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>.
36 #include "interrupt.h"
42 #include "gc-internal.h"
44 #include "genesis/vector.h"
45 #include "genesis/weak-pointer.h"
46 #include "genesis/simple-fun.h"
48 /* forward declarations */
49 long gc_find_freeish_pages(long *restart_page_ptr, long nbytes, int unboxed);
50 static void gencgc_pickup_dynamic(void);
57 /* the number of actual generations. (The number of 'struct
58 * generation' objects is one more than this, because one object
59 * serves as scratch when GC'ing.) */
60 #define NUM_GENERATIONS 6
62 /* Should we use page protection to help avoid the scavenging of pages
63 * that don't have pointers to younger generations? */
64 boolean enable_page_protection = 1;
66 /* Should we unmap a page and re-mmap it to have it zero filled? */
67 #if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__)
68 /* comment from cmucl-2.4.8: This can waste a lot of swap on FreeBSD
69 * so don't unmap there.
71 * The CMU CL comment didn't specify a version, but was probably an
72 * old version of FreeBSD (pre-4.0), so this might no longer be true.
73 * OTOH, if it is true, this behavior might exist on OpenBSD too, so
74 * for now we don't unmap there either. -- WHN 2001-04-07 */
75 boolean gencgc_unmap_zero = 0;
77 boolean gencgc_unmap_zero = 1;
80 /* the minimum size (in bytes) for a large object*/
81 unsigned large_object_size = 4 * PAGE_BYTES;
90 /* the verbosity level. All non-error messages are disabled at level 0;
91 * and only a few rare messages are printed at level 1. */
93 unsigned gencgc_verbose = 1;
95 unsigned gencgc_verbose = 0;
98 /* FIXME: At some point enable the various error-checking things below
99 * and see what they say. */
101 /* We hunt for pointers to old-space, when GCing generations >= verify_gen.
102 * Set verify_gens to NUM_GENERATIONS to disable this kind of check. */
103 int verify_gens = NUM_GENERATIONS;
105 /* Should we do a pre-scan verify of generation 0 before it's GCed? */
106 boolean pre_verify_gen_0 = 0;
108 /* Should we check for bad pointers after gc_free_heap is called
109 * from Lisp PURIFY? */
110 boolean verify_after_free_heap = 0;
112 /* Should we print a note when code objects are found in the dynamic space
113 * during a heap verify? */
114 boolean verify_dynamic_code_check = 0;
116 /* Should we check code objects for fixup errors after they are transported? */
117 boolean check_code_fixups = 0;
119 /* Should we check that newly allocated regions are zero filled? */
120 boolean gencgc_zero_check = 0;
122 /* Should we check that the free space is zero filled? */
123 boolean gencgc_enable_verify_zero_fill = 0;
125 /* Should we check that free pages are zero filled during gc_free_heap
126 * called after Lisp PURIFY? */
127 boolean gencgc_zero_check_during_free_heap = 0;
130 * GC structures and variables
133 /* the total bytes allocated. These are seen by Lisp DYNAMIC-USAGE. */
134 unsigned long bytes_allocated = 0;
135 extern unsigned long bytes_consed_between_gcs; /* gc-common.c */
136 unsigned long auto_gc_trigger = 0;
138 /* the source and destination generations. These are set before a GC starts
144 /* An array of page structures is statically allocated.
145 * This helps quickly map between an address its page structure.
146 * NUM_PAGES is set from the size of the dynamic space. */
147 struct page page_table[NUM_PAGES];
149 /* To map addresses to page structures the address of the first page
151 static void *heap_base = NULL;
153 #if N_WORD_BITS == 32
154 #define SIMPLE_ARRAY_WORD_WIDETAG SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG
155 #elif N_WORD_BITS == 64
156 #define SIMPLE_ARRAY_WORD_WIDETAG SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
159 /* Calculate the start address for the given page number. */
161 page_address(long page_num)
163 return (heap_base + (page_num * PAGE_BYTES));
166 /* Find the page index within the page_table for the given
167 * address. Return -1 on failure. */
169 find_page_index(void *addr)
171 long index = addr-heap_base;
174 index = ((unsigned long)index)/PAGE_BYTES;
175 if (index < NUM_PAGES)
182 /* a structure to hold the state of a generation */
185 /* the first page that gc_alloc() checks on its next call */
186 long alloc_start_page;
188 /* the first page that gc_alloc_unboxed() checks on its next call */
189 long alloc_unboxed_start_page;
191 /* the first page that gc_alloc_large (boxed) considers on its next
192 * call. (Although it always allocates after the boxed_region.) */
193 long alloc_large_start_page;
195 /* the first page that gc_alloc_large (unboxed) considers on its
196 * next call. (Although it always allocates after the
197 * current_unboxed_region.) */
198 long alloc_large_unboxed_start_page;
200 /* the bytes allocated to this generation */
201 long bytes_allocated;
203 /* the number of bytes at which to trigger a GC */
206 /* to calculate a new level for gc_trigger */
207 long bytes_consed_between_gc;
209 /* the number of GCs since the last raise */
212 /* the average age after which a GC will raise objects to the
216 /* the cumulative sum of the bytes allocated to this generation. It is
217 * cleared after a GC on this generations, and update before new
218 * objects are added from a GC of a younger generation. Dividing by
219 * the bytes_allocated will give the average age of the memory in
220 * this generation since its last GC. */
221 long cum_sum_bytes_allocated;
223 /* a minimum average memory age before a GC will occur helps
224 * prevent a GC when a large number of new live objects have been
225 * added, in which case a GC could be a waste of time */
226 double min_av_mem_age;
228 /* the number of actual generations. (The number of 'struct
229 * generation' objects is one more than this, because one object
230 * serves as scratch when GC'ing.) */
231 #define NUM_GENERATIONS 6
233 /* an array of generation structures. There needs to be one more
234 * generation structure than actual generations as the oldest
235 * generation is temporarily raised then lowered. */
236 struct generation generations[NUM_GENERATIONS+1];
238 /* the oldest generation that is will currently be GCed by default.
239 * Valid values are: 0, 1, ... (NUM_GENERATIONS-1)
241 * The default of (NUM_GENERATIONS-1) enables GC on all generations.
243 * Setting this to 0 effectively disables the generational nature of
244 * the GC. In some applications generational GC may not be useful
245 * because there are no long-lived objects.
247 * An intermediate value could be handy after moving long-lived data
248 * into an older generation so an unnecessary GC of this long-lived
249 * data can be avoided. */
250 unsigned int gencgc_oldest_gen_to_gc = NUM_GENERATIONS-1;
252 /* The maximum free page in the heap is maintained and used to update
253 * ALLOCATION_POINTER which is used by the room function to limit its
254 * search of the heap. XX Gencgc obviously needs to be better
255 * integrated with the Lisp code. */
256 static long last_free_page;
258 /* This lock is to prevent multiple threads from simultaneously
259 * allocating new regions which overlap each other. Note that the
260 * majority of GC is single-threaded, but alloc() may be called from
261 * >1 thread at a time and must be thread-safe. This lock must be
262 * seized before all accesses to generations[] or to parts of
263 * page_table[] that other threads may want to see */
265 static lispobj free_pages_lock=0;
269 * miscellaneous heap functions
272 /* Count the number of pages which are write-protected within the
273 * given generation. */
275 count_write_protect_generation_pages(int generation)
280 for (i = 0; i < last_free_page; i++)
281 if ((page_table[i].allocated != FREE_PAGE_FLAG)
282 && (page_table[i].gen == generation)
283 && (page_table[i].write_protected == 1))
288 /* Count the number of pages within the given generation. */
290 count_generation_pages(int generation)
295 for (i = 0; i < last_free_page; i++)
296 if ((page_table[i].allocated != 0)
297 && (page_table[i].gen == generation))
304 count_dont_move_pages(void)
308 for (i = 0; i < last_free_page; i++) {
309 if ((page_table[i].allocated != 0) && (page_table[i].dont_move != 0)) {
317 /* Work through the pages and add up the number of bytes used for the
318 * given generation. */
320 count_generation_bytes_allocated (int gen)
324 for (i = 0; i < last_free_page; i++) {
325 if ((page_table[i].allocated != 0) && (page_table[i].gen == gen))
326 result += page_table[i].bytes_used;
331 /* Return the average age of the memory in a generation. */
333 gen_av_mem_age(int gen)
335 if (generations[gen].bytes_allocated == 0)
339 ((double)generations[gen].cum_sum_bytes_allocated)
340 / ((double)generations[gen].bytes_allocated);
343 void fpu_save(int *); /* defined in x86-assem.S */
344 void fpu_restore(int *); /* defined in x86-assem.S */
345 /* The verbose argument controls how much to print: 0 for normal
346 * level of detail; 1 for debugging. */
348 print_generation_stats(int verbose) /* FIXME: should take FILE argument */
353 /* This code uses the FP instructions which may be set up for Lisp
354 * so they need to be saved and reset for C. */
357 /* number of generations to print */
359 gens = NUM_GENERATIONS+1;
361 gens = NUM_GENERATIONS;
363 /* Print the heap stats. */
365 " Gen Boxed Unboxed LB LUB !move Alloc Waste Trig WP GCs Mem-age\n");
367 for (i = 0; i < gens; i++) {
371 int large_boxed_cnt = 0;
372 int large_unboxed_cnt = 0;
375 for (j = 0; j < last_free_page; j++)
376 if (page_table[j].gen == i) {
378 /* Count the number of boxed pages within the given
380 if (page_table[j].allocated & BOXED_PAGE_FLAG) {
381 if (page_table[j].large_object)
386 if(page_table[j].dont_move) pinned_cnt++;
387 /* Count the number of unboxed pages within the given
389 if (page_table[j].allocated & UNBOXED_PAGE_FLAG) {
390 if (page_table[j].large_object)
397 gc_assert(generations[i].bytes_allocated
398 == count_generation_bytes_allocated(i));
400 " %1d: %5d %5d %5d %5d %5d %8ld %5ld %8ld %4ld %3d %7.4f\n",
402 boxed_cnt, unboxed_cnt, large_boxed_cnt, large_unboxed_cnt,
404 generations[i].bytes_allocated,
405 (count_generation_pages(i)*PAGE_BYTES
406 - generations[i].bytes_allocated),
407 generations[i].gc_trigger,
408 count_write_protect_generation_pages(i),
409 generations[i].num_gc,
412 fprintf(stderr," Total bytes allocated=%ld\n", bytes_allocated);
414 fpu_restore(fpu_state);
418 * allocation routines
422 * To support quick and inline allocation, regions of memory can be
423 * allocated and then allocated from with just a free pointer and a
424 * check against an end address.
426 * Since objects can be allocated to spaces with different properties
427 * e.g. boxed/unboxed, generation, ages; there may need to be many
428 * allocation regions.
430 * Each allocation region may be start within a partly used page. Many
431 * features of memory use are noted on a page wise basis, e.g. the
432 * generation; so if a region starts within an existing allocated page
433 * it must be consistent with this page.
435 * During the scavenging of the newspace, objects will be transported
436 * into an allocation region, and pointers updated to point to this
437 * allocation region. It is possible that these pointers will be
438 * scavenged again before the allocation region is closed, e.g. due to
439 * trans_list which jumps all over the place to cleanup the list. It
440 * is important to be able to determine properties of all objects
441 * pointed to when scavenging, e.g to detect pointers to the oldspace.
442 * Thus it's important that the allocation regions have the correct
443 * properties set when allocated, and not just set when closed. The
444 * region allocation routines return regions with the specified
445 * properties, and grab all the pages, setting their properties
446 * appropriately, except that the amount used is not known.
448 * These regions are used to support quicker allocation using just a
449 * free pointer. The actual space used by the region is not reflected
450 * in the pages tables until it is closed. It can't be scavenged until
453 * When finished with the region it should be closed, which will
454 * update the page tables for the actual space used returning unused
455 * space. Further it may be noted in the new regions which is
456 * necessary when scavenging the newspace.
458 * Large objects may be allocated directly without an allocation
459 * region, the page tables are updated immediately.
461 * Unboxed objects don't contain pointers to other objects and so
462 * don't need scavenging. Further they can't contain pointers to
463 * younger generations so WP is not needed. By allocating pages to
464 * unboxed objects the whole page never needs scavenging or
465 * write-protecting. */
467 /* We are only using two regions at present. Both are for the current
468 * newspace generation. */
469 struct alloc_region boxed_region;
470 struct alloc_region unboxed_region;
472 /* The generation currently being allocated to. */
473 static int gc_alloc_generation;
475 /* Find a new region with room for at least the given number of bytes.
477 * It starts looking at the current generation's alloc_start_page. So
478 * may pick up from the previous region if there is enough space. This
479 * keeps the allocation contiguous when scavenging the newspace.
481 * The alloc_region should have been closed by a call to
482 * gc_alloc_update_page_tables(), and will thus be in an empty state.
484 * To assist the scavenging functions write-protected pages are not
485 * used. Free pages should not be write-protected.
487 * It is critical to the conservative GC that the start of regions be
488 * known. To help achieve this only small regions are allocated at a
491 * During scavenging, pointers may be found to within the current
492 * region and the page generation must be set so that pointers to the
493 * from space can be recognized. Therefore the generation of pages in
494 * the region are set to gc_alloc_generation. To prevent another
495 * allocation call using the same pages, all the pages in the region
496 * are allocated, although they will initially be empty.
499 gc_alloc_new_region(long nbytes, int unboxed, struct alloc_region *alloc_region)
508 "/alloc_new_region for %d bytes from gen %d\n",
509 nbytes, gc_alloc_generation));
512 /* Check that the region is in a reset state. */
513 gc_assert((alloc_region->first_page == 0)
514 && (alloc_region->last_page == -1)
515 && (alloc_region->free_pointer == alloc_region->end_addr));
516 get_spinlock(&free_pages_lock,(long) alloc_region);
519 generations[gc_alloc_generation].alloc_unboxed_start_page;
522 generations[gc_alloc_generation].alloc_start_page;
524 last_page=gc_find_freeish_pages(&first_page,nbytes,unboxed);
525 bytes_found=(PAGE_BYTES - page_table[first_page].bytes_used)
526 + PAGE_BYTES*(last_page-first_page);
528 /* Set up the alloc_region. */
529 alloc_region->first_page = first_page;
530 alloc_region->last_page = last_page;
531 alloc_region->start_addr = page_table[first_page].bytes_used
532 + page_address(first_page);
533 alloc_region->free_pointer = alloc_region->start_addr;
534 alloc_region->end_addr = alloc_region->start_addr + bytes_found;
536 /* Set up the pages. */
538 /* The first page may have already been in use. */
539 if (page_table[first_page].bytes_used == 0) {
541 page_table[first_page].allocated = UNBOXED_PAGE_FLAG;
543 page_table[first_page].allocated = BOXED_PAGE_FLAG;
544 page_table[first_page].gen = gc_alloc_generation;
545 page_table[first_page].large_object = 0;
546 page_table[first_page].first_object_offset = 0;
550 gc_assert(page_table[first_page].allocated == UNBOXED_PAGE_FLAG);
552 gc_assert(page_table[first_page].allocated == BOXED_PAGE_FLAG);
553 page_table[first_page].allocated |= OPEN_REGION_PAGE_FLAG;
555 gc_assert(page_table[first_page].gen == gc_alloc_generation);
556 gc_assert(page_table[first_page].large_object == 0);
558 for (i = first_page+1; i <= last_page; i++) {
560 page_table[i].allocated = UNBOXED_PAGE_FLAG;
562 page_table[i].allocated = BOXED_PAGE_FLAG;
563 page_table[i].gen = gc_alloc_generation;
564 page_table[i].large_object = 0;
565 /* This may not be necessary for unboxed regions (think it was
567 page_table[i].first_object_offset =
568 alloc_region->start_addr - page_address(i);
569 page_table[i].allocated |= OPEN_REGION_PAGE_FLAG ;
571 /* Bump up last_free_page. */
572 if (last_page+1 > last_free_page) {
573 last_free_page = last_page+1;
574 SetSymbolValue(ALLOCATION_POINTER,
575 (lispobj)(((char *)heap_base) + last_free_page*PAGE_BYTES),
578 release_spinlock(&free_pages_lock);
580 /* we can do this after releasing free_pages_lock */
581 if (gencgc_zero_check) {
583 for (p = (long *)alloc_region->start_addr;
584 p < (long *)alloc_region->end_addr; p++) {
586 /* KLUDGE: It would be nice to use %lx and explicit casts
587 * (long) in code like this, so that it is less likely to
588 * break randomly when running on a machine with different
589 * word sizes. -- WHN 19991129 */
590 lose("The new region at %x is not zero.", p);
597 /* If the record_new_objects flag is 2 then all new regions created
600 * If it's 1 then then it is only recorded if the first page of the
601 * current region is <= new_areas_ignore_page. This helps avoid
602 * unnecessary recording when doing full scavenge pass.
604 * The new_object structure holds the page, byte offset, and size of
605 * new regions of objects. Each new area is placed in the array of
606 * these structures pointer to by new_areas. new_areas_index holds the
607 * offset into new_areas.
609 * If new_area overflows NUM_NEW_AREAS then it stops adding them. The
610 * later code must detect this and handle it, probably by doing a full
611 * scavenge of a generation. */
612 #define NUM_NEW_AREAS 512
613 static int record_new_objects = 0;
614 static long new_areas_ignore_page;
620 static struct new_area (*new_areas)[];
621 static long new_areas_index;
624 /* Add a new area to new_areas. */
626 add_new_area(long first_page, long offset, long size)
628 unsigned new_area_start,c;
631 /* Ignore if full. */
632 if (new_areas_index >= NUM_NEW_AREAS)
635 switch (record_new_objects) {
639 if (first_page > new_areas_ignore_page)
648 new_area_start = PAGE_BYTES*first_page + offset;
650 /* Search backwards for a prior area that this follows from. If
651 found this will save adding a new area. */
652 for (i = new_areas_index-1, c = 0; (i >= 0) && (c < 8); i--, c++) {
654 PAGE_BYTES*((*new_areas)[i].page)
655 + (*new_areas)[i].offset
656 + (*new_areas)[i].size;
658 "/add_new_area S1 %d %d %d %d\n",
659 i, c, new_area_start, area_end));*/
660 if (new_area_start == area_end) {
662 "/adding to [%d] %d %d %d with %d %d %d:\n",
664 (*new_areas)[i].page,
665 (*new_areas)[i].offset,
666 (*new_areas)[i].size,
670 (*new_areas)[i].size += size;
675 (*new_areas)[new_areas_index].page = first_page;
676 (*new_areas)[new_areas_index].offset = offset;
677 (*new_areas)[new_areas_index].size = size;
679 "/new_area %d page %d offset %d size %d\n",
680 new_areas_index, first_page, offset, size));*/
683 /* Note the max new_areas used. */
684 if (new_areas_index > max_new_areas)
685 max_new_areas = new_areas_index;
688 /* Update the tables for the alloc_region. The region may be added to
691 * When done the alloc_region is set up so that the next quick alloc
692 * will fail safely and thus a new region will be allocated. Further
693 * it is safe to try to re-update the page table of this reset
696 gc_alloc_update_page_tables(int unboxed, struct alloc_region *alloc_region)
702 long orig_first_page_bytes_used;
707 first_page = alloc_region->first_page;
709 /* Catch an unused alloc_region. */
710 if ((first_page == 0) && (alloc_region->last_page == -1))
713 next_page = first_page+1;
715 get_spinlock(&free_pages_lock,(long) alloc_region);
716 if (alloc_region->free_pointer != alloc_region->start_addr) {
717 /* some bytes were allocated in the region */
718 orig_first_page_bytes_used = page_table[first_page].bytes_used;
720 gc_assert(alloc_region->start_addr == (page_address(first_page) + page_table[first_page].bytes_used));
722 /* All the pages used need to be updated */
724 /* Update the first page. */
726 /* If the page was free then set up the gen, and
727 * first_object_offset. */
728 if (page_table[first_page].bytes_used == 0)
729 gc_assert(page_table[first_page].first_object_offset == 0);
730 page_table[first_page].allocated &= ~(OPEN_REGION_PAGE_FLAG);
733 gc_assert(page_table[first_page].allocated == UNBOXED_PAGE_FLAG);
735 gc_assert(page_table[first_page].allocated == BOXED_PAGE_FLAG);
736 gc_assert(page_table[first_page].gen == gc_alloc_generation);
737 gc_assert(page_table[first_page].large_object == 0);
741 /* Calculate the number of bytes used in this page. This is not
742 * always the number of new bytes, unless it was free. */
744 if ((bytes_used = (alloc_region->free_pointer - page_address(first_page)))>PAGE_BYTES) {
745 bytes_used = PAGE_BYTES;
748 page_table[first_page].bytes_used = bytes_used;
749 byte_cnt += bytes_used;
752 /* All the rest of the pages should be free. We need to set their
753 * first_object_offset pointer to the start of the region, and set
756 page_table[next_page].allocated &= ~(OPEN_REGION_PAGE_FLAG);
758 gc_assert(page_table[next_page].allocated==UNBOXED_PAGE_FLAG);
760 gc_assert(page_table[next_page].allocated == BOXED_PAGE_FLAG);
761 gc_assert(page_table[next_page].bytes_used == 0);
762 gc_assert(page_table[next_page].gen == gc_alloc_generation);
763 gc_assert(page_table[next_page].large_object == 0);
765 gc_assert(page_table[next_page].first_object_offset ==
766 alloc_region->start_addr - page_address(next_page));
768 /* Calculate the number of bytes used in this page. */
770 if ((bytes_used = (alloc_region->free_pointer
771 - page_address(next_page)))>PAGE_BYTES) {
772 bytes_used = PAGE_BYTES;
775 page_table[next_page].bytes_used = bytes_used;
776 byte_cnt += bytes_used;
781 region_size = alloc_region->free_pointer - alloc_region->start_addr;
782 bytes_allocated += region_size;
783 generations[gc_alloc_generation].bytes_allocated += region_size;
785 gc_assert((byte_cnt- orig_first_page_bytes_used) == region_size);
787 /* Set the generations alloc restart page to the last page of
790 generations[gc_alloc_generation].alloc_unboxed_start_page =
793 generations[gc_alloc_generation].alloc_start_page = next_page-1;
795 /* Add the region to the new_areas if requested. */
797 add_new_area(first_page,orig_first_page_bytes_used, region_size);
801 "/gc_alloc_update_page_tables update %d bytes to gen %d\n",
803 gc_alloc_generation));
806 /* There are no bytes allocated. Unallocate the first_page if
807 * there are 0 bytes_used. */
808 page_table[first_page].allocated &= ~(OPEN_REGION_PAGE_FLAG);
809 if (page_table[first_page].bytes_used == 0)
810 page_table[first_page].allocated = FREE_PAGE_FLAG;
813 /* Unallocate any unused pages. */
814 while (next_page <= alloc_region->last_page) {
815 gc_assert(page_table[next_page].bytes_used == 0);
816 page_table[next_page].allocated = FREE_PAGE_FLAG;
819 release_spinlock(&free_pages_lock);
820 /* alloc_region is per-thread, we're ok to do this unlocked */
821 gc_set_region_empty(alloc_region);
824 static inline void *gc_quick_alloc(long nbytes);
826 /* Allocate a possibly large object. */
828 gc_alloc_large(long nbytes, int unboxed, struct alloc_region *alloc_region)
832 long orig_first_page_bytes_used;
838 get_spinlock(&free_pages_lock,(long) alloc_region);
842 generations[gc_alloc_generation].alloc_large_unboxed_start_page;
844 first_page = generations[gc_alloc_generation].alloc_large_start_page;
846 if (first_page <= alloc_region->last_page) {
847 first_page = alloc_region->last_page+1;
850 last_page=gc_find_freeish_pages(&first_page,nbytes,unboxed);
852 gc_assert(first_page > alloc_region->last_page);
854 generations[gc_alloc_generation].alloc_large_unboxed_start_page =
857 generations[gc_alloc_generation].alloc_large_start_page = last_page;
859 /* Set up the pages. */
860 orig_first_page_bytes_used = page_table[first_page].bytes_used;
862 /* If the first page was free then set up the gen, and
863 * first_object_offset. */
864 if (page_table[first_page].bytes_used == 0) {
866 page_table[first_page].allocated = UNBOXED_PAGE_FLAG;
868 page_table[first_page].allocated = BOXED_PAGE_FLAG;
869 page_table[first_page].gen = gc_alloc_generation;
870 page_table[first_page].first_object_offset = 0;
871 page_table[first_page].large_object = 1;
875 gc_assert(page_table[first_page].allocated == UNBOXED_PAGE_FLAG);
877 gc_assert(page_table[first_page].allocated == BOXED_PAGE_FLAG);
878 gc_assert(page_table[first_page].gen == gc_alloc_generation);
879 gc_assert(page_table[first_page].large_object == 1);
883 /* Calc. the number of bytes used in this page. This is not
884 * always the number of new bytes, unless it was free. */
886 if ((bytes_used = nbytes+orig_first_page_bytes_used) > PAGE_BYTES) {
887 bytes_used = PAGE_BYTES;
890 page_table[first_page].bytes_used = bytes_used;
891 byte_cnt += bytes_used;
893 next_page = first_page+1;
895 /* All the rest of the pages should be free. We need to set their
896 * first_object_offset pointer to the start of the region, and
897 * set the bytes_used. */
899 gc_assert(page_table[next_page].allocated == FREE_PAGE_FLAG);
900 gc_assert(page_table[next_page].bytes_used == 0);
902 page_table[next_page].allocated = UNBOXED_PAGE_FLAG;
904 page_table[next_page].allocated = BOXED_PAGE_FLAG;
905 page_table[next_page].gen = gc_alloc_generation;
906 page_table[next_page].large_object = 1;
908 page_table[next_page].first_object_offset =
909 orig_first_page_bytes_used - PAGE_BYTES*(next_page-first_page);
911 /* Calculate the number of bytes used in this page. */
913 if ((bytes_used=(nbytes+orig_first_page_bytes_used)-byte_cnt) > PAGE_BYTES) {
914 bytes_used = PAGE_BYTES;
917 page_table[next_page].bytes_used = bytes_used;
918 page_table[next_page].write_protected=0;
919 page_table[next_page].dont_move=0;
920 byte_cnt += bytes_used;
924 gc_assert((byte_cnt-orig_first_page_bytes_used) == nbytes);
926 bytes_allocated += nbytes;
927 generations[gc_alloc_generation].bytes_allocated += nbytes;
929 /* Add the region to the new_areas if requested. */
931 add_new_area(first_page,orig_first_page_bytes_used,nbytes);
933 /* Bump up last_free_page */
934 if (last_page+1 > last_free_page) {
935 last_free_page = last_page+1;
936 SetSymbolValue(ALLOCATION_POINTER,
937 (lispobj)(((char *)heap_base) + last_free_page*PAGE_BYTES),0);
939 release_spinlock(&free_pages_lock);
941 return((void *)(page_address(first_page)+orig_first_page_bytes_used));
945 gc_find_freeish_pages(long *restart_page_ptr, long nbytes, int unboxed)
950 long restart_page=*restart_page_ptr;
953 long large_p=(nbytes>=large_object_size);
954 gc_assert(free_pages_lock);
956 /* Search for a contiguous free space of at least nbytes. If it's
957 * a large object then align it on a page boundary by searching
958 * for a free page. */
961 first_page = restart_page;
963 while ((first_page < NUM_PAGES)
964 && (page_table[first_page].allocated != FREE_PAGE_FLAG))
967 while (first_page < NUM_PAGES) {
968 if(page_table[first_page].allocated == FREE_PAGE_FLAG)
970 if((page_table[first_page].allocated ==
971 (unboxed ? UNBOXED_PAGE_FLAG : BOXED_PAGE_FLAG)) &&
972 (page_table[first_page].large_object == 0) &&
973 (page_table[first_page].gen == gc_alloc_generation) &&
974 (page_table[first_page].bytes_used < (PAGE_BYTES-32)) &&
975 (page_table[first_page].write_protected == 0) &&
976 (page_table[first_page].dont_move == 0)) {
982 if (first_page >= NUM_PAGES) {
984 "Argh! gc_find_free_space failed (first_page), nbytes=%ld.\n",
986 print_generation_stats(1);
990 gc_assert(page_table[first_page].write_protected == 0);
992 last_page = first_page;
993 bytes_found = PAGE_BYTES - page_table[first_page].bytes_used;
995 while (((bytes_found < nbytes)
996 || (!large_p && (num_pages < 2)))
997 && (last_page < (NUM_PAGES-1))
998 && (page_table[last_page+1].allocated == FREE_PAGE_FLAG)) {
1001 bytes_found += PAGE_BYTES;
1002 gc_assert(page_table[last_page].write_protected == 0);
1005 region_size = (PAGE_BYTES - page_table[first_page].bytes_used)
1006 + PAGE_BYTES*(last_page-first_page);
1008 gc_assert(bytes_found == region_size);
1009 restart_page = last_page + 1;
1010 } while ((restart_page < NUM_PAGES) && (bytes_found < nbytes));
1012 /* Check for a failure */
1013 if ((restart_page >= NUM_PAGES) && (bytes_found < nbytes)) {
1015 "Argh! gc_find_freeish_pages failed (restart_page), nbytes=%ld.\n",
1017 print_generation_stats(1);
1020 *restart_page_ptr=first_page;
1024 /* Allocate bytes. All the rest of the special-purpose allocation
1025 * functions will eventually call this */
1028 gc_alloc_with_region(long nbytes,int unboxed_p, struct alloc_region *my_region,
1031 void *new_free_pointer;
1033 if(nbytes>=large_object_size)
1034 return gc_alloc_large(nbytes,unboxed_p,my_region);
1036 /* Check whether there is room in the current alloc region. */
1037 new_free_pointer = my_region->free_pointer + nbytes;
1039 /* fprintf(stderr, "alloc %d bytes from %p to %p\n", nbytes,
1040 my_region->free_pointer, new_free_pointer); */
1042 if (new_free_pointer <= my_region->end_addr) {
1043 /* If so then allocate from the current alloc region. */
1044 void *new_obj = my_region->free_pointer;
1045 my_region->free_pointer = new_free_pointer;
1047 /* Unless a `quick' alloc was requested, check whether the
1048 alloc region is almost empty. */
1050 (my_region->end_addr - my_region->free_pointer) <= 32) {
1051 /* If so, finished with the current region. */
1052 gc_alloc_update_page_tables(unboxed_p, my_region);
1053 /* Set up a new region. */
1054 gc_alloc_new_region(32 /*bytes*/, unboxed_p, my_region);
1057 return((void *)new_obj);
1060 /* Else not enough free space in the current region: retry with a
1063 gc_alloc_update_page_tables(unboxed_p, my_region);
1064 gc_alloc_new_region(nbytes, unboxed_p, my_region);
1065 return gc_alloc_with_region(nbytes,unboxed_p,my_region,0);
1068 /* these are only used during GC: all allocation from the mutator calls
1069 * alloc() -> gc_alloc_with_region() with the appropriate per-thread
1073 gc_general_alloc(long nbytes,int unboxed_p,int quick_p)
1075 struct alloc_region *my_region =
1076 unboxed_p ? &unboxed_region : &boxed_region;
1077 return gc_alloc_with_region(nbytes,unboxed_p, my_region,quick_p);
1080 static inline void *
1081 gc_quick_alloc(long nbytes)
1083 return gc_general_alloc(nbytes,ALLOC_BOXED,ALLOC_QUICK);
1086 static inline void *
1087 gc_quick_alloc_large(long nbytes)
1089 return gc_general_alloc(nbytes,ALLOC_BOXED,ALLOC_QUICK);
1092 static inline void *
1093 gc_alloc_unboxed(long nbytes)
1095 return gc_general_alloc(nbytes,ALLOC_UNBOXED,0);
1098 static inline void *
1099 gc_quick_alloc_unboxed(long nbytes)
1101 return gc_general_alloc(nbytes,ALLOC_UNBOXED,ALLOC_QUICK);
1104 static inline void *
1105 gc_quick_alloc_large_unboxed(long nbytes)
1107 return gc_general_alloc(nbytes,ALLOC_UNBOXED,ALLOC_QUICK);
1111 * scavenging/transporting routines derived from gc.c in CMU CL ca. 18b
1114 extern long (*scavtab[256])(lispobj *where, lispobj object);
1115 extern lispobj (*transother[256])(lispobj object);
1116 extern long (*sizetab[256])(lispobj *where);
1118 /* Copy a large boxed object. If the object is in a large object
1119 * region then it is simply promoted, else it is copied. If it's large
1120 * enough then it's copied to a large object region.
1122 * Vectors may have shrunk. If the object is not copied the space
1123 * needs to be reclaimed, and the page_tables corrected. */
1125 copy_large_object(lispobj object, long nwords)
1131 gc_assert(is_lisp_pointer(object));
1132 gc_assert(from_space_p(object));
1133 gc_assert((nwords & 0x01) == 0);
1136 /* Check whether it's in a large object region. */
1137 first_page = find_page_index((void *)object);
1138 gc_assert(first_page >= 0);
1140 if (page_table[first_page].large_object) {
1142 /* Promote the object. */
1144 long remaining_bytes;
1147 long old_bytes_used;
1149 /* Note: Any page write-protection must be removed, else a
1150 * later scavenge_newspace may incorrectly not scavenge these
1151 * pages. This would not be necessary if they are added to the
1152 * new areas, but let's do it for them all (they'll probably
1153 * be written anyway?). */
1155 gc_assert(page_table[first_page].first_object_offset == 0);
1157 next_page = first_page;
1158 remaining_bytes = nwords*N_WORD_BYTES;
1159 while (remaining_bytes > PAGE_BYTES) {
1160 gc_assert(page_table[next_page].gen == from_space);
1161 gc_assert(page_table[next_page].allocated == BOXED_PAGE_FLAG);
1162 gc_assert(page_table[next_page].large_object);
1163 gc_assert(page_table[next_page].first_object_offset==
1164 -PAGE_BYTES*(next_page-first_page));
1165 gc_assert(page_table[next_page].bytes_used == PAGE_BYTES);
1167 page_table[next_page].gen = new_space;
1169 /* Remove any write-protection. We should be able to rely
1170 * on the write-protect flag to avoid redundant calls. */
1171 if (page_table[next_page].write_protected) {
1172 os_protect(page_address(next_page), PAGE_BYTES, OS_VM_PROT_ALL);
1173 page_table[next_page].write_protected = 0;
1175 remaining_bytes -= PAGE_BYTES;
1179 /* Now only one page remains, but the object may have shrunk
1180 * so there may be more unused pages which will be freed. */
1182 /* The object may have shrunk but shouldn't have grown. */
1183 gc_assert(page_table[next_page].bytes_used >= remaining_bytes);
1185 page_table[next_page].gen = new_space;
1186 gc_assert(page_table[next_page].allocated == BOXED_PAGE_FLAG);
1188 /* Adjust the bytes_used. */
1189 old_bytes_used = page_table[next_page].bytes_used;
1190 page_table[next_page].bytes_used = remaining_bytes;
1192 bytes_freed = old_bytes_used - remaining_bytes;
1194 /* Free any remaining pages; needs care. */
1196 while ((old_bytes_used == PAGE_BYTES) &&
1197 (page_table[next_page].gen == from_space) &&
1198 (page_table[next_page].allocated == BOXED_PAGE_FLAG) &&
1199 page_table[next_page].large_object &&
1200 (page_table[next_page].first_object_offset ==
1201 -(next_page - first_page)*PAGE_BYTES)) {
1202 /* Checks out OK, free the page. Don't need to bother zeroing
1203 * pages as this should have been done before shrinking the
1204 * object. These pages shouldn't be write-protected as they
1205 * should be zero filled. */
1206 gc_assert(page_table[next_page].write_protected == 0);
1208 old_bytes_used = page_table[next_page].bytes_used;
1209 page_table[next_page].allocated = FREE_PAGE_FLAG;
1210 page_table[next_page].bytes_used = 0;
1211 bytes_freed += old_bytes_used;
1215 generations[from_space].bytes_allocated -= N_WORD_BYTES*nwords +
1217 generations[new_space].bytes_allocated += N_WORD_BYTES*nwords;
1218 bytes_allocated -= bytes_freed;
1220 /* Add the region to the new_areas if requested. */
1221 add_new_area(first_page,0,nwords*N_WORD_BYTES);
1225 /* Get tag of object. */
1226 tag = lowtag_of(object);
1228 /* Allocate space. */
1229 new = gc_quick_alloc_large(nwords*N_WORD_BYTES);
1231 memcpy(new,native_pointer(object),nwords*N_WORD_BYTES);
1233 /* Return Lisp pointer of new object. */
1234 return ((lispobj) new) | tag;
1238 /* to copy unboxed objects */
1240 copy_unboxed_object(lispobj object, long nwords)
1245 gc_assert(is_lisp_pointer(object));
1246 gc_assert(from_space_p(object));
1247 gc_assert((nwords & 0x01) == 0);
1249 /* Get tag of object. */
1250 tag = lowtag_of(object);
1252 /* Allocate space. */
1253 new = gc_quick_alloc_unboxed(nwords*N_WORD_BYTES);
1255 memcpy(new,native_pointer(object),nwords*N_WORD_BYTES);
1257 /* Return Lisp pointer of new object. */
1258 return ((lispobj) new) | tag;
1261 /* to copy large unboxed objects
1263 * If the object is in a large object region then it is simply
1264 * promoted, else it is copied. If it's large enough then it's copied
1265 * to a large object region.
1267 * Bignums and vectors may have shrunk. If the object is not copied
1268 * the space needs to be reclaimed, and the page_tables corrected.
1270 * KLUDGE: There's a lot of cut-and-paste duplication between this
1271 * function and copy_large_object(..). -- WHN 20000619 */
1273 copy_large_unboxed_object(lispobj object, long nwords)
1279 gc_assert(is_lisp_pointer(object));
1280 gc_assert(from_space_p(object));
1281 gc_assert((nwords & 0x01) == 0);
1283 if ((nwords > 1024*1024) && gencgc_verbose)
1284 FSHOW((stderr, "/copy_large_unboxed_object: %d bytes\n", nwords*N_WORD_BYTES));
1286 /* Check whether it's a large object. */
1287 first_page = find_page_index((void *)object);
1288 gc_assert(first_page >= 0);
1290 if (page_table[first_page].large_object) {
1291 /* Promote the object. Note: Unboxed objects may have been
1292 * allocated to a BOXED region so it may be necessary to
1293 * change the region to UNBOXED. */
1294 long remaining_bytes;
1297 long old_bytes_used;
1299 gc_assert(page_table[first_page].first_object_offset == 0);
1301 next_page = first_page;
1302 remaining_bytes = nwords*N_WORD_BYTES;
1303 while (remaining_bytes > PAGE_BYTES) {
1304 gc_assert(page_table[next_page].gen == from_space);
1305 gc_assert((page_table[next_page].allocated == UNBOXED_PAGE_FLAG)
1306 || (page_table[next_page].allocated == BOXED_PAGE_FLAG));
1307 gc_assert(page_table[next_page].large_object);
1308 gc_assert(page_table[next_page].first_object_offset==
1309 -PAGE_BYTES*(next_page-first_page));
1310 gc_assert(page_table[next_page].bytes_used == PAGE_BYTES);
1312 page_table[next_page].gen = new_space;
1313 page_table[next_page].allocated = UNBOXED_PAGE_FLAG;
1314 remaining_bytes -= PAGE_BYTES;
1318 /* Now only one page remains, but the object may have shrunk so
1319 * there may be more unused pages which will be freed. */
1321 /* Object may have shrunk but shouldn't have grown - check. */
1322 gc_assert(page_table[next_page].bytes_used >= remaining_bytes);
1324 page_table[next_page].gen = new_space;
1325 page_table[next_page].allocated = UNBOXED_PAGE_FLAG;
1327 /* Adjust the bytes_used. */
1328 old_bytes_used = page_table[next_page].bytes_used;
1329 page_table[next_page].bytes_used = remaining_bytes;
1331 bytes_freed = old_bytes_used - remaining_bytes;
1333 /* Free any remaining pages; needs care. */
1335 while ((old_bytes_used == PAGE_BYTES) &&
1336 (page_table[next_page].gen == from_space) &&
1337 ((page_table[next_page].allocated == UNBOXED_PAGE_FLAG)
1338 || (page_table[next_page].allocated == BOXED_PAGE_FLAG)) &&
1339 page_table[next_page].large_object &&
1340 (page_table[next_page].first_object_offset ==
1341 -(next_page - first_page)*PAGE_BYTES)) {
1342 /* Checks out OK, free the page. Don't need to both zeroing
1343 * pages as this should have been done before shrinking the
1344 * object. These pages shouldn't be write-protected, even if
1345 * boxed they should be zero filled. */
1346 gc_assert(page_table[next_page].write_protected == 0);
1348 old_bytes_used = page_table[next_page].bytes_used;
1349 page_table[next_page].allocated = FREE_PAGE_FLAG;
1350 page_table[next_page].bytes_used = 0;
1351 bytes_freed += old_bytes_used;
1355 if ((bytes_freed > 0) && gencgc_verbose)
1357 "/copy_large_unboxed bytes_freed=%d\n",
1360 generations[from_space].bytes_allocated -= nwords*N_WORD_BYTES + bytes_freed;
1361 generations[new_space].bytes_allocated += nwords*N_WORD_BYTES;
1362 bytes_allocated -= bytes_freed;
1367 /* Get tag of object. */
1368 tag = lowtag_of(object);
1370 /* Allocate space. */
1371 new = gc_quick_alloc_large_unboxed(nwords*N_WORD_BYTES);
1373 /* Copy the object. */
1374 memcpy(new,native_pointer(object),nwords*N_WORD_BYTES);
1376 /* Return Lisp pointer of new object. */
1377 return ((lispobj) new) | tag;
1386 * code and code-related objects
1389 static lispobj trans_fun_header(lispobj object);
1390 static lispobj trans_boxed(lispobj object);
1393 /* Scan a x86 compiled code object, looking for possible fixups that
1394 * have been missed after a move.
1396 * Two types of fixups are needed:
1397 * 1. Absolute fixups to within the code object.
1398 * 2. Relative fixups to outside the code object.
1400 * Currently only absolute fixups to the constant vector, or to the
1401 * code area are checked. */
1403 sniff_code_object(struct code *code, unsigned displacement)
1405 long nheader_words, ncode_words, nwords;
1407 void *constants_start_addr, *constants_end_addr;
1408 void *code_start_addr, *code_end_addr;
1409 int fixup_found = 0;
1411 if (!check_code_fixups)
1414 ncode_words = fixnum_value(code->code_size);
1415 nheader_words = HeaderValue(*(lispobj *)code);
1416 nwords = ncode_words + nheader_words;
1418 constants_start_addr = (void *)code + 5*N_WORD_BYTES;
1419 constants_end_addr = (void *)code + nheader_words*N_WORD_BYTES;
1420 code_start_addr = (void *)code + nheader_words*N_WORD_BYTES;
1421 code_end_addr = (void *)code + nwords*N_WORD_BYTES;
1423 /* Work through the unboxed code. */
1424 for (p = code_start_addr; p < code_end_addr; p++) {
1425 void *data = *(void **)p;
1426 unsigned d1 = *((unsigned char *)p - 1);
1427 unsigned d2 = *((unsigned char *)p - 2);
1428 unsigned d3 = *((unsigned char *)p - 3);
1429 unsigned d4 = *((unsigned char *)p - 4);
1431 unsigned d5 = *((unsigned char *)p - 5);
1432 unsigned d6 = *((unsigned char *)p - 6);
1435 /* Check for code references. */
1436 /* Check for a 32 bit word that looks like an absolute
1437 reference to within the code adea of the code object. */
1438 if ((data >= (code_start_addr-displacement))
1439 && (data < (code_end_addr-displacement))) {
1440 /* function header */
1442 && (((unsigned)p - 4 - 4*HeaderValue(*((unsigned *)p-1))) == (unsigned)code)) {
1443 /* Skip the function header */
1447 /* the case of PUSH imm32 */
1451 "/code ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1452 p, d6, d5, d4, d3, d2, d1, data));
1453 FSHOW((stderr, "/PUSH $0x%.8x\n", data));
1455 /* the case of MOV [reg-8],imm32 */
1457 && (d2==0x40 || d2==0x41 || d2==0x42 || d2==0x43
1458 || d2==0x45 || d2==0x46 || d2==0x47)
1462 "/code ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1463 p, d6, d5, d4, d3, d2, d1, data));
1464 FSHOW((stderr, "/MOV [reg-8],$0x%.8x\n", data));
1466 /* the case of LEA reg,[disp32] */
1467 if ((d2 == 0x8d) && ((d1 & 0xc7) == 5)) {
1470 "/code ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1471 p, d6, d5, d4, d3, d2, d1, data));
1472 FSHOW((stderr,"/LEA reg,[$0x%.8x]\n", data));
1476 /* Check for constant references. */
1477 /* Check for a 32 bit word that looks like an absolute
1478 reference to within the constant vector. Constant references
1480 if ((data >= (constants_start_addr-displacement))
1481 && (data < (constants_end_addr-displacement))
1482 && (((unsigned)data & 0x3) == 0)) {
1487 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1488 p, d6, d5, d4, d3, d2, d1, data));
1489 FSHOW((stderr,"/MOV eax,0x%.8x\n", data));
1492 /* the case of MOV m32,EAX */
1496 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1497 p, d6, d5, d4, d3, d2, d1, data));
1498 FSHOW((stderr, "/MOV 0x%.8x,eax\n", data));
1501 /* the case of CMP m32,imm32 */
1502 if ((d1 == 0x3d) && (d2 == 0x81)) {
1505 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1506 p, d6, d5, d4, d3, d2, d1, data));
1508 FSHOW((stderr, "/CMP 0x%.8x,immed32\n", data));
1511 /* Check for a mod=00, r/m=101 byte. */
1512 if ((d1 & 0xc7) == 5) {
1517 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1518 p, d6, d5, d4, d3, d2, d1, data));
1519 FSHOW((stderr,"/CMP 0x%.8x,reg\n", data));
1521 /* the case of CMP reg32,m32 */
1525 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1526 p, d6, d5, d4, d3, d2, d1, data));
1527 FSHOW((stderr, "/CMP reg32,0x%.8x\n", data));
1529 /* the case of MOV m32,reg32 */
1533 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1534 p, d6, d5, d4, d3, d2, d1, data));
1535 FSHOW((stderr, "/MOV 0x%.8x,reg32\n", data));
1537 /* the case of MOV reg32,m32 */
1541 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1542 p, d6, d5, d4, d3, d2, d1, data));
1543 FSHOW((stderr, "/MOV reg32,0x%.8x\n", data));
1545 /* the case of LEA reg32,m32 */
1549 "abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1550 p, d6, d5, d4, d3, d2, d1, data));
1551 FSHOW((stderr, "/LEA reg32,0x%.8x\n", data));
1557 /* If anything was found, print some information on the code
1561 "/compiled code object at %x: header words = %d, code words = %d\n",
1562 code, nheader_words, ncode_words));
1564 "/const start = %x, end = %x\n",
1565 constants_start_addr, constants_end_addr));
1567 "/code start = %x, end = %x\n",
1568 code_start_addr, code_end_addr));
1573 gencgc_apply_code_fixups(struct code *old_code, struct code *new_code)
1575 long nheader_words, ncode_words, nwords;
1576 void *constants_start_addr, *constants_end_addr;
1577 void *code_start_addr, *code_end_addr;
1578 lispobj fixups = NIL;
1579 unsigned displacement = (unsigned)new_code - (unsigned)old_code;
1580 struct vector *fixups_vector;
1582 ncode_words = fixnum_value(new_code->code_size);
1583 nheader_words = HeaderValue(*(lispobj *)new_code);
1584 nwords = ncode_words + nheader_words;
1586 "/compiled code object at %x: header words = %d, code words = %d\n",
1587 new_code, nheader_words, ncode_words)); */
1588 constants_start_addr = (void *)new_code + 5*N_WORD_BYTES;
1589 constants_end_addr = (void *)new_code + nheader_words*N_WORD_BYTES;
1590 code_start_addr = (void *)new_code + nheader_words*N_WORD_BYTES;
1591 code_end_addr = (void *)new_code + nwords*N_WORD_BYTES;
1594 "/const start = %x, end = %x\n",
1595 constants_start_addr,constants_end_addr));
1597 "/code start = %x; end = %x\n",
1598 code_start_addr,code_end_addr));
1601 /* The first constant should be a pointer to the fixups for this
1602 code objects. Check. */
1603 fixups = new_code->constants[0];
1605 /* It will be 0 or the unbound-marker if there are no fixups (as
1606 * will be the case if the code object has been purified, for
1607 * example) and will be an other pointer if it is valid. */
1608 if ((fixups == 0) || (fixups == UNBOUND_MARKER_WIDETAG) ||
1609 !is_lisp_pointer(fixups)) {
1610 /* Check for possible errors. */
1611 if (check_code_fixups)
1612 sniff_code_object(new_code, displacement);
1617 fixups_vector = (struct vector *)native_pointer(fixups);
1619 /* Could be pointing to a forwarding pointer. */
1620 /* FIXME is this always in from_space? if so, could replace this code with
1621 * forwarding_pointer_p/forwarding_pointer_value */
1622 if (is_lisp_pointer(fixups) &&
1623 (find_page_index((void*)fixups_vector) != -1) &&
1624 (fixups_vector->header == 0x01)) {
1625 /* If so, then follow it. */
1626 /*SHOW("following pointer to a forwarding pointer");*/
1627 fixups_vector = (struct vector *)native_pointer((lispobj)fixups_vector->length);
1630 /*SHOW("got fixups");*/
1632 if (widetag_of(fixups_vector->header) == SIMPLE_ARRAY_WORD_WIDETAG) {
1633 /* Got the fixups for the code block. Now work through the vector,
1634 and apply a fixup at each address. */
1635 long length = fixnum_value(fixups_vector->length);
1637 for (i = 0; i < length; i++) {
1638 unsigned offset = fixups_vector->data[i];
1639 /* Now check the current value of offset. */
1640 unsigned old_value =
1641 *(unsigned *)((unsigned)code_start_addr + offset);
1643 /* If it's within the old_code object then it must be an
1644 * absolute fixup (relative ones are not saved) */
1645 if ((old_value >= (unsigned)old_code)
1646 && (old_value < ((unsigned)old_code + nwords*N_WORD_BYTES)))
1647 /* So add the dispacement. */
1648 *(unsigned *)((unsigned)code_start_addr + offset) =
1649 old_value + displacement;
1651 /* It is outside the old code object so it must be a
1652 * relative fixup (absolute fixups are not saved). So
1653 * subtract the displacement. */
1654 *(unsigned *)((unsigned)code_start_addr + offset) =
1655 old_value - displacement;
1658 fprintf(stderr, "widetag of fixup vector is %d\n", widetag_of(fixups_vector->header));
1661 /* Check for possible errors. */
1662 if (check_code_fixups) {
1663 sniff_code_object(new_code,displacement);
1669 trans_boxed_large(lispobj object)
1672 unsigned long length;
1674 gc_assert(is_lisp_pointer(object));
1676 header = *((lispobj *) native_pointer(object));
1677 length = HeaderValue(header) + 1;
1678 length = CEILING(length, 2);
1680 return copy_large_object(object, length);
1685 trans_unboxed_large(lispobj object)
1688 unsigned long length;
1691 gc_assert(is_lisp_pointer(object));
1693 header = *((lispobj *) native_pointer(object));
1694 length = HeaderValue(header) + 1;
1695 length = CEILING(length, 2);
1697 return copy_large_unboxed_object(object, length);
1702 * vector-like objects
1706 /* FIXME: What does this mean? */
1707 int gencgc_hash = 1;
1710 scav_vector(lispobj *where, lispobj object)
1712 unsigned long kv_length;
1714 unsigned long length = 0; /* (0 = dummy to stop GCC warning) */
1715 lispobj *hash_table;
1716 lispobj empty_symbol;
1717 unsigned long *index_vector = NULL; /* (NULL = dummy to stop GCC warning) */
1718 unsigned long *next_vector = NULL; /* (NULL = dummy to stop GCC warning) */
1719 unsigned long *hash_vector = NULL; /* (NULL = dummy to stop GCC warning) */
1721 unsigned next_vector_length = 0;
1723 /* FIXME: A comment explaining this would be nice. It looks as
1724 * though SB-VM:VECTOR-VALID-HASHING-SUBTYPE is set for EQ-based
1725 * hash tables in the Lisp HASH-TABLE code, and nowhere else. */
1726 if (HeaderValue(object) != subtype_VectorValidHashing)
1730 /* This is set for backward compatibility. FIXME: Do we need
1733 (subtype_VectorMustRehash<<N_WIDETAG_BITS) | SIMPLE_VECTOR_WIDETAG;
1737 kv_length = fixnum_value(where[1]);
1738 kv_vector = where + 2; /* Skip the header and length. */
1739 /*FSHOW((stderr,"/kv_length = %d\n", kv_length));*/
1741 /* Scavenge element 0, which may be a hash-table structure. */
1742 scavenge(where+2, 1);
1743 if (!is_lisp_pointer(where[2])) {
1744 lose("no pointer at %x in hash table", where[2]);
1746 hash_table = (lispobj *)native_pointer(where[2]);
1747 /*FSHOW((stderr,"/hash_table = %x\n", hash_table));*/
1748 if (widetag_of(hash_table[0]) != INSTANCE_HEADER_WIDETAG) {
1749 lose("hash table not instance (%x at %x)", hash_table[0], hash_table);
1752 /* Scavenge element 1, which should be some internal symbol that
1753 * the hash table code reserves for marking empty slots. */
1754 scavenge(where+3, 1);
1755 if (!is_lisp_pointer(where[3])) {
1756 lose("not empty-hash-table-slot symbol pointer: %x", where[3]);
1758 empty_symbol = where[3];
1759 /* fprintf(stderr,"* empty_symbol = %x\n", empty_symbol);*/
1760 if (widetag_of(*(lispobj *)native_pointer(empty_symbol)) !=
1761 SYMBOL_HEADER_WIDETAG) {
1762 lose("not a symbol where empty-hash-table-slot symbol expected: %x",
1763 *(lispobj *)native_pointer(empty_symbol));
1766 /* Scavenge hash table, which will fix the positions of the other
1767 * needed objects. */
1768 scavenge(hash_table, 16);
1770 /* Cross-check the kv_vector. */
1771 if (where != (lispobj *)native_pointer(hash_table[9])) {
1772 lose("hash_table table!=this table %x", hash_table[9]);
1776 weak_p_obj = hash_table[10];
1780 lispobj index_vector_obj = hash_table[13];
1782 if (is_lisp_pointer(index_vector_obj) &&
1783 (widetag_of(*(lispobj *)native_pointer(index_vector_obj)) ==
1784 SIMPLE_ARRAY_WORD_WIDETAG)) {
1785 index_vector = ((lispobj *)native_pointer(index_vector_obj)) + 2;
1786 /*FSHOW((stderr, "/index_vector = %x\n",index_vector));*/
1787 length = fixnum_value(((lispobj *)native_pointer(index_vector_obj))[1]);
1788 /*FSHOW((stderr, "/length = %d\n", length));*/
1790 lose("invalid index_vector %x", index_vector_obj);
1796 lispobj next_vector_obj = hash_table[14];
1798 if (is_lisp_pointer(next_vector_obj) &&
1799 (widetag_of(*(lispobj *)native_pointer(next_vector_obj)) ==
1800 SIMPLE_ARRAY_WORD_WIDETAG)) {
1801 next_vector = ((lispobj *)native_pointer(next_vector_obj)) + 2;
1802 /*FSHOW((stderr, "/next_vector = %x\n", next_vector));*/
1803 next_vector_length = fixnum_value(((lispobj *)native_pointer(next_vector_obj))[1]);
1804 /*FSHOW((stderr, "/next_vector_length = %d\n", next_vector_length));*/
1806 lose("invalid next_vector %x", next_vector_obj);
1810 /* maybe hash vector */
1812 /* FIXME: This bare "15" offset should become a symbolic
1813 * expression of some sort. And all the other bare offsets
1814 * too. And the bare "16" in scavenge(hash_table, 16). And
1815 * probably other stuff too. Ugh.. */
1816 lispobj hash_vector_obj = hash_table[15];
1818 if (is_lisp_pointer(hash_vector_obj) &&
1819 (widetag_of(*(lispobj *)native_pointer(hash_vector_obj)) ==
1820 SIMPLE_ARRAY_WORD_WIDETAG)){
1821 hash_vector = ((lispobj *)native_pointer(hash_vector_obj)) + 2;
1822 /*FSHOW((stderr, "/hash_vector = %x\n", hash_vector));*/
1823 gc_assert(fixnum_value(((lispobj *)native_pointer(hash_vector_obj))[1])
1824 == next_vector_length);
1827 /*FSHOW((stderr, "/no hash_vector: %x\n", hash_vector_obj));*/
1831 /* These lengths could be different as the index_vector can be a
1832 * different length from the others, a larger index_vector could help
1833 * reduce collisions. */
1834 gc_assert(next_vector_length*2 == kv_length);
1836 /* now all set up.. */
1838 /* Work through the KV vector. */
1841 for (i = 1; i < next_vector_length; i++) {
1842 lispobj old_key = kv_vector[2*i];
1844 #if N_WORD_BITS == 32
1845 unsigned long old_index = (old_key & 0x1fffffff)%length;
1846 #elif N_WORD_BITS == 64
1847 unsigned long old_index = (old_key & 0x1fffffffffffffff)%length;
1850 /* Scavenge the key and value. */
1851 scavenge(&kv_vector[2*i],2);
1853 /* Check whether the key has moved and is EQ based. */
1855 lispobj new_key = kv_vector[2*i];
1856 #if N_WORD_BITS == 32
1857 unsigned long new_index = (new_key & 0x1fffffff)%length;
1858 #elif N_WORD_BITS == 64
1859 unsigned long new_index = (new_key & 0x1fffffffffffffff)%length;
1862 if ((old_index != new_index) &&
1863 ((!hash_vector) || (hash_vector[i] == 0x80000000)) &&
1864 ((new_key != empty_symbol) ||
1865 (kv_vector[2*i] != empty_symbol))) {
1868 "* EQ key %d moved from %x to %x; index %d to %d\n",
1869 i, old_key, new_key, old_index, new_index));*/
1871 if (index_vector[old_index] != 0) {
1872 /*FSHOW((stderr, "/P1 %d\n", index_vector[old_index]));*/
1874 /* Unlink the key from the old_index chain. */
1875 if (index_vector[old_index] == i) {
1876 /*FSHOW((stderr, "/P2a %d\n", next_vector[i]));*/
1877 index_vector[old_index] = next_vector[i];
1878 /* Link it into the needing rehash chain. */
1879 next_vector[i] = fixnum_value(hash_table[11]);
1880 hash_table[11] = make_fixnum(i);
1883 unsigned prior = index_vector[old_index];
1884 unsigned next = next_vector[prior];
1886 /*FSHOW((stderr, "/P3a %d %d\n", prior, next));*/
1889 /*FSHOW((stderr, "/P3b %d %d\n", prior, next));*/
1892 next_vector[prior] = next_vector[next];
1893 /* Link it into the needing rehash
1896 fixnum_value(hash_table[11]);
1897 hash_table[11] = make_fixnum(next);
1902 next = next_vector[next];
1910 return (CEILING(kv_length + 2, 2));
1919 /* XX This is a hack adapted from cgc.c. These don't work too
1920 * efficiently with the gencgc as a list of the weak pointers is
1921 * maintained within the objects which causes writes to the pages. A
1922 * limited attempt is made to avoid unnecessary writes, but this needs
1924 #define WEAK_POINTER_NWORDS \
1925 CEILING((sizeof(struct weak_pointer) / sizeof(lispobj)), 2)
1928 scav_weak_pointer(lispobj *where, lispobj object)
1930 struct weak_pointer *wp = weak_pointers;
1931 /* Push the weak pointer onto the list of weak pointers.
1932 * Do I have to watch for duplicates? Originally this was
1933 * part of trans_weak_pointer but that didn't work in the
1934 * case where the WP was in a promoted region.
1937 /* Check whether it's already in the list. */
1938 while (wp != NULL) {
1939 if (wp == (struct weak_pointer*)where) {
1945 /* Add it to the start of the list. */
1946 wp = (struct weak_pointer*)where;
1947 if (wp->next != weak_pointers) {
1948 wp->next = weak_pointers;
1950 /*SHOW("avoided write to weak pointer");*/
1955 /* Do not let GC scavenge the value slot of the weak pointer.
1956 * (That is why it is a weak pointer.) */
1958 return WEAK_POINTER_NWORDS;
1963 search_read_only_space(void *pointer)
1965 lispobj *start = (lispobj *) READ_ONLY_SPACE_START;
1966 lispobj *end = (lispobj *) SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0);
1967 if ((pointer < (void *)start) || (pointer >= (void *)end))
1969 return (gc_search_space(start,
1970 (((lispobj *)pointer)+2)-start,
1971 (lispobj *) pointer));
1975 search_static_space(void *pointer)
1977 lispobj *start = (lispobj *)STATIC_SPACE_START;
1978 lispobj *end = (lispobj *)SymbolValue(STATIC_SPACE_FREE_POINTER,0);
1979 if ((pointer < (void *)start) || (pointer >= (void *)end))
1981 return (gc_search_space(start,
1982 (((lispobj *)pointer)+2)-start,
1983 (lispobj *) pointer));
1986 /* a faster version for searching the dynamic space. This will work even
1987 * if the object is in a current allocation region. */
1989 search_dynamic_space(void *pointer)
1991 long page_index = find_page_index(pointer);
1994 /* The address may be invalid, so do some checks. */
1995 if ((page_index == -1) ||
1996 (page_table[page_index].allocated == FREE_PAGE_FLAG))
1998 start = (lispobj *)((void *)page_address(page_index)
1999 + page_table[page_index].first_object_offset);
2000 return (gc_search_space(start,
2001 (((lispobj *)pointer)+2)-start,
2002 (lispobj *)pointer));
2005 /* Is there any possibility that pointer is a valid Lisp object
2006 * reference, and/or something else (e.g. subroutine call return
2007 * address) which should prevent us from moving the referred-to thing?
2008 * This is called from preserve_pointers() */
2010 possibly_valid_dynamic_space_pointer(lispobj *pointer)
2012 lispobj *start_addr;
2014 /* Find the object start address. */
2015 if ((start_addr = search_dynamic_space(pointer)) == NULL) {
2019 /* We need to allow raw pointers into Code objects for return
2020 * addresses. This will also pick up pointers to functions in code
2022 if (widetag_of(*start_addr) == CODE_HEADER_WIDETAG) {
2023 /* XXX could do some further checks here */
2027 /* If it's not a return address then it needs to be a valid Lisp
2029 if (!is_lisp_pointer((lispobj)pointer)) {
2033 /* Check that the object pointed to is consistent with the pointer
2036 switch (lowtag_of((lispobj)pointer)) {
2037 case FUN_POINTER_LOWTAG:
2038 /* Start_addr should be the enclosing code object, or a closure
2040 switch (widetag_of(*start_addr)) {
2041 case CODE_HEADER_WIDETAG:
2042 /* This case is probably caught above. */
2044 case CLOSURE_HEADER_WIDETAG:
2045 case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
2046 if ((unsigned)pointer !=
2047 ((unsigned)start_addr+FUN_POINTER_LOWTAG)) {
2051 pointer, start_addr, *start_addr));
2059 pointer, start_addr, *start_addr));
2063 case LIST_POINTER_LOWTAG:
2064 if ((unsigned)pointer !=
2065 ((unsigned)start_addr+LIST_POINTER_LOWTAG)) {
2069 pointer, start_addr, *start_addr));
2072 /* Is it plausible cons? */
2073 if ((is_lisp_pointer(start_addr[0])
2074 || (fixnump(start_addr[0]))
2075 || (widetag_of(start_addr[0]) == CHARACTER_WIDETAG)
2076 #if N_WORD_BITS == 64
2077 || (widetag_of(start_addr[0]) == SINGLE_FLOAT_WIDETAG)
2079 || (widetag_of(start_addr[0]) == UNBOUND_MARKER_WIDETAG))
2080 && (is_lisp_pointer(start_addr[1])
2081 || (fixnump(start_addr[1]))
2082 || (widetag_of(start_addr[1]) == CHARACTER_WIDETAG)
2083 #if N_WORD_BITS == 64
2084 || (widetag_of(start_addr[1]) == SINGLE_FLOAT_WIDETAG)
2086 || (widetag_of(start_addr[1]) == UNBOUND_MARKER_WIDETAG)))
2092 pointer, start_addr, *start_addr));
2095 case INSTANCE_POINTER_LOWTAG:
2096 if ((unsigned)pointer !=
2097 ((unsigned)start_addr+INSTANCE_POINTER_LOWTAG)) {
2101 pointer, start_addr, *start_addr));
2104 if (widetag_of(start_addr[0]) != INSTANCE_HEADER_WIDETAG) {
2108 pointer, start_addr, *start_addr));
2112 case OTHER_POINTER_LOWTAG:
2113 if ((unsigned)pointer !=
2114 ((int)start_addr+OTHER_POINTER_LOWTAG)) {
2118 pointer, start_addr, *start_addr));
2121 /* Is it plausible? Not a cons. XXX should check the headers. */
2122 if (is_lisp_pointer(start_addr[0]) || ((start_addr[0] & 3) == 0)) {
2126 pointer, start_addr, *start_addr));
2129 switch (widetag_of(start_addr[0])) {
2130 case UNBOUND_MARKER_WIDETAG:
2131 case CHARACTER_WIDETAG:
2132 #if N_WORD_BITS == 64
2133 case SINGLE_FLOAT_WIDETAG:
2138 pointer, start_addr, *start_addr));
2141 /* only pointed to by function pointers? */
2142 case CLOSURE_HEADER_WIDETAG:
2143 case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
2147 pointer, start_addr, *start_addr));
2150 case INSTANCE_HEADER_WIDETAG:
2154 pointer, start_addr, *start_addr));
2157 /* the valid other immediate pointer objects */
2158 case SIMPLE_VECTOR_WIDETAG:
2160 case COMPLEX_WIDETAG:
2161 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
2162 case COMPLEX_SINGLE_FLOAT_WIDETAG:
2164 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
2165 case COMPLEX_DOUBLE_FLOAT_WIDETAG:
2167 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
2168 case COMPLEX_LONG_FLOAT_WIDETAG:
2170 case SIMPLE_ARRAY_WIDETAG:
2171 case COMPLEX_BASE_STRING_WIDETAG:
2172 #ifdef COMPLEX_CHARACTER_STRING_WIDETAG
2173 case COMPLEX_CHARACTER_STRING_WIDETAG:
2175 case COMPLEX_VECTOR_NIL_WIDETAG:
2176 case COMPLEX_BIT_VECTOR_WIDETAG:
2177 case COMPLEX_VECTOR_WIDETAG:
2178 case COMPLEX_ARRAY_WIDETAG:
2179 case VALUE_CELL_HEADER_WIDETAG:
2180 case SYMBOL_HEADER_WIDETAG:
2182 case CODE_HEADER_WIDETAG:
2183 case BIGNUM_WIDETAG:
2184 #if N_WORD_BITS != 64
2185 case SINGLE_FLOAT_WIDETAG:
2187 case DOUBLE_FLOAT_WIDETAG:
2188 #ifdef LONG_FLOAT_WIDETAG
2189 case LONG_FLOAT_WIDETAG:
2191 case SIMPLE_BASE_STRING_WIDETAG:
2192 #ifdef SIMPLE_CHARACTER_STRING_WIDETAG
2193 case SIMPLE_CHARACTER_STRING_WIDETAG:
2195 case SIMPLE_BIT_VECTOR_WIDETAG:
2196 case SIMPLE_ARRAY_NIL_WIDETAG:
2197 case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
2198 case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
2199 case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
2200 case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
2201 case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
2202 case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
2203 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
2204 case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
2206 case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
2207 case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
2208 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
2209 case SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG:
2211 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
2212 case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG:
2214 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
2215 case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG:
2217 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
2218 case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
2220 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
2221 case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
2223 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
2224 case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
2226 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
2227 case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
2229 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
2230 case SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG:
2232 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
2233 case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG:
2235 case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
2236 case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
2237 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
2238 case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
2240 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
2241 case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
2243 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
2244 case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
2246 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
2247 case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
2250 case WEAK_POINTER_WIDETAG:
2257 pointer, start_addr, *start_addr));
2265 pointer, start_addr, *start_addr));
2273 /* Adjust large bignum and vector objects. This will adjust the
2274 * allocated region if the size has shrunk, and move unboxed objects
2275 * into unboxed pages. The pages are not promoted here, and the
2276 * promoted region is not added to the new_regions; this is really
2277 * only designed to be called from preserve_pointer(). Shouldn't fail
2278 * if this is missed, just may delay the moving of objects to unboxed
2279 * pages, and the freeing of pages. */
2281 maybe_adjust_large_object(lispobj *where)
2286 long remaining_bytes;
2289 long old_bytes_used;
2293 /* Check whether it's a vector or bignum object. */
2294 switch (widetag_of(where[0])) {
2295 case SIMPLE_VECTOR_WIDETAG:
2296 boxed = BOXED_PAGE_FLAG;
2298 case BIGNUM_WIDETAG:
2299 case SIMPLE_BASE_STRING_WIDETAG:
2300 #ifdef SIMPLE_CHARACTER_STRING_WIDETAG
2301 case SIMPLE_CHARACTER_STRING_WIDETAG:
2303 case SIMPLE_BIT_VECTOR_WIDETAG:
2304 case SIMPLE_ARRAY_NIL_WIDETAG:
2305 case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
2306 case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
2307 case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
2308 case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
2309 case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
2310 case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
2311 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
2312 case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
2314 case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
2315 case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
2316 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
2317 case SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG:
2319 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
2320 case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG:
2322 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
2323 case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG:
2325 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
2326 case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
2328 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
2329 case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
2331 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
2332 case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
2334 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
2335 case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
2337 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
2338 case SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG:
2340 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
2341 case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG:
2343 case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
2344 case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
2345 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
2346 case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
2348 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
2349 case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
2351 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
2352 case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
2354 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
2355 case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
2357 boxed = UNBOXED_PAGE_FLAG;
2363 /* Find its current size. */
2364 nwords = (sizetab[widetag_of(where[0])])(where);
2366 first_page = find_page_index((void *)where);
2367 gc_assert(first_page >= 0);
2369 /* Note: Any page write-protection must be removed, else a later
2370 * scavenge_newspace may incorrectly not scavenge these pages.
2371 * This would not be necessary if they are added to the new areas,
2372 * but lets do it for them all (they'll probably be written
2375 gc_assert(page_table[first_page].first_object_offset == 0);
2377 next_page = first_page;
2378 remaining_bytes = nwords*N_WORD_BYTES;
2379 while (remaining_bytes > PAGE_BYTES) {
2380 gc_assert(page_table[next_page].gen == from_space);
2381 gc_assert((page_table[next_page].allocated == BOXED_PAGE_FLAG)
2382 || (page_table[next_page].allocated == UNBOXED_PAGE_FLAG));
2383 gc_assert(page_table[next_page].large_object);
2384 gc_assert(page_table[next_page].first_object_offset ==
2385 -PAGE_BYTES*(next_page-first_page));
2386 gc_assert(page_table[next_page].bytes_used == PAGE_BYTES);
2388 page_table[next_page].allocated = boxed;
2390 /* Shouldn't be write-protected at this stage. Essential that the
2392 gc_assert(!page_table[next_page].write_protected);
2393 remaining_bytes -= PAGE_BYTES;
2397 /* Now only one page remains, but the object may have shrunk so
2398 * there may be more unused pages which will be freed. */
2400 /* Object may have shrunk but shouldn't have grown - check. */
2401 gc_assert(page_table[next_page].bytes_used >= remaining_bytes);
2403 page_table[next_page].allocated = boxed;
2404 gc_assert(page_table[next_page].allocated ==
2405 page_table[first_page].allocated);
2407 /* Adjust the bytes_used. */
2408 old_bytes_used = page_table[next_page].bytes_used;
2409 page_table[next_page].bytes_used = remaining_bytes;
2411 bytes_freed = old_bytes_used - remaining_bytes;
2413 /* Free any remaining pages; needs care. */
2415 while ((old_bytes_used == PAGE_BYTES) &&
2416 (page_table[next_page].gen == from_space) &&
2417 ((page_table[next_page].allocated == UNBOXED_PAGE_FLAG)
2418 || (page_table[next_page].allocated == BOXED_PAGE_FLAG)) &&
2419 page_table[next_page].large_object &&
2420 (page_table[next_page].first_object_offset ==
2421 -(next_page - first_page)*PAGE_BYTES)) {
2422 /* It checks out OK, free the page. We don't need to both zeroing
2423 * pages as this should have been done before shrinking the
2424 * object. These pages shouldn't be write protected as they
2425 * should be zero filled. */
2426 gc_assert(page_table[next_page].write_protected == 0);
2428 old_bytes_used = page_table[next_page].bytes_used;
2429 page_table[next_page].allocated = FREE_PAGE_FLAG;
2430 page_table[next_page].bytes_used = 0;
2431 bytes_freed += old_bytes_used;
2435 if ((bytes_freed > 0) && gencgc_verbose) {
2437 "/maybe_adjust_large_object() freed %d\n",
2441 generations[from_space].bytes_allocated -= bytes_freed;
2442 bytes_allocated -= bytes_freed;
2447 /* Take a possible pointer to a Lisp object and mark its page in the
2448 * page_table so that it will not be relocated during a GC.
2450 * This involves locating the page it points to, then backing up to
2451 * the start of its region, then marking all pages dont_move from there
2452 * up to the first page that's not full or has a different generation
2454 * It is assumed that all the page static flags have been cleared at
2455 * the start of a GC.
2457 * It is also assumed that the current gc_alloc() region has been
2458 * flushed and the tables updated. */
2460 preserve_pointer(void *addr)
2462 long addr_page_index = find_page_index(addr);
2465 unsigned region_allocation;
2467 /* quick check 1: Address is quite likely to have been invalid. */
2468 if ((addr_page_index == -1)
2469 || (page_table[addr_page_index].allocated == FREE_PAGE_FLAG)
2470 || (page_table[addr_page_index].bytes_used == 0)
2471 || (page_table[addr_page_index].gen != from_space)
2472 /* Skip if already marked dont_move. */
2473 || (page_table[addr_page_index].dont_move != 0))
2475 gc_assert(!(page_table[addr_page_index].allocated&OPEN_REGION_PAGE_FLAG));
2476 /* (Now that we know that addr_page_index is in range, it's
2477 * safe to index into page_table[] with it.) */
2478 region_allocation = page_table[addr_page_index].allocated;
2480 /* quick check 2: Check the offset within the page.
2483 if (((unsigned)addr & (PAGE_BYTES - 1)) > page_table[addr_page_index].bytes_used)
2486 /* Filter out anything which can't be a pointer to a Lisp object
2487 * (or, as a special case which also requires dont_move, a return
2488 * address referring to something in a CodeObject). This is
2489 * expensive but important, since it vastly reduces the
2490 * probability that random garbage will be bogusly interpreted as
2491 * a pointer which prevents a page from moving. */
2492 if (!(possibly_valid_dynamic_space_pointer(addr)))
2495 /* Find the beginning of the region. Note that there may be
2496 * objects in the region preceding the one that we were passed a
2497 * pointer to: if this is the case, we will write-protect all the
2498 * previous objects' pages too. */
2501 /* I think this'd work just as well, but without the assertions.
2502 * -dan 2004.01.01 */
2504 find_page_index(page_address(addr_page_index)+
2505 page_table[addr_page_index].first_object_offset);
2507 first_page = addr_page_index;
2508 while (page_table[first_page].first_object_offset != 0) {
2510 /* Do some checks. */
2511 gc_assert(page_table[first_page].bytes_used == PAGE_BYTES);
2512 gc_assert(page_table[first_page].gen == from_space);
2513 gc_assert(page_table[first_page].allocated == region_allocation);
2517 /* Adjust any large objects before promotion as they won't be
2518 * copied after promotion. */
2519 if (page_table[first_page].large_object) {
2520 maybe_adjust_large_object(page_address(first_page));
2521 /* If a large object has shrunk then addr may now point to a
2522 * free area in which case it's ignored here. Note it gets
2523 * through the valid pointer test above because the tail looks
2525 if ((page_table[addr_page_index].allocated == FREE_PAGE_FLAG)
2526 || (page_table[addr_page_index].bytes_used == 0)
2527 /* Check the offset within the page. */
2528 || (((unsigned)addr & (PAGE_BYTES - 1))
2529 > page_table[addr_page_index].bytes_used)) {
2531 "weird? ignore ptr 0x%x to freed area of large object\n",
2535 /* It may have moved to unboxed pages. */
2536 region_allocation = page_table[first_page].allocated;
2539 /* Now work forward until the end of this contiguous area is found,
2540 * marking all pages as dont_move. */
2541 for (i = first_page; ;i++) {
2542 gc_assert(page_table[i].allocated == region_allocation);
2544 /* Mark the page static. */
2545 page_table[i].dont_move = 1;
2547 /* Move the page to the new_space. XX I'd rather not do this
2548 * but the GC logic is not quite able to copy with the static
2549 * pages remaining in the from space. This also requires the
2550 * generation bytes_allocated counters be updated. */
2551 page_table[i].gen = new_space;
2552 generations[new_space].bytes_allocated += page_table[i].bytes_used;
2553 generations[from_space].bytes_allocated -= page_table[i].bytes_used;
2555 /* It is essential that the pages are not write protected as
2556 * they may have pointers into the old-space which need
2557 * scavenging. They shouldn't be write protected at this
2559 gc_assert(!page_table[i].write_protected);
2561 /* Check whether this is the last page in this contiguous block.. */
2562 if ((page_table[i].bytes_used < PAGE_BYTES)
2563 /* ..or it is PAGE_BYTES and is the last in the block */
2564 || (page_table[i+1].allocated == FREE_PAGE_FLAG)
2565 || (page_table[i+1].bytes_used == 0) /* next page free */
2566 || (page_table[i+1].gen != from_space) /* diff. gen */
2567 || (page_table[i+1].first_object_offset == 0))
2571 /* Check that the page is now static. */
2572 gc_assert(page_table[addr_page_index].dont_move != 0);
2575 /* If the given page is not write-protected, then scan it for pointers
2576 * to younger generations or the top temp. generation, if no
2577 * suspicious pointers are found then the page is write-protected.
2579 * Care is taken to check for pointers to the current gc_alloc()
2580 * region if it is a younger generation or the temp. generation. This
2581 * frees the caller from doing a gc_alloc_update_page_tables(). Actually
2582 * the gc_alloc_generation does not need to be checked as this is only
2583 * called from scavenge_generation() when the gc_alloc generation is
2584 * younger, so it just checks if there is a pointer to the current
2587 * We return 1 if the page was write-protected, else 0. */
2589 update_page_write_prot(long page)
2591 int gen = page_table[page].gen;
2594 void **page_addr = (void **)page_address(page);
2595 long num_words = page_table[page].bytes_used / N_WORD_BYTES;
2597 /* Shouldn't be a free page. */
2598 gc_assert(page_table[page].allocated != FREE_PAGE_FLAG);
2599 gc_assert(page_table[page].bytes_used != 0);
2601 /* Skip if it's already write-protected, pinned, or unboxed */
2602 if (page_table[page].write_protected
2603 || page_table[page].dont_move
2604 || (page_table[page].allocated & UNBOXED_PAGE_FLAG))
2607 /* Scan the page for pointers to younger generations or the
2608 * top temp. generation. */
2610 for (j = 0; j < num_words; j++) {
2611 void *ptr = *(page_addr+j);
2612 long index = find_page_index(ptr);
2614 /* Check that it's in the dynamic space */
2616 if (/* Does it point to a younger or the temp. generation? */
2617 ((page_table[index].allocated != FREE_PAGE_FLAG)
2618 && (page_table[index].bytes_used != 0)
2619 && ((page_table[index].gen < gen)
2620 || (page_table[index].gen == NUM_GENERATIONS)))
2622 /* Or does it point within a current gc_alloc() region? */
2623 || ((boxed_region.start_addr <= ptr)
2624 && (ptr <= boxed_region.free_pointer))
2625 || ((unboxed_region.start_addr <= ptr)
2626 && (ptr <= unboxed_region.free_pointer))) {
2633 /* Write-protect the page. */
2634 /*FSHOW((stderr, "/write-protecting page %d gen %d\n", page, gen));*/
2636 os_protect((void *)page_addr,
2638 OS_VM_PROT_READ|OS_VM_PROT_EXECUTE);
2640 /* Note the page as protected in the page tables. */
2641 page_table[page].write_protected = 1;
2647 /* Scavenge a generation.
2649 * This will not resolve all pointers when generation is the new
2650 * space, as new objects may be added which are not checked here - use
2651 * scavenge_newspace generation.
2653 * Write-protected pages should not have any pointers to the
2654 * from_space so do need scavenging; thus write-protected pages are
2655 * not always scavenged. There is some code to check that these pages
2656 * are not written; but to check fully the write-protected pages need
2657 * to be scavenged by disabling the code to skip them.
2659 * Under the current scheme when a generation is GCed the younger
2660 * generations will be empty. So, when a generation is being GCed it
2661 * is only necessary to scavenge the older generations for pointers
2662 * not the younger. So a page that does not have pointers to younger
2663 * generations does not need to be scavenged.
2665 * The write-protection can be used to note pages that don't have
2666 * pointers to younger pages. But pages can be written without having
2667 * pointers to younger generations. After the pages are scavenged here
2668 * they can be scanned for pointers to younger generations and if
2669 * there are none the page can be write-protected.
2671 * One complication is when the newspace is the top temp. generation.
2673 * Enabling SC_GEN_CK scavenges the write-protected pages and checks
2674 * that none were written, which they shouldn't be as they should have
2675 * no pointers to younger generations. This breaks down for weak
2676 * pointers as the objects contain a link to the next and are written
2677 * if a weak pointer is scavenged. Still it's a useful check. */
2679 scavenge_generation(int generation)
2686 /* Clear the write_protected_cleared flags on all pages. */
2687 for (i = 0; i < NUM_PAGES; i++)
2688 page_table[i].write_protected_cleared = 0;
2691 for (i = 0; i < last_free_page; i++) {
2692 if ((page_table[i].allocated & BOXED_PAGE_FLAG)
2693 && (page_table[i].bytes_used != 0)
2694 && (page_table[i].gen == generation)) {
2696 int write_protected=1;
2698 /* This should be the start of a region */
2699 gc_assert(page_table[i].first_object_offset == 0);
2701 /* Now work forward until the end of the region */
2702 for (last_page = i; ; last_page++) {
2704 write_protected && page_table[last_page].write_protected;
2705 if ((page_table[last_page].bytes_used < PAGE_BYTES)
2706 /* Or it is PAGE_BYTES and is the last in the block */
2707 || (!(page_table[last_page+1].allocated & BOXED_PAGE_FLAG))
2708 || (page_table[last_page+1].bytes_used == 0)
2709 || (page_table[last_page+1].gen != generation)
2710 || (page_table[last_page+1].first_object_offset == 0))
2713 if (!write_protected) {
2714 scavenge(page_address(i),
2715 (page_table[last_page].bytes_used +
2716 (last_page-i)*PAGE_BYTES)/N_WORD_BYTES);
2718 /* Now scan the pages and write protect those that
2719 * don't have pointers to younger generations. */
2720 if (enable_page_protection) {
2721 for (j = i; j <= last_page; j++) {
2722 num_wp += update_page_write_prot(j);
2729 if ((gencgc_verbose > 1) && (num_wp != 0)) {
2731 "/write protected %d pages within generation %d\n",
2732 num_wp, generation));
2736 /* Check that none of the write_protected pages in this generation
2737 * have been written to. */
2738 for (i = 0; i < NUM_PAGES; i++) {
2739 if ((page_table[i].allocation != FREE_PAGE_FLAG)
2740 && (page_table[i].bytes_used != 0)
2741 && (page_table[i].gen == generation)
2742 && (page_table[i].write_protected_cleared != 0)) {
2743 FSHOW((stderr, "/scavenge_generation() %d\n", generation));
2745 "/page bytes_used=%d first_object_offset=%d dont_move=%d\n",
2746 page_table[i].bytes_used,
2747 page_table[i].first_object_offset,
2748 page_table[i].dont_move));
2749 lose("write to protected page %d in scavenge_generation()", i);
2756 /* Scavenge a newspace generation. As it is scavenged new objects may
2757 * be allocated to it; these will also need to be scavenged. This
2758 * repeats until there are no more objects unscavenged in the
2759 * newspace generation.
2761 * To help improve the efficiency, areas written are recorded by
2762 * gc_alloc() and only these scavenged. Sometimes a little more will be
2763 * scavenged, but this causes no harm. An easy check is done that the
2764 * scavenged bytes equals the number allocated in the previous
2767 * Write-protected pages are not scanned except if they are marked
2768 * dont_move in which case they may have been promoted and still have
2769 * pointers to the from space.
2771 * Write-protected pages could potentially be written by alloc however
2772 * to avoid having to handle re-scavenging of write-protected pages
2773 * gc_alloc() does not write to write-protected pages.
2775 * New areas of objects allocated are recorded alternatively in the two
2776 * new_areas arrays below. */
2777 static struct new_area new_areas_1[NUM_NEW_AREAS];
2778 static struct new_area new_areas_2[NUM_NEW_AREAS];
2780 /* Do one full scan of the new space generation. This is not enough to
2781 * complete the job as new objects may be added to the generation in
2782 * the process which are not scavenged. */
2784 scavenge_newspace_generation_one_scan(int generation)
2789 "/starting one full scan of newspace generation %d\n",
2791 for (i = 0; i < last_free_page; i++) {
2792 /* Note that this skips over open regions when it encounters them. */
2793 if ((page_table[i].allocated & BOXED_PAGE_FLAG)
2794 && (page_table[i].bytes_used != 0)
2795 && (page_table[i].gen == generation)
2796 && ((page_table[i].write_protected == 0)
2797 /* (This may be redundant as write_protected is now
2798 * cleared before promotion.) */
2799 || (page_table[i].dont_move == 1))) {
2803 /* The scavenge will start at the first_object_offset of page i.
2805 * We need to find the full extent of this contiguous
2806 * block in case objects span pages.
2808 * Now work forward until the end of this contiguous area
2809 * is found. A small area is preferred as there is a
2810 * better chance of its pages being write-protected. */
2811 for (last_page = i; ;last_page++) {
2812 /* If all pages are write-protected and movable,
2813 * then no need to scavenge */
2814 all_wp=all_wp && page_table[last_page].write_protected &&
2815 !page_table[last_page].dont_move;
2817 /* Check whether this is the last page in this
2818 * contiguous block */
2819 if ((page_table[last_page].bytes_used < PAGE_BYTES)
2820 /* Or it is PAGE_BYTES and is the last in the block */
2821 || (!(page_table[last_page+1].allocated & BOXED_PAGE_FLAG))
2822 || (page_table[last_page+1].bytes_used == 0)
2823 || (page_table[last_page+1].gen != generation)
2824 || (page_table[last_page+1].first_object_offset == 0))
2828 /* Do a limited check for write-protected pages. */
2832 size = (page_table[last_page].bytes_used
2833 + (last_page-i)*PAGE_BYTES
2834 - page_table[i].first_object_offset)/N_WORD_BYTES;
2835 new_areas_ignore_page = last_page;
2837 scavenge(page_address(i) +
2838 page_table[i].first_object_offset,
2846 "/done with one full scan of newspace generation %d\n",
2850 /* Do a complete scavenge of the newspace generation. */
2852 scavenge_newspace_generation(int generation)
2856 /* the new_areas array currently being written to by gc_alloc() */
2857 struct new_area (*current_new_areas)[] = &new_areas_1;
2858 long current_new_areas_index;
2860 /* the new_areas created by the previous scavenge cycle */
2861 struct new_area (*previous_new_areas)[] = NULL;
2862 long previous_new_areas_index;
2864 /* Flush the current regions updating the tables. */
2865 gc_alloc_update_all_page_tables();
2867 /* Turn on the recording of new areas by gc_alloc(). */
2868 new_areas = current_new_areas;
2869 new_areas_index = 0;
2871 /* Don't need to record new areas that get scavenged anyway during
2872 * scavenge_newspace_generation_one_scan. */
2873 record_new_objects = 1;
2875 /* Start with a full scavenge. */
2876 scavenge_newspace_generation_one_scan(generation);
2878 /* Record all new areas now. */
2879 record_new_objects = 2;
2881 /* Flush the current regions updating the tables. */
2882 gc_alloc_update_all_page_tables();
2884 /* Grab new_areas_index. */
2885 current_new_areas_index = new_areas_index;
2888 "The first scan is finished; current_new_areas_index=%d.\n",
2889 current_new_areas_index));*/
2891 while (current_new_areas_index > 0) {
2892 /* Move the current to the previous new areas */
2893 previous_new_areas = current_new_areas;
2894 previous_new_areas_index = current_new_areas_index;
2896 /* Scavenge all the areas in previous new areas. Any new areas
2897 * allocated are saved in current_new_areas. */
2899 /* Allocate an array for current_new_areas; alternating between
2900 * new_areas_1 and 2 */
2901 if (previous_new_areas == &new_areas_1)
2902 current_new_areas = &new_areas_2;
2904 current_new_areas = &new_areas_1;
2906 /* Set up for gc_alloc(). */
2907 new_areas = current_new_areas;
2908 new_areas_index = 0;
2910 /* Check whether previous_new_areas had overflowed. */
2911 if (previous_new_areas_index >= NUM_NEW_AREAS) {
2913 /* New areas of objects allocated have been lost so need to do a
2914 * full scan to be sure! If this becomes a problem try
2915 * increasing NUM_NEW_AREAS. */
2917 SHOW("new_areas overflow, doing full scavenge");
2919 /* Don't need to record new areas that get scavenge anyway
2920 * during scavenge_newspace_generation_one_scan. */
2921 record_new_objects = 1;
2923 scavenge_newspace_generation_one_scan(generation);
2925 /* Record all new areas now. */
2926 record_new_objects = 2;
2928 /* Flush the current regions updating the tables. */
2929 gc_alloc_update_all_page_tables();
2933 /* Work through previous_new_areas. */
2934 for (i = 0; i < previous_new_areas_index; i++) {
2935 long page = (*previous_new_areas)[i].page;
2936 long offset = (*previous_new_areas)[i].offset;
2937 long size = (*previous_new_areas)[i].size / N_WORD_BYTES;
2938 gc_assert((*previous_new_areas)[i].size % N_WORD_BYTES == 0);
2939 scavenge(page_address(page)+offset, size);
2942 /* Flush the current regions updating the tables. */
2943 gc_alloc_update_all_page_tables();
2946 current_new_areas_index = new_areas_index;
2949 "The re-scan has finished; current_new_areas_index=%d.\n",
2950 current_new_areas_index));*/
2953 /* Turn off recording of areas allocated by gc_alloc(). */
2954 record_new_objects = 0;
2957 /* Check that none of the write_protected pages in this generation
2958 * have been written to. */
2959 for (i = 0; i < NUM_PAGES; i++) {
2960 if ((page_table[i].allocation != FREE_PAGE_FLAG)
2961 && (page_table[i].bytes_used != 0)
2962 && (page_table[i].gen == generation)
2963 && (page_table[i].write_protected_cleared != 0)
2964 && (page_table[i].dont_move == 0)) {
2965 lose("write protected page %d written to in scavenge_newspace_generation\ngeneration=%d dont_move=%d",
2966 i, generation, page_table[i].dont_move);
2972 /* Un-write-protect all the pages in from_space. This is done at the
2973 * start of a GC else there may be many page faults while scavenging
2974 * the newspace (I've seen drive the system time to 99%). These pages
2975 * would need to be unprotected anyway before unmapping in
2976 * free_oldspace; not sure what effect this has on paging.. */
2978 unprotect_oldspace(void)
2982 for (i = 0; i < last_free_page; i++) {
2983 if ((page_table[i].allocated != FREE_PAGE_FLAG)
2984 && (page_table[i].bytes_used != 0)
2985 && (page_table[i].gen == from_space)) {
2988 page_start = (void *)page_address(i);
2990 /* Remove any write-protection. We should be able to rely
2991 * on the write-protect flag to avoid redundant calls. */
2992 if (page_table[i].write_protected) {
2993 os_protect(page_start, PAGE_BYTES, OS_VM_PROT_ALL);
2994 page_table[i].write_protected = 0;
3000 /* Work through all the pages and free any in from_space. This
3001 * assumes that all objects have been copied or promoted to an older
3002 * generation. Bytes_allocated and the generation bytes_allocated
3003 * counter are updated. The number of bytes freed is returned. */
3007 long bytes_freed = 0;
3008 long first_page, last_page;
3013 /* Find a first page for the next region of pages. */
3014 while ((first_page < last_free_page)
3015 && ((page_table[first_page].allocated == FREE_PAGE_FLAG)
3016 || (page_table[first_page].bytes_used == 0)
3017 || (page_table[first_page].gen != from_space)))
3020 if (first_page >= last_free_page)
3023 /* Find the last page of this region. */
3024 last_page = first_page;
3027 /* Free the page. */
3028 bytes_freed += page_table[last_page].bytes_used;
3029 generations[page_table[last_page].gen].bytes_allocated -=
3030 page_table[last_page].bytes_used;
3031 page_table[last_page].allocated = FREE_PAGE_FLAG;
3032 page_table[last_page].bytes_used = 0;
3034 /* Remove any write-protection. We should be able to rely
3035 * on the write-protect flag to avoid redundant calls. */
3037 void *page_start = (void *)page_address(last_page);
3039 if (page_table[last_page].write_protected) {
3040 os_protect(page_start, PAGE_BYTES, OS_VM_PROT_ALL);
3041 page_table[last_page].write_protected = 0;
3046 while ((last_page < last_free_page)
3047 && (page_table[last_page].allocated != FREE_PAGE_FLAG)
3048 && (page_table[last_page].bytes_used != 0)
3049 && (page_table[last_page].gen == from_space));
3051 /* Zero pages from first_page to (last_page-1).
3053 * FIXME: Why not use os_zero(..) function instead of
3054 * hand-coding this again? (Check other gencgc_unmap_zero
3056 if (gencgc_unmap_zero) {
3057 void *page_start, *addr;
3059 page_start = (void *)page_address(first_page);
3061 os_invalidate(page_start, PAGE_BYTES*(last_page-first_page));
3062 addr = os_validate(page_start, PAGE_BYTES*(last_page-first_page));
3063 if (addr == NULL || addr != page_start) {
3064 lose("free_oldspace: page moved, 0x%08x ==> 0x%08x",page_start,
3070 page_start = (long *)page_address(first_page);
3071 memset(page_start, 0,PAGE_BYTES*(last_page-first_page));
3074 first_page = last_page;
3076 } while (first_page < last_free_page);
3078 bytes_allocated -= bytes_freed;
3083 /* Print some information about a pointer at the given address. */
3085 print_ptr(lispobj *addr)
3087 /* If addr is in the dynamic space then out the page information. */
3088 long pi1 = find_page_index((void*)addr);
3091 fprintf(stderr," %x: page %d alloc %d gen %d bytes_used %d offset %d dont_move %d\n",
3092 (unsigned long) addr,
3094 page_table[pi1].allocated,
3095 page_table[pi1].gen,
3096 page_table[pi1].bytes_used,
3097 page_table[pi1].first_object_offset,
3098 page_table[pi1].dont_move);
3099 fprintf(stderr," %x %x %x %x (%x) %x %x %x %x\n",
3112 extern long undefined_tramp;
3115 verify_space(lispobj *start, size_t words)
3117 int is_in_dynamic_space = (find_page_index((void*)start) != -1);
3118 int is_in_readonly_space =
3119 (READ_ONLY_SPACE_START <= (unsigned)start &&
3120 (unsigned)start < SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0));
3124 lispobj thing = *(lispobj*)start;
3126 if (is_lisp_pointer(thing)) {
3127 long page_index = find_page_index((void*)thing);
3128 long to_readonly_space =
3129 (READ_ONLY_SPACE_START <= thing &&
3130 thing < SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0));
3131 long to_static_space =
3132 (STATIC_SPACE_START <= thing &&
3133 thing < SymbolValue(STATIC_SPACE_FREE_POINTER,0));
3135 /* Does it point to the dynamic space? */
3136 if (page_index != -1) {
3137 /* If it's within the dynamic space it should point to a used
3138 * page. XX Could check the offset too. */
3139 if ((page_table[page_index].allocated != FREE_PAGE_FLAG)
3140 && (page_table[page_index].bytes_used == 0))
3141 lose ("Ptr %x @ %x sees free page.", thing, start);
3142 /* Check that it doesn't point to a forwarding pointer! */
3143 if (*((lispobj *)native_pointer(thing)) == 0x01) {
3144 lose("Ptr %x @ %x sees forwarding ptr.", thing, start);
3146 /* Check that its not in the RO space as it would then be a
3147 * pointer from the RO to the dynamic space. */
3148 if (is_in_readonly_space) {
3149 lose("ptr to dynamic space %x from RO space %x",
3152 /* Does it point to a plausible object? This check slows
3153 * it down a lot (so it's commented out).
3155 * "a lot" is serious: it ate 50 minutes cpu time on
3156 * my duron 950 before I came back from lunch and
3159 * FIXME: Add a variable to enable this
3162 if (!possibly_valid_dynamic_space_pointer((lispobj *)thing)) {
3163 lose("ptr %x to invalid object %x", thing, start);
3167 /* Verify that it points to another valid space. */
3168 if (!to_readonly_space && !to_static_space
3169 && (thing != (unsigned)&undefined_tramp)) {
3170 lose("Ptr %x @ %x sees junk.", thing, start);
3174 if (!(fixnump(thing))) {
3176 switch(widetag_of(*start)) {
3179 case SIMPLE_VECTOR_WIDETAG:
3181 case COMPLEX_WIDETAG:
3182 case SIMPLE_ARRAY_WIDETAG:
3183 case COMPLEX_BASE_STRING_WIDETAG:
3184 #ifdef COMPLEX_CHARACTER_STRING_WIDETAG
3185 case COMPLEX_CHARACTER_STRING_WIDETAG:
3187 case COMPLEX_VECTOR_NIL_WIDETAG:
3188 case COMPLEX_BIT_VECTOR_WIDETAG:
3189 case COMPLEX_VECTOR_WIDETAG:
3190 case COMPLEX_ARRAY_WIDETAG:
3191 case CLOSURE_HEADER_WIDETAG:
3192 case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
3193 case VALUE_CELL_HEADER_WIDETAG:
3194 case SYMBOL_HEADER_WIDETAG:
3195 case CHARACTER_WIDETAG:
3196 #if N_WORD_BITS == 64
3197 case SINGLE_FLOAT_WIDETAG:
3199 case UNBOUND_MARKER_WIDETAG:
3200 case INSTANCE_HEADER_WIDETAG:
3205 case CODE_HEADER_WIDETAG:
3207 lispobj object = *start;
3209 long nheader_words, ncode_words, nwords;
3211 struct simple_fun *fheaderp;
3213 code = (struct code *) start;
3215 /* Check that it's not in the dynamic space.
3216 * FIXME: Isn't is supposed to be OK for code
3217 * objects to be in the dynamic space these days? */
3218 if (is_in_dynamic_space
3219 /* It's ok if it's byte compiled code. The trace
3220 * table offset will be a fixnum if it's x86
3221 * compiled code - check.
3223 * FIXME: #^#@@! lack of abstraction here..
3224 * This line can probably go away now that
3225 * there's no byte compiler, but I've got
3226 * too much to worry about right now to try
3227 * to make sure. -- WHN 2001-10-06 */
3228 && fixnump(code->trace_table_offset)
3229 /* Only when enabled */
3230 && verify_dynamic_code_check) {
3232 "/code object at %x in the dynamic space\n",
3236 ncode_words = fixnum_value(code->code_size);
3237 nheader_words = HeaderValue(object);
3238 nwords = ncode_words + nheader_words;
3239 nwords = CEILING(nwords, 2);
3240 /* Scavenge the boxed section of the code data block */
3241 verify_space(start + 1, nheader_words - 1);
3243 /* Scavenge the boxed section of each function
3244 * object in the code data block. */
3245 fheaderl = code->entry_points;
3246 while (fheaderl != NIL) {
3248 (struct simple_fun *) native_pointer(fheaderl);
3249 gc_assert(widetag_of(fheaderp->header) == SIMPLE_FUN_HEADER_WIDETAG);
3250 verify_space(&fheaderp->name, 1);
3251 verify_space(&fheaderp->arglist, 1);
3252 verify_space(&fheaderp->type, 1);
3253 fheaderl = fheaderp->next;
3259 /* unboxed objects */
3260 case BIGNUM_WIDETAG:
3261 #if N_WORD_BITS != 64
3262 case SINGLE_FLOAT_WIDETAG:
3264 case DOUBLE_FLOAT_WIDETAG:
3265 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
3266 case LONG_FLOAT_WIDETAG:
3268 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
3269 case COMPLEX_SINGLE_FLOAT_WIDETAG:
3271 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
3272 case COMPLEX_DOUBLE_FLOAT_WIDETAG:
3274 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
3275 case COMPLEX_LONG_FLOAT_WIDETAG:
3277 case SIMPLE_BASE_STRING_WIDETAG:
3278 #ifdef SIMPLE_CHARACTER_STRING_WIDETAG
3279 case SIMPLE_CHARACTER_STRING_WIDETAG:
3281 case SIMPLE_BIT_VECTOR_WIDETAG:
3282 case SIMPLE_ARRAY_NIL_WIDETAG:
3283 case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
3284 case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
3285 case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
3286 case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
3287 case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
3288 case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
3289 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
3290 case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
3292 case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
3293 case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
3294 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
3295 case SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG:
3297 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
3298 case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG:
3300 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
3301 case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG:
3303 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
3304 case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
3306 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
3307 case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
3309 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
3310 case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
3312 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
3313 case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
3315 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
3316 case SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG:
3318 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
3319 case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG:
3321 case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
3322 case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
3323 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
3324 case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
3326 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
3327 case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
3329 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
3330 case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
3332 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
3333 case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
3336 case WEAK_POINTER_WIDETAG:
3337 count = (sizetab[widetag_of(*start)])(start);
3353 /* FIXME: It would be nice to make names consistent so that
3354 * foo_size meant size *in* *bytes* instead of size in some
3355 * arbitrary units. (Yes, this caused a bug, how did you guess?:-)
3356 * Some counts of lispobjs are called foo_count; it might be good
3357 * to grep for all foo_size and rename the appropriate ones to
3359 long read_only_space_size =
3360 (lispobj*)SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0)
3361 - (lispobj*)READ_ONLY_SPACE_START;
3362 long static_space_size =
3363 (lispobj*)SymbolValue(STATIC_SPACE_FREE_POINTER,0)
3364 - (lispobj*)STATIC_SPACE_START;
3366 for_each_thread(th) {
3367 long binding_stack_size =
3368 (lispobj*)SymbolValue(BINDING_STACK_POINTER,th)
3369 - (lispobj*)th->binding_stack_start;
3370 verify_space(th->binding_stack_start, binding_stack_size);
3372 verify_space((lispobj*)READ_ONLY_SPACE_START, read_only_space_size);
3373 verify_space((lispobj*)STATIC_SPACE_START , static_space_size);
3377 verify_generation(int generation)
3381 for (i = 0; i < last_free_page; i++) {
3382 if ((page_table[i].allocated != FREE_PAGE_FLAG)
3383 && (page_table[i].bytes_used != 0)
3384 && (page_table[i].gen == generation)) {
3386 int region_allocation = page_table[i].allocated;
3388 /* This should be the start of a contiguous block */
3389 gc_assert(page_table[i].first_object_offset == 0);
3391 /* Need to find the full extent of this contiguous block in case
3392 objects span pages. */
3394 /* Now work forward until the end of this contiguous area is
3396 for (last_page = i; ;last_page++)
3397 /* Check whether this is the last page in this contiguous
3399 if ((page_table[last_page].bytes_used < PAGE_BYTES)
3400 /* Or it is PAGE_BYTES and is the last in the block */
3401 || (page_table[last_page+1].allocated != region_allocation)
3402 || (page_table[last_page+1].bytes_used == 0)
3403 || (page_table[last_page+1].gen != generation)
3404 || (page_table[last_page+1].first_object_offset == 0))
3407 verify_space(page_address(i), (page_table[last_page].bytes_used
3408 + (last_page-i)*PAGE_BYTES)/N_WORD_BYTES);
3414 /* Check that all the free space is zero filled. */
3416 verify_zero_fill(void)
3420 for (page = 0; page < last_free_page; page++) {
3421 if (page_table[page].allocated == FREE_PAGE_FLAG) {
3422 /* The whole page should be zero filled. */
3423 long *start_addr = (long *)page_address(page);
3426 for (i = 0; i < size; i++) {
3427 if (start_addr[i] != 0) {
3428 lose("free page not zero at %x", start_addr + i);
3432 long free_bytes = PAGE_BYTES - page_table[page].bytes_used;
3433 if (free_bytes > 0) {
3434 long *start_addr = (long *)((unsigned)page_address(page)
3435 + page_table[page].bytes_used);
3436 long size = free_bytes / N_WORD_BYTES;
3438 for (i = 0; i < size; i++) {
3439 if (start_addr[i] != 0) {
3440 lose("free region not zero at %x", start_addr + i);
3448 /* External entry point for verify_zero_fill */
3450 gencgc_verify_zero_fill(void)
3452 /* Flush the alloc regions updating the tables. */
3453 gc_alloc_update_all_page_tables();
3454 SHOW("verifying zero fill");
3459 verify_dynamic_space(void)
3463 for (i = 0; i < NUM_GENERATIONS; i++)
3464 verify_generation(i);
3466 if (gencgc_enable_verify_zero_fill)
3470 /* Write-protect all the dynamic boxed pages in the given generation. */
3472 write_protect_generation_pages(int generation)
3476 gc_assert(generation < NUM_GENERATIONS);
3478 for (i = 0; i < last_free_page; i++)
3479 if ((page_table[i].allocated == BOXED_PAGE_FLAG)
3480 && (page_table[i].bytes_used != 0)
3481 && !page_table[i].dont_move
3482 && (page_table[i].gen == generation)) {
3485 page_start = (void *)page_address(i);
3487 os_protect(page_start,
3489 OS_VM_PROT_READ | OS_VM_PROT_EXECUTE);
3491 /* Note the page as protected in the page tables. */
3492 page_table[i].write_protected = 1;
3495 if (gencgc_verbose > 1) {
3497 "/write protected %d of %d pages in generation %d\n",
3498 count_write_protect_generation_pages(generation),
3499 count_generation_pages(generation),
3504 /* Garbage collect a generation. If raise is 0 then the remains of the
3505 * generation are not raised to the next generation. */
3507 garbage_collect_generation(int generation, int raise)
3509 unsigned long bytes_freed;
3511 unsigned long static_space_size;
3513 gc_assert(generation <= (NUM_GENERATIONS-1));
3515 /* The oldest generation can't be raised. */
3516 gc_assert((generation != (NUM_GENERATIONS-1)) || (raise == 0));
3518 /* Initialize the weak pointer list. */
3519 weak_pointers = NULL;
3521 /* When a generation is not being raised it is transported to a
3522 * temporary generation (NUM_GENERATIONS), and lowered when
3523 * done. Set up this new generation. There should be no pages
3524 * allocated to it yet. */
3526 gc_assert(generations[NUM_GENERATIONS].bytes_allocated == 0);
3529 /* Set the global src and dest. generations */
3530 from_space = generation;
3532 new_space = generation+1;
3534 new_space = NUM_GENERATIONS;
3536 /* Change to a new space for allocation, resetting the alloc_start_page */
3537 gc_alloc_generation = new_space;
3538 generations[new_space].alloc_start_page = 0;
3539 generations[new_space].alloc_unboxed_start_page = 0;
3540 generations[new_space].alloc_large_start_page = 0;
3541 generations[new_space].alloc_large_unboxed_start_page = 0;
3543 /* Before any pointers are preserved, the dont_move flags on the
3544 * pages need to be cleared. */
3545 for (i = 0; i < last_free_page; i++)
3546 if(page_table[i].gen==from_space)
3547 page_table[i].dont_move = 0;
3549 /* Un-write-protect the old-space pages. This is essential for the
3550 * promoted pages as they may contain pointers into the old-space
3551 * which need to be scavenged. It also helps avoid unnecessary page
3552 * faults as forwarding pointers are written into them. They need to
3553 * be un-protected anyway before unmapping later. */
3554 unprotect_oldspace();
3556 /* Scavenge the stacks' conservative roots. */
3558 /* there are potentially two stacks for each thread: the main
3559 * stack, which may contain Lisp pointers, and the alternate stack.
3560 * We don't ever run Lisp code on the altstack, but it may
3561 * host a sigcontext with lisp objects in it */
3563 /* what we need to do: (1) find the stack pointer for the main
3564 * stack; scavenge it (2) find the interrupt context on the
3565 * alternate stack that might contain lisp values, and scavenge
3568 /* we assume that none of the preceding applies to the thread that
3569 * initiates GC. If you ever call GC from inside an altstack
3570 * handler, you will lose. */
3571 for_each_thread(th) {
3573 void **esp=(void **)-1;
3574 #ifdef LISP_FEATURE_SB_THREAD
3576 if(th==arch_os_get_current_thread()) {
3577 esp = (void **) &raise;
3580 free=fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,th));
3581 for(i=free-1;i>=0;i--) {
3582 os_context_t *c=th->interrupt_contexts[i];
3583 esp1 = (void **) *os_context_register_addr(c,reg_SP);
3584 if(esp1>=th->control_stack_start&& esp1<th->control_stack_end){
3585 if(esp1<esp) esp=esp1;
3586 for(ptr = (void **)(c+1); ptr>=(void **)c; ptr--) {
3587 preserve_pointer(*ptr);
3593 esp = (void **) &raise;
3595 for (ptr = (void **)th->control_stack_end; ptr > esp; ptr--) {
3596 preserve_pointer(*ptr);
3601 if (gencgc_verbose > 1) {
3602 long num_dont_move_pages = count_dont_move_pages();
3604 "/non-movable pages due to conservative pointers = %d (%d bytes)\n",
3605 num_dont_move_pages,
3606 num_dont_move_pages * PAGE_BYTES);
3610 /* Scavenge all the rest of the roots. */
3612 /* Scavenge the Lisp functions of the interrupt handlers, taking
3613 * care to avoid SIG_DFL and SIG_IGN. */
3614 for_each_thread(th) {
3615 struct interrupt_data *data=th->interrupt_data;
3616 for (i = 0; i < NSIG; i++) {
3617 union interrupt_handler handler = data->interrupt_handlers[i];
3618 if (!ARE_SAME_HANDLER(handler.c, SIG_IGN) &&
3619 !ARE_SAME_HANDLER(handler.c, SIG_DFL)) {
3620 scavenge((lispobj *)(data->interrupt_handlers + i), 1);
3624 /* Scavenge the binding stacks. */
3627 for_each_thread(th) {
3628 long len= (lispobj *)SymbolValue(BINDING_STACK_POINTER,th) -
3629 th->binding_stack_start;
3630 scavenge((lispobj *) th->binding_stack_start,len);
3631 #ifdef LISP_FEATURE_SB_THREAD
3632 /* do the tls as well */
3633 len=fixnum_value(SymbolValue(FREE_TLS_INDEX,0)) -
3634 (sizeof (struct thread))/(sizeof (lispobj));
3635 scavenge((lispobj *) (th+1),len);
3640 /* The original CMU CL code had scavenge-read-only-space code
3641 * controlled by the Lisp-level variable
3642 * *SCAVENGE-READ-ONLY-SPACE*. It was disabled by default, and it
3643 * wasn't documented under what circumstances it was useful or
3644 * safe to turn it on, so it's been turned off in SBCL. If you
3645 * want/need this functionality, and can test and document it,
3646 * please submit a patch. */
3648 if (SymbolValue(SCAVENGE_READ_ONLY_SPACE) != NIL) {
3649 unsigned long read_only_space_size =
3650 (lispobj*)SymbolValue(READ_ONLY_SPACE_FREE_POINTER) -
3651 (lispobj*)READ_ONLY_SPACE_START;
3653 "/scavenge read only space: %d bytes\n",
3654 read_only_space_size * sizeof(lispobj)));
3655 scavenge( (lispobj *) READ_ONLY_SPACE_START, read_only_space_size);
3659 /* Scavenge static space. */
3661 (lispobj *)SymbolValue(STATIC_SPACE_FREE_POINTER,0) -
3662 (lispobj *)STATIC_SPACE_START;
3663 if (gencgc_verbose > 1) {
3665 "/scavenge static space: %d bytes\n",
3666 static_space_size * sizeof(lispobj)));
3668 scavenge( (lispobj *) STATIC_SPACE_START, static_space_size);
3670 /* All generations but the generation being GCed need to be
3671 * scavenged. The new_space generation needs special handling as
3672 * objects may be moved in - it is handled separately below. */
3673 for (i = 0; i < NUM_GENERATIONS; i++) {
3674 if ((i != generation) && (i != new_space)) {
3675 scavenge_generation(i);
3679 /* Finally scavenge the new_space generation. Keep going until no
3680 * more objects are moved into the new generation */
3681 scavenge_newspace_generation(new_space);
3683 /* FIXME: I tried reenabling this check when debugging unrelated
3684 * GC weirdness ca. sbcl-0.6.12.45, and it failed immediately.
3685 * Since the current GC code seems to work well, I'm guessing that
3686 * this debugging code is just stale, but I haven't tried to
3687 * figure it out. It should be figured out and then either made to
3688 * work or just deleted. */
3689 #define RESCAN_CHECK 0
3691 /* As a check re-scavenge the newspace once; no new objects should
3694 long old_bytes_allocated = bytes_allocated;
3695 long bytes_allocated;
3697 /* Start with a full scavenge. */
3698 scavenge_newspace_generation_one_scan(new_space);
3700 /* Flush the current regions, updating the tables. */
3701 gc_alloc_update_all_page_tables();
3703 bytes_allocated = bytes_allocated - old_bytes_allocated;
3705 if (bytes_allocated != 0) {
3706 lose("Rescan of new_space allocated %d more bytes.",
3712 scan_weak_pointers();
3714 /* Flush the current regions, updating the tables. */
3715 gc_alloc_update_all_page_tables();
3717 /* Free the pages in oldspace, but not those marked dont_move. */
3718 bytes_freed = free_oldspace();
3720 /* If the GC is not raising the age then lower the generation back
3721 * to its normal generation number */
3723 for (i = 0; i < last_free_page; i++)
3724 if ((page_table[i].bytes_used != 0)
3725 && (page_table[i].gen == NUM_GENERATIONS))
3726 page_table[i].gen = generation;
3727 gc_assert(generations[generation].bytes_allocated == 0);
3728 generations[generation].bytes_allocated =
3729 generations[NUM_GENERATIONS].bytes_allocated;
3730 generations[NUM_GENERATIONS].bytes_allocated = 0;
3733 /* Reset the alloc_start_page for generation. */
3734 generations[generation].alloc_start_page = 0;
3735 generations[generation].alloc_unboxed_start_page = 0;
3736 generations[generation].alloc_large_start_page = 0;
3737 generations[generation].alloc_large_unboxed_start_page = 0;
3739 if (generation >= verify_gens) {
3743 verify_dynamic_space();
3746 /* Set the new gc trigger for the GCed generation. */
3747 generations[generation].gc_trigger =
3748 generations[generation].bytes_allocated
3749 + generations[generation].bytes_consed_between_gc;
3752 generations[generation].num_gc = 0;
3754 ++generations[generation].num_gc;
3757 /* Update last_free_page, then SymbolValue(ALLOCATION_POINTER). */
3759 update_x86_dynamic_space_free_pointer(void)
3761 long last_page = -1;
3764 for (i = 0; i < last_free_page; i++)
3765 if ((page_table[i].allocated != FREE_PAGE_FLAG)
3766 && (page_table[i].bytes_used != 0))
3769 last_free_page = last_page+1;
3771 SetSymbolValue(ALLOCATION_POINTER,
3772 (lispobj)(((char *)heap_base) + last_free_page*PAGE_BYTES),0);
3773 return 0; /* dummy value: return something ... */
3776 /* GC all generations newer than last_gen, raising the objects in each
3777 * to the next older generation - we finish when all generations below
3778 * last_gen are empty. Then if last_gen is due for a GC, or if
3779 * last_gen==NUM_GENERATIONS (the scratch generation? eh?) we GC that
3780 * too. The valid range for last_gen is: 0,1,...,NUM_GENERATIONS.
3782 * We stop collecting at gencgc_oldest_gen_to_gc, even if this is less than
3783 * last_gen (oh, and note that by default it is NUM_GENERATIONS-1) */
3786 collect_garbage(unsigned last_gen)
3793 FSHOW((stderr, "/entering collect_garbage(%d)\n", last_gen));
3795 if (last_gen > NUM_GENERATIONS) {
3797 "/collect_garbage: last_gen = %d, doing a level 0 GC\n",
3802 /* Flush the alloc regions updating the tables. */
3803 gc_alloc_update_all_page_tables();
3805 /* Verify the new objects created by Lisp code. */
3806 if (pre_verify_gen_0) {
3807 FSHOW((stderr, "pre-checking generation 0\n"));
3808 verify_generation(0);
3811 if (gencgc_verbose > 1)
3812 print_generation_stats(0);
3815 /* Collect the generation. */
3817 if (gen >= gencgc_oldest_gen_to_gc) {
3818 /* Never raise the oldest generation. */
3823 || (generations[gen].num_gc >= generations[gen].trigger_age);
3826 if (gencgc_verbose > 1) {
3828 "starting GC of generation %d with raise=%d alloc=%d trig=%d GCs=%d\n",
3831 generations[gen].bytes_allocated,
3832 generations[gen].gc_trigger,
3833 generations[gen].num_gc));
3836 /* If an older generation is being filled, then update its
3839 generations[gen+1].cum_sum_bytes_allocated +=
3840 generations[gen+1].bytes_allocated;
3843 garbage_collect_generation(gen, raise);
3845 /* Reset the memory age cum_sum. */
3846 generations[gen].cum_sum_bytes_allocated = 0;
3848 if (gencgc_verbose > 1) {
3849 FSHOW((stderr, "GC of generation %d finished:\n", gen));
3850 print_generation_stats(0);
3854 } while ((gen <= gencgc_oldest_gen_to_gc)
3855 && ((gen < last_gen)
3856 || ((gen <= gencgc_oldest_gen_to_gc)
3858 && (generations[gen].bytes_allocated
3859 > generations[gen].gc_trigger)
3860 && (gen_av_mem_age(gen)
3861 > generations[gen].min_av_mem_age))));
3863 /* Now if gen-1 was raised all generations before gen are empty.
3864 * If it wasn't raised then all generations before gen-1 are empty.
3866 * Now objects within this gen's pages cannot point to younger
3867 * generations unless they are written to. This can be exploited
3868 * by write-protecting the pages of gen; then when younger
3869 * generations are GCed only the pages which have been written
3874 gen_to_wp = gen - 1;
3876 /* There's not much point in WPing pages in generation 0 as it is
3877 * never scavenged (except promoted pages). */
3878 if ((gen_to_wp > 0) && enable_page_protection) {
3879 /* Check that they are all empty. */
3880 for (i = 0; i < gen_to_wp; i++) {
3881 if (generations[i].bytes_allocated)
3882 lose("trying to write-protect gen. %d when gen. %d nonempty",
3885 write_protect_generation_pages(gen_to_wp);
3888 /* Set gc_alloc() back to generation 0. The current regions should
3889 * be flushed after the above GCs. */
3890 gc_assert((boxed_region.free_pointer - boxed_region.start_addr) == 0);
3891 gc_alloc_generation = 0;
3893 update_x86_dynamic_space_free_pointer();
3894 auto_gc_trigger = bytes_allocated + bytes_consed_between_gcs;
3896 fprintf(stderr,"Next gc when %ld bytes have been consed\n",
3898 SHOW("returning from collect_garbage");
3901 /* This is called by Lisp PURIFY when it is finished. All live objects
3902 * will have been moved to the RO and Static heaps. The dynamic space
3903 * will need a full re-initialization. We don't bother having Lisp
3904 * PURIFY flush the current gc_alloc() region, as the page_tables are
3905 * re-initialized, and every page is zeroed to be sure. */
3911 if (gencgc_verbose > 1)
3912 SHOW("entering gc_free_heap");
3914 for (page = 0; page < NUM_PAGES; page++) {
3915 /* Skip free pages which should already be zero filled. */
3916 if (page_table[page].allocated != FREE_PAGE_FLAG) {
3917 void *page_start, *addr;
3919 /* Mark the page free. The other slots are assumed invalid
3920 * when it is a FREE_PAGE_FLAG and bytes_used is 0 and it
3921 * should not be write-protected -- except that the
3922 * generation is used for the current region but it sets
3924 page_table[page].allocated = FREE_PAGE_FLAG;
3925 page_table[page].bytes_used = 0;
3927 /* Zero the page. */
3928 page_start = (void *)page_address(page);
3930 /* First, remove any write-protection. */
3931 os_protect(page_start, PAGE_BYTES, OS_VM_PROT_ALL);
3932 page_table[page].write_protected = 0;
3934 os_invalidate(page_start,PAGE_BYTES);
3935 addr = os_validate(page_start,PAGE_BYTES);
3936 if (addr == NULL || addr != page_start) {
3937 lose("gc_free_heap: page moved, 0x%08x ==> 0x%08x",
3941 } else if (gencgc_zero_check_during_free_heap) {
3942 /* Double-check that the page is zero filled. */
3943 long *page_start, i;
3944 gc_assert(page_table[page].allocated == FREE_PAGE_FLAG);
3945 gc_assert(page_table[page].bytes_used == 0);
3946 page_start = (long *)page_address(page);
3947 for (i=0; i<1024; i++) {
3948 if (page_start[i] != 0) {
3949 lose("free region not zero at %x", page_start + i);
3955 bytes_allocated = 0;
3957 /* Initialize the generations. */
3958 for (page = 0; page < NUM_GENERATIONS; page++) {
3959 generations[page].alloc_start_page = 0;
3960 generations[page].alloc_unboxed_start_page = 0;
3961 generations[page].alloc_large_start_page = 0;
3962 generations[page].alloc_large_unboxed_start_page = 0;
3963 generations[page].bytes_allocated = 0;
3964 generations[page].gc_trigger = 2000000;
3965 generations[page].num_gc = 0;
3966 generations[page].cum_sum_bytes_allocated = 0;
3969 if (gencgc_verbose > 1)
3970 print_generation_stats(0);
3972 /* Initialize gc_alloc(). */
3973 gc_alloc_generation = 0;
3975 gc_set_region_empty(&boxed_region);
3976 gc_set_region_empty(&unboxed_region);
3979 SetSymbolValue(ALLOCATION_POINTER, (lispobj)((char *)heap_base),0);
3981 if (verify_after_free_heap) {
3982 /* Check whether purify has left any bad pointers. */
3984 SHOW("checking after free_heap\n");
3995 scavtab[SIMPLE_VECTOR_WIDETAG] = scav_vector;
3996 scavtab[WEAK_POINTER_WIDETAG] = scav_weak_pointer;
3997 transother[SIMPLE_ARRAY_WIDETAG] = trans_boxed_large;
3999 heap_base = (void*)DYNAMIC_SPACE_START;
4001 /* Initialize each page structure. */
4002 for (i = 0; i < NUM_PAGES; i++) {
4003 /* Initialize all pages as free. */
4004 page_table[i].allocated = FREE_PAGE_FLAG;
4005 page_table[i].bytes_used = 0;
4007 /* Pages are not write-protected at startup. */
4008 page_table[i].write_protected = 0;
4011 bytes_allocated = 0;
4013 /* Initialize the generations.
4015 * FIXME: very similar to code in gc_free_heap(), should be shared */
4016 for (i = 0; i < NUM_GENERATIONS; i++) {
4017 generations[i].alloc_start_page = 0;
4018 generations[i].alloc_unboxed_start_page = 0;
4019 generations[i].alloc_large_start_page = 0;
4020 generations[i].alloc_large_unboxed_start_page = 0;
4021 generations[i].bytes_allocated = 0;
4022 generations[i].gc_trigger = 2000000;
4023 generations[i].num_gc = 0;
4024 generations[i].cum_sum_bytes_allocated = 0;
4025 /* the tune-able parameters */
4026 generations[i].bytes_consed_between_gc = 2000000;
4027 generations[i].trigger_age = 1;
4028 generations[i].min_av_mem_age = 0.75;
4031 /* Initialize gc_alloc. */
4032 gc_alloc_generation = 0;
4033 gc_set_region_empty(&boxed_region);
4034 gc_set_region_empty(&unboxed_region);
4040 /* Pick up the dynamic space from after a core load.
4042 * The ALLOCATION_POINTER points to the end of the dynamic space.
4046 gencgc_pickup_dynamic(void)
4049 long alloc_ptr = SymbolValue(ALLOCATION_POINTER,0);
4050 lispobj *prev=(lispobj *)page_address(page);
4053 lispobj *first,*ptr= (lispobj *)page_address(page);
4054 page_table[page].allocated = BOXED_PAGE_FLAG;
4055 page_table[page].gen = 0;
4056 page_table[page].bytes_used = PAGE_BYTES;
4057 page_table[page].large_object = 0;
4059 first=gc_search_space(prev,(ptr+2)-prev,ptr);
4060 if(ptr == first) prev=ptr;
4061 page_table[page].first_object_offset =
4062 (void *)prev - page_address(page);
4064 } while (page_address(page) < alloc_ptr);
4066 generations[0].bytes_allocated = PAGE_BYTES*page;
4067 bytes_allocated = PAGE_BYTES*page;
4073 gc_initialize_pointers(void)
4075 gencgc_pickup_dynamic();
4081 /* alloc(..) is the external interface for memory allocation. It
4082 * allocates to generation 0. It is not called from within the garbage
4083 * collector as it is only external uses that need the check for heap
4084 * size (GC trigger) and to disable the interrupts (interrupts are
4085 * always disabled during a GC).
4087 * The vops that call alloc(..) assume that the returned space is zero-filled.
4088 * (E.g. the most significant word of a 2-word bignum in MOVE-FROM-UNSIGNED.)
4090 * The check for a GC trigger is only performed when the current
4091 * region is full, so in most cases it's not needed. */
4096 struct thread *th=arch_os_get_current_thread();
4097 struct alloc_region *region=
4098 #ifdef LISP_FEATURE_SB_THREAD
4099 th ? &(th->alloc_region) : &boxed_region;
4104 void *new_free_pointer;
4105 gc_assert(nbytes>0);
4106 /* Check for alignment allocation problems. */
4107 gc_assert((((unsigned)region->free_pointer & LOWTAG_MASK) == 0)
4108 && ((nbytes & LOWTAG_MASK) == 0));
4111 /* there are a few places in the C code that allocate data in the
4112 * heap before Lisp starts. This is before interrupts are enabled,
4113 * so we don't need to check for pseudo-atomic */
4114 #ifdef LISP_FEATURE_SB_THREAD
4115 if(!SymbolValue(PSEUDO_ATOMIC_ATOMIC,th)) {
4117 fprintf(stderr, "fatal error in thread 0x%x, pid=%d\n",
4119 __asm__("movl %fs,%0" : "=r" (fs) : );
4120 fprintf(stderr, "fs is %x, th->tls_cookie=%x \n",
4121 debug_get_fs(),th->tls_cookie);
4122 lose("If you see this message before 2004.01.31, mail details to sbcl-devel\n");
4125 gc_assert(SymbolValue(PSEUDO_ATOMIC_ATOMIC,th));
4129 /* maybe we can do this quickly ... */
4130 new_free_pointer = region->free_pointer + nbytes;
4131 if (new_free_pointer <= region->end_addr) {
4132 new_obj = (void*)(region->free_pointer);
4133 region->free_pointer = new_free_pointer;
4134 return(new_obj); /* yup */
4137 /* we have to go the long way around, it seems. Check whether
4138 * we should GC in the near future
4140 if (auto_gc_trigger && bytes_allocated > auto_gc_trigger) {
4141 struct thread *thread=arch_os_get_current_thread();
4142 /* Don't flood the system with interrupts if the need to gc is
4143 * already noted. This can happen for example when SUB-GC
4144 * allocates or after a gc triggered in a WITHOUT-GCING. */
4145 if (SymbolValue(NEED_TO_COLLECT_GARBAGE,thread) == NIL) {
4146 /* set things up so that GC happens when we finish the PA
4147 * section. We only do this if there wasn't a pending
4148 * handler already, in case it was a gc. If it wasn't a
4149 * GC, the next allocation will get us back to this point
4150 * anyway, so no harm done
4152 struct interrupt_data *data=th->interrupt_data;
4153 sigset_t new_mask,old_mask;
4154 sigemptyset(&new_mask);
4155 sigaddset_blockable(&new_mask);
4156 sigprocmask(SIG_BLOCK,&new_mask,&old_mask);
4158 if((!data->pending_handler) &&
4159 maybe_defer_handler(interrupt_maybe_gc_int,data,0,0,0)) {
4160 /* Leave the signals blocked just as if it was
4161 * deferred the normal way and set the
4163 sigcopyset(&(data->pending_mask),&old_mask);
4164 SetSymbolValue(NEED_TO_COLLECT_GARBAGE,T,thread);
4166 sigprocmask(SIG_SETMASK,&old_mask,0);
4170 new_obj = gc_alloc_with_region(nbytes,0,region,0);
4175 * shared support for the OS-dependent signal handlers which
4176 * catch GENCGC-related write-protect violations
4179 void unhandled_sigmemoryfault(void);
4181 /* Depending on which OS we're running under, different signals might
4182 * be raised for a violation of write protection in the heap. This
4183 * function factors out the common generational GC magic which needs
4184 * to invoked in this case, and should be called from whatever signal
4185 * handler is appropriate for the OS we're running under.
4187 * Return true if this signal is a normal generational GC thing that
4188 * we were able to handle, or false if it was abnormal and control
4189 * should fall through to the general SIGSEGV/SIGBUS/whatever logic. */
4192 gencgc_handle_wp_violation(void* fault_addr)
4194 long page_index = find_page_index(fault_addr);
4196 #ifdef QSHOW_SIGNALS
4197 FSHOW((stderr, "heap WP violation? fault_addr=%x, page_index=%d\n",
4198 fault_addr, page_index));
4201 /* Check whether the fault is within the dynamic space. */
4202 if (page_index == (-1)) {
4204 /* It can be helpful to be able to put a breakpoint on this
4205 * case to help diagnose low-level problems. */
4206 unhandled_sigmemoryfault();
4208 /* not within the dynamic space -- not our responsibility */
4212 if (page_table[page_index].write_protected) {
4213 /* Unprotect the page. */
4214 os_protect(page_address(page_index), PAGE_BYTES, OS_VM_PROT_ALL);
4215 page_table[page_index].write_protected_cleared = 1;
4216 page_table[page_index].write_protected = 0;
4218 /* The only acceptable reason for this signal on a heap
4219 * access is that GENCGC write-protected the page.
4220 * However, if two CPUs hit a wp page near-simultaneously,
4221 * we had better not have the second one lose here if it
4222 * does this test after the first one has already set wp=0
4224 if(page_table[page_index].write_protected_cleared != 1)
4225 lose("fault in heap page not marked as write-protected");
4227 /* Don't worry, we can handle it. */
4231 /* This is to be called when we catch a SIGSEGV/SIGBUS, determine that
4232 * it's not just a case of the program hitting the write barrier, and
4233 * are about to let Lisp deal with it. It's basically just a
4234 * convenient place to set a gdb breakpoint. */
4236 unhandled_sigmemoryfault()
4239 void gc_alloc_update_all_page_tables(void)
4241 /* Flush the alloc regions updating the tables. */
4244 gc_alloc_update_page_tables(0, &th->alloc_region);
4245 gc_alloc_update_page_tables(1, &unboxed_region);
4246 gc_alloc_update_page_tables(0, &boxed_region);
4249 gc_set_region_empty(struct alloc_region *region)
4251 region->first_page = 0;
4252 region->last_page = -1;
4253 region->start_addr = page_address(0);
4254 region->free_pointer = page_address(0);
4255 region->end_addr = page_address(0);