4455 * region if it is a younger generation or the temp. generation. This
4456 * frees the caller from doing a gc_alloc_update_page_tables(). Actually
4457 * the gc_alloc_generation does not need to be checked as this is only
4458 * called from scavenge_generation() when the gc_alloc generation is
4459 * younger, so it just checks if there is a pointer to the current
4462 * We return 1 if the page was write-protected, else 0. */
4464 update_page_write_prot(int page)
4466 int gen = page_table[page].gen;
4469 void **page_addr = (void **)page_address(page);
4470 int num_words = page_table[page].bytes_used / 4;
4472 /* Shouldn't be a free page. */
4473 gc_assert(page_table[page].allocated != FREE_PAGE);
4474 gc_assert(page_table[page].bytes_used != 0);
4476 /* Skip if it's already write-protected or an unboxed page. */
4477 if (page_table[page].write_protected
4478 || (page_table[page].allocated == UNBOXED_PAGE))
4481 /* Scan the page for pointers to younger generations or the
4482 * top temp. generation. */
4484 for (j = 0; j < num_words; j++) {
4485 void *ptr = *(page_addr+j);
4486 int index = find_page_index(ptr);
4488 /* Check that it's in the dynamic space */
4490 if (/* Does it point to a younger or the temp. generation? */
4491 ((page_table[index].allocated != FREE_PAGE)
4492 && (page_table[index].bytes_used != 0)
4493 && ((page_table[index].gen < gen)
4494 || (page_table[index].gen == NUM_GENERATIONS)))
4496 /* Or does it point within a current gc_alloc() region? */
4497 || ((boxed_region.start_addr <= ptr)
4498 && (ptr <= boxed_region.free_pointer))
4499 || ((unboxed_region.start_addr <= ptr)
4500 && (ptr <= unboxed_region.free_pointer))) {
4507 /* Write-protect the page. */
4508 /*FSHOW((stderr, "/write-protecting page %d gen %d\n", page, gen));*/
4510 os_protect((void *)page_addr,
4512 OS_VM_PROT_READ|OS_VM_PROT_EXECUTE);
4514 /* Note the page as protected in the page tables. */
4515 page_table[page].write_protected = 1;
4521 /* Scavenge a generation.
4523 * This will not resolve all pointers when generation is the new
4524 * space, as new objects may be added which are not check here - use
4525 * scavenge_newspace generation.
4527 * Write-protected pages should not have any pointers to the
4528 * from_space so do need scavenging; thus write-protected pages are
4529 * not always scavenged. There is some code to check that these pages
4530 * are not written; but to check fully the write-protected pages need
4531 * to be scavenged by disabling the code to skip them.
4533 * Under the current scheme when a generation is GCed the younger
4534 * generations will be empty. So, when a generation is being GCed it
4535 * is only necessary to scavenge the older generations for pointers
4536 * not the younger. So a page that does not have pointers to younger
4537 * generations does not need to be scavenged.
4539 * The write-protection can be used to note pages that don't have
4540 * pointers to younger pages. But pages can be written without having
4541 * pointers to younger generations. After the pages are scavenged here
4542 * they can be scanned for pointers to younger generations and if
4543 * there are none the page can be write-protected.
4545 * One complication is when the newspace is the top temp. generation.
4547 * Enabling SC_GEN_CK scavenges the write-protected pages and checks
4548 * that none were written, which they shouldn't be as they should have
4549 * no pointers to younger generations. This breaks down for weak
4550 * pointers as the objects contain a link to the next and are written
4551 * if a weak pointer is scavenged. Still it's a useful check. */
4553 scavenge_generation(int generation)
4560 /* Clear the write_protected_cleared flags on all pages. */
4561 for (i = 0; i < NUM_PAGES; i++)
4562 page_table[i].write_protected_cleared = 0;
4565 for (i = 0; i < last_free_page; i++) {
4566 if ((page_table[i].allocated == BOXED_PAGE)
4567 && (page_table[i].bytes_used != 0)
4568 && (page_table[i].gen == generation)) {
4571 /* This should be the start of a contiguous block. */
4572 gc_assert(page_table[i].first_object_offset == 0);
4574 /* We need to find the full extent of this contiguous
4575 * block in case objects span pages. */
4577 /* Now work forward until the end of this contiguous area
4578 * is found. A small area is preferred as there is a
4579 * better chance of its pages being write-protected. */
4580 for (last_page = i; ; last_page++)
4581 /* Check whether this is the last page in this contiguous
4583 if ((page_table[last_page].bytes_used < 4096)
4584 /* Or it is 4096 and is the last in the block */
4585 || (page_table[last_page+1].allocated != BOXED_PAGE)
4586 || (page_table[last_page+1].bytes_used == 0)
4587 || (page_table[last_page+1].gen != generation)
4588 || (page_table[last_page+1].first_object_offset == 0))
4591 /* Do a limited check for write_protected pages. If all pages
4592 * are write_protected then there is no need to scavenge. */
4595 for (j = i; j <= last_page; j++)
4596 if (page_table[j].write_protected == 0) {
4604 scavenge(page_address(i), (page_table[last_page].bytes_used
4605 + (last_page-i)*4096)/4);
4607 /* Now scan the pages and write protect those
4608 * that don't have pointers to younger
4610 if (enable_page_protection) {
4611 for (j = i; j <= last_page; j++) {
4612 num_wp += update_page_write_prot(j);
4621 if ((gencgc_verbose > 1) && (num_wp != 0)) {
4623 "/write protected %d pages within generation %d\n",
4624 num_wp, generation));
4628 /* Check that none of the write_protected pages in this generation
4629 * have been written to. */
4630 for (i = 0; i < NUM_PAGES; i++) {
4631 if ((page_table[i].allocation ! =FREE_PAGE)
4632 && (page_table[i].bytes_used != 0)
4633 && (page_table[i].gen == generation)
4634 && (page_table[i].write_protected_cleared != 0)) {
4635 FSHOW((stderr, "/scavenge_generation() %d\n", generation));
4637 "/page bytes_used=%d first_object_offset=%d dont_move=%d\n",
4638 page_table[i].bytes_used,
4639 page_table[i].first_object_offset,
4640 page_table[i].dont_move));
4641 lose("write to protected page %d in scavenge_generation()", i);
4648 /* Scavenge a newspace generation. As it is scavenged new objects may
4649 * be allocated to it; these will also need to be scavenged. This
4650 * repeats until there are no more objects unscavenged in the
4651 * newspace generation.
4653 * To help improve the efficiency, areas written are recorded by
4654 * gc_alloc() and only these scavenged. Sometimes a little more will be
4655 * scavenged, but this causes no harm. An easy check is done that the
4656 * scavenged bytes equals the number allocated in the previous
4659 * Write-protected pages are not scanned except if they are marked
4660 * dont_move in which case they may have been promoted and still have
4661 * pointers to the from space.
4663 * Write-protected pages could potentially be written by alloc however
4664 * to avoid having to handle re-scavenging of write-protected pages
4665 * gc_alloc() does not write to write-protected pages.
4667 * New areas of objects allocated are recorded alternatively in the two
4668 * new_areas arrays below. */
4669 static struct new_area new_areas_1[NUM_NEW_AREAS];
4670 static struct new_area new_areas_2[NUM_NEW_AREAS];
4672 /* Do one full scan of the new space generation. This is not enough to
4673 * complete the job as new objects may be added to the generation in
4674 * the process which are not scavenged. */
4676 scavenge_newspace_generation_one_scan(int generation)
4681 "/starting one full scan of newspace generation %d\n",
4684 for (i = 0; i < last_free_page; i++) {
4685 if ((page_table[i].allocated == BOXED_PAGE)
4686 && (page_table[i].bytes_used != 0)
4687 && (page_table[i].gen == generation)
4688 && ((page_table[i].write_protected == 0)
4689 /* (This may be redundant as write_protected is now
4690 * cleared before promotion.) */
4691 || (page_table[i].dont_move == 1))) {
4694 /* The scavenge will start at the first_object_offset of page i.
4696 * We need to find the full extent of this contiguous
4697 * block in case objects span pages.
4699 * Now work forward until the end of this contiguous area
4700 * is found. A small area is preferred as there is a
4701 * better chance of its pages being write-protected. */
4702 for (last_page = i; ;last_page++) {
4703 /* Check whether this is the last page in this
4704 * contiguous block */
4705 if ((page_table[last_page].bytes_used < 4096)
4706 /* Or it is 4096 and is the last in the block */
4707 || (page_table[last_page+1].allocated != BOXED_PAGE)
4708 || (page_table[last_page+1].bytes_used == 0)
4709 || (page_table[last_page+1].gen != generation)
4710 || (page_table[last_page+1].first_object_offset == 0))
4714 /* Do a limited check for write-protected pages. If all
4715 * pages are write-protected then no need to scavenge,
4716 * except if the pages are marked dont_move. */
4719 for (j = i; j <= last_page; j++)
4720 if ((page_table[j].write_protected == 0)
4721 || (page_table[j].dont_move != 0)) {
4729 /* Calculate the size. */
4731 size = (page_table[last_page].bytes_used
4732 - page_table[i].first_object_offset)/4;
4734 size = (page_table[last_page].bytes_used
4735 + (last_page-i)*4096
4736 - page_table[i].first_object_offset)/4;
4739 new_areas_ignore_page = last_page;
4741 scavenge(page_address(i) +
4742 page_table[i].first_object_offset,
4753 "/done with one full scan of newspace generation %d\n",
4757 /* Do a complete scavenge of the newspace generation. */
4759 scavenge_newspace_generation(int generation)
4763 /* the new_areas array currently being written to by gc_alloc() */
4764 struct new_area (*current_new_areas)[] = &new_areas_1;
4765 int current_new_areas_index;
4767 /* the new_areas created but the previous scavenge cycle */
4768 struct new_area (*previous_new_areas)[] = NULL;
4769 int previous_new_areas_index;
4771 /* Flush the current regions updating the tables. */
4772 gc_alloc_update_page_tables(0, &boxed_region);
4773 gc_alloc_update_page_tables(1, &unboxed_region);
4775 /* Turn on the recording of new areas by gc_alloc(). */
4776 new_areas = current_new_areas;
4777 new_areas_index = 0;
4779 /* Don't need to record new areas that get scavenged anyway during
4780 * scavenge_newspace_generation_one_scan. */
4781 record_new_objects = 1;
4783 /* Start with a full scavenge. */
4784 scavenge_newspace_generation_one_scan(generation);
4786 /* Record all new areas now. */
4787 record_new_objects = 2;
4789 /* Flush the current regions updating the tables. */
4790 gc_alloc_update_page_tables(0, &boxed_region);
4791 gc_alloc_update_page_tables(1, &unboxed_region);
4793 /* Grab new_areas_index. */
4794 current_new_areas_index = new_areas_index;
4797 "The first scan is finished; current_new_areas_index=%d.\n",
4798 current_new_areas_index));*/
4800 while (current_new_areas_index > 0) {
4801 /* Move the current to the previous new areas */
4802 previous_new_areas = current_new_areas;
4803 previous_new_areas_index = current_new_areas_index;
4805 /* Scavenge all the areas in previous new areas. Any new areas
4806 * allocated are saved in current_new_areas. */
4808 /* Allocate an array for current_new_areas; alternating between
4809 * new_areas_1 and 2 */
4810 if (previous_new_areas == &new_areas_1)
4811 current_new_areas = &new_areas_2;
4813 current_new_areas = &new_areas_1;
4815 /* Set up for gc_alloc(). */
4816 new_areas = current_new_areas;
4817 new_areas_index = 0;
4819 /* Check whether previous_new_areas had overflowed. */
4820 if (previous_new_areas_index >= NUM_NEW_AREAS) {
4822 /* New areas of objects allocated have been lost so need to do a
4823 * full scan to be sure! If this becomes a problem try
4824 * increasing NUM_NEW_AREAS. */
4826 SHOW("new_areas overflow, doing full scavenge");
4828 /* Don't need to record new areas that get scavenge anyway
4829 * during scavenge_newspace_generation_one_scan. */
4830 record_new_objects = 1;
4832 scavenge_newspace_generation_one_scan(generation);
4834 /* Record all new areas now. */
4835 record_new_objects = 2;
4837 /* Flush the current regions updating the tables. */
4838 gc_alloc_update_page_tables(0, &boxed_region);
4839 gc_alloc_update_page_tables(1, &unboxed_region);
4843 /* Work through previous_new_areas. */
4844 for (i = 0; i < previous_new_areas_index; i++) {
4845 /* FIXME: All these bare *4 and /4 should be something
4846 * like BYTES_PER_WORD or WBYTES. */
4847 int page = (*previous_new_areas)[i].page;
4848 int offset = (*previous_new_areas)[i].offset;
4849 int size = (*previous_new_areas)[i].size / 4;
4850 gc_assert((*previous_new_areas)[i].size % 4 == 0);
4852 scavenge(page_address(page)+offset, size);
4855 /* Flush the current regions updating the tables. */
4856 gc_alloc_update_page_tables(0, &boxed_region);
4857 gc_alloc_update_page_tables(1, &unboxed_region);
4860 current_new_areas_index = new_areas_index;
4863 "The re-scan has finished; current_new_areas_index=%d.\n",
4864 current_new_areas_index));*/
4867 /* Turn off recording of areas allocated by gc_alloc(). */
4868 record_new_objects = 0;
4871 /* Check that none of the write_protected pages in this generation
4872 * have been written to. */
4873 for (i = 0; i < NUM_PAGES; i++) {
4874 if ((page_table[i].allocation != FREE_PAGE)
4875 && (page_table[i].bytes_used != 0)
4876 && (page_table[i].gen == generation)
4877 && (page_table[i].write_protected_cleared != 0)
4878 && (page_table[i].dont_move == 0)) {
4879 lose("write protected page %d written to in scavenge_newspace_generation\ngeneration=%d dont_move=%d",
4880 i, generation, page_table[i].dont_move);
4886 /* Un-write-protect all the pages in from_space. This is done at the
4887 * start of a GC else there may be many page faults while scavenging
4888 * the newspace (I've seen drive the system time to 99%). These pages
4889 * would need to be unprotected anyway before unmapping in
4890 * free_oldspace; not sure what effect this has on paging.. */
4892 unprotect_oldspace(void)
4896 for (i = 0; i < last_free_page; i++) {
4897 if ((page_table[i].allocated != FREE_PAGE)
4898 && (page_table[i].bytes_used != 0)
4899 && (page_table[i].gen == from_space)) {
4902 page_start = (void *)page_address(i);
4904 /* Remove any write-protection. We should be able to rely
4905 * on the write-protect flag to avoid redundant calls. */
4906 if (page_table[i].write_protected) {
4907 os_protect(page_start, 4096, OS_VM_PROT_ALL);
4908 page_table[i].write_protected = 0;
4914 /* Work through all the pages and free any in from_space. This
4915 * assumes that all objects have been copied or promoted to an older
4916 * generation. Bytes_allocated and the generation bytes_allocated
4917 * counter are updated. The number of bytes freed is returned. */
4918 extern void i586_bzero(void *addr, int nbytes);
4922 int bytes_freed = 0;
4923 int first_page, last_page;
4928 /* Find a first page for the next region of pages. */
4929 while ((first_page < last_free_page)
4930 && ((page_table[first_page].allocated == FREE_PAGE)
4931 || (page_table[first_page].bytes_used == 0)
4932 || (page_table[first_page].gen != from_space)))
4935 if (first_page >= last_free_page)
4938 /* Find the last page of this region. */
4939 last_page = first_page;
4942 /* Free the page. */
4943 bytes_freed += page_table[last_page].bytes_used;
4944 generations[page_table[last_page].gen].bytes_allocated -=
4945 page_table[last_page].bytes_used;
4946 page_table[last_page].allocated = FREE_PAGE;
4947 page_table[last_page].bytes_used = 0;
4949 /* Remove any write-protection. We should be able to rely
4950 * on the write-protect flag to avoid redundant calls. */
4952 void *page_start = (void *)page_address(last_page);
4954 if (page_table[last_page].write_protected) {
4955 os_protect(page_start, 4096, OS_VM_PROT_ALL);
4956 page_table[last_page].write_protected = 0;
4961 while ((last_page < last_free_page)
4962 && (page_table[last_page].allocated != FREE_PAGE)
4963 && (page_table[last_page].bytes_used != 0)
4964 && (page_table[last_page].gen == from_space));
4966 /* Zero pages from first_page to (last_page-1).
4968 * FIXME: Why not use os_zero(..) function instead of
4969 * hand-coding this again? (Check other gencgc_unmap_zero
4971 if (gencgc_unmap_zero) {
4972 void *page_start, *addr;
4974 page_start = (void *)page_address(first_page);
4976 os_invalidate(page_start, 4096*(last_page-first_page));
4977 addr = os_validate(page_start, 4096*(last_page-first_page));
4978 if (addr == NULL || addr != page_start) {
4979 /* Is this an error condition? I couldn't really tell from
4980 * the old CMU CL code, which fprintf'ed a message with
4981 * an exclamation point at the end. But I've never seen the
4982 * message, so it must at least be unusual..
4984 * (The same condition is also tested for in gc_free_heap.)
4986 * -- WHN 19991129 */
4987 lose("i586_bzero: page moved, 0x%08x ==> 0x%08x",
4994 page_start = (int *)page_address(first_page);
4995 i586_bzero(page_start, 4096*(last_page-first_page));
4998 first_page = last_page;
5000 } while (first_page < last_free_page);
5002 bytes_allocated -= bytes_freed;
5007 /* Print some information about a pointer at the given address. */
5009 print_ptr(lispobj *addr)
5011 /* If addr is in the dynamic space then out the page information. */
5012 int pi1 = find_page_index((void*)addr);
5015 fprintf(stderr," %x: page %d alloc %d gen %d bytes_used %d offset %d dont_move %d\n",
5016 (unsigned int) addr,
5018 page_table[pi1].allocated,
5019 page_table[pi1].gen,
5020 page_table[pi1].bytes_used,
5021 page_table[pi1].first_object_offset,
5022 page_table[pi1].dont_move);
5023 fprintf(stderr," %x %x %x %x (%x) %x %x %x %x\n",
5036 extern int undefined_tramp;
5039 verify_space(lispobj *start, size_t words)
5041 int is_in_dynamic_space = (find_page_index((void*)start) != -1);
5042 int is_in_readonly_space =
5043 (READ_ONLY_SPACE_START <= (unsigned)start &&
5044 (unsigned)start < SymbolValue(READ_ONLY_SPACE_FREE_POINTER));
5048 lispobj thing = *(lispobj*)start;
5050 if (is_lisp_pointer(thing)) {
5051 int page_index = find_page_index((void*)thing);
5052 int to_readonly_space =
5053 (READ_ONLY_SPACE_START <= thing &&
5054 thing < SymbolValue(READ_ONLY_SPACE_FREE_POINTER));
5055 int to_static_space =
5056 (STATIC_SPACE_START <= thing &&
5057 thing < SymbolValue(STATIC_SPACE_FREE_POINTER));
5059 /* Does it point to the dynamic space? */
5060 if (page_index != -1) {
5061 /* If it's within the dynamic space it should point to a used
5062 * page. XX Could check the offset too. */
5063 if ((page_table[page_index].allocated != FREE_PAGE)
5064 && (page_table[page_index].bytes_used == 0))
5065 lose ("Ptr %x @ %x sees free page.", thing, start);
5066 /* Check that it doesn't point to a forwarding pointer! */
5067 if (*((lispobj *)native_pointer(thing)) == 0x01) {
5068 lose("Ptr %x @ %x sees forwarding ptr.", thing, start);
5070 /* Check that its not in the RO space as it would then be a
5071 * pointer from the RO to the dynamic space. */
5072 if (is_in_readonly_space) {
5073 lose("ptr to dynamic space %x from RO space %x",
5076 /* Does it point to a plausible object? This check slows
5077 * it down a lot (so it's commented out).
5079 * FIXME: Add a variable to enable this dynamically. */
5080 /* if (!possibly_valid_dynamic_space_pointer((lispobj *)thing)) {
5081 * lose("ptr %x to invalid object %x", thing, start); */
5083 /* Verify that it points to another valid space. */
5084 if (!to_readonly_space && !to_static_space
5085 && (thing != (unsigned)&undefined_tramp)) {
5086 lose("Ptr %x @ %x sees junk.", thing, start);
5090 if (thing & 0x3) { /* Skip fixnums. FIXME: There should be an
5091 * is_fixnum for this. */
5093 switch(widetag_of(*start)) {
5096 case SIMPLE_VECTOR_WIDETAG:
5098 case COMPLEX_WIDETAG:
5099 case SIMPLE_ARRAY_WIDETAG:
5100 case COMPLEX_STRING_WIDETAG:
5101 case COMPLEX_BIT_VECTOR_WIDETAG:
5102 case COMPLEX_VECTOR_WIDETAG:
5103 case COMPLEX_ARRAY_WIDETAG:
5104 case CLOSURE_HEADER_WIDETAG:
5105 case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
5106 case VALUE_CELL_HEADER_WIDETAG:
5107 case SYMBOL_HEADER_WIDETAG:
5108 case BASE_CHAR_WIDETAG:
5109 case UNBOUND_MARKER_WIDETAG:
5110 case INSTANCE_HEADER_WIDETAG:
5115 case CODE_HEADER_WIDETAG:
5117 lispobj object = *start;
5119 int nheader_words, ncode_words, nwords;
5121 struct simple_fun *fheaderp;
5123 code = (struct code *) start;
5125 /* Check that it's not in the dynamic space.
5126 * FIXME: Isn't is supposed to be OK for code
5127 * objects to be in the dynamic space these days? */
5128 if (is_in_dynamic_space
5129 /* It's ok if it's byte compiled code. The trace
5130 * table offset will be a fixnum if it's x86
5131 * compiled code - check.
5133 * FIXME: #^#@@! lack of abstraction here..
5134 * This line can probably go away now that
5135 * there's no byte compiler, but I've got
5136 * too much to worry about right now to try
5137 * to make sure. -- WHN 2001-10-06 */
5138 && !(code->trace_table_offset & 0x3)
5139 /* Only when enabled */
5140 && verify_dynamic_code_check) {
5142 "/code object at %x in the dynamic space\n",
5146 ncode_words = fixnum_value(code->code_size);
5147 nheader_words = HeaderValue(object);
5148 nwords = ncode_words + nheader_words;
5149 nwords = CEILING(nwords, 2);
5150 /* Scavenge the boxed section of the code data block */
5151 verify_space(start + 1, nheader_words - 1);
5153 /* Scavenge the boxed section of each function object in
5154 * the code data block. */
5155 fheaderl = code->entry_points;
5156 while (fheaderl != NIL) {
5158 (struct simple_fun *) native_pointer(fheaderl);
5159 gc_assert(widetag_of(fheaderp->header) == SIMPLE_FUN_HEADER_WIDETAG);
5160 verify_space(&fheaderp->name, 1);
5161 verify_space(&fheaderp->arglist, 1);
5162 verify_space(&fheaderp->type, 1);
5163 fheaderl = fheaderp->next;
5169 /* unboxed objects */
5170 case BIGNUM_WIDETAG:
5171 case SINGLE_FLOAT_WIDETAG:
5172 case DOUBLE_FLOAT_WIDETAG:
5173 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
5174 case LONG_FLOAT_WIDETAG:
5176 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
5177 case COMPLEX_SINGLE_FLOAT_WIDETAG:
5179 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
5180 case COMPLEX_DOUBLE_FLOAT_WIDETAG:
5182 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
5183 case COMPLEX_LONG_FLOAT_WIDETAG:
5185 case SIMPLE_STRING_WIDETAG:
5186 case SIMPLE_BIT_VECTOR_WIDETAG:
5187 case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
5188 case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
5189 case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
5190 case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
5191 case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
5192 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
5193 case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
5195 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
5196 case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
5198 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
5199 case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
5201 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
5202 case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
5204 case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
5205 case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
5206 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
5207 case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
5209 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
5210 case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
5212 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
5213 case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
5215 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
5216 case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
5219 case WEAK_POINTER_WIDETAG:
5220 count = (sizetab[widetag_of(*start)])(start);
5236 /* FIXME: It would be nice to make names consistent so that
5237 * foo_size meant size *in* *bytes* instead of size in some
5238 * arbitrary units. (Yes, this caused a bug, how did you guess?:-)
5239 * Some counts of lispobjs are called foo_count; it might be good
5240 * to grep for all foo_size and rename the appropriate ones to
5242 int read_only_space_size =
5243 (lispobj*)SymbolValue(READ_ONLY_SPACE_FREE_POINTER)
5244 - (lispobj*)READ_ONLY_SPACE_START;
5245 int static_space_size =
5246 (lispobj*)SymbolValue(STATIC_SPACE_FREE_POINTER)
5247 - (lispobj*)STATIC_SPACE_START;
5248 int binding_stack_size =
5249 (lispobj*)SymbolValue(BINDING_STACK_POINTER)
5250 - (lispobj*)BINDING_STACK_START;
5252 verify_space((lispobj*)READ_ONLY_SPACE_START, read_only_space_size);
5253 verify_space((lispobj*)STATIC_SPACE_START , static_space_size);
5254 verify_space((lispobj*)BINDING_STACK_START , binding_stack_size);
5258 verify_generation(int generation)
5262 for (i = 0; i < last_free_page; i++) {
5263 if ((page_table[i].allocated != FREE_PAGE)
5264 && (page_table[i].bytes_used != 0)
5265 && (page_table[i].gen == generation)) {
5267 int region_allocation = page_table[i].allocated;
5269 /* This should be the start of a contiguous block */
5270 gc_assert(page_table[i].first_object_offset == 0);
5272 /* Need to find the full extent of this contiguous block in case
5273 objects span pages. */
5275 /* Now work forward until the end of this contiguous area is
5277 for (last_page = i; ;last_page++)
5278 /* Check whether this is the last page in this contiguous
5280 if ((page_table[last_page].bytes_used < 4096)
5281 /* Or it is 4096 and is the last in the block */
5282 || (page_table[last_page+1].allocated != region_allocation)
5283 || (page_table[last_page+1].bytes_used == 0)
5284 || (page_table[last_page+1].gen != generation)
5285 || (page_table[last_page+1].first_object_offset == 0))
5288 verify_space(page_address(i), (page_table[last_page].bytes_used
5289 + (last_page-i)*4096)/4);
5295 /* Check that all the free space is zero filled. */
5297 verify_zero_fill(void)
5301 for (page = 0; page < last_free_page; page++) {
5302 if (page_table[page].allocated == FREE_PAGE) {
5303 /* The whole page should be zero filled. */
5304 int *start_addr = (int *)page_address(page);
5307 for (i = 0; i < size; i++) {
5308 if (start_addr[i] != 0) {
5309 lose("free page not zero at %x", start_addr + i);
5313 int free_bytes = 4096 - page_table[page].bytes_used;
5314 if (free_bytes > 0) {
5315 int *start_addr = (int *)((unsigned)page_address(page)
5316 + page_table[page].bytes_used);
5317 int size = free_bytes / 4;
5319 for (i = 0; i < size; i++) {
5320 if (start_addr[i] != 0) {
5321 lose("free region not zero at %x", start_addr + i);
5329 /* External entry point for verify_zero_fill */
5331 gencgc_verify_zero_fill(void)
5333 /* Flush the alloc regions updating the tables. */
5334 boxed_region.free_pointer = current_region_free_pointer;
5335 gc_alloc_update_page_tables(0, &boxed_region);
5336 gc_alloc_update_page_tables(1, &unboxed_region);
5337 SHOW("verifying zero fill");
5339 current_region_free_pointer = boxed_region.free_pointer;
5340 current_region_end_addr = boxed_region.end_addr;
5344 verify_dynamic_space(void)
5348 for (i = 0; i < NUM_GENERATIONS; i++)
5349 verify_generation(i);
5351 if (gencgc_enable_verify_zero_fill)
5355 /* Write-protect all the dynamic boxed pages in the given generation. */
5357 write_protect_generation_pages(int generation)
5361 gc_assert(generation < NUM_GENERATIONS);
5363 for (i = 0; i < last_free_page; i++)
5364 if ((page_table[i].allocated == BOXED_PAGE)
5365 && (page_table[i].bytes_used != 0)
5366 && (page_table[i].gen == generation)) {
5369 page_start = (void *)page_address(i);
5371 os_protect(page_start,
5373 OS_VM_PROT_READ | OS_VM_PROT_EXECUTE);
5375 /* Note the page as protected in the page tables. */
5376 page_table[i].write_protected = 1;
5379 if (gencgc_verbose > 1) {
5381 "/write protected %d of %d pages in generation %d\n",
5382 count_write_protect_generation_pages(generation),
5383 count_generation_pages(generation),
5388 /* Garbage collect a generation. If raise is 0 then the remains of the
5389 * generation are not raised to the next generation. */
5391 garbage_collect_generation(int generation, int raise)
5393 unsigned long bytes_freed;
5395 unsigned long static_space_size;
5397 gc_assert(generation <= (NUM_GENERATIONS-1));
5399 /* The oldest generation can't be raised. */
5400 gc_assert((generation != (NUM_GENERATIONS-1)) || (raise == 0));
5402 /* Initialize the weak pointer list. */
5403 weak_pointers = NULL;
5405 /* When a generation is not being raised it is transported to a
5406 * temporary generation (NUM_GENERATIONS), and lowered when
5407 * done. Set up this new generation. There should be no pages
5408 * allocated to it yet. */
5410 gc_assert(generations[NUM_GENERATIONS].bytes_allocated == 0);
5412 /* Set the global src and dest. generations */
5413 from_space = generation;
5415 new_space = generation+1;
5417 new_space = NUM_GENERATIONS;
5419 /* Change to a new space for allocation, resetting the alloc_start_page */
5420 gc_alloc_generation = new_space;
5421 generations[new_space].alloc_start_page = 0;
5422 generations[new_space].alloc_unboxed_start_page = 0;
5423 generations[new_space].alloc_large_start_page = 0;
5424 generations[new_space].alloc_large_unboxed_start_page = 0;
5426 /* Before any pointers are preserved, the dont_move flags on the
5427 * pages need to be cleared. */
5428 for (i = 0; i < last_free_page; i++)
5429 page_table[i].dont_move = 0;
5431 /* Un-write-protect the old-space pages. This is essential for the
5432 * promoted pages as they may contain pointers into the old-space
5433 * which need to be scavenged. It also helps avoid unnecessary page
5434 * faults as forwarding pointers are written into them. They need to
5435 * be un-protected anyway before unmapping later. */
5436 unprotect_oldspace();
5438 /* Scavenge the stack's conservative roots. */
5441 for (ptr = (void **)CONTROL_STACK_END - 1;
5442 ptr > (void **)&raise;
5444 preserve_pointer(*ptr);
5449 if (gencgc_verbose > 1) {
5450 int num_dont_move_pages = count_dont_move_pages();
5452 "/non-movable pages due to conservative pointers = %d (%d bytes)\n",
5453 num_dont_move_pages,
5454 /* FIXME: 4096 should be symbolic constant here and
5455 * prob'ly elsewhere too. */
5456 num_dont_move_pages * 4096);
5460 /* Scavenge all the rest of the roots. */
5462 /* Scavenge the Lisp functions of the interrupt handlers, taking
5463 * care to avoid SIG_DFL and SIG_IGN. */
5464 for (i = 0; i < NSIG; i++) {
5465 union interrupt_handler handler = interrupt_handlers[i];
5466 if (!ARE_SAME_HANDLER(handler.c, SIG_IGN) &&
5467 !ARE_SAME_HANDLER(handler.c, SIG_DFL)) {
5468 scavenge((lispobj *)(interrupt_handlers + i), 1);
5472 /* Scavenge the binding stack. */
5473 scavenge((lispobj *) BINDING_STACK_START,
5474 (lispobj *)SymbolValue(BINDING_STACK_POINTER) -
5475 (lispobj *)BINDING_STACK_START);
5477 /* The original CMU CL code had scavenge-read-only-space code
5478 * controlled by the Lisp-level variable
5479 * *SCAVENGE-READ-ONLY-SPACE*. It was disabled by default, and it
5480 * wasn't documented under what circumstances it was useful or
5481 * safe to turn it on, so it's been turned off in SBCL. If you
5482 * want/need this functionality, and can test and document it,
5483 * please submit a patch. */
5485 if (SymbolValue(SCAVENGE_READ_ONLY_SPACE) != NIL) {
5486 unsigned long read_only_space_size =
5487 (lispobj*)SymbolValue(READ_ONLY_SPACE_FREE_POINTER) -
5488 (lispobj*)READ_ONLY_SPACE_START;
5490 "/scavenge read only space: %d bytes\n",
5491 read_only_space_size * sizeof(lispobj)));
5492 scavenge( (lispobj *) READ_ONLY_SPACE_START, read_only_space_size);
5496 /* Scavenge static space. */
5498 (lispobj *)SymbolValue(STATIC_SPACE_FREE_POINTER) -
5499 (lispobj *)STATIC_SPACE_START;
5500 if (gencgc_verbose > 1) {
5502 "/scavenge static space: %d bytes\n",
5503 static_space_size * sizeof(lispobj)));
5505 scavenge( (lispobj *) STATIC_SPACE_START, static_space_size);
5507 /* All generations but the generation being GCed need to be
5508 * scavenged. The new_space generation needs special handling as
5509 * objects may be moved in - it is handled separately below. */
5510 for (i = 0; i < NUM_GENERATIONS; i++) {
5511 if ((i != generation) && (i != new_space)) {
5512 scavenge_generation(i);
5516 /* Finally scavenge the new_space generation. Keep going until no
5517 * more objects are moved into the new generation */
5518 scavenge_newspace_generation(new_space);
5520 /* FIXME: I tried reenabling this check when debugging unrelated
5521 * GC weirdness ca. sbcl-0.6.12.45, and it failed immediately.
5522 * Since the current GC code seems to work well, I'm guessing that
5523 * this debugging code is just stale, but I haven't tried to
5524 * figure it out. It should be figured out and then either made to
5525 * work or just deleted. */
5526 #define RESCAN_CHECK 0
5528 /* As a check re-scavenge the newspace once; no new objects should
5531 int old_bytes_allocated = bytes_allocated;
5532 int bytes_allocated;
5534 /* Start with a full scavenge. */
5535 scavenge_newspace_generation_one_scan(new_space);
5537 /* Flush the current regions, updating the tables. */
5538 gc_alloc_update_page_tables(0, &boxed_region);
5539 gc_alloc_update_page_tables(1, &unboxed_region);
5541 bytes_allocated = bytes_allocated - old_bytes_allocated;
5543 if (bytes_allocated != 0) {
5544 lose("Rescan of new_space allocated %d more bytes.",
5550 scan_weak_pointers();
5552 /* Flush the current regions, updating the tables. */
5553 gc_alloc_update_page_tables(0, &boxed_region);
5554 gc_alloc_update_page_tables(1, &unboxed_region);
5556 /* Free the pages in oldspace, but not those marked dont_move. */
5557 bytes_freed = free_oldspace();
5559 /* If the GC is not raising the age then lower the generation back
5560 * to its normal generation number */
5562 for (i = 0; i < last_free_page; i++)
5563 if ((page_table[i].bytes_used != 0)
5564 && (page_table[i].gen == NUM_GENERATIONS))
5565 page_table[i].gen = generation;
5566 gc_assert(generations[generation].bytes_allocated == 0);
5567 generations[generation].bytes_allocated =
5568 generations[NUM_GENERATIONS].bytes_allocated;
5569 generations[NUM_GENERATIONS].bytes_allocated = 0;
5572 /* Reset the alloc_start_page for generation. */
5573 generations[generation].alloc_start_page = 0;
5574 generations[generation].alloc_unboxed_start_page = 0;
5575 generations[generation].alloc_large_start_page = 0;
5576 generations[generation].alloc_large_unboxed_start_page = 0;
5578 if (generation >= verify_gens) {
5582 verify_dynamic_space();
5585 /* Set the new gc trigger for the GCed generation. */
5586 generations[generation].gc_trigger =
5587 generations[generation].bytes_allocated
5588 + generations[generation].bytes_consed_between_gc;
5591 generations[generation].num_gc = 0;
5593 ++generations[generation].num_gc;
5596 /* Update last_free_page, then SymbolValue(ALLOCATION_POINTER). */
5598 update_x86_dynamic_space_free_pointer(void)
5603 for (i = 0; i < NUM_PAGES; i++)
5604 if ((page_table[i].allocated != FREE_PAGE)
5605 && (page_table[i].bytes_used != 0))
5608 last_free_page = last_page+1;
5610 SetSymbolValue(ALLOCATION_POINTER,
5611 (lispobj)(((char *)heap_base) + last_free_page*4096));
5612 return 0; /* dummy value: return something ... */
5615 /* GC all generations below last_gen, raising their objects to the
5616 * next generation until all generations below last_gen are empty.
5617 * Then if last_gen is due for a GC then GC it. In the special case
5618 * that last_gen==NUM_GENERATIONS, the last generation is always
5619 * GC'ed. The valid range for last_gen is: 0,1,...,NUM_GENERATIONS.
5621 * The oldest generation to be GCed will always be
5622 * gencgc_oldest_gen_to_gc, partly ignoring last_gen if necessary. */
5624 collect_garbage(unsigned last_gen)
5631 boxed_region.free_pointer = current_region_free_pointer;
5633 FSHOW((stderr, "/entering collect_garbage(%d)\n", last_gen));
5635 if (last_gen > NUM_GENERATIONS) {
5637 "/collect_garbage: last_gen = %d, doing a level 0 GC\n",
5642 /* Flush the alloc regions updating the tables. */
5643 gc_alloc_update_page_tables(0, &boxed_region);
5644 gc_alloc_update_page_tables(1, &unboxed_region);
5646 /* Verify the new objects created by Lisp code. */
5647 if (pre_verify_gen_0) {
5648 SHOW((stderr, "pre-checking generation 0\n"));
5649 verify_generation(0);
5652 if (gencgc_verbose > 1)
5653 print_generation_stats(0);
5656 /* Collect the generation. */
5658 if (gen >= gencgc_oldest_gen_to_gc) {
5659 /* Never raise the oldest generation. */
5664 || (generations[gen].num_gc >= generations[gen].trigger_age);
5667 if (gencgc_verbose > 1) {
5669 "starting GC of generation %d with raise=%d alloc=%d trig=%d GCs=%d\n",
5672 generations[gen].bytes_allocated,
5673 generations[gen].gc_trigger,
5674 generations[gen].num_gc));
5677 /* If an older generation is being filled, then update its
5680 generations[gen+1].cum_sum_bytes_allocated +=
5681 generations[gen+1].bytes_allocated;
5684 garbage_collect_generation(gen, raise);
5686 /* Reset the memory age cum_sum. */
5687 generations[gen].cum_sum_bytes_allocated = 0;
5689 if (gencgc_verbose > 1) {
5690 FSHOW((stderr, "GC of generation %d finished:\n", gen));
5691 print_generation_stats(0);
5695 } while ((gen <= gencgc_oldest_gen_to_gc)
5696 && ((gen < last_gen)
5697 || ((gen <= gencgc_oldest_gen_to_gc)
5699 && (generations[gen].bytes_allocated
5700 > generations[gen].gc_trigger)
5701 && (gen_av_mem_age(gen)
5702 > generations[gen].min_av_mem_age))));
5704 /* Now if gen-1 was raised all generations before gen are empty.
5705 * If it wasn't raised then all generations before gen-1 are empty.
5707 * Now objects within this gen's pages cannot point to younger
5708 * generations unless they are written to. This can be exploited
5709 * by write-protecting the pages of gen; then when younger
5710 * generations are GCed only the pages which have been written
5715 gen_to_wp = gen - 1;
5717 /* There's not much point in WPing pages in generation 0 as it is
5718 * never scavenged (except promoted pages). */
5719 if ((gen_to_wp > 0) && enable_page_protection) {
5720 /* Check that they are all empty. */
5721 for (i = 0; i < gen_to_wp; i++) {
5722 if (generations[i].bytes_allocated)
5723 lose("trying to write-protect gen. %d when gen. %d nonempty",
5726 write_protect_generation_pages(gen_to_wp);
5729 /* Set gc_alloc() back to generation 0. The current regions should
5730 * be flushed after the above GCs. */
5731 gc_assert((boxed_region.free_pointer - boxed_region.start_addr) == 0);
5732 gc_alloc_generation = 0;
5734 update_x86_dynamic_space_free_pointer();
5736 /* This is now done by Lisp SCRUB-CONTROL-STACK in Lisp SUB-GC, so
5737 * we needn't do it here: */
5740 current_region_free_pointer = boxed_region.free_pointer;
5741 current_region_end_addr = boxed_region.end_addr;
5743 SHOW("returning from collect_garbage");
5746 /* This is called by Lisp PURIFY when it is finished. All live objects
5747 * will have been moved to the RO and Static heaps. The dynamic space
5748 * will need a full re-initialization. We don't bother having Lisp
5749 * PURIFY flush the current gc_alloc() region, as the page_tables are
5750 * re-initialized, and every page is zeroed to be sure. */
5756 if (gencgc_verbose > 1)
5757 SHOW("entering gc_free_heap");
5759 for (page = 0; page < NUM_PAGES; page++) {
5760 /* Skip free pages which should already be zero filled. */
5761 if (page_table[page].allocated != FREE_PAGE) {
5762 void *page_start, *addr;
5764 /* Mark the page free. The other slots are assumed invalid
5765 * when it is a FREE_PAGE and bytes_used is 0 and it
5766 * should not be write-protected -- except that the
5767 * generation is used for the current region but it sets
5769 page_table[page].allocated = FREE_PAGE;
5770 page_table[page].bytes_used = 0;
5772 /* Zero the page. */
5773 page_start = (void *)page_address(page);
5775 /* First, remove any write-protection. */
5776 os_protect(page_start, 4096, OS_VM_PROT_ALL);
5777 page_table[page].write_protected = 0;
5779 os_invalidate(page_start,4096);
5780 addr = os_validate(page_start,4096);
5781 if (addr == NULL || addr != page_start) {
5782 lose("gc_free_heap: page moved, 0x%08x ==> 0x%08x",
5786 } else if (gencgc_zero_check_during_free_heap) {
5787 /* Double-check that the page is zero filled. */
5789 gc_assert(page_table[page].allocated == FREE_PAGE);
5790 gc_assert(page_table[page].bytes_used == 0);
5791 page_start = (int *)page_address(page);
5792 for (i=0; i<1024; i++) {
5793 if (page_start[i] != 0) {
5794 lose("free region not zero at %x", page_start + i);
5800 bytes_allocated = 0;
5802 /* Initialize the generations. */
5803 for (page = 0; page < NUM_GENERATIONS; page++) {
5804 generations[page].alloc_start_page = 0;
5805 generations[page].alloc_unboxed_start_page = 0;
5806 generations[page].alloc_large_start_page = 0;
5807 generations[page].alloc_large_unboxed_start_page = 0;
5808 generations[page].bytes_allocated = 0;
5809 generations[page].gc_trigger = 2000000;
5810 generations[page].num_gc = 0;
5811 generations[page].cum_sum_bytes_allocated = 0;
5814 if (gencgc_verbose > 1)
5815 print_generation_stats(0);
5817 /* Initialize gc_alloc(). */
5818 gc_alloc_generation = 0;
5819 boxed_region.first_page = 0;
5820 boxed_region.last_page = -1;
5821 boxed_region.start_addr = page_address(0);
5822 boxed_region.free_pointer = page_address(0);
5823 boxed_region.end_addr = page_address(0);
5824 unboxed_region.first_page = 0;
5825 unboxed_region.last_page = -1;
5826 unboxed_region.start_addr = page_address(0);
5827 unboxed_region.free_pointer = page_address(0);
5828 unboxed_region.end_addr = page_address(0);
5830 #if 0 /* Lisp PURIFY is currently running on the C stack so don't do this. */
5835 SetSymbolValue(ALLOCATION_POINTER, (lispobj)((char *)heap_base));
5837 current_region_free_pointer = boxed_region.free_pointer;
5838 current_region_end_addr = boxed_region.end_addr;
5840 if (verify_after_free_heap) {
5841 /* Check whether purify has left any bad pointers. */
5843 SHOW("checking after free_heap\n");
5855 heap_base = (void*)DYNAMIC_SPACE_START;
5857 /* Initialize each page structure. */
5858 for (i = 0; i < NUM_PAGES; i++) {
5859 /* Initialize all pages as free. */
5860 page_table[i].allocated = FREE_PAGE;
5861 page_table[i].bytes_used = 0;
5863 /* Pages are not write-protected at startup. */
5864 page_table[i].write_protected = 0;
5867 bytes_allocated = 0;
5869 /* Initialize the generations.
5871 * FIXME: very similar to code in gc_free_heap(), should be shared */
5872 for (i = 0; i < NUM_GENERATIONS; i++) {
5873 generations[i].alloc_start_page = 0;
5874 generations[i].alloc_unboxed_start_page = 0;
5875 generations[i].alloc_large_start_page = 0;
5876 generations[i].alloc_large_unboxed_start_page = 0;
5877 generations[i].bytes_allocated = 0;
5878 generations[i].gc_trigger = 2000000;
5879 generations[i].num_gc = 0;
5880 generations[i].cum_sum_bytes_allocated = 0;
5881 /* the tune-able parameters */
5882 generations[i].bytes_consed_between_gc = 2000000;
5883 generations[i].trigger_age = 1;
5884 generations[i].min_av_mem_age = 0.75;
5887 /* Initialize gc_alloc.
5889 * FIXME: identical with code in gc_free_heap(), should be shared */
5890 gc_alloc_generation = 0;
5891 boxed_region.first_page = 0;
5892 boxed_region.last_page = -1;
5893 boxed_region.start_addr = page_address(0);
5894 boxed_region.free_pointer = page_address(0);
5895 boxed_region.end_addr = page_address(0);
5896 unboxed_region.first_page = 0;
5897 unboxed_region.last_page = -1;
5898 unboxed_region.start_addr = page_address(0);
5899 unboxed_region.free_pointer = page_address(0);
5900 unboxed_region.end_addr = page_address(0);
5904 current_region_free_pointer = boxed_region.free_pointer;
5905 current_region_end_addr = boxed_region.end_addr;
5908 /* Pick up the dynamic space from after a core load.
5910 * The ALLOCATION_POINTER points to the end of the dynamic space.
5912 * XX A scan is needed to identify the closest first objects for pages. */
5914 gencgc_pickup_dynamic(void)
5917 int addr = DYNAMIC_SPACE_START;
5918 int alloc_ptr = SymbolValue(ALLOCATION_POINTER);
5920 /* Initialize the first region. */
5922 page_table[page].allocated = BOXED_PAGE;
5923 page_table[page].gen = 0;
5924 page_table[page].bytes_used = 4096;
5925 page_table[page].large_object = 0;
5926 page_table[page].first_object_offset =
5927 (void *)DYNAMIC_SPACE_START - page_address(page);
5930 } while (addr < alloc_ptr);
5932 generations[0].bytes_allocated = 4096*page;
5933 bytes_allocated = 4096*page;
5935 current_region_free_pointer = boxed_region.free_pointer;
5936 current_region_end_addr = boxed_region.end_addr;
5939 /* a counter for how deep we are in alloc(..) calls */
5940 int alloc_entered = 0;
5942 /* alloc(..) is the external interface for memory allocation. It
5943 * allocates to generation 0. It is not called from within the garbage
5944 * collector as it is only external uses that need the check for heap
5945 * size (GC trigger) and to disable the interrupts (interrupts are
5946 * always disabled during a GC).
5948 * The vops that call alloc(..) assume that the returned space is zero-filled.
5949 * (E.g. the most significant word of a 2-word bignum in MOVE-FROM-UNSIGNED.)
5951 * The check for a GC trigger is only performed when the current
5952 * region is full, so in most cases it's not needed. Further MAYBE-GC
5953 * is only called once because Lisp will remember "need to collect
5954 * garbage" and get around to it when it can. */
5958 /* Check for alignment allocation problems. */
5959 gc_assert((((unsigned)current_region_free_pointer & 0x7) == 0)
5960 && ((nbytes & 0x7) == 0));
5962 if (SymbolValue(PSEUDO_ATOMIC_ATOMIC)) {/* if already in a pseudo atomic */
5964 void *new_free_pointer;
5967 if (alloc_entered) {
5968 SHOW("alloc re-entered in already-pseudo-atomic case");
5972 /* Check whether there is room in the current region. */
5973 new_free_pointer = current_region_free_pointer + nbytes;
5975 /* FIXME: Shouldn't we be doing some sort of lock here, to
5976 * keep from getting screwed if an interrupt service routine
5977 * allocates memory between the time we calculate new_free_pointer
5978 * and the time we write it back to current_region_free_pointer?
5979 * Perhaps I just don't understand pseudo-atomics..
5981 * Perhaps I don't. It looks as though what happens is if we
5982 * were interrupted any time during the pseudo-atomic
5983 * interval (which includes now) we discard the allocated
5984 * memory and try again. So, at least we don't return
5985 * a memory area that was allocated out from underneath us
5986 * by code in an ISR.
5987 * Still, that doesn't seem to prevent
5988 * current_region_free_pointer from getting corrupted:
5989 * We read current_region_free_pointer.
5990 * They read current_region_free_pointer.
5991 * They write current_region_free_pointer.
5992 * We write current_region_free_pointer, scribbling over
5993 * whatever they wrote. */
5995 if (new_free_pointer <= boxed_region.end_addr) {
5996 /* If so then allocate from the current region. */
5997 void *new_obj = current_region_free_pointer;
5998 current_region_free_pointer = new_free_pointer;
6000 return((void *)new_obj);
6003 if (auto_gc_trigger && bytes_allocated > auto_gc_trigger) {
6004 /* Double the trigger. */
6005 auto_gc_trigger *= 2;
6007 /* Exit the pseudo-atomic. */
6008 SetSymbolValue(PSEUDO_ATOMIC_ATOMIC, make_fixnum(0));
6009 if (SymbolValue(PSEUDO_ATOMIC_INTERRUPTED) != 0) {
6010 /* Handle any interrupts that occurred during
6012 do_pending_interrupt();
6014 funcall0(SymbolFunction(MAYBE_GC));
6015 /* Re-enter the pseudo-atomic. */
6016 SetSymbolValue(PSEUDO_ATOMIC_INTERRUPTED, make_fixnum(0));
6017 SetSymbolValue(PSEUDO_ATOMIC_ATOMIC, make_fixnum(1));
6020 /* Call gc_alloc(). */
6021 boxed_region.free_pointer = current_region_free_pointer;
6023 void *new_obj = gc_alloc(nbytes);
6024 current_region_free_pointer = boxed_region.free_pointer;
6025 current_region_end_addr = boxed_region.end_addr;
6031 void *new_free_pointer;
6034 /* At least wrap this allocation in a pseudo atomic to prevent
6035 * gc_alloc() from being re-entered. */
6036 SetSymbolValue(PSEUDO_ATOMIC_INTERRUPTED, make_fixnum(0));
6037 SetSymbolValue(PSEUDO_ATOMIC_ATOMIC, make_fixnum(1));
6040 SHOW("alloc re-entered in not-already-pseudo-atomic case");
6043 /* Check whether there is room in the current region. */
6044 new_free_pointer = current_region_free_pointer + nbytes;
6046 if (new_free_pointer <= boxed_region.end_addr) {
6047 /* If so then allocate from the current region. */
6048 void *new_obj = current_region_free_pointer;
6049 current_region_free_pointer = new_free_pointer;
6051 SetSymbolValue(PSEUDO_ATOMIC_ATOMIC, make_fixnum(0));
6052 if (SymbolValue(PSEUDO_ATOMIC_INTERRUPTED)) {
6053 /* Handle any interrupts that occurred during
6055 do_pending_interrupt();
6059 return((void *)new_obj);
6062 /* KLUDGE: There's lots of code around here shared with the
6063 * the other branch. Is there some way to factor out the
6064 * duplicate code? -- WHN 19991129 */
6065 if (auto_gc_trigger && bytes_allocated > auto_gc_trigger) {
6066 /* Double the trigger. */
6067 auto_gc_trigger *= 2;
6069 /* Exit the pseudo atomic. */
6070 SetSymbolValue(PSEUDO_ATOMIC_ATOMIC, make_fixnum(0));
6071 if (SymbolValue(PSEUDO_ATOMIC_INTERRUPTED) != 0) {
6072 /* Handle any interrupts that occurred during
6074 do_pending_interrupt();
6076 funcall0(SymbolFunction(MAYBE_GC));
6080 /* Else call gc_alloc(). */
6081 boxed_region.free_pointer = current_region_free_pointer;
6082 result = gc_alloc(nbytes);
6083 current_region_free_pointer = boxed_region.free_pointer;
6084 current_region_end_addr = boxed_region.end_addr;
6087 SetSymbolValue(PSEUDO_ATOMIC_ATOMIC, make_fixnum(0));
6088 if (SymbolValue(PSEUDO_ATOMIC_INTERRUPTED) != 0) {
6089 /* Handle any interrupts that occurred during gc_alloc(..). */
6090 do_pending_interrupt();
6099 * noise to manipulate the gc trigger stuff
6103 set_auto_gc_trigger(os_vm_size_t dynamic_usage)
6105 auto_gc_trigger += dynamic_usage;
6109 clear_auto_gc_trigger(void)
6111 auto_gc_trigger = 0;
6114 /* Find the code object for the given pc, or return NULL on failure.
6116 * FIXME: PC shouldn't be lispobj*, should it? Maybe void*? */
6118 component_ptr_from_pc(lispobj *pc)
6120 lispobj *object = NULL;
6122 if ( (object = search_read_only_space(pc)) )
6124 else if ( (object = search_static_space(pc)) )
6127 object = search_dynamic_space(pc);
6129 if (object) /* if we found something */
6130 if (widetag_of(*object) == CODE_HEADER_WIDETAG) /* if it's a code object */
6137 * shared support for the OS-dependent signal handlers which
6138 * catch GENCGC-related write-protect violations
6141 void unhandled_sigmemoryfault(void);
6143 /* Depending on which OS we're running under, different signals might
6144 * be raised for a violation of write protection in the heap. This
6145 * function factors out the common generational GC magic which needs
6146 * to invoked in this case, and should be called from whatever signal
6147 * handler is appropriate for the OS we're running under.
6149 * Return true if this signal is a normal generational GC thing that
6150 * we were able to handle, or false if it was abnormal and control
6151 * should fall through to the general SIGSEGV/SIGBUS/whatever logic. */
6153 gencgc_handle_wp_violation(void* fault_addr)
6155 int page_index = find_page_index(fault_addr);
6157 #if defined QSHOW_SIGNALS
6158 FSHOW((stderr, "heap WP violation? fault_addr=%x, page_index=%d\n",
6159 fault_addr, page_index));
6162 /* Check whether the fault is within the dynamic space. */
6163 if (page_index == (-1)) {
6165 /* It can be helpful to be able to put a breakpoint on this
6166 * case to help diagnose low-level problems. */
6167 unhandled_sigmemoryfault();
6169 /* not within the dynamic space -- not our responsibility */
6174 /* The only acceptable reason for an signal like this from the
6175 * heap is that the generational GC write-protected the page. */
6176 if (page_table[page_index].write_protected != 1) {
6177 lose("access failure in heap page not marked as write-protected");
6180 /* Unprotect the page. */
6181 os_protect(page_address(page_index), 4096, OS_VM_PROT_ALL);
6182 page_table[page_index].write_protected = 0;
6183 page_table[page_index].write_protected_cleared = 1;
6185 /* Don't worry, we can handle it. */
6190 /* This is to be called when we catch a SIGSEGV/SIGBUS, determine that
6191 * it's not just a case of the program hitting the write barrier, and
6192 * are about to let Lisp deal with it. It's basically just a
6193 * convenient place to set a gdb breakpoint. */
6195 unhandled_sigmemoryfault()