2 * GENerational Conservative Garbage Collector for SBCL
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>.
37 #include "interrupt.h"
42 #include "gc-internal.h"
44 #include "pseudo-atomic.h"
46 #include "genesis/vector.h"
47 #include "genesis/weak-pointer.h"
48 #include "genesis/fdefn.h"
49 #include "genesis/simple-fun.h"
51 #include "genesis/hash-table.h"
52 #include "genesis/instance.h"
53 #include "genesis/layout.h"
55 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
56 #include "genesis/cons.h"
59 /* forward declarations */
60 page_index_t gc_find_freeish_pages(page_index_t *restart_page_ptr, long nbytes,
68 /* Generations 0-5 are normal collected generations, 6 is only used as
69 * scratch space by the collector, and should never get collected.
72 SCRATCH_GENERATION = PSEUDO_STATIC_GENERATION+1,
76 /* Should we use page protection to help avoid the scavenging of pages
77 * that don't have pointers to younger generations? */
78 boolean enable_page_protection = 1;
80 /* the minimum size (in bytes) for a large object*/
81 #if (GENCGC_ALLOC_GRANULARITY >= PAGE_BYTES) && (GENCGC_ALLOC_GRANULARITY >= GENCGC_CARD_BYTES)
82 os_vm_size_t large_object_size = 4 * GENCGC_ALLOC_GRANULARITY;
83 #elif (GENCGC_CARD_BYTES >= PAGE_BYTES) && (GENCGC_CARD_BYTES >= GENCGC_ALLOC_GRANULARITY)
84 os_vm_size_t large_object_size = 4 * GENCGC_CARD_BYTES;
86 os_vm_size_t large_object_size = 4 * PAGE_BYTES;
94 /* the verbosity level. All non-error messages are disabled at level 0;
95 * and only a few rare messages are printed at level 1. */
97 boolean gencgc_verbose = 1;
99 boolean gencgc_verbose = 0;
102 /* FIXME: At some point enable the various error-checking things below
103 * and see what they say. */
105 /* We hunt for pointers to old-space, when GCing generations >= verify_gen.
106 * Set verify_gens to HIGHEST_NORMAL_GENERATION + 1 to disable this kind of
108 generation_index_t verify_gens = HIGHEST_NORMAL_GENERATION + 1;
110 /* Should we do a pre-scan verify of generation 0 before it's GCed? */
111 boolean pre_verify_gen_0 = 0;
113 /* Should we check for bad pointers after gc_free_heap is called
114 * from Lisp PURIFY? */
115 boolean verify_after_free_heap = 0;
117 /* Should we print a note when code objects are found in the dynamic space
118 * during a heap verify? */
119 boolean verify_dynamic_code_check = 0;
121 /* Should we check code objects for fixup errors after they are transported? */
122 boolean check_code_fixups = 0;
124 /* Should we check that newly allocated regions are zero filled? */
125 boolean gencgc_zero_check = 0;
127 /* Should we check that the free space is zero filled? */
128 boolean gencgc_enable_verify_zero_fill = 0;
130 /* Should we check that free pages are zero filled during gc_free_heap
131 * called after Lisp PURIFY? */
132 boolean gencgc_zero_check_during_free_heap = 0;
134 /* When loading a core, don't do a full scan of the memory for the
135 * memory region boundaries. (Set to true by coreparse.c if the core
136 * contained a pagetable entry).
138 boolean gencgc_partial_pickup = 0;
140 /* If defined, free pages are read-protected to ensure that nothing
144 /* #define READ_PROTECT_FREE_PAGES */
148 * GC structures and variables
151 /* the total bytes allocated. These are seen by Lisp DYNAMIC-USAGE. */
152 os_vm_size_t bytes_allocated = 0;
153 os_vm_size_t auto_gc_trigger = 0;
155 /* the source and destination generations. These are set before a GC starts
157 generation_index_t from_space;
158 generation_index_t new_space;
160 /* Set to 1 when in GC */
161 boolean gc_active_p = 0;
163 /* should the GC be conservative on stack. If false (only right before
164 * saving a core), don't scan the stack / mark pages dont_move. */
165 static boolean conservative_stack = 1;
167 /* An array of page structures is allocated on gc initialization.
168 * This helps quickly map between an address its page structure.
169 * page_table_pages is set from the size of the dynamic space. */
170 page_index_t page_table_pages;
171 struct page *page_table;
173 static inline boolean page_allocated_p(page_index_t page) {
174 return (page_table[page].allocated != FREE_PAGE_FLAG);
177 static inline boolean page_no_region_p(page_index_t page) {
178 return !(page_table[page].allocated & OPEN_REGION_PAGE_FLAG);
181 static inline boolean page_allocated_no_region_p(page_index_t page) {
182 return ((page_table[page].allocated & (UNBOXED_PAGE_FLAG | BOXED_PAGE_FLAG))
183 && page_no_region_p(page));
186 static inline boolean page_free_p(page_index_t page) {
187 return (page_table[page].allocated == FREE_PAGE_FLAG);
190 static inline boolean page_boxed_p(page_index_t page) {
191 return (page_table[page].allocated & BOXED_PAGE_FLAG);
194 static inline boolean code_page_p(page_index_t page) {
195 return (page_table[page].allocated & CODE_PAGE_FLAG);
198 static inline boolean page_boxed_no_region_p(page_index_t page) {
199 return page_boxed_p(page) && page_no_region_p(page);
202 static inline boolean page_unboxed_p(page_index_t page) {
203 /* Both flags set == boxed code page */
204 return ((page_table[page].allocated & UNBOXED_PAGE_FLAG)
205 && !page_boxed_p(page));
208 static inline boolean protect_page_p(page_index_t page, generation_index_t generation) {
209 return (page_boxed_no_region_p(page)
210 && (page_table[page].bytes_used != 0)
211 && !page_table[page].dont_move
212 && (page_table[page].gen == generation));
215 /* To map addresses to page structures the address of the first page
217 static void *heap_base = NULL;
219 /* Calculate the start address for the given page number. */
221 page_address(page_index_t page_num)
223 return (heap_base + (page_num * GENCGC_CARD_BYTES));
226 /* Calculate the address where the allocation region associated with
227 * the page starts. */
229 page_region_start(page_index_t page_index)
231 return page_address(page_index)-page_table[page_index].region_start_offset;
234 /* Find the page index within the page_table for the given
235 * address. Return -1 on failure. */
237 find_page_index(void *addr)
239 if (addr >= heap_base) {
240 page_index_t index = ((pointer_sized_uint_t)addr -
241 (pointer_sized_uint_t)heap_base) / GENCGC_CARD_BYTES;
242 if (index < page_table_pages)
249 npage_bytes(page_index_t npages)
251 gc_assert(npages>=0);
252 return ((os_vm_size_t)npages)*GENCGC_CARD_BYTES;
255 /* Check that X is a higher address than Y and return offset from Y to
257 static inline os_vm_size_t
258 void_diff(void *x, void *y)
261 return (pointer_sized_uint_t)x - (pointer_sized_uint_t)y;
264 /* a structure to hold the state of a generation
266 * CAUTION: If you modify this, make sure to touch up the alien
267 * definition in src/code/gc.lisp accordingly. ...or better yes,
268 * deal with the FIXME there...
272 /* the first page that gc_alloc() checks on its next call */
273 page_index_t alloc_start_page;
275 /* the first page that gc_alloc_unboxed() checks on its next call */
276 page_index_t alloc_unboxed_start_page;
278 /* the first page that gc_alloc_large (boxed) considers on its next
279 * call. (Although it always allocates after the boxed_region.) */
280 page_index_t alloc_large_start_page;
282 /* the first page that gc_alloc_large (unboxed) considers on its
283 * next call. (Although it always allocates after the
284 * current_unboxed_region.) */
285 page_index_t alloc_large_unboxed_start_page;
287 /* the bytes allocated to this generation */
288 os_vm_size_t bytes_allocated;
290 /* the number of bytes at which to trigger a GC */
291 os_vm_size_t gc_trigger;
293 /* to calculate a new level for gc_trigger */
294 os_vm_size_t bytes_consed_between_gc;
296 /* the number of GCs since the last raise */
299 /* the number of GCs to run on the generations before raising objects to the
301 int number_of_gcs_before_promotion;
303 /* the cumulative sum of the bytes allocated to this generation. It is
304 * cleared after a GC on this generations, and update before new
305 * objects are added from a GC of a younger generation. Dividing by
306 * the bytes_allocated will give the average age of the memory in
307 * this generation since its last GC. */
308 os_vm_size_t cum_sum_bytes_allocated;
310 /* a minimum average memory age before a GC will occur helps
311 * prevent a GC when a large number of new live objects have been
312 * added, in which case a GC could be a waste of time */
313 double minimum_age_before_gc;
316 /* an array of generation structures. There needs to be one more
317 * generation structure than actual generations as the oldest
318 * generation is temporarily raised then lowered. */
319 struct generation generations[NUM_GENERATIONS];
321 /* the oldest generation that is will currently be GCed by default.
322 * Valid values are: 0, 1, ... HIGHEST_NORMAL_GENERATION
324 * The default of HIGHEST_NORMAL_GENERATION enables GC on all generations.
326 * Setting this to 0 effectively disables the generational nature of
327 * the GC. In some applications generational GC may not be useful
328 * because there are no long-lived objects.
330 * An intermediate value could be handy after moving long-lived data
331 * into an older generation so an unnecessary GC of this long-lived
332 * data can be avoided. */
333 generation_index_t gencgc_oldest_gen_to_gc = HIGHEST_NORMAL_GENERATION;
335 /* The maximum free page in the heap is maintained and used to update
336 * ALLOCATION_POINTER which is used by the room function to limit its
337 * search of the heap. XX Gencgc obviously needs to be better
338 * integrated with the Lisp code. */
339 page_index_t last_free_page;
341 #ifdef LISP_FEATURE_SB_THREAD
342 /* This lock is to prevent multiple threads from simultaneously
343 * allocating new regions which overlap each other. Note that the
344 * majority of GC is single-threaded, but alloc() may be called from
345 * >1 thread at a time and must be thread-safe. This lock must be
346 * seized before all accesses to generations[] or to parts of
347 * page_table[] that other threads may want to see */
348 static pthread_mutex_t free_pages_lock = PTHREAD_MUTEX_INITIALIZER;
349 /* This lock is used to protect non-thread-local allocation. */
350 static pthread_mutex_t allocation_lock = PTHREAD_MUTEX_INITIALIZER;
353 extern os_vm_size_t gencgc_release_granularity;
354 os_vm_size_t gencgc_release_granularity = GENCGC_RELEASE_GRANULARITY;
356 extern os_vm_size_t gencgc_alloc_granularity;
357 os_vm_size_t gencgc_alloc_granularity = GENCGC_ALLOC_GRANULARITY;
361 * miscellaneous heap functions
364 /* Count the number of pages which are write-protected within the
365 * given generation. */
367 count_write_protect_generation_pages(generation_index_t generation)
369 page_index_t i, count = 0;
371 for (i = 0; i < last_free_page; i++)
372 if (page_allocated_p(i)
373 && (page_table[i].gen == generation)
374 && (page_table[i].write_protected == 1))
379 /* Count the number of pages within the given generation. */
381 count_generation_pages(generation_index_t generation)
384 page_index_t count = 0;
386 for (i = 0; i < last_free_page; i++)
387 if (page_allocated_p(i)
388 && (page_table[i].gen == generation))
395 count_dont_move_pages(void)
398 page_index_t count = 0;
399 for (i = 0; i < last_free_page; i++) {
400 if (page_allocated_p(i)
401 && (page_table[i].dont_move != 0)) {
409 /* Work through the pages and add up the number of bytes used for the
410 * given generation. */
412 count_generation_bytes_allocated (generation_index_t gen)
415 os_vm_size_t result = 0;
416 for (i = 0; i < last_free_page; i++) {
417 if (page_allocated_p(i)
418 && (page_table[i].gen == gen))
419 result += page_table[i].bytes_used;
424 /* Return the average age of the memory in a generation. */
426 generation_average_age(generation_index_t gen)
428 if (generations[gen].bytes_allocated == 0)
432 ((double)generations[gen].cum_sum_bytes_allocated)
433 / ((double)generations[gen].bytes_allocated);
437 write_generation_stats(FILE *file)
439 generation_index_t i;
441 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
442 #define FPU_STATE_SIZE 27
443 int fpu_state[FPU_STATE_SIZE];
444 #elif defined(LISP_FEATURE_PPC)
445 #define FPU_STATE_SIZE 32
446 long long fpu_state[FPU_STATE_SIZE];
449 /* This code uses the FP instructions which may be set up for Lisp
450 * so they need to be saved and reset for C. */
453 /* Print the heap stats. */
455 " Gen StaPg UbSta LaSta LUbSt Boxed Unboxed LB LUB !move Alloc Waste Trig WP GCs Mem-age\n");
457 for (i = 0; i < SCRATCH_GENERATION; i++) {
459 page_index_t boxed_cnt = 0;
460 page_index_t unboxed_cnt = 0;
461 page_index_t large_boxed_cnt = 0;
462 page_index_t large_unboxed_cnt = 0;
463 page_index_t pinned_cnt=0;
465 for (j = 0; j < last_free_page; j++)
466 if (page_table[j].gen == i) {
468 /* Count the number of boxed pages within the given
470 if (page_boxed_p(j)) {
471 if (page_table[j].large_object)
476 if(page_table[j].dont_move) pinned_cnt++;
477 /* Count the number of unboxed pages within the given
479 if (page_unboxed_p(j)) {
480 if (page_table[j].large_object)
487 gc_assert(generations[i].bytes_allocated
488 == count_generation_bytes_allocated(i));
490 " %1d: %5ld %5ld %5ld %5ld",
492 generations[i].alloc_start_page,
493 generations[i].alloc_unboxed_start_page,
494 generations[i].alloc_large_start_page,
495 generations[i].alloc_large_unboxed_start_page);
497 " %5"PAGE_INDEX_FMT" %5"PAGE_INDEX_FMT" %5"PAGE_INDEX_FMT
498 " %5"PAGE_INDEX_FMT" %5"PAGE_INDEX_FMT,
499 boxed_cnt, unboxed_cnt, large_boxed_cnt,
500 large_unboxed_cnt, pinned_cnt);
505 " %4"PAGE_INDEX_FMT" %3d %7.4f\n",
506 generations[i].bytes_allocated,
507 (npage_bytes(count_generation_pages(i)) - generations[i].bytes_allocated),
508 generations[i].gc_trigger,
509 count_write_protect_generation_pages(i),
510 generations[i].num_gc,
511 generation_average_age(i));
513 fprintf(file," Total bytes allocated = %"OS_VM_SIZE_FMT"\n", bytes_allocated);
514 fprintf(file," Dynamic-space-size bytes = %"OS_VM_SIZE_FMT"\n", dynamic_space_size);
516 fpu_restore(fpu_state);
520 write_heap_exhaustion_report(FILE *file, long available, long requested,
521 struct thread *thread)
524 "Heap exhausted during %s: %ld bytes available, %ld requested.\n",
525 gc_active_p ? "garbage collection" : "allocation",
528 write_generation_stats(file);
529 fprintf(file, "GC control variables:\n");
530 fprintf(file, " *GC-INHIBIT* = %s\n *GC-PENDING* = %s\n",
531 SymbolValue(GC_INHIBIT,thread)==NIL ? "false" : "true",
532 (SymbolValue(GC_PENDING, thread) == T) ?
533 "true" : ((SymbolValue(GC_PENDING, thread) == NIL) ?
534 "false" : "in progress"));
535 #ifdef LISP_FEATURE_SB_THREAD
536 fprintf(file, " *STOP-FOR-GC-PENDING* = %s\n",
537 SymbolValue(STOP_FOR_GC_PENDING,thread)==NIL ? "false" : "true");
542 print_generation_stats(void)
544 write_generation_stats(stderr);
547 extern char* gc_logfile;
548 char * gc_logfile = NULL;
551 log_generation_stats(char *logfile, char *header)
554 FILE * log = fopen(logfile, "a");
556 fprintf(log, "%s\n", header);
557 write_generation_stats(log);
560 fprintf(stderr, "Could not open gc logfile: %s\n", logfile);
567 report_heap_exhaustion(long available, long requested, struct thread *th)
570 FILE * log = fopen(gc_logfile, "a");
572 write_heap_exhaustion_report(log, available, requested, th);
575 fprintf(stderr, "Could not open gc logfile: %s\n", gc_logfile);
579 /* Always to stderr as well. */
580 write_heap_exhaustion_report(stderr, available, requested, th);
584 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
585 void fast_bzero(void*, size_t); /* in <arch>-assem.S */
588 /* Zero the pages from START to END (inclusive), but use mmap/munmap instead
589 * if zeroing it ourselves, i.e. in practice give the memory back to the
590 * OS. Generally done after a large GC.
592 void zero_pages_with_mmap(page_index_t start, page_index_t end) {
594 void *addr = page_address(start), *new_addr;
595 os_vm_size_t length = npage_bytes(1+end-start);
600 gc_assert(length >= gencgc_release_granularity);
601 gc_assert((length % gencgc_release_granularity) == 0);
603 os_invalidate(addr, length);
604 new_addr = os_validate(addr, length);
605 if (new_addr == NULL || new_addr != addr) {
606 lose("remap_free_pages: page moved, 0x%08x ==> 0x%08x",
610 for (i = start; i <= end; i++) {
611 page_table[i].need_to_zero = 0;
615 /* Zero the pages from START to END (inclusive). Generally done just after
616 * a new region has been allocated.
619 zero_pages(page_index_t start, page_index_t end) {
623 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
624 fast_bzero(page_address(start), npage_bytes(1+end-start));
626 bzero(page_address(start), npage_bytes(1+end-start));
632 zero_and_mark_pages(page_index_t start, page_index_t end) {
635 zero_pages(start, end);
636 for (i = start; i <= end; i++)
637 page_table[i].need_to_zero = 0;
640 /* Zero the pages from START to END (inclusive), except for those
641 * pages that are known to already zeroed. Mark all pages in the
642 * ranges as non-zeroed.
645 zero_dirty_pages(page_index_t start, page_index_t end) {
648 for (i = start; i <= end; i++) {
649 if (!page_table[i].need_to_zero) continue;
650 for (j = i+1; (j <= end) && (page_table[j].need_to_zero); j++);
655 for (i = start; i <= end; i++) {
656 page_table[i].need_to_zero = 1;
662 * To support quick and inline allocation, regions of memory can be
663 * allocated and then allocated from with just a free pointer and a
664 * check against an end address.
666 * Since objects can be allocated to spaces with different properties
667 * e.g. boxed/unboxed, generation, ages; there may need to be many
668 * allocation regions.
670 * Each allocation region may start within a partly used page. Many
671 * features of memory use are noted on a page wise basis, e.g. the
672 * generation; so if a region starts within an existing allocated page
673 * it must be consistent with this page.
675 * During the scavenging of the newspace, objects will be transported
676 * into an allocation region, and pointers updated to point to this
677 * allocation region. It is possible that these pointers will be
678 * scavenged again before the allocation region is closed, e.g. due to
679 * trans_list which jumps all over the place to cleanup the list. It
680 * is important to be able to determine properties of all objects
681 * pointed to when scavenging, e.g to detect pointers to the oldspace.
682 * Thus it's important that the allocation regions have the correct
683 * properties set when allocated, and not just set when closed. The
684 * region allocation routines return regions with the specified
685 * properties, and grab all the pages, setting their properties
686 * appropriately, except that the amount used is not known.
688 * These regions are used to support quicker allocation using just a
689 * free pointer. The actual space used by the region is not reflected
690 * in the pages tables until it is closed. It can't be scavenged until
693 * When finished with the region it should be closed, which will
694 * update the page tables for the actual space used returning unused
695 * space. Further it may be noted in the new regions which is
696 * necessary when scavenging the newspace.
698 * Large objects may be allocated directly without an allocation
699 * region, the page tables are updated immediately.
701 * Unboxed objects don't contain pointers to other objects and so
702 * don't need scavenging. Further they can't contain pointers to
703 * younger generations so WP is not needed. By allocating pages to
704 * unboxed objects the whole page never needs scavenging or
705 * write-protecting. */
707 /* We are only using two regions at present. Both are for the current
708 * newspace generation. */
709 struct alloc_region boxed_region;
710 struct alloc_region unboxed_region;
712 /* The generation currently being allocated to. */
713 static generation_index_t gc_alloc_generation;
715 static inline page_index_t
716 generation_alloc_start_page(generation_index_t generation, int page_type_flag, int large)
719 if (UNBOXED_PAGE_FLAG == page_type_flag) {
720 return generations[generation].alloc_large_unboxed_start_page;
721 } else if (BOXED_PAGE_FLAG & page_type_flag) {
722 /* Both code and data. */
723 return generations[generation].alloc_large_start_page;
725 lose("bad page type flag: %d", page_type_flag);
728 if (UNBOXED_PAGE_FLAG == page_type_flag) {
729 return generations[generation].alloc_unboxed_start_page;
730 } else if (BOXED_PAGE_FLAG & page_type_flag) {
731 /* Both code and data. */
732 return generations[generation].alloc_start_page;
734 lose("bad page_type_flag: %d", page_type_flag);
740 set_generation_alloc_start_page(generation_index_t generation, int page_type_flag, int large,
744 if (UNBOXED_PAGE_FLAG == page_type_flag) {
745 generations[generation].alloc_large_unboxed_start_page = page;
746 } else if (BOXED_PAGE_FLAG & page_type_flag) {
747 /* Both code and data. */
748 generations[generation].alloc_large_start_page = page;
750 lose("bad page type flag: %d", page_type_flag);
753 if (UNBOXED_PAGE_FLAG == page_type_flag) {
754 generations[generation].alloc_unboxed_start_page = page;
755 } else if (BOXED_PAGE_FLAG & page_type_flag) {
756 /* Both code and data. */
757 generations[generation].alloc_start_page = page;
759 lose("bad page type flag: %d", page_type_flag);
764 /* Find a new region with room for at least the given number of bytes.
766 * It starts looking at the current generation's alloc_start_page. So
767 * may pick up from the previous region if there is enough space. This
768 * keeps the allocation contiguous when scavenging the newspace.
770 * The alloc_region should have been closed by a call to
771 * gc_alloc_update_page_tables(), and will thus be in an empty state.
773 * To assist the scavenging functions write-protected pages are not
774 * used. Free pages should not be write-protected.
776 * It is critical to the conservative GC that the start of regions be
777 * known. To help achieve this only small regions are allocated at a
780 * During scavenging, pointers may be found to within the current
781 * region and the page generation must be set so that pointers to the
782 * from space can be recognized. Therefore the generation of pages in
783 * the region are set to gc_alloc_generation. To prevent another
784 * allocation call using the same pages, all the pages in the region
785 * are allocated, although they will initially be empty.
788 gc_alloc_new_region(long nbytes, int page_type_flag, struct alloc_region *alloc_region)
790 page_index_t first_page;
791 page_index_t last_page;
792 os_vm_size_t bytes_found;
798 "/alloc_new_region for %d bytes from gen %d\n",
799 nbytes, gc_alloc_generation));
802 /* Check that the region is in a reset state. */
803 gc_assert((alloc_region->first_page == 0)
804 && (alloc_region->last_page == -1)
805 && (alloc_region->free_pointer == alloc_region->end_addr));
806 ret = thread_mutex_lock(&free_pages_lock);
808 first_page = generation_alloc_start_page(gc_alloc_generation, page_type_flag, 0);
809 last_page=gc_find_freeish_pages(&first_page, nbytes, page_type_flag);
810 bytes_found=(GENCGC_CARD_BYTES - page_table[first_page].bytes_used)
811 + npage_bytes(last_page-first_page);
813 /* Set up the alloc_region. */
814 alloc_region->first_page = first_page;
815 alloc_region->last_page = last_page;
816 alloc_region->start_addr = page_table[first_page].bytes_used
817 + page_address(first_page);
818 alloc_region->free_pointer = alloc_region->start_addr;
819 alloc_region->end_addr = alloc_region->start_addr + bytes_found;
821 /* Set up the pages. */
823 /* The first page may have already been in use. */
824 if (page_table[first_page].bytes_used == 0) {
825 page_table[first_page].allocated = page_type_flag;
826 page_table[first_page].gen = gc_alloc_generation;
827 page_table[first_page].large_object = 0;
828 page_table[first_page].region_start_offset = 0;
831 gc_assert(page_table[first_page].allocated == page_type_flag);
832 page_table[first_page].allocated |= OPEN_REGION_PAGE_FLAG;
834 gc_assert(page_table[first_page].gen == gc_alloc_generation);
835 gc_assert(page_table[first_page].large_object == 0);
837 for (i = first_page+1; i <= last_page; i++) {
838 page_table[i].allocated = page_type_flag;
839 page_table[i].gen = gc_alloc_generation;
840 page_table[i].large_object = 0;
841 /* This may not be necessary for unboxed regions (think it was
843 page_table[i].region_start_offset =
844 void_diff(page_address(i),alloc_region->start_addr);
845 page_table[i].allocated |= OPEN_REGION_PAGE_FLAG ;
847 /* Bump up last_free_page. */
848 if (last_page+1 > last_free_page) {
849 last_free_page = last_page+1;
850 /* do we only want to call this on special occasions? like for
852 set_alloc_pointer((lispobj)page_address(last_free_page));
854 ret = thread_mutex_unlock(&free_pages_lock);
857 #ifdef READ_PROTECT_FREE_PAGES
858 os_protect(page_address(first_page),
859 npage_bytes(1+last_page-first_page),
863 /* If the first page was only partial, don't check whether it's
864 * zeroed (it won't be) and don't zero it (since the parts that
865 * we're interested in are guaranteed to be zeroed).
867 if (page_table[first_page].bytes_used) {
871 zero_dirty_pages(first_page, last_page);
873 /* we can do this after releasing free_pages_lock */
874 if (gencgc_zero_check) {
876 for (p = (word_t *)alloc_region->start_addr;
877 p < (word_t *)alloc_region->end_addr; p++) {
879 lose("The new region is not zero at %p (start=%p, end=%p).\n",
880 p, alloc_region->start_addr, alloc_region->end_addr);
886 /* If the record_new_objects flag is 2 then all new regions created
889 * If it's 1 then then it is only recorded if the first page of the
890 * current region is <= new_areas_ignore_page. This helps avoid
891 * unnecessary recording when doing full scavenge pass.
893 * The new_object structure holds the page, byte offset, and size of
894 * new regions of objects. Each new area is placed in the array of
895 * these structures pointer to by new_areas. new_areas_index holds the
896 * offset into new_areas.
898 * If new_area overflows NUM_NEW_AREAS then it stops adding them. The
899 * later code must detect this and handle it, probably by doing a full
900 * scavenge of a generation. */
901 #define NUM_NEW_AREAS 512
902 static int record_new_objects = 0;
903 static page_index_t new_areas_ignore_page;
909 static struct new_area (*new_areas)[];
910 static long new_areas_index;
913 /* Add a new area to new_areas. */
915 add_new_area(page_index_t first_page, size_t offset, size_t size)
917 unsigned long new_area_start,c;
920 /* Ignore if full. */
921 if (new_areas_index >= NUM_NEW_AREAS)
924 switch (record_new_objects) {
928 if (first_page > new_areas_ignore_page)
937 new_area_start = npage_bytes(first_page) + offset;
939 /* Search backwards for a prior area that this follows from. If
940 found this will save adding a new area. */
941 for (i = new_areas_index-1, c = 0; (i >= 0) && (c < 8); i--, c++) {
942 unsigned long area_end =
943 npage_bytes((*new_areas)[i].page)
944 + (*new_areas)[i].offset
945 + (*new_areas)[i].size;
947 "/add_new_area S1 %d %d %d %d\n",
948 i, c, new_area_start, area_end));*/
949 if (new_area_start == area_end) {
951 "/adding to [%d] %d %d %d with %d %d %d:\n",
953 (*new_areas)[i].page,
954 (*new_areas)[i].offset,
955 (*new_areas)[i].size,
959 (*new_areas)[i].size += size;
964 (*new_areas)[new_areas_index].page = first_page;
965 (*new_areas)[new_areas_index].offset = offset;
966 (*new_areas)[new_areas_index].size = size;
968 "/new_area %d page %d offset %d size %d\n",
969 new_areas_index, first_page, offset, size));*/
972 /* Note the max new_areas used. */
973 if (new_areas_index > max_new_areas)
974 max_new_areas = new_areas_index;
977 /* Update the tables for the alloc_region. The region may be added to
980 * When done the alloc_region is set up so that the next quick alloc
981 * will fail safely and thus a new region will be allocated. Further
982 * it is safe to try to re-update the page table of this reset
985 gc_alloc_update_page_tables(int page_type_flag, struct alloc_region *alloc_region)
988 page_index_t first_page;
989 page_index_t next_page;
990 os_vm_size_t bytes_used;
991 os_vm_size_t region_size;
992 os_vm_size_t byte_cnt;
993 page_bytes_t orig_first_page_bytes_used;
997 first_page = alloc_region->first_page;
999 /* Catch an unused alloc_region. */
1000 if ((first_page == 0) && (alloc_region->last_page == -1))
1003 next_page = first_page+1;
1005 ret = thread_mutex_lock(&free_pages_lock);
1006 gc_assert(ret == 0);
1007 if (alloc_region->free_pointer != alloc_region->start_addr) {
1008 /* some bytes were allocated in the region */
1009 orig_first_page_bytes_used = page_table[first_page].bytes_used;
1011 gc_assert(alloc_region->start_addr ==
1012 (page_address(first_page)
1013 + page_table[first_page].bytes_used));
1015 /* All the pages used need to be updated */
1017 /* Update the first page. */
1019 /* If the page was free then set up the gen, and
1020 * region_start_offset. */
1021 if (page_table[first_page].bytes_used == 0)
1022 gc_assert(page_table[first_page].region_start_offset == 0);
1023 page_table[first_page].allocated &= ~(OPEN_REGION_PAGE_FLAG);
1025 gc_assert(page_table[first_page].allocated & page_type_flag);
1026 gc_assert(page_table[first_page].gen == gc_alloc_generation);
1027 gc_assert(page_table[first_page].large_object == 0);
1031 /* Calculate the number of bytes used in this page. This is not
1032 * always the number of new bytes, unless it was free. */
1034 if ((bytes_used = void_diff(alloc_region->free_pointer,
1035 page_address(first_page)))
1036 >GENCGC_CARD_BYTES) {
1037 bytes_used = GENCGC_CARD_BYTES;
1040 page_table[first_page].bytes_used = bytes_used;
1041 byte_cnt += bytes_used;
1044 /* All the rest of the pages should be free. We need to set
1045 * their region_start_offset pointer to the start of the
1046 * region, and set the bytes_used. */
1048 page_table[next_page].allocated &= ~(OPEN_REGION_PAGE_FLAG);
1049 gc_assert(page_table[next_page].allocated & page_type_flag);
1050 gc_assert(page_table[next_page].bytes_used == 0);
1051 gc_assert(page_table[next_page].gen == gc_alloc_generation);
1052 gc_assert(page_table[next_page].large_object == 0);
1054 gc_assert(page_table[next_page].region_start_offset ==
1055 void_diff(page_address(next_page),
1056 alloc_region->start_addr));
1058 /* Calculate the number of bytes used in this page. */
1060 if ((bytes_used = void_diff(alloc_region->free_pointer,
1061 page_address(next_page)))>GENCGC_CARD_BYTES) {
1062 bytes_used = GENCGC_CARD_BYTES;
1065 page_table[next_page].bytes_used = bytes_used;
1066 byte_cnt += bytes_used;
1071 region_size = void_diff(alloc_region->free_pointer,
1072 alloc_region->start_addr);
1073 bytes_allocated += region_size;
1074 generations[gc_alloc_generation].bytes_allocated += region_size;
1076 gc_assert((byte_cnt- orig_first_page_bytes_used) == region_size);
1078 /* Set the generations alloc restart page to the last page of
1080 set_generation_alloc_start_page(gc_alloc_generation, page_type_flag, 0, next_page-1);
1082 /* Add the region to the new_areas if requested. */
1083 if (BOXED_PAGE_FLAG & page_type_flag)
1084 add_new_area(first_page,orig_first_page_bytes_used, region_size);
1088 "/gc_alloc_update_page_tables update %d bytes to gen %d\n",
1090 gc_alloc_generation));
1093 /* There are no bytes allocated. Unallocate the first_page if
1094 * there are 0 bytes_used. */
1095 page_table[first_page].allocated &= ~(OPEN_REGION_PAGE_FLAG);
1096 if (page_table[first_page].bytes_used == 0)
1097 page_table[first_page].allocated = FREE_PAGE_FLAG;
1100 /* Unallocate any unused pages. */
1101 while (next_page <= alloc_region->last_page) {
1102 gc_assert(page_table[next_page].bytes_used == 0);
1103 page_table[next_page].allocated = FREE_PAGE_FLAG;
1106 ret = thread_mutex_unlock(&free_pages_lock);
1107 gc_assert(ret == 0);
1109 /* alloc_region is per-thread, we're ok to do this unlocked */
1110 gc_set_region_empty(alloc_region);
1113 static inline void *gc_quick_alloc(long nbytes);
1115 /* Allocate a possibly large object. */
1117 gc_alloc_large(long nbytes, int page_type_flag, struct alloc_region *alloc_region)
1120 page_index_t first_page, next_page, last_page;
1121 page_bytes_t orig_first_page_bytes_used;
1122 os_vm_size_t byte_cnt;
1123 os_vm_size_t bytes_used;
1126 ret = thread_mutex_lock(&free_pages_lock);
1127 gc_assert(ret == 0);
1129 first_page = generation_alloc_start_page(gc_alloc_generation, page_type_flag, 1);
1130 if (first_page <= alloc_region->last_page) {
1131 first_page = alloc_region->last_page+1;
1134 last_page=gc_find_freeish_pages(&first_page,nbytes, page_type_flag);
1136 gc_assert(first_page > alloc_region->last_page);
1138 set_generation_alloc_start_page(gc_alloc_generation, page_type_flag, 1, last_page);
1140 /* Set up the pages. */
1141 orig_first_page_bytes_used = page_table[first_page].bytes_used;
1143 /* If the first page was free then set up the gen, and
1144 * region_start_offset. */
1145 if (page_table[first_page].bytes_used == 0) {
1146 page_table[first_page].allocated = page_type_flag;
1147 page_table[first_page].gen = gc_alloc_generation;
1148 page_table[first_page].region_start_offset = 0;
1149 page_table[first_page].large_object = 1;
1152 gc_assert(page_table[first_page].allocated == page_type_flag);
1153 gc_assert(page_table[first_page].gen == gc_alloc_generation);
1154 gc_assert(page_table[first_page].large_object == 1);
1158 /* Calc. the number of bytes used in this page. This is not
1159 * always the number of new bytes, unless it was free. */
1161 if ((bytes_used = nbytes+orig_first_page_bytes_used) > GENCGC_CARD_BYTES) {
1162 bytes_used = GENCGC_CARD_BYTES;
1165 page_table[first_page].bytes_used = bytes_used;
1166 byte_cnt += bytes_used;
1168 next_page = first_page+1;
1170 /* All the rest of the pages should be free. We need to set their
1171 * region_start_offset pointer to the start of the region, and set
1172 * the bytes_used. */
1174 gc_assert(page_free_p(next_page));
1175 gc_assert(page_table[next_page].bytes_used == 0);
1176 page_table[next_page].allocated = page_type_flag;
1177 page_table[next_page].gen = gc_alloc_generation;
1178 page_table[next_page].large_object = 1;
1180 page_table[next_page].region_start_offset =
1181 npage_bytes(next_page-first_page) - orig_first_page_bytes_used;
1183 /* Calculate the number of bytes used in this page. */
1185 bytes_used=(nbytes+orig_first_page_bytes_used)-byte_cnt;
1186 if (bytes_used > GENCGC_CARD_BYTES) {
1187 bytes_used = GENCGC_CARD_BYTES;
1190 page_table[next_page].bytes_used = bytes_used;
1191 page_table[next_page].write_protected=0;
1192 page_table[next_page].dont_move=0;
1193 byte_cnt += bytes_used;
1197 gc_assert((byte_cnt-orig_first_page_bytes_used) == nbytes);
1199 bytes_allocated += nbytes;
1200 generations[gc_alloc_generation].bytes_allocated += nbytes;
1202 /* Add the region to the new_areas if requested. */
1203 if (BOXED_PAGE_FLAG & page_type_flag)
1204 add_new_area(first_page,orig_first_page_bytes_used,nbytes);
1206 /* Bump up last_free_page */
1207 if (last_page+1 > last_free_page) {
1208 last_free_page = last_page+1;
1209 set_alloc_pointer((lispobj)(page_address(last_free_page)));
1211 ret = thread_mutex_unlock(&free_pages_lock);
1212 gc_assert(ret == 0);
1214 #ifdef READ_PROTECT_FREE_PAGES
1215 os_protect(page_address(first_page),
1216 npage_bytes(1+last_page-first_page),
1220 zero_dirty_pages(first_page, last_page);
1222 return page_address(first_page);
1225 static page_index_t gencgc_alloc_start_page = -1;
1228 gc_heap_exhausted_error_or_lose (long available, long requested)
1230 struct thread *thread = arch_os_get_current_thread();
1231 /* Write basic information before doing anything else: if we don't
1232 * call to lisp this is a must, and even if we do there is always
1233 * the danger that we bounce back here before the error has been
1234 * handled, or indeed even printed.
1236 report_heap_exhaustion(available, requested, thread);
1237 if (gc_active_p || (available == 0)) {
1238 /* If we are in GC, or totally out of memory there is no way
1239 * to sanely transfer control to the lisp-side of things.
1241 lose("Heap exhausted, game over.");
1244 /* FIXME: assert free_pages_lock held */
1245 (void)thread_mutex_unlock(&free_pages_lock);
1246 gc_assert(get_pseudo_atomic_atomic(thread));
1247 clear_pseudo_atomic_atomic(thread);
1248 if (get_pseudo_atomic_interrupted(thread))
1249 do_pending_interrupt();
1250 /* Another issue is that signalling HEAP-EXHAUSTED error leads
1251 * to running user code at arbitrary places, even in a
1252 * WITHOUT-INTERRUPTS which may lead to a deadlock without
1253 * running out of the heap. So at this point all bets are
1255 if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL)
1256 corruption_warning_and_maybe_lose
1257 ("Signalling HEAP-EXHAUSTED in a WITHOUT-INTERRUPTS.");
1258 funcall2(StaticSymbolFunction(HEAP_EXHAUSTED_ERROR),
1259 alloc_number(available), alloc_number(requested));
1260 lose("HEAP-EXHAUSTED-ERROR fell through");
1265 gc_find_freeish_pages(page_index_t *restart_page_ptr, long bytes,
1268 page_index_t most_bytes_found_from = 0, most_bytes_found_to = 0;
1269 page_index_t first_page, last_page, restart_page = *restart_page_ptr;
1270 os_vm_size_t nbytes = bytes;
1271 os_vm_size_t nbytes_goal = nbytes;
1272 os_vm_size_t bytes_found = 0;
1273 os_vm_size_t most_bytes_found = 0;
1274 boolean small_object = nbytes < GENCGC_CARD_BYTES;
1275 /* FIXME: assert(free_pages_lock is held); */
1277 if (nbytes_goal < gencgc_alloc_granularity)
1278 nbytes_goal = gencgc_alloc_granularity;
1280 /* Toggled by gc_and_save for heap compaction, normally -1. */
1281 if (gencgc_alloc_start_page != -1) {
1282 restart_page = gencgc_alloc_start_page;
1285 /* FIXME: This is on bytes instead of nbytes pending cleanup of
1286 * long from the interface. */
1287 gc_assert(bytes>=0);
1288 /* Search for a page with at least nbytes of space. We prefer
1289 * not to split small objects on multiple pages, to reduce the
1290 * number of contiguous allocation regions spaning multiple
1291 * pages: this helps avoid excessive conservativism.
1293 * For other objects, we guarantee that they start on their own
1296 first_page = restart_page;
1297 while (first_page < page_table_pages) {
1299 if (page_free_p(first_page)) {
1300 gc_assert(0 == page_table[first_page].bytes_used);
1301 bytes_found = GENCGC_CARD_BYTES;
1302 } else if (small_object &&
1303 (page_table[first_page].allocated == page_type_flag) &&
1304 (page_table[first_page].large_object == 0) &&
1305 (page_table[first_page].gen == gc_alloc_generation) &&
1306 (page_table[first_page].write_protected == 0) &&
1307 (page_table[first_page].dont_move == 0)) {
1308 bytes_found = GENCGC_CARD_BYTES - page_table[first_page].bytes_used;
1309 if (bytes_found < nbytes) {
1310 if (bytes_found > most_bytes_found)
1311 most_bytes_found = bytes_found;
1320 gc_assert(page_table[first_page].write_protected == 0);
1321 for (last_page = first_page+1;
1322 ((last_page < page_table_pages) &&
1323 page_free_p(last_page) &&
1324 (bytes_found < nbytes_goal));
1326 bytes_found += GENCGC_CARD_BYTES;
1327 gc_assert(0 == page_table[last_page].bytes_used);
1328 gc_assert(0 == page_table[last_page].write_protected);
1331 if (bytes_found > most_bytes_found) {
1332 most_bytes_found = bytes_found;
1333 most_bytes_found_from = first_page;
1334 most_bytes_found_to = last_page;
1336 if (bytes_found >= nbytes_goal)
1339 first_page = last_page;
1342 bytes_found = most_bytes_found;
1343 restart_page = first_page + 1;
1345 /* Check for a failure */
1346 if (bytes_found < nbytes) {
1347 gc_assert(restart_page >= page_table_pages);
1348 gc_heap_exhausted_error_or_lose(most_bytes_found, nbytes);
1351 gc_assert(most_bytes_found_to);
1352 *restart_page_ptr = most_bytes_found_from;
1353 return most_bytes_found_to-1;
1356 /* Allocate bytes. All the rest of the special-purpose allocation
1357 * functions will eventually call this */
1360 gc_alloc_with_region(long nbytes,int page_type_flag, struct alloc_region *my_region,
1363 void *new_free_pointer;
1365 if (nbytes>=large_object_size)
1366 return gc_alloc_large(nbytes, page_type_flag, my_region);
1368 /* Check whether there is room in the current alloc region. */
1369 new_free_pointer = my_region->free_pointer + nbytes;
1371 /* fprintf(stderr, "alloc %d bytes from %p to %p\n", nbytes,
1372 my_region->free_pointer, new_free_pointer); */
1374 if (new_free_pointer <= my_region->end_addr) {
1375 /* If so then allocate from the current alloc region. */
1376 void *new_obj = my_region->free_pointer;
1377 my_region->free_pointer = new_free_pointer;
1379 /* Unless a `quick' alloc was requested, check whether the
1380 alloc region is almost empty. */
1382 void_diff(my_region->end_addr,my_region->free_pointer) <= 32) {
1383 /* If so, finished with the current region. */
1384 gc_alloc_update_page_tables(page_type_flag, my_region);
1385 /* Set up a new region. */
1386 gc_alloc_new_region(32 /*bytes*/, page_type_flag, my_region);
1389 return((void *)new_obj);
1392 /* Else not enough free space in the current region: retry with a
1395 gc_alloc_update_page_tables(page_type_flag, my_region);
1396 gc_alloc_new_region(nbytes, page_type_flag, my_region);
1397 return gc_alloc_with_region(nbytes, page_type_flag, my_region,0);
1400 /* these are only used during GC: all allocation from the mutator calls
1401 * alloc() -> gc_alloc_with_region() with the appropriate per-thread
1404 static inline void *
1405 gc_quick_alloc(long nbytes)
1407 return gc_general_alloc(nbytes, BOXED_PAGE_FLAG, ALLOC_QUICK);
1410 static inline void *
1411 gc_alloc_unboxed(long nbytes)
1413 return gc_general_alloc(nbytes, UNBOXED_PAGE_FLAG, 0);
1416 static inline void *
1417 gc_quick_alloc_unboxed(long nbytes)
1419 return gc_general_alloc(nbytes, UNBOXED_PAGE_FLAG, ALLOC_QUICK);
1422 /* Copy a large object. If the object is in a large object region then
1423 * it is simply promoted, else it is copied. If it's large enough then
1424 * it's copied to a large object region.
1426 * Bignums and vectors may have shrunk. If the object is not copied
1427 * the space needs to be reclaimed, and the page_tables corrected. */
1429 general_copy_large_object(lispobj object, long nwords, boolean boxedp)
1433 page_index_t first_page;
1435 gc_assert(is_lisp_pointer(object));
1436 gc_assert(from_space_p(object));
1437 gc_assert((nwords & 0x01) == 0);
1439 if ((nwords > 1024*1024) && gencgc_verbose) {
1440 FSHOW((stderr, "/general_copy_large_object: %d bytes\n",
1441 nwords*N_WORD_BYTES));
1444 /* Check whether it's a large object. */
1445 first_page = find_page_index((void *)object);
1446 gc_assert(first_page >= 0);
1448 if (page_table[first_page].large_object) {
1449 /* Promote the object. Note: Unboxed objects may have been
1450 * allocated to a BOXED region so it may be necessary to
1451 * change the region to UNBOXED. */
1452 os_vm_size_t remaining_bytes;
1453 os_vm_size_t bytes_freed;
1454 page_index_t next_page;
1455 page_bytes_t old_bytes_used;
1457 /* FIXME: This comment is somewhat stale.
1459 * Note: Any page write-protection must be removed, else a
1460 * later scavenge_newspace may incorrectly not scavenge these
1461 * pages. This would not be necessary if they are added to the
1462 * new areas, but let's do it for them all (they'll probably
1463 * be written anyway?). */
1465 gc_assert(page_table[first_page].region_start_offset == 0);
1466 next_page = first_page;
1467 remaining_bytes = nwords*N_WORD_BYTES;
1469 while (remaining_bytes > GENCGC_CARD_BYTES) {
1470 gc_assert(page_table[next_page].gen == from_space);
1471 gc_assert(page_table[next_page].large_object);
1472 gc_assert(page_table[next_page].region_start_offset ==
1473 npage_bytes(next_page-first_page));
1474 gc_assert(page_table[next_page].bytes_used == GENCGC_CARD_BYTES);
1475 /* Should have been unprotected by unprotect_oldspace()
1476 * for boxed objects, and after promotion unboxed ones
1477 * should not be on protected pages at all. */
1478 gc_assert(!page_table[next_page].write_protected);
1481 gc_assert(page_boxed_p(next_page));
1483 gc_assert(page_allocated_no_region_p(next_page));
1484 page_table[next_page].allocated = UNBOXED_PAGE_FLAG;
1486 page_table[next_page].gen = new_space;
1488 remaining_bytes -= GENCGC_CARD_BYTES;
1492 /* Now only one page remains, but the object may have shrunk so
1493 * there may be more unused pages which will be freed. */
1495 /* Object may have shrunk but shouldn't have grown - check. */
1496 gc_assert(page_table[next_page].bytes_used >= remaining_bytes);
1498 page_table[next_page].gen = new_space;
1501 gc_assert(page_boxed_p(next_page));
1503 page_table[next_page].allocated = UNBOXED_PAGE_FLAG;
1505 /* Adjust the bytes_used. */
1506 old_bytes_used = page_table[next_page].bytes_used;
1507 page_table[next_page].bytes_used = remaining_bytes;
1509 bytes_freed = old_bytes_used - remaining_bytes;
1511 /* Free any remaining pages; needs care. */
1513 while ((old_bytes_used == GENCGC_CARD_BYTES) &&
1514 (page_table[next_page].gen == from_space) &&
1515 /* FIXME: It is not obvious to me why this is necessary
1516 * as a loop condition: it seems to me that the
1517 * region_start_offset test should be sufficient, but
1518 * experimentally that is not the case. --NS
1521 page_boxed_p(next_page) :
1522 page_allocated_no_region_p(next_page)) &&
1523 page_table[next_page].large_object &&
1524 (page_table[next_page].region_start_offset ==
1525 npage_bytes(next_page - first_page))) {
1526 /* Checks out OK, free the page. Don't need to both zeroing
1527 * pages as this should have been done before shrinking the
1528 * object. These pages shouldn't be write-protected, even if
1529 * boxed they should be zero filled. */
1530 gc_assert(page_table[next_page].write_protected == 0);
1532 old_bytes_used = page_table[next_page].bytes_used;
1533 page_table[next_page].allocated = FREE_PAGE_FLAG;
1534 page_table[next_page].bytes_used = 0;
1535 bytes_freed += old_bytes_used;
1539 if ((bytes_freed > 0) && gencgc_verbose) {
1541 "/general_copy_large_object bytes_freed=%"OS_VM_SIZE_FMT"\n",
1545 generations[from_space].bytes_allocated -= nwords*N_WORD_BYTES
1547 generations[new_space].bytes_allocated += nwords*N_WORD_BYTES;
1548 bytes_allocated -= bytes_freed;
1550 /* Add the region to the new_areas if requested. */
1552 add_new_area(first_page,0,nwords*N_WORD_BYTES);
1557 /* Get tag of object. */
1558 tag = lowtag_of(object);
1560 /* Allocate space. */
1561 new = gc_general_alloc(nwords*N_WORD_BYTES,
1562 (boxedp ? BOXED_PAGE_FLAG : UNBOXED_PAGE_FLAG),
1565 /* Copy the object. */
1566 memcpy(new,native_pointer(object),nwords*N_WORD_BYTES);
1568 /* Return Lisp pointer of new object. */
1569 return ((lispobj) new) | tag;
1574 copy_large_object(lispobj object, long nwords)
1576 return general_copy_large_object(object, nwords, 1);
1580 copy_large_unboxed_object(lispobj object, long nwords)
1582 return general_copy_large_object(object, nwords, 0);
1585 /* to copy unboxed objects */
1587 copy_unboxed_object(lispobj object, long nwords)
1592 gc_assert(is_lisp_pointer(object));
1593 gc_assert(from_space_p(object));
1594 gc_assert((nwords & 0x01) == 0);
1596 /* Get tag of object. */
1597 tag = lowtag_of(object);
1599 /* Allocate space. */
1600 new = gc_quick_alloc_unboxed(nwords*N_WORD_BYTES);
1602 memcpy(new,native_pointer(object),nwords*N_WORD_BYTES);
1604 /* Return Lisp pointer of new object. */
1605 return ((lispobj) new) | tag;
1610 * code and code-related objects
1613 static lispobj trans_fun_header(lispobj object);
1614 static lispobj trans_boxed(lispobj object);
1617 /* Scan a x86 compiled code object, looking for possible fixups that
1618 * have been missed after a move.
1620 * Two types of fixups are needed:
1621 * 1. Absolute fixups to within the code object.
1622 * 2. Relative fixups to outside the code object.
1624 * Currently only absolute fixups to the constant vector, or to the
1625 * code area are checked. */
1627 sniff_code_object(struct code *code, unsigned long displacement)
1629 #ifdef LISP_FEATURE_X86
1630 long nheader_words, ncode_words, nwords;
1632 void *constants_start_addr = NULL, *constants_end_addr;
1633 void *code_start_addr, *code_end_addr;
1634 int fixup_found = 0;
1636 if (!check_code_fixups)
1639 FSHOW((stderr, "/sniffing code: %p, %lu\n", code, displacement));
1641 ncode_words = fixnum_value(code->code_size);
1642 nheader_words = HeaderValue(*(lispobj *)code);
1643 nwords = ncode_words + nheader_words;
1645 constants_start_addr = (void *)code + 5*N_WORD_BYTES;
1646 constants_end_addr = (void *)code + nheader_words*N_WORD_BYTES;
1647 code_start_addr = (void *)code + nheader_words*N_WORD_BYTES;
1648 code_end_addr = (void *)code + nwords*N_WORD_BYTES;
1650 /* Work through the unboxed code. */
1651 for (p = code_start_addr; p < code_end_addr; p++) {
1652 void *data = *(void **)p;
1653 unsigned d1 = *((unsigned char *)p - 1);
1654 unsigned d2 = *((unsigned char *)p - 2);
1655 unsigned d3 = *((unsigned char *)p - 3);
1656 unsigned d4 = *((unsigned char *)p - 4);
1658 unsigned d5 = *((unsigned char *)p - 5);
1659 unsigned d6 = *((unsigned char *)p - 6);
1662 /* Check for code references. */
1663 /* Check for a 32 bit word that looks like an absolute
1664 reference to within the code adea of the code object. */
1665 if ((data >= (code_start_addr-displacement))
1666 && (data < (code_end_addr-displacement))) {
1667 /* function header */
1669 && (((unsigned)p - 4 - 4*HeaderValue(*((unsigned *)p-1))) ==
1671 /* Skip the function header */
1675 /* the case of PUSH imm32 */
1679 "/code ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1680 p, d6, d5, d4, d3, d2, d1, data));
1681 FSHOW((stderr, "/PUSH $0x%.8x\n", data));
1683 /* the case of MOV [reg-8],imm32 */
1685 && (d2==0x40 || d2==0x41 || d2==0x42 || d2==0x43
1686 || d2==0x45 || d2==0x46 || d2==0x47)
1690 "/code ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1691 p, d6, d5, d4, d3, d2, d1, data));
1692 FSHOW((stderr, "/MOV [reg-8],$0x%.8x\n", data));
1694 /* the case of LEA reg,[disp32] */
1695 if ((d2 == 0x8d) && ((d1 & 0xc7) == 5)) {
1698 "/code ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1699 p, d6, d5, d4, d3, d2, d1, data));
1700 FSHOW((stderr,"/LEA reg,[$0x%.8x]\n", data));
1704 /* Check for constant references. */
1705 /* Check for a 32 bit word that looks like an absolute
1706 reference to within the constant vector. Constant references
1708 if ((data >= (constants_start_addr-displacement))
1709 && (data < (constants_end_addr-displacement))
1710 && (((unsigned)data & 0x3) == 0)) {
1715 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1716 p, d6, d5, d4, d3, d2, d1, data));
1717 FSHOW((stderr,"/MOV eax,0x%.8x\n", data));
1720 /* the case of MOV m32,EAX */
1724 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1725 p, d6, d5, d4, d3, d2, d1, data));
1726 FSHOW((stderr, "/MOV 0x%.8x,eax\n", data));
1729 /* the case of CMP m32,imm32 */
1730 if ((d1 == 0x3d) && (d2 == 0x81)) {
1733 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1734 p, d6, d5, d4, d3, d2, d1, data));
1736 FSHOW((stderr, "/CMP 0x%.8x,immed32\n", data));
1739 /* Check for a mod=00, r/m=101 byte. */
1740 if ((d1 & 0xc7) == 5) {
1745 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1746 p, d6, d5, d4, d3, d2, d1, data));
1747 FSHOW((stderr,"/CMP 0x%.8x,reg\n", data));
1749 /* the case of CMP reg32,m32 */
1753 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1754 p, d6, d5, d4, d3, d2, d1, data));
1755 FSHOW((stderr, "/CMP reg32,0x%.8x\n", data));
1757 /* the case of MOV m32,reg32 */
1761 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1762 p, d6, d5, d4, d3, d2, d1, data));
1763 FSHOW((stderr, "/MOV 0x%.8x,reg32\n", data));
1765 /* the case of MOV reg32,m32 */
1769 "/abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1770 p, d6, d5, d4, d3, d2, d1, data));
1771 FSHOW((stderr, "/MOV reg32,0x%.8x\n", data));
1773 /* the case of LEA reg32,m32 */
1777 "abs const ref @%x: %.2x %.2x %.2x %.2x %.2x %.2x (%.8x)\n",
1778 p, d6, d5, d4, d3, d2, d1, data));
1779 FSHOW((stderr, "/LEA reg32,0x%.8x\n", data));
1785 /* If anything was found, print some information on the code
1789 "/compiled code object at %x: header words = %d, code words = %d\n",
1790 code, nheader_words, ncode_words));
1792 "/const start = %x, end = %x\n",
1793 constants_start_addr, constants_end_addr));
1795 "/code start = %x, end = %x\n",
1796 code_start_addr, code_end_addr));
1802 gencgc_apply_code_fixups(struct code *old_code, struct code *new_code)
1804 /* x86-64 uses pc-relative addressing instead of this kludge */
1805 #ifndef LISP_FEATURE_X86_64
1806 long nheader_words, ncode_words, nwords;
1807 void *constants_start_addr, *constants_end_addr;
1808 void *code_start_addr, *code_end_addr;
1809 lispobj fixups = NIL;
1810 unsigned long displacement =
1811 (unsigned long)new_code - (unsigned long)old_code;
1812 struct vector *fixups_vector;
1814 ncode_words = fixnum_value(new_code->code_size);
1815 nheader_words = HeaderValue(*(lispobj *)new_code);
1816 nwords = ncode_words + nheader_words;
1818 "/compiled code object at %x: header words = %d, code words = %d\n",
1819 new_code, nheader_words, ncode_words)); */
1820 constants_start_addr = (void *)new_code + 5*N_WORD_BYTES;
1821 constants_end_addr = (void *)new_code + nheader_words*N_WORD_BYTES;
1822 code_start_addr = (void *)new_code + nheader_words*N_WORD_BYTES;
1823 code_end_addr = (void *)new_code + nwords*N_WORD_BYTES;
1826 "/const start = %x, end = %x\n",
1827 constants_start_addr,constants_end_addr));
1829 "/code start = %x; end = %x\n",
1830 code_start_addr,code_end_addr));
1833 /* The first constant should be a pointer to the fixups for this
1834 code objects. Check. */
1835 fixups = new_code->constants[0];
1837 /* It will be 0 or the unbound-marker if there are no fixups (as
1838 * will be the case if the code object has been purified, for
1839 * example) and will be an other pointer if it is valid. */
1840 if ((fixups == 0) || (fixups == UNBOUND_MARKER_WIDETAG) ||
1841 !is_lisp_pointer(fixups)) {
1842 /* Check for possible errors. */
1843 if (check_code_fixups)
1844 sniff_code_object(new_code, displacement);
1849 fixups_vector = (struct vector *)native_pointer(fixups);
1851 /* Could be pointing to a forwarding pointer. */
1852 /* FIXME is this always in from_space? if so, could replace this code with
1853 * forwarding_pointer_p/forwarding_pointer_value */
1854 if (is_lisp_pointer(fixups) &&
1855 (find_page_index((void*)fixups_vector) != -1) &&
1856 (fixups_vector->header == 0x01)) {
1857 /* If so, then follow it. */
1858 /*SHOW("following pointer to a forwarding pointer");*/
1860 (struct vector *)native_pointer((lispobj)fixups_vector->length);
1863 /*SHOW("got fixups");*/
1865 if (widetag_of(fixups_vector->header) == SIMPLE_ARRAY_WORD_WIDETAG) {
1866 /* Got the fixups for the code block. Now work through the vector,
1867 and apply a fixup at each address. */
1868 long length = fixnum_value(fixups_vector->length);
1870 for (i = 0; i < length; i++) {
1871 unsigned long offset = fixups_vector->data[i];
1872 /* Now check the current value of offset. */
1873 unsigned long old_value =
1874 *(unsigned long *)((unsigned long)code_start_addr + offset);
1876 /* If it's within the old_code object then it must be an
1877 * absolute fixup (relative ones are not saved) */
1878 if ((old_value >= (unsigned long)old_code)
1879 && (old_value < ((unsigned long)old_code
1880 + nwords*N_WORD_BYTES)))
1881 /* So add the dispacement. */
1882 *(unsigned long *)((unsigned long)code_start_addr + offset) =
1883 old_value + displacement;
1885 /* It is outside the old code object so it must be a
1886 * relative fixup (absolute fixups are not saved). So
1887 * subtract the displacement. */
1888 *(unsigned long *)((unsigned long)code_start_addr + offset) =
1889 old_value - displacement;
1892 /* This used to just print a note to stderr, but a bogus fixup seems to
1893 * indicate real heap corruption, so a hard hailure is in order. */
1894 lose("fixup vector %p has a bad widetag: %d\n",
1895 fixups_vector, widetag_of(fixups_vector->header));
1898 /* Check for possible errors. */
1899 if (check_code_fixups) {
1900 sniff_code_object(new_code,displacement);
1907 trans_boxed_large(lispobj object)
1910 unsigned long length;
1912 gc_assert(is_lisp_pointer(object));
1914 header = *((lispobj *) native_pointer(object));
1915 length = HeaderValue(header) + 1;
1916 length = CEILING(length, 2);
1918 return copy_large_object(object, length);
1921 /* Doesn't seem to be used, delete it after the grace period. */
1924 trans_unboxed_large(lispobj object)
1927 unsigned long length;
1929 gc_assert(is_lisp_pointer(object));
1931 header = *((lispobj *) native_pointer(object));
1932 length = HeaderValue(header) + 1;
1933 length = CEILING(length, 2);
1935 return copy_large_unboxed_object(object, length);
1943 /* XX This is a hack adapted from cgc.c. These don't work too
1944 * efficiently with the gencgc as a list of the weak pointers is
1945 * maintained within the objects which causes writes to the pages. A
1946 * limited attempt is made to avoid unnecessary writes, but this needs
1948 #define WEAK_POINTER_NWORDS \
1949 CEILING((sizeof(struct weak_pointer) / sizeof(lispobj)), 2)
1952 scav_weak_pointer(lispobj *where, lispobj object)
1954 /* Since we overwrite the 'next' field, we have to make
1955 * sure not to do so for pointers already in the list.
1956 * Instead of searching the list of weak_pointers each
1957 * time, we ensure that next is always NULL when the weak
1958 * pointer isn't in the list, and not NULL otherwise.
1959 * Since we can't use NULL to denote end of list, we
1960 * use a pointer back to the same weak_pointer.
1962 struct weak_pointer * wp = (struct weak_pointer*)where;
1964 if (NULL == wp->next) {
1965 wp->next = weak_pointers;
1967 if (NULL == wp->next)
1971 /* Do not let GC scavenge the value slot of the weak pointer.
1972 * (That is why it is a weak pointer.) */
1974 return WEAK_POINTER_NWORDS;
1979 search_read_only_space(void *pointer)
1981 lispobj *start = (lispobj *) READ_ONLY_SPACE_START;
1982 lispobj *end = (lispobj *) SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0);
1983 if ((pointer < (void *)start) || (pointer >= (void *)end))
1985 return (gc_search_space(start,
1986 (((lispobj *)pointer)+2)-start,
1987 (lispobj *) pointer));
1991 search_static_space(void *pointer)
1993 lispobj *start = (lispobj *)STATIC_SPACE_START;
1994 lispobj *end = (lispobj *)SymbolValue(STATIC_SPACE_FREE_POINTER,0);
1995 if ((pointer < (void *)start) || (pointer >= (void *)end))
1997 return (gc_search_space(start,
1998 (((lispobj *)pointer)+2)-start,
1999 (lispobj *) pointer));
2002 /* a faster version for searching the dynamic space. This will work even
2003 * if the object is in a current allocation region. */
2005 search_dynamic_space(void *pointer)
2007 page_index_t page_index = find_page_index(pointer);
2010 /* The address may be invalid, so do some checks. */
2011 if ((page_index == -1) || page_free_p(page_index))
2013 start = (lispobj *)page_region_start(page_index);
2014 return (gc_search_space(start,
2015 (((lispobj *)pointer)+2)-start,
2016 (lispobj *)pointer));
2019 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
2021 /* Is there any possibility that pointer is a valid Lisp object
2022 * reference, and/or something else (e.g. subroutine call return
2023 * address) which should prevent us from moving the referred-to thing?
2024 * This is called from preserve_pointers() */
2026 possibly_valid_dynamic_space_pointer(lispobj *pointer)
2028 lispobj *start_addr;
2030 /* Find the object start address. */
2031 if ((start_addr = search_dynamic_space(pointer)) == NULL) {
2035 return looks_like_valid_lisp_pointer_p(pointer, start_addr);
2038 #endif // defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
2040 /* Adjust large bignum and vector objects. This will adjust the
2041 * allocated region if the size has shrunk, and move unboxed objects
2042 * into unboxed pages. The pages are not promoted here, and the
2043 * promoted region is not added to the new_regions; this is really
2044 * only designed to be called from preserve_pointer(). Shouldn't fail
2045 * if this is missed, just may delay the moving of objects to unboxed
2046 * pages, and the freeing of pages. */
2048 maybe_adjust_large_object(lispobj *where)
2050 page_index_t first_page;
2051 page_index_t next_page;
2054 unsigned long remaining_bytes;
2055 unsigned long bytes_freed;
2056 unsigned long old_bytes_used;
2060 /* Check whether it's a vector or bignum object. */
2061 switch (widetag_of(where[0])) {
2062 case SIMPLE_VECTOR_WIDETAG:
2063 boxed = BOXED_PAGE_FLAG;
2065 case BIGNUM_WIDETAG:
2066 case SIMPLE_BASE_STRING_WIDETAG:
2067 #ifdef SIMPLE_CHARACTER_STRING_WIDETAG
2068 case SIMPLE_CHARACTER_STRING_WIDETAG:
2070 case SIMPLE_BIT_VECTOR_WIDETAG:
2071 case SIMPLE_ARRAY_NIL_WIDETAG:
2072 case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
2073 case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
2074 case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
2075 case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
2076 case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
2077 case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
2079 case SIMPLE_ARRAY_UNSIGNED_FIXNUM_WIDETAG:
2081 case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
2082 case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
2083 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
2084 case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG:
2086 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
2087 case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG:
2089 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
2090 case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
2092 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
2093 case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
2096 case SIMPLE_ARRAY_FIXNUM_WIDETAG:
2098 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
2099 case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
2101 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
2102 case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG:
2104 case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
2105 case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
2106 #ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
2107 case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
2109 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
2110 case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
2112 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
2113 case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
2115 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
2116 case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
2118 boxed = UNBOXED_PAGE_FLAG;
2124 /* Find its current size. */
2125 nwords = (sizetab[widetag_of(where[0])])(where);
2127 first_page = find_page_index((void *)where);
2128 gc_assert(first_page >= 0);
2130 /* Note: Any page write-protection must be removed, else a later
2131 * scavenge_newspace may incorrectly not scavenge these pages.
2132 * This would not be necessary if they are added to the new areas,
2133 * but lets do it for them all (they'll probably be written
2136 gc_assert(page_table[first_page].region_start_offset == 0);
2138 next_page = first_page;
2139 remaining_bytes = nwords*N_WORD_BYTES;
2140 while (remaining_bytes > GENCGC_CARD_BYTES) {
2141 gc_assert(page_table[next_page].gen == from_space);
2142 gc_assert(page_allocated_no_region_p(next_page));
2143 gc_assert(page_table[next_page].large_object);
2144 gc_assert(page_table[next_page].region_start_offset ==
2145 npage_bytes(next_page-first_page));
2146 gc_assert(page_table[next_page].bytes_used == GENCGC_CARD_BYTES);
2148 page_table[next_page].allocated = boxed;
2150 /* Shouldn't be write-protected at this stage. Essential that the
2152 gc_assert(!page_table[next_page].write_protected);
2153 remaining_bytes -= GENCGC_CARD_BYTES;
2157 /* Now only one page remains, but the object may have shrunk so
2158 * there may be more unused pages which will be freed. */
2160 /* Object may have shrunk but shouldn't have grown - check. */
2161 gc_assert(page_table[next_page].bytes_used >= remaining_bytes);
2163 page_table[next_page].allocated = boxed;
2164 gc_assert(page_table[next_page].allocated ==
2165 page_table[first_page].allocated);
2167 /* Adjust the bytes_used. */
2168 old_bytes_used = page_table[next_page].bytes_used;
2169 page_table[next_page].bytes_used = remaining_bytes;
2171 bytes_freed = old_bytes_used - remaining_bytes;
2173 /* Free any remaining pages; needs care. */
2175 while ((old_bytes_used == GENCGC_CARD_BYTES) &&
2176 (page_table[next_page].gen == from_space) &&
2177 page_allocated_no_region_p(next_page) &&
2178 page_table[next_page].large_object &&
2179 (page_table[next_page].region_start_offset ==
2180 npage_bytes(next_page - first_page))) {
2181 /* It checks out OK, free the page. We don't need to both zeroing
2182 * pages as this should have been done before shrinking the
2183 * object. These pages shouldn't be write protected as they
2184 * should be zero filled. */
2185 gc_assert(page_table[next_page].write_protected == 0);
2187 old_bytes_used = page_table[next_page].bytes_used;
2188 page_table[next_page].allocated = FREE_PAGE_FLAG;
2189 page_table[next_page].bytes_used = 0;
2190 bytes_freed += old_bytes_used;
2194 if ((bytes_freed > 0) && gencgc_verbose) {
2196 "/maybe_adjust_large_object() freed %d\n",
2200 generations[from_space].bytes_allocated -= bytes_freed;
2201 bytes_allocated -= bytes_freed;
2206 /* Take a possible pointer to a Lisp object and mark its page in the
2207 * page_table so that it will not be relocated during a GC.
2209 * This involves locating the page it points to, then backing up to
2210 * the start of its region, then marking all pages dont_move from there
2211 * up to the first page that's not full or has a different generation
2213 * It is assumed that all the page static flags have been cleared at
2214 * the start of a GC.
2216 * It is also assumed that the current gc_alloc() region has been
2217 * flushed and the tables updated. */
2220 preserve_pointer(void *addr)
2222 page_index_t addr_page_index = find_page_index(addr);
2223 page_index_t first_page;
2225 unsigned int region_allocation;
2227 /* quick check 1: Address is quite likely to have been invalid. */
2228 if ((addr_page_index == -1)
2229 || page_free_p(addr_page_index)
2230 || (page_table[addr_page_index].bytes_used == 0)
2231 || (page_table[addr_page_index].gen != from_space)
2232 /* Skip if already marked dont_move. */
2233 || (page_table[addr_page_index].dont_move != 0))
2235 gc_assert(!(page_table[addr_page_index].allocated&OPEN_REGION_PAGE_FLAG));
2236 /* (Now that we know that addr_page_index is in range, it's
2237 * safe to index into page_table[] with it.) */
2238 region_allocation = page_table[addr_page_index].allocated;
2240 /* quick check 2: Check the offset within the page.
2243 if (((unsigned long)addr & (GENCGC_CARD_BYTES - 1)) >
2244 page_table[addr_page_index].bytes_used)
2247 /* Filter out anything which can't be a pointer to a Lisp object
2248 * (or, as a special case which also requires dont_move, a return
2249 * address referring to something in a CodeObject). This is
2250 * expensive but important, since it vastly reduces the
2251 * probability that random garbage will be bogusly interpreted as
2252 * a pointer which prevents a page from moving.
2254 * This only needs to happen on x86oids, where this is used for
2255 * conservative roots. Non-x86oid systems only ever call this
2256 * function on known-valid lisp objects. */
2257 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
2258 if (!(code_page_p(addr_page_index)
2259 || (is_lisp_pointer((lispobj)addr) &&
2260 possibly_valid_dynamic_space_pointer(addr))))
2264 /* Find the beginning of the region. Note that there may be
2265 * objects in the region preceding the one that we were passed a
2266 * pointer to: if this is the case, we will write-protect all the
2267 * previous objects' pages too. */
2270 /* I think this'd work just as well, but without the assertions.
2271 * -dan 2004.01.01 */
2272 first_page = find_page_index(page_region_start(addr_page_index))
2274 first_page = addr_page_index;
2275 while (page_table[first_page].region_start_offset != 0) {
2277 /* Do some checks. */
2278 gc_assert(page_table[first_page].bytes_used == GENCGC_CARD_BYTES);
2279 gc_assert(page_table[first_page].gen == from_space);
2280 gc_assert(page_table[first_page].allocated == region_allocation);
2284 /* Adjust any large objects before promotion as they won't be
2285 * copied after promotion. */
2286 if (page_table[first_page].large_object) {
2287 maybe_adjust_large_object(page_address(first_page));
2288 /* If a large object has shrunk then addr may now point to a
2289 * free area in which case it's ignored here. Note it gets
2290 * through the valid pointer test above because the tail looks
2292 if (page_free_p(addr_page_index)
2293 || (page_table[addr_page_index].bytes_used == 0)
2294 /* Check the offset within the page. */
2295 || (((unsigned long)addr & (GENCGC_CARD_BYTES - 1))
2296 > page_table[addr_page_index].bytes_used)) {
2298 "weird? ignore ptr 0x%x to freed area of large object\n",
2302 /* It may have moved to unboxed pages. */
2303 region_allocation = page_table[first_page].allocated;
2306 /* Now work forward until the end of this contiguous area is found,
2307 * marking all pages as dont_move. */
2308 for (i = first_page; ;i++) {
2309 gc_assert(page_table[i].allocated == region_allocation);
2311 /* Mark the page static. */
2312 page_table[i].dont_move = 1;
2314 /* Move the page to the new_space. XX I'd rather not do this
2315 * but the GC logic is not quite able to copy with the static
2316 * pages remaining in the from space. This also requires the
2317 * generation bytes_allocated counters be updated. */
2318 page_table[i].gen = new_space;
2319 generations[new_space].bytes_allocated += page_table[i].bytes_used;
2320 generations[from_space].bytes_allocated -= page_table[i].bytes_used;
2322 /* It is essential that the pages are not write protected as
2323 * they may have pointers into the old-space which need
2324 * scavenging. They shouldn't be write protected at this
2326 gc_assert(!page_table[i].write_protected);
2328 /* Check whether this is the last page in this contiguous block.. */
2329 if ((page_table[i].bytes_used < GENCGC_CARD_BYTES)
2330 /* ..or it is CARD_BYTES and is the last in the block */
2332 || (page_table[i+1].bytes_used == 0) /* next page free */
2333 || (page_table[i+1].gen != from_space) /* diff. gen */
2334 || (page_table[i+1].region_start_offset == 0))
2338 /* Check that the page is now static. */
2339 gc_assert(page_table[addr_page_index].dont_move != 0);
2342 /* If the given page is not write-protected, then scan it for pointers
2343 * to younger generations or the top temp. generation, if no
2344 * suspicious pointers are found then the page is write-protected.
2346 * Care is taken to check for pointers to the current gc_alloc()
2347 * region if it is a younger generation or the temp. generation. This
2348 * frees the caller from doing a gc_alloc_update_page_tables(). Actually
2349 * the gc_alloc_generation does not need to be checked as this is only
2350 * called from scavenge_generation() when the gc_alloc generation is
2351 * younger, so it just checks if there is a pointer to the current
2354 * We return 1 if the page was write-protected, else 0. */
2356 update_page_write_prot(page_index_t page)
2358 generation_index_t gen = page_table[page].gen;
2361 void **page_addr = (void **)page_address(page);
2362 long num_words = page_table[page].bytes_used / N_WORD_BYTES;
2364 /* Shouldn't be a free page. */
2365 gc_assert(page_allocated_p(page));
2366 gc_assert(page_table[page].bytes_used != 0);
2368 /* Skip if it's already write-protected, pinned, or unboxed */
2369 if (page_table[page].write_protected
2370 /* FIXME: What's the reason for not write-protecting pinned pages? */
2371 || page_table[page].dont_move
2372 || page_unboxed_p(page))
2375 /* Scan the page for pointers to younger generations or the
2376 * top temp. generation. */
2378 for (j = 0; j < num_words; j++) {
2379 void *ptr = *(page_addr+j);
2380 page_index_t index = find_page_index(ptr);
2382 /* Check that it's in the dynamic space */
2384 if (/* Does it point to a younger or the temp. generation? */
2385 (page_allocated_p(index)
2386 && (page_table[index].bytes_used != 0)
2387 && ((page_table[index].gen < gen)
2388 || (page_table[index].gen == SCRATCH_GENERATION)))
2390 /* Or does it point within a current gc_alloc() region? */
2391 || ((boxed_region.start_addr <= ptr)
2392 && (ptr <= boxed_region.free_pointer))
2393 || ((unboxed_region.start_addr <= ptr)
2394 && (ptr <= unboxed_region.free_pointer))) {
2401 /* Write-protect the page. */
2402 /*FSHOW((stderr, "/write-protecting page %d gen %d\n", page, gen));*/
2404 os_protect((void *)page_addr,
2406 OS_VM_PROT_READ|OS_VM_PROT_EXECUTE);
2408 /* Note the page as protected in the page tables. */
2409 page_table[page].write_protected = 1;
2415 /* Scavenge all generations from FROM to TO, inclusive, except for
2416 * new_space which needs special handling, as new objects may be
2417 * added which are not checked here - use scavenge_newspace generation.
2419 * Write-protected pages should not have any pointers to the
2420 * from_space so do need scavenging; thus write-protected pages are
2421 * not always scavenged. There is some code to check that these pages
2422 * are not written; but to check fully the write-protected pages need
2423 * to be scavenged by disabling the code to skip them.
2425 * Under the current scheme when a generation is GCed the younger
2426 * generations will be empty. So, when a generation is being GCed it
2427 * is only necessary to scavenge the older generations for pointers
2428 * not the younger. So a page that does not have pointers to younger
2429 * generations does not need to be scavenged.
2431 * The write-protection can be used to note pages that don't have
2432 * pointers to younger pages. But pages can be written without having
2433 * pointers to younger generations. After the pages are scavenged here
2434 * they can be scanned for pointers to younger generations and if
2435 * there are none the page can be write-protected.
2437 * One complication is when the newspace is the top temp. generation.
2439 * Enabling SC_GEN_CK scavenges the write-protected pages and checks
2440 * that none were written, which they shouldn't be as they should have
2441 * no pointers to younger generations. This breaks down for weak
2442 * pointers as the objects contain a link to the next and are written
2443 * if a weak pointer is scavenged. Still it's a useful check. */
2445 scavenge_generations(generation_index_t from, generation_index_t to)
2448 page_index_t num_wp = 0;
2452 /* Clear the write_protected_cleared flags on all pages. */
2453 for (i = 0; i < page_table_pages; i++)
2454 page_table[i].write_protected_cleared = 0;
2457 for (i = 0; i < last_free_page; i++) {
2458 generation_index_t generation = page_table[i].gen;
2460 && (page_table[i].bytes_used != 0)
2461 && (generation != new_space)
2462 && (generation >= from)
2463 && (generation <= to)) {
2464 page_index_t last_page,j;
2465 int write_protected=1;
2467 /* This should be the start of a region */
2468 gc_assert(page_table[i].region_start_offset == 0);
2470 /* Now work forward until the end of the region */
2471 for (last_page = i; ; last_page++) {
2473 write_protected && page_table[last_page].write_protected;
2474 if ((page_table[last_page].bytes_used < GENCGC_CARD_BYTES)
2475 /* Or it is CARD_BYTES and is the last in the block */
2476 || (!page_boxed_p(last_page+1))
2477 || (page_table[last_page+1].bytes_used == 0)
2478 || (page_table[last_page+1].gen != generation)
2479 || (page_table[last_page+1].region_start_offset == 0))
2482 if (!write_protected) {
2483 scavenge(page_address(i),
2484 ((unsigned long)(page_table[last_page].bytes_used
2485 + npage_bytes(last_page-i)))
2488 /* Now scan the pages and write protect those that
2489 * don't have pointers to younger generations. */
2490 if (enable_page_protection) {
2491 for (j = i; j <= last_page; j++) {
2492 num_wp += update_page_write_prot(j);
2495 if ((gencgc_verbose > 1) && (num_wp != 0)) {
2497 "/write protected %d pages within generation %d\n",
2498 num_wp, generation));
2506 /* Check that none of the write_protected pages in this generation
2507 * have been written to. */
2508 for (i = 0; i < page_table_pages; i++) {
2509 if (page_allocated_p(i)
2510 && (page_table[i].bytes_used != 0)
2511 && (page_table[i].gen == generation)
2512 && (page_table[i].write_protected_cleared != 0)) {
2513 FSHOW((stderr, "/scavenge_generation() %d\n", generation));
2515 "/page bytes_used=%d region_start_offset=%lu dont_move=%d\n",
2516 page_table[i].bytes_used,
2517 page_table[i].region_start_offset,
2518 page_table[i].dont_move));
2519 lose("write to protected page %d in scavenge_generation()\n", i);
2526 /* Scavenge a newspace generation. As it is scavenged new objects may
2527 * be allocated to it; these will also need to be scavenged. This
2528 * repeats until there are no more objects unscavenged in the
2529 * newspace generation.
2531 * To help improve the efficiency, areas written are recorded by
2532 * gc_alloc() and only these scavenged. Sometimes a little more will be
2533 * scavenged, but this causes no harm. An easy check is done that the
2534 * scavenged bytes equals the number allocated in the previous
2537 * Write-protected pages are not scanned except if they are marked
2538 * dont_move in which case they may have been promoted and still have
2539 * pointers to the from space.
2541 * Write-protected pages could potentially be written by alloc however
2542 * to avoid having to handle re-scavenging of write-protected pages
2543 * gc_alloc() does not write to write-protected pages.
2545 * New areas of objects allocated are recorded alternatively in the two
2546 * new_areas arrays below. */
2547 static struct new_area new_areas_1[NUM_NEW_AREAS];
2548 static struct new_area new_areas_2[NUM_NEW_AREAS];
2550 /* Do one full scan of the new space generation. This is not enough to
2551 * complete the job as new objects may be added to the generation in
2552 * the process which are not scavenged. */
2554 scavenge_newspace_generation_one_scan(generation_index_t generation)
2559 "/starting one full scan of newspace generation %d\n",
2561 for (i = 0; i < last_free_page; i++) {
2562 /* Note that this skips over open regions when it encounters them. */
2564 && (page_table[i].bytes_used != 0)
2565 && (page_table[i].gen == generation)
2566 && ((page_table[i].write_protected == 0)
2567 /* (This may be redundant as write_protected is now
2568 * cleared before promotion.) */
2569 || (page_table[i].dont_move == 1))) {
2570 page_index_t last_page;
2573 /* The scavenge will start at the region_start_offset of
2576 * We need to find the full extent of this contiguous
2577 * block in case objects span pages.
2579 * Now work forward until the end of this contiguous area
2580 * is found. A small area is preferred as there is a
2581 * better chance of its pages being write-protected. */
2582 for (last_page = i; ;last_page++) {
2583 /* If all pages are write-protected and movable,
2584 * then no need to scavenge */
2585 all_wp=all_wp && page_table[last_page].write_protected &&
2586 !page_table[last_page].dont_move;
2588 /* Check whether this is the last page in this
2589 * contiguous block */
2590 if ((page_table[last_page].bytes_used < GENCGC_CARD_BYTES)
2591 /* Or it is CARD_BYTES and is the last in the block */
2592 || (!page_boxed_p(last_page+1))
2593 || (page_table[last_page+1].bytes_used == 0)
2594 || (page_table[last_page+1].gen != generation)
2595 || (page_table[last_page+1].region_start_offset == 0))
2599 /* Do a limited check for write-protected pages. */
2601 long nwords = (((unsigned long)
2602 (page_table[last_page].bytes_used
2603 + npage_bytes(last_page-i)
2604 + page_table[i].region_start_offset))
2606 new_areas_ignore_page = last_page;
2608 scavenge(page_region_start(i), nwords);
2615 "/done with one full scan of newspace generation %d\n",
2619 /* Do a complete scavenge of the newspace generation. */
2621 scavenge_newspace_generation(generation_index_t generation)
2625 /* the new_areas array currently being written to by gc_alloc() */
2626 struct new_area (*current_new_areas)[] = &new_areas_1;
2627 long current_new_areas_index;
2629 /* the new_areas created by the previous scavenge cycle */
2630 struct new_area (*previous_new_areas)[] = NULL;
2631 long previous_new_areas_index;
2633 /* Flush the current regions updating the tables. */
2634 gc_alloc_update_all_page_tables();
2636 /* Turn on the recording of new areas by gc_alloc(). */
2637 new_areas = current_new_areas;
2638 new_areas_index = 0;
2640 /* Don't need to record new areas that get scavenged anyway during
2641 * scavenge_newspace_generation_one_scan. */
2642 record_new_objects = 1;
2644 /* Start with a full scavenge. */
2645 scavenge_newspace_generation_one_scan(generation);
2647 /* Record all new areas now. */
2648 record_new_objects = 2;
2650 /* Give a chance to weak hash tables to make other objects live.
2651 * FIXME: The algorithm implemented here for weak hash table gcing
2652 * is O(W^2+N) as Bruno Haible warns in
2653 * http://www.haible.de/bruno/papers/cs/weak/WeakDatastructures-writeup.html
2654 * see "Implementation 2". */
2655 scav_weak_hash_tables();
2657 /* Flush the current regions updating the tables. */
2658 gc_alloc_update_all_page_tables();
2660 /* Grab new_areas_index. */
2661 current_new_areas_index = new_areas_index;
2664 "The first scan is finished; current_new_areas_index=%d.\n",
2665 current_new_areas_index));*/
2667 while (current_new_areas_index > 0) {
2668 /* Move the current to the previous new areas */
2669 previous_new_areas = current_new_areas;
2670 previous_new_areas_index = current_new_areas_index;
2672 /* Scavenge all the areas in previous new areas. Any new areas
2673 * allocated are saved in current_new_areas. */
2675 /* Allocate an array for current_new_areas; alternating between
2676 * new_areas_1 and 2 */
2677 if (previous_new_areas == &new_areas_1)
2678 current_new_areas = &new_areas_2;
2680 current_new_areas = &new_areas_1;
2682 /* Set up for gc_alloc(). */
2683 new_areas = current_new_areas;
2684 new_areas_index = 0;
2686 /* Check whether previous_new_areas had overflowed. */
2687 if (previous_new_areas_index >= NUM_NEW_AREAS) {
2689 /* New areas of objects allocated have been lost so need to do a
2690 * full scan to be sure! If this becomes a problem try
2691 * increasing NUM_NEW_AREAS. */
2692 if (gencgc_verbose) {
2693 SHOW("new_areas overflow, doing full scavenge");
2696 /* Don't need to record new areas that get scavenged
2697 * anyway during scavenge_newspace_generation_one_scan. */
2698 record_new_objects = 1;
2700 scavenge_newspace_generation_one_scan(generation);
2702 /* Record all new areas now. */
2703 record_new_objects = 2;
2705 scav_weak_hash_tables();
2707 /* Flush the current regions updating the tables. */
2708 gc_alloc_update_all_page_tables();
2712 /* Work through previous_new_areas. */
2713 for (i = 0; i < previous_new_areas_index; i++) {
2714 page_index_t page = (*previous_new_areas)[i].page;
2715 size_t offset = (*previous_new_areas)[i].offset;
2716 size_t size = (*previous_new_areas)[i].size / N_WORD_BYTES;
2717 gc_assert((*previous_new_areas)[i].size % N_WORD_BYTES == 0);
2718 scavenge(page_address(page)+offset, size);
2721 scav_weak_hash_tables();
2723 /* Flush the current regions updating the tables. */
2724 gc_alloc_update_all_page_tables();
2727 current_new_areas_index = new_areas_index;
2730 "The re-scan has finished; current_new_areas_index=%d.\n",
2731 current_new_areas_index));*/
2734 /* Turn off recording of areas allocated by gc_alloc(). */
2735 record_new_objects = 0;
2740 /* Check that none of the write_protected pages in this generation
2741 * have been written to. */
2742 for (i = 0; i < page_table_pages; i++) {
2743 if (page_allocated_p(i)
2744 && (page_table[i].bytes_used != 0)
2745 && (page_table[i].gen == generation)
2746 && (page_table[i].write_protected_cleared != 0)
2747 && (page_table[i].dont_move == 0)) {
2748 lose("write protected page %d written to in scavenge_newspace_generation\ngeneration=%d dont_move=%d\n",
2749 i, generation, page_table[i].dont_move);
2756 /* Un-write-protect all the pages in from_space. This is done at the
2757 * start of a GC else there may be many page faults while scavenging
2758 * the newspace (I've seen drive the system time to 99%). These pages
2759 * would need to be unprotected anyway before unmapping in
2760 * free_oldspace; not sure what effect this has on paging.. */
2762 unprotect_oldspace(void)
2765 void *region_addr = 0;
2766 void *page_addr = 0;
2767 unsigned long region_bytes = 0;
2769 for (i = 0; i < last_free_page; i++) {
2770 if (page_allocated_p(i)
2771 && (page_table[i].bytes_used != 0)
2772 && (page_table[i].gen == from_space)) {
2774 /* Remove any write-protection. We should be able to rely
2775 * on the write-protect flag to avoid redundant calls. */
2776 if (page_table[i].write_protected) {
2777 page_table[i].write_protected = 0;
2778 page_addr = page_address(i);
2781 region_addr = page_addr;
2782 region_bytes = GENCGC_CARD_BYTES;
2783 } else if (region_addr + region_bytes == page_addr) {
2784 /* Region continue. */
2785 region_bytes += GENCGC_CARD_BYTES;
2787 /* Unprotect previous region. */
2788 os_protect(region_addr, region_bytes, OS_VM_PROT_ALL);
2789 /* First page in new region. */
2790 region_addr = page_addr;
2791 region_bytes = GENCGC_CARD_BYTES;
2797 /* Unprotect last region. */
2798 os_protect(region_addr, region_bytes, OS_VM_PROT_ALL);
2802 /* Work through all the pages and free any in from_space. This
2803 * assumes that all objects have been copied or promoted to an older
2804 * generation. Bytes_allocated and the generation bytes_allocated
2805 * counter are updated. The number of bytes freed is returned. */
2806 static unsigned long
2809 unsigned long bytes_freed = 0;
2810 page_index_t first_page, last_page;
2815 /* Find a first page for the next region of pages. */
2816 while ((first_page < last_free_page)
2817 && (page_free_p(first_page)
2818 || (page_table[first_page].bytes_used == 0)
2819 || (page_table[first_page].gen != from_space)))
2822 if (first_page >= last_free_page)
2825 /* Find the last page of this region. */
2826 last_page = first_page;
2829 /* Free the page. */
2830 bytes_freed += page_table[last_page].bytes_used;
2831 generations[page_table[last_page].gen].bytes_allocated -=
2832 page_table[last_page].bytes_used;
2833 page_table[last_page].allocated = FREE_PAGE_FLAG;
2834 page_table[last_page].bytes_used = 0;
2835 /* Should already be unprotected by unprotect_oldspace(). */
2836 gc_assert(!page_table[last_page].write_protected);
2839 while ((last_page < last_free_page)
2840 && page_allocated_p(last_page)
2841 && (page_table[last_page].bytes_used != 0)
2842 && (page_table[last_page].gen == from_space));
2844 #ifdef READ_PROTECT_FREE_PAGES
2845 os_protect(page_address(first_page),
2846 npage_bytes(last_page-first_page),
2849 first_page = last_page;
2850 } while (first_page < last_free_page);
2852 bytes_allocated -= bytes_freed;
2857 /* Print some information about a pointer at the given address. */
2859 print_ptr(lispobj *addr)
2861 /* If addr is in the dynamic space then out the page information. */
2862 page_index_t pi1 = find_page_index((void*)addr);
2865 fprintf(stderr," %x: page %d alloc %d gen %d bytes_used %d offset %lu dont_move %d\n",
2866 (unsigned long) addr,
2868 page_table[pi1].allocated,
2869 page_table[pi1].gen,
2870 page_table[pi1].bytes_used,
2871 page_table[pi1].region_start_offset,
2872 page_table[pi1].dont_move);
2873 fprintf(stderr," %x %x %x %x (%x) %x %x %x %x\n",
2887 is_in_stack_space(lispobj ptr)
2889 /* For space verification: Pointers can be valid if they point
2890 * to a thread stack space. This would be faster if the thread
2891 * structures had page-table entries as if they were part of
2892 * the heap space. */
2894 for_each_thread(th) {
2895 if ((th->control_stack_start <= (lispobj *)ptr) &&
2896 (th->control_stack_end >= (lispobj *)ptr)) {
2904 verify_space(lispobj *start, size_t words)
2906 int is_in_dynamic_space = (find_page_index((void*)start) != -1);
2907 int is_in_readonly_space =
2908 (READ_ONLY_SPACE_START <= (unsigned long)start &&
2909 (unsigned long)start < SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0));
2913 lispobj thing = *(lispobj*)start;
2915 if (is_lisp_pointer(thing)) {
2916 page_index_t page_index = find_page_index((void*)thing);
2917 long to_readonly_space =
2918 (READ_ONLY_SPACE_START <= thing &&
2919 thing < SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0));
2920 long to_static_space =
2921 (STATIC_SPACE_START <= thing &&
2922 thing < SymbolValue(STATIC_SPACE_FREE_POINTER,0));
2924 /* Does it point to the dynamic space? */
2925 if (page_index != -1) {
2926 /* If it's within the dynamic space it should point to a used
2927 * page. XX Could check the offset too. */
2928 if (page_allocated_p(page_index)
2929 && (page_table[page_index].bytes_used == 0))
2930 lose ("Ptr %p @ %p sees free page.\n", thing, start);
2931 /* Check that it doesn't point to a forwarding pointer! */
2932 if (*((lispobj *)native_pointer(thing)) == 0x01) {
2933 lose("Ptr %p @ %p sees forwarding ptr.\n", thing, start);
2935 /* Check that its not in the RO space as it would then be a
2936 * pointer from the RO to the dynamic space. */
2937 if (is_in_readonly_space) {
2938 lose("ptr to dynamic space %p from RO space %x\n",
2941 /* Does it point to a plausible object? This check slows
2942 * it down a lot (so it's commented out).
2944 * "a lot" is serious: it ate 50 minutes cpu time on
2945 * my duron 950 before I came back from lunch and
2948 * FIXME: Add a variable to enable this
2951 if (!possibly_valid_dynamic_space_pointer((lispobj *)thing)) {
2952 lose("ptr %p to invalid object %p\n", thing, start);
2956 extern void funcallable_instance_tramp;
2957 /* Verify that it points to another valid space. */
2958 if (!to_readonly_space && !to_static_space
2959 && (thing != (lispobj)&funcallable_instance_tramp)
2960 && !is_in_stack_space(thing)) {
2961 lose("Ptr %p @ %p sees junk.\n", thing, start);
2965 if (!(fixnump(thing))) {
2967 switch(widetag_of(*start)) {
2970 case SIMPLE_VECTOR_WIDETAG:
2972 case COMPLEX_WIDETAG:
2973 case SIMPLE_ARRAY_WIDETAG:
2974 case COMPLEX_BASE_STRING_WIDETAG:
2975 #ifdef COMPLEX_CHARACTER_STRING_WIDETAG
2976 case COMPLEX_CHARACTER_STRING_WIDETAG:
2978 case COMPLEX_VECTOR_NIL_WIDETAG:
2979 case COMPLEX_BIT_VECTOR_WIDETAG:
2980 case COMPLEX_VECTOR_WIDETAG:
2981 case COMPLEX_ARRAY_WIDETAG:
2982 case CLOSURE_HEADER_WIDETAG:
2983 case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
2984 case VALUE_CELL_HEADER_WIDETAG:
2985 case SYMBOL_HEADER_WIDETAG:
2986 case CHARACTER_WIDETAG:
2987 #if N_WORD_BITS == 64
2988 case SINGLE_FLOAT_WIDETAG:
2990 case UNBOUND_MARKER_WIDETAG:
2995 case INSTANCE_HEADER_WIDETAG:
2998 long ntotal = HeaderValue(thing);
2999 lispobj layout = ((struct instance *)start)->slots[0];
3004 nuntagged = ((struct layout *)
3005 native_pointer(layout))->n_untagged_slots;
3006 verify_space(start + 1,
3007 ntotal - fixnum_value(nuntagged));
3011 case CODE_HEADER_WIDETAG:
3013 lispobj object = *start;
3015 long nheader_words, ncode_words, nwords;
3017 struct simple_fun *fheaderp;
3019 code = (struct code *) start;
3021 /* Check that it's not in the dynamic space.
3022 * FIXME: Isn't is supposed to be OK for code
3023 * objects to be in the dynamic space these days? */
3024 if (is_in_dynamic_space
3025 /* It's ok if it's byte compiled code. The trace
3026 * table offset will be a fixnum if it's x86
3027 * compiled code - check.
3029 * FIXME: #^#@@! lack of abstraction here..
3030 * This line can probably go away now that
3031 * there's no byte compiler, but I've got
3032 * too much to worry about right now to try
3033 * to make sure. -- WHN 2001-10-06 */
3034 && fixnump(code->trace_table_offset)
3035 /* Only when enabled */
3036 && verify_dynamic_code_check) {
3038 "/code object at %p in the dynamic space\n",
3042 ncode_words = fixnum_value(code->code_size);
3043 nheader_words = HeaderValue(object);
3044 nwords = ncode_words + nheader_words;
3045 nwords = CEILING(nwords, 2);
3046 /* Scavenge the boxed section of the code data block */
3047 verify_space(start + 1, nheader_words - 1);
3049 /* Scavenge the boxed section of each function
3050 * object in the code data block. */
3051 fheaderl = code->entry_points;
3052 while (fheaderl != NIL) {
3054 (struct simple_fun *) native_pointer(fheaderl);
3055 gc_assert(widetag_of(fheaderp->header) ==
3056 SIMPLE_FUN_HEADER_WIDETAG);
3057 verify_space(&fheaderp->name, 1);
3058 verify_space(&fheaderp->arglist, 1);
3059 verify_space(&fheaderp->type, 1);
3060 fheaderl = fheaderp->next;
3066 /* unboxed objects */
3067 case BIGNUM_WIDETAG:
3068 #if N_WORD_BITS != 64
3069 case SINGLE_FLOAT_WIDETAG:
3071 case DOUBLE_FLOAT_WIDETAG:
3072 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
3073 case LONG_FLOAT_WIDETAG:
3075 #ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
3076 case COMPLEX_SINGLE_FLOAT_WIDETAG:
3078 #ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
3079 case COMPLEX_DOUBLE_FLOAT_WIDETAG:
3081 #ifdef COMPLEX_LONG_FLOAT_WIDETAG
3082 case COMPLEX_LONG_FLOAT_WIDETAG:
3084 case SIMPLE_BASE_STRING_WIDETAG:
3085 #ifdef SIMPLE_CHARACTER_STRING_WIDETAG
3086 case SIMPLE_CHARACTER_STRING_WIDETAG:
3088 case SIMPLE_BIT_VECTOR_WIDETAG:
3089 case SIMPLE_ARRAY_NIL_WIDETAG:
3090 case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
3091 case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
3092 case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
3093 case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
3094 case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
3095 case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
3097 case SIMPLE_ARRAY_UNSIGNED_FIXNUM_WIDETAG:
3099 case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
3100 case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
3101 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
3102 case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG:
3104 #ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
3105 case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG:
3107 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
3108 case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
3110 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
3111 case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
3114 case SIMPLE_ARRAY_FIXNUM_WIDETAG:
3116 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
3117 case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
3119 #ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
3120 case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG:
3122 case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
3123 case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
3124 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
3125 case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
3127 #ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
3128 case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
3130 #ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
3131 case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
3133 #ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
3134 case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
3137 case WEAK_POINTER_WIDETAG:
3138 #ifdef NO_TLS_VALUE_MARKER_WIDETAG
3139 case NO_TLS_VALUE_MARKER_WIDETAG:
3141 count = (sizetab[widetag_of(*start)])(start);
3145 lose("Unhandled widetag %p at %p\n",
3146 widetag_of(*start), start);
3158 /* FIXME: It would be nice to make names consistent so that
3159 * foo_size meant size *in* *bytes* instead of size in some
3160 * arbitrary units. (Yes, this caused a bug, how did you guess?:-)
3161 * Some counts of lispobjs are called foo_count; it might be good
3162 * to grep for all foo_size and rename the appropriate ones to
3164 long read_only_space_size =
3165 (lispobj*)SymbolValue(READ_ONLY_SPACE_FREE_POINTER,0)
3166 - (lispobj*)READ_ONLY_SPACE_START;
3167 long static_space_size =
3168 (lispobj*)SymbolValue(STATIC_SPACE_FREE_POINTER,0)
3169 - (lispobj*)STATIC_SPACE_START;
3171 for_each_thread(th) {
3172 long binding_stack_size =
3173 (lispobj*)get_binding_stack_pointer(th)
3174 - (lispobj*)th->binding_stack_start;
3175 verify_space(th->binding_stack_start, binding_stack_size);
3177 verify_space((lispobj*)READ_ONLY_SPACE_START, read_only_space_size);
3178 verify_space((lispobj*)STATIC_SPACE_START , static_space_size);
3182 verify_generation(generation_index_t generation)
3186 for (i = 0; i < last_free_page; i++) {
3187 if (page_allocated_p(i)
3188 && (page_table[i].bytes_used != 0)
3189 && (page_table[i].gen == generation)) {
3190 page_index_t last_page;
3191 int region_allocation = page_table[i].allocated;
3193 /* This should be the start of a contiguous block */
3194 gc_assert(page_table[i].region_start_offset == 0);
3196 /* Need to find the full extent of this contiguous block in case
3197 objects span pages. */
3199 /* Now work forward until the end of this contiguous area is
3201 for (last_page = i; ;last_page++)
3202 /* Check whether this is the last page in this contiguous
3204 if ((page_table[last_page].bytes_used < GENCGC_CARD_BYTES)
3205 /* Or it is CARD_BYTES and is the last in the block */
3206 || (page_table[last_page+1].allocated != region_allocation)
3207 || (page_table[last_page+1].bytes_used == 0)
3208 || (page_table[last_page+1].gen != generation)
3209 || (page_table[last_page+1].region_start_offset == 0))
3212 verify_space(page_address(i),
3214 (page_table[last_page].bytes_used
3215 + npage_bytes(last_page-i)))
3222 /* Check that all the free space is zero filled. */
3224 verify_zero_fill(void)
3228 for (page = 0; page < last_free_page; page++) {
3229 if (page_free_p(page)) {
3230 /* The whole page should be zero filled. */
3231 long *start_addr = (long *)page_address(page);
3234 for (i = 0; i < size; i++) {
3235 if (start_addr[i] != 0) {
3236 lose("free page not zero at %x\n", start_addr + i);
3240 long free_bytes = GENCGC_CARD_BYTES - page_table[page].bytes_used;
3241 if (free_bytes > 0) {
3242 long *start_addr = (long *)((unsigned long)page_address(page)
3243 + page_table[page].bytes_used);
3244 long size = free_bytes / N_WORD_BYTES;
3246 for (i = 0; i < size; i++) {
3247 if (start_addr[i] != 0) {
3248 lose("free region not zero at %x\n", start_addr + i);
3256 /* External entry point for verify_zero_fill */
3258 gencgc_verify_zero_fill(void)
3260 /* Flush the alloc regions updating the tables. */
3261 gc_alloc_update_all_page_tables();
3262 SHOW("verifying zero fill");
3267 verify_dynamic_space(void)
3269 generation_index_t i;
3271 for (i = 0; i <= HIGHEST_NORMAL_GENERATION; i++)
3272 verify_generation(i);
3274 if (gencgc_enable_verify_zero_fill)
3278 /* Write-protect all the dynamic boxed pages in the given generation. */
3280 write_protect_generation_pages(generation_index_t generation)
3284 gc_assert(generation < SCRATCH_GENERATION);
3286 for (start = 0; start < last_free_page; start++) {
3287 if (protect_page_p(start, generation)) {
3291 /* Note the page as protected in the page tables. */
3292 page_table[start].write_protected = 1;
3294 for (last = start + 1; last < last_free_page; last++) {
3295 if (!protect_page_p(last, generation))
3297 page_table[last].write_protected = 1;
3300 page_start = (void *)page_address(start);
3302 os_protect(page_start,
3303 npage_bytes(last - start),
3304 OS_VM_PROT_READ | OS_VM_PROT_EXECUTE);
3310 if (gencgc_verbose > 1) {
3312 "/write protected %d of %d pages in generation %d\n",
3313 count_write_protect_generation_pages(generation),
3314 count_generation_pages(generation),
3319 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
3321 scavenge_control_stack(struct thread *th)
3323 lispobj *control_stack =
3324 (lispobj *)(th->control_stack_start);
3325 unsigned long control_stack_size =
3326 access_control_stack_pointer(th) - control_stack;
3328 scavenge(control_stack, control_stack_size);
3332 #if defined(LISP_FEATURE_SB_THREAD) && (defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
3334 preserve_context_registers (os_context_t *c)
3337 /* On Darwin the signal context isn't a contiguous block of memory,
3338 * so just preserve_pointering its contents won't be sufficient.
3340 #if defined(LISP_FEATURE_DARWIN)
3341 #if defined LISP_FEATURE_X86
3342 preserve_pointer((void*)*os_context_register_addr(c,reg_EAX));
3343 preserve_pointer((void*)*os_context_register_addr(c,reg_ECX));
3344 preserve_pointer((void*)*os_context_register_addr(c,reg_EDX));
3345 preserve_pointer((void*)*os_context_register_addr(c,reg_EBX));
3346 preserve_pointer((void*)*os_context_register_addr(c,reg_ESI));
3347 preserve_pointer((void*)*os_context_register_addr(c,reg_EDI));
3348 preserve_pointer((void*)*os_context_pc_addr(c));
3349 #elif defined LISP_FEATURE_X86_64
3350 preserve_pointer((void*)*os_context_register_addr(c,reg_RAX));
3351 preserve_pointer((void*)*os_context_register_addr(c,reg_RCX));
3352 preserve_pointer((void*)*os_context_register_addr(c,reg_RDX));
3353 preserve_pointer((void*)*os_context_register_addr(c,reg_RBX));
3354 preserve_pointer((void*)*os_context_register_addr(c,reg_RSI));
3355 preserve_pointer((void*)*os_context_register_addr(c,reg_RDI));
3356 preserve_pointer((void*)*os_context_register_addr(c,reg_R8));
3357 preserve_pointer((void*)*os_context_register_addr(c,reg_R9));
3358 preserve_pointer((void*)*os_context_register_addr(c,reg_R10));
3359 preserve_pointer((void*)*os_context_register_addr(c,reg_R11));
3360 preserve_pointer((void*)*os_context_register_addr(c,reg_R12));
3361 preserve_pointer((void*)*os_context_register_addr(c,reg_R13));
3362 preserve_pointer((void*)*os_context_register_addr(c,reg_R14));
3363 preserve_pointer((void*)*os_context_register_addr(c,reg_R15));
3364 preserve_pointer((void*)*os_context_pc_addr(c));
3366 #error "preserve_context_registers needs to be tweaked for non-x86 Darwin"
3369 for(ptr = ((void **)(c+1))-1; ptr>=(void **)c; ptr--) {
3370 preserve_pointer(*ptr);
3375 /* Garbage collect a generation. If raise is 0 then the remains of the
3376 * generation are not raised to the next generation. */
3378 garbage_collect_generation(generation_index_t generation, int raise)
3380 unsigned long bytes_freed;
3382 unsigned long static_space_size;
3385 gc_assert(generation <= HIGHEST_NORMAL_GENERATION);
3387 /* The oldest generation can't be raised. */
3388 gc_assert((generation != HIGHEST_NORMAL_GENERATION) || (raise == 0));
3390 /* Check if weak hash tables were processed in the previous GC. */
3391 gc_assert(weak_hash_tables == NULL);
3393 /* Initialize the weak pointer list. */
3394 weak_pointers = NULL;
3396 /* When a generation is not being raised it is transported to a
3397 * temporary generation (NUM_GENERATIONS), and lowered when
3398 * done. Set up this new generation. There should be no pages
3399 * allocated to it yet. */
3401 gc_assert(generations[SCRATCH_GENERATION].bytes_allocated == 0);
3404 /* Set the global src and dest. generations */
3405 from_space = generation;
3407 new_space = generation+1;
3409 new_space = SCRATCH_GENERATION;
3411 /* Change to a new space for allocation, resetting the alloc_start_page */
3412 gc_alloc_generation = new_space;
3413 generations[new_space].alloc_start_page = 0;
3414 generations[new_space].alloc_unboxed_start_page = 0;
3415 generations[new_space].alloc_large_start_page = 0;
3416 generations[new_space].alloc_large_unboxed_start_page = 0;
3418 /* Before any pointers are preserved, the dont_move flags on the
3419 * pages need to be cleared. */
3420 for (i = 0; i < last_free_page; i++)
3421 if(page_table[i].gen==from_space)
3422 page_table[i].dont_move = 0;
3424 /* Un-write-protect the old-space pages. This is essential for the
3425 * promoted pages as they may contain pointers into the old-space
3426 * which need to be scavenged. It also helps avoid unnecessary page
3427 * faults as forwarding pointers are written into them. They need to
3428 * be un-protected anyway before unmapping later. */
3429 unprotect_oldspace();
3431 /* Scavenge the stacks' conservative roots. */
3433 /* there are potentially two stacks for each thread: the main
3434 * stack, which may contain Lisp pointers, and the alternate stack.
3435 * We don't ever run Lisp code on the altstack, but it may
3436 * host a sigcontext with lisp objects in it */
3438 /* what we need to do: (1) find the stack pointer for the main
3439 * stack; scavenge it (2) find the interrupt context on the
3440 * alternate stack that might contain lisp values, and scavenge
3443 /* we assume that none of the preceding applies to the thread that
3444 * initiates GC. If you ever call GC from inside an altstack
3445 * handler, you will lose. */
3447 #if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
3448 /* And if we're saving a core, there's no point in being conservative. */
3449 if (conservative_stack) {
3450 for_each_thread(th) {
3452 void **esp=(void **)-1;
3453 #ifdef LISP_FEATURE_SB_THREAD
3455 if(th==arch_os_get_current_thread()) {
3456 /* Somebody is going to burn in hell for this, but casting
3457 * it in two steps shuts gcc up about strict aliasing. */
3458 esp = (void **)((void *)&raise);
3461 free=fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,th));
3462 for(i=free-1;i>=0;i--) {
3463 os_context_t *c=th->interrupt_contexts[i];
3464 esp1 = (void **) *os_context_register_addr(c,reg_SP);
3465 if (esp1>=(void **)th->control_stack_start &&
3466 esp1<(void **)th->control_stack_end) {
3467 if(esp1<esp) esp=esp1;
3468 preserve_context_registers(c);
3473 esp = (void **)((void *)&raise);
3475 for (ptr = ((void **)th->control_stack_end)-1; ptr >= esp; ptr--) {
3476 preserve_pointer(*ptr);
3481 /* Non-x86oid systems don't have "conservative roots" as such, but
3482 * the same mechanism is used for objects pinned for use by alien
3484 for_each_thread(th) {
3485 lispobj pin_list = SymbolTlValue(PINNED_OBJECTS,th);
3486 while (pin_list != NIL) {
3487 struct cons *list_entry =
3488 (struct cons *)native_pointer(pin_list);
3489 preserve_pointer(list_entry->car);
3490 pin_list = list_entry->cdr;
3496 if (gencgc_verbose > 1) {
3497 long num_dont_move_pages = count_dont_move_pages();
3499 "/non-movable pages due to conservative pointers = %d (%d bytes)\n",
3500 num_dont_move_pages,
3501 npage_bytes(num_dont_move_pages));
3505 /* Scavenge all the rest of the roots. */
3507 #if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
3509 * If not x86, we need to scavenge the interrupt context(s) and the
3514 for_each_thread(th) {
3515 scavenge_interrupt_contexts(th);
3516 scavenge_control_stack(th);
3519 /* Scrub the unscavenged control stack space, so that we can't run
3520 * into any stale pointers in a later GC (this is done by the
3521 * stop-for-gc handler in the other threads). */
3522 scrub_control_stack();
3526 /* Scavenge the Lisp functions of the interrupt handlers, taking
3527 * care to avoid SIG_DFL and SIG_IGN. */
3528 for (i = 0; i < NSIG; i++) {
3529 union interrupt_handler handler = interrupt_handlers[i];
3530 if (!ARE_SAME_HANDLER(handler.c, SIG_IGN) &&
3531 !ARE_SAME_HANDLER(handler.c, SIG_DFL)) {
3532 scavenge((lispobj *)(interrupt_handlers + i), 1);
3535 /* Scavenge the binding stacks. */
3538 for_each_thread(th) {
3539 long len= (lispobj *)get_binding_stack_pointer(th) -
3540 th->binding_stack_start;
3541 scavenge((lispobj *) th->binding_stack_start,len);
3542 #ifdef LISP_FEATURE_SB_THREAD
3543 /* do the tls as well */
3544 len=(SymbolValue(FREE_TLS_INDEX,0) >> WORD_SHIFT) -
3545 (sizeof (struct thread))/(sizeof (lispobj));
3546 scavenge((lispobj *) (th+1),len);
3551 /* The original CMU CL code had scavenge-read-only-space code
3552 * controlled by the Lisp-level variable
3553 * *SCAVENGE-READ-ONLY-SPACE*. It was disabled by default, and it
3554 * wasn't documented under what circumstances it was useful or
3555 * safe to turn it on, so it's been turned off in SBCL. If you
3556 * want/need this functionality, and can test and document it,
3557 * please submit a patch. */
3559 if (SymbolValue(SCAVENGE_READ_ONLY_SPACE) != NIL) {
3560 unsigned long read_only_space_size =
3561 (lispobj*)SymbolValue(READ_ONLY_SPACE_FREE_POINTER) -
3562 (lispobj*)READ_ONLY_SPACE_START;
3564 "/scavenge read only space: %d bytes\n",
3565 read_only_space_size * sizeof(lispobj)));
3566 scavenge( (lispobj *) READ_ONLY_SPACE_START, read_only_space_size);
3570 /* Scavenge static space. */
3572 (lispobj *)SymbolValue(STATIC_SPACE_FREE_POINTER,0) -
3573 (lispobj *)STATIC_SPACE_START;
3574 if (gencgc_verbose > 1) {
3576 "/scavenge static space: %d bytes\n",
3577 static_space_size * sizeof(lispobj)));
3579 scavenge( (lispobj *) STATIC_SPACE_START, static_space_size);
3581 /* All generations but the generation being GCed need to be
3582 * scavenged. The new_space generation needs special handling as
3583 * objects may be moved in - it is handled separately below. */
3584 scavenge_generations(generation+1, PSEUDO_STATIC_GENERATION);
3586 /* Finally scavenge the new_space generation. Keep going until no
3587 * more objects are moved into the new generation */
3588 scavenge_newspace_generation(new_space);
3590 /* FIXME: I tried reenabling this check when debugging unrelated
3591 * GC weirdness ca. sbcl-0.6.12.45, and it failed immediately.
3592 * Since the current GC code seems to work well, I'm guessing that
3593 * this debugging code is just stale, but I haven't tried to
3594 * figure it out. It should be figured out and then either made to
3595 * work or just deleted. */
3596 #define RESCAN_CHECK 0
3598 /* As a check re-scavenge the newspace once; no new objects should
3601 os_vm_size_t old_bytes_allocated = bytes_allocated;
3602 os_vm_size_t bytes_allocated;
3604 /* Start with a full scavenge. */
3605 scavenge_newspace_generation_one_scan(new_space);
3607 /* Flush the current regions, updating the tables. */
3608 gc_alloc_update_all_page_tables();
3610 bytes_allocated = bytes_allocated - old_bytes_allocated;
3612 if (bytes_allocated != 0) {
3613 lose("Rescan of new_space allocated %d more bytes.\n",
3619 scan_weak_hash_tables();
3620 scan_weak_pointers();
3622 /* Flush the current regions, updating the tables. */
3623 gc_alloc_update_all_page_tables();
3625 /* Free the pages in oldspace, but not those marked dont_move. */
3626 bytes_freed = free_oldspace();
3628 /* If the GC is not raising the age then lower the generation back
3629 * to its normal generation number */
3631 for (i = 0; i < last_free_page; i++)
3632 if ((page_table[i].bytes_used != 0)
3633 && (page_table[i].gen == SCRATCH_GENERATION))
3634 page_table[i].gen = generation;
3635 gc_assert(generations[generation].bytes_allocated == 0);
3636 generations[generation].bytes_allocated =
3637 generations[SCRATCH_GENERATION].bytes_allocated;
3638 generations[SCRATCH_GENERATION].bytes_allocated = 0;
3641 /* Reset the alloc_start_page for generation. */
3642 generations[generation].alloc_start_page = 0;
3643 generations[generation].alloc_unboxed_start_page = 0;
3644 generations[generation].alloc_large_start_page = 0;
3645 generations[generation].alloc_large_unboxed_start_page = 0;
3647 if (generation >= verify_gens) {
3648 if (gencgc_verbose) {
3652 verify_dynamic_space();
3655 /* Set the new gc trigger for the GCed generation. */
3656 generations[generation].gc_trigger =
3657 generations[generation].bytes_allocated
3658 + generations[generation].bytes_consed_between_gc;
3661 generations[generation].num_gc = 0;
3663 ++generations[generation].num_gc;
3667 /* Update last_free_page, then SymbolValue(ALLOCATION_POINTER). */
3669 update_dynamic_space_free_pointer(void)
3671 page_index_t last_page = -1, i;
3673 for (i = 0; i < last_free_page; i++)
3674 if (page_allocated_p(i) && (page_table[i].bytes_used != 0))
3677 last_free_page = last_page+1;
3679 set_alloc_pointer((lispobj)(page_address(last_free_page)));
3680 return 0; /* dummy value: return something ... */
3684 remap_page_range (page_index_t from, page_index_t to)
3686 /* There's a mysterious Solaris/x86 problem with using mmap
3687 * tricks for memory zeroing. See sbcl-devel thread
3688 * "Re: patch: standalone executable redux".
3690 #if defined(LISP_FEATURE_SUNOS)
3691 zero_and_mark_pages(from, to);
3694 release_granularity = gencgc_release_granularity/GENCGC_CARD_BYTES,
3695 release_mask = release_granularity-1,
3697 aligned_from = (from+release_mask)&~release_mask,
3698 aligned_end = (end&~release_mask);
3700 if (aligned_from < aligned_end) {
3701 zero_pages_with_mmap(aligned_from, aligned_end-1);
3702 if (aligned_from != from)
3703 zero_and_mark_pages(from, aligned_from-1);
3704 if (aligned_end != end)
3705 zero_and_mark_pages(aligned_end, end-1);
3707 zero_and_mark_pages(from, to);
3713 remap_free_pages (page_index_t from, page_index_t to, int forcibly)
3715 page_index_t first_page, last_page;
3718 return remap_page_range(from, to);
3720 for (first_page = from; first_page <= to; first_page++) {
3721 if (page_allocated_p(first_page) ||
3722 (page_table[first_page].need_to_zero == 0))
3725 last_page = first_page + 1;
3726 while (page_free_p(last_page) &&
3727 (last_page <= to) &&
3728 (page_table[last_page].need_to_zero == 1))
3731 remap_page_range(first_page, last_page-1);
3733 first_page = last_page;
3737 generation_index_t small_generation_limit = 1;
3739 /* GC all generations newer than last_gen, raising the objects in each
3740 * to the next older generation - we finish when all generations below
3741 * last_gen are empty. Then if last_gen is due for a GC, or if
3742 * last_gen==NUM_GENERATIONS (the scratch generation? eh?) we GC that
3743 * too. The valid range for last_gen is: 0,1,...,NUM_GENERATIONS.
3745 * We stop collecting at gencgc_oldest_gen_to_gc, even if this is less than
3746 * last_gen (oh, and note that by default it is NUM_GENERATIONS-1) */
3748 collect_garbage(generation_index_t last_gen)
3750 generation_index_t gen = 0, i;
3753 /* The largest value of last_free_page seen since the time
3754 * remap_free_pages was called. */
3755 static page_index_t high_water_mark = 0;
3757 FSHOW((stderr, "/entering collect_garbage(%d)\n", last_gen));
3758 log_generation_stats(gc_logfile, "=== GC Start ===");
3762 if (last_gen > HIGHEST_NORMAL_GENERATION+1) {
3764 "/collect_garbage: last_gen = %d, doing a level 0 GC\n",
3769 /* Flush the alloc regions updating the tables. */
3770 gc_alloc_update_all_page_tables();
3772 /* Verify the new objects created by Lisp code. */
3773 if (pre_verify_gen_0) {
3774 FSHOW((stderr, "pre-checking generation 0\n"));
3775 verify_generation(0);
3778 if (gencgc_verbose > 1)
3779 print_generation_stats();
3782 /* Collect the generation. */
3784 if (gen >= gencgc_oldest_gen_to_gc) {
3785 /* Never raise the oldest generation. */
3790 || (generations[gen].num_gc >= generations[gen].number_of_gcs_before_promotion);
3793 if (gencgc_verbose > 1) {
3795 "starting GC of generation %d with raise=%d alloc=%d trig=%d GCs=%d\n",
3798 generations[gen].bytes_allocated,
3799 generations[gen].gc_trigger,
3800 generations[gen].num_gc));
3803 /* If an older generation is being filled, then update its
3806 generations[gen+1].cum_sum_bytes_allocated +=
3807 generations[gen+1].bytes_allocated;
3810 garbage_collect_generation(gen, raise);
3812 /* Reset the memory age cum_sum. */
3813 generations[gen].cum_sum_bytes_allocated = 0;
3815 if (gencgc_verbose > 1) {
3816 FSHOW((stderr, "GC of generation %d finished:\n", gen));
3817 print_generation_stats();
3821 } while ((gen <= gencgc_oldest_gen_to_gc)
3822 && ((gen < last_gen)
3823 || ((gen <= gencgc_oldest_gen_to_gc)
3825 && (generations[gen].bytes_allocated
3826 > generations[gen].gc_trigger)
3827 && (generation_average_age(gen)
3828 > generations[gen].minimum_age_before_gc))));
3830 /* Now if gen-1 was raised all generations before gen are empty.
3831 * If it wasn't raised then all generations before gen-1 are empty.
3833 * Now objects within this gen's pages cannot point to younger
3834 * generations unless they are written to. This can be exploited
3835 * by write-protecting the pages of gen; then when younger
3836 * generations are GCed only the pages which have been written
3841 gen_to_wp = gen - 1;
3843 /* There's not much point in WPing pages in generation 0 as it is
3844 * never scavenged (except promoted pages). */
3845 if ((gen_to_wp > 0) && enable_page_protection) {
3846 /* Check that they are all empty. */
3847 for (i = 0; i < gen_to_wp; i++) {
3848 if (generations[i].bytes_allocated)
3849 lose("trying to write-protect gen. %d when gen. %d nonempty\n",
3852 write_protect_generation_pages(gen_to_wp);
3855 /* Set gc_alloc() back to generation 0. The current regions should
3856 * be flushed after the above GCs. */
3857 gc_assert((boxed_region.free_pointer - boxed_region.start_addr) == 0);
3858 gc_alloc_generation = 0;
3860 /* Save the high-water mark before updating last_free_page */
3861 if (last_free_page > high_water_mark)
3862 high_water_mark = last_free_page;
3864 update_dynamic_space_free_pointer();
3866 auto_gc_trigger = bytes_allocated + bytes_consed_between_gcs;
3868 fprintf(stderr,"Next gc when %"OS_VM_SIZE_FMT" bytes have been consed\n",
3871 /* If we did a big GC (arbitrarily defined as gen > 1), release memory
3874 if (gen > small_generation_limit) {
3875 if (last_free_page > high_water_mark)
3876 high_water_mark = last_free_page;
3877 remap_free_pages(0, high_water_mark, 0);
3878 high_water_mark = 0;
3883 log_generation_stats(gc_logfile, "=== GC End ===");
3884 SHOW("returning from collect_garbage");
3887 /* This is called by Lisp PURIFY when it is finished. All live objects
3888 * will have been moved to the RO and Static heaps. The dynamic space
3889 * will need a full re-initialization. We don't bother having Lisp
3890 * PURIFY flush the current gc_alloc() region, as the page_tables are
3891 * re-initialized, and every page is zeroed to be sure. */
3895 page_index_t page, last_page;
3897 if (gencgc_verbose > 1) {
3898 SHOW("entering gc_free_heap");
3901 for (page = 0; page < page_table_pages; page++) {
3902 /* Skip free pages which should already be zero filled. */
3903 if (page_allocated_p(page)) {
3905 for (last_page = page;
3906 (last_page < page_table_pages) && page_allocated_p(last_page);
3908 /* Mark the page free. The other slots are assumed invalid
3909 * when it is a FREE_PAGE_FLAG and bytes_used is 0 and it
3910 * should not be write-protected -- except that the
3911 * generation is used for the current region but it sets
3913 page_table[page].allocated = FREE_PAGE_FLAG;
3914 page_table[page].bytes_used = 0;
3915 page_table[page].write_protected = 0;
3918 #ifndef LISP_FEATURE_WIN32 /* Pages already zeroed on win32? Not sure
3919 * about this change. */
3920 page_start = (void *)page_address(page);
3921 os_protect(page_start, npage_bytes(last_page-page), OS_VM_PROT_ALL);
3922 remap_free_pages(page, last_page-1, 1);
3925 } else if (gencgc_zero_check_during_free_heap) {
3926 /* Double-check that the page is zero filled. */
3929 gc_assert(page_free_p(page));
3930 gc_assert(page_table[page].bytes_used == 0);
3931 page_start = (long *)page_address(page);
3932 for (i=0; i<GENCGC_CARD_BYTES/sizeof(long); i++) {
3933 if (page_start[i] != 0) {
3934 lose("free region not zero at %x\n", page_start + i);
3940 bytes_allocated = 0;
3942 /* Initialize the generations. */
3943 for (page = 0; page < NUM_GENERATIONS; page++) {
3944 generations[page].alloc_start_page = 0;
3945 generations[page].alloc_unboxed_start_page = 0;
3946 generations[page].alloc_large_start_page = 0;
3947 generations[page].alloc_large_unboxed_start_page = 0;
3948 generations[page].bytes_allocated = 0;
3949 generations[page].gc_trigger = 2000000;
3950 generations[page].num_gc = 0;
3951 generations[page].cum_sum_bytes_allocated = 0;
3954 if (gencgc_verbose > 1)
3955 print_generation_stats();
3957 /* Initialize gc_alloc(). */
3958 gc_alloc_generation = 0;
3960 gc_set_region_empty(&boxed_region);
3961 gc_set_region_empty(&unboxed_region);
3964 set_alloc_pointer((lispobj)((char *)heap_base));
3966 if (verify_after_free_heap) {
3967 /* Check whether purify has left any bad pointers. */
3968 FSHOW((stderr, "checking after free_heap\n"));
3978 /* Compute the number of pages needed for the dynamic space.
3979 * Dynamic space size should be aligned on page size. */
3980 page_table_pages = dynamic_space_size/GENCGC_CARD_BYTES;
3981 gc_assert(dynamic_space_size == npage_bytes(page_table_pages));
3983 /* Default nursery size to 5% of the total dynamic space size,
3985 bytes_consed_between_gcs = dynamic_space_size/(os_vm_size_t)20;
3986 if (bytes_consed_between_gcs < (1024*1024))
3987 bytes_consed_between_gcs = 1024*1024;
3989 /* The page_table must be allocated using "calloc" to initialize
3990 * the page structures correctly. There used to be a separate
3991 * initialization loop (now commented out; see below) but that was
3992 * unnecessary and did hurt startup time. */
3993 page_table = calloc(page_table_pages, sizeof(struct page));
3994 gc_assert(page_table);
3997 scavtab[WEAK_POINTER_WIDETAG] = scav_weak_pointer;
3998 transother[SIMPLE_ARRAY_WIDETAG] = trans_boxed_large;
4000 heap_base = (void*)DYNAMIC_SPACE_START;
4002 /* The page structures are initialized implicitly when page_table
4003 * is allocated with "calloc" above. Formerly we had the following
4004 * explicit initialization here (comments converted to C99 style
4005 * for readability as C's block comments don't nest):
4007 * // Initialize each page structure.
4008 * for (i = 0; i < page_table_pages; i++) {
4009 * // Initialize all pages as free.
4010 * page_table[i].allocated = FREE_PAGE_FLAG;
4011 * page_table[i].bytes_used = 0;
4013 * // Pages are not write-protected at startup.
4014 * page_table[i].write_protected = 0;
4017 * Without this loop the image starts up much faster when dynamic
4018 * space is large -- which it is on 64-bit platforms already by
4019 * default -- and when "calloc" for large arrays is implemented
4020 * using copy-on-write of a page of zeroes -- which it is at least
4021 * on Linux. In this case the pages that page_table_pages is stored
4022 * in are mapped and cleared not before the corresponding part of
4023 * dynamic space is used. For example, this saves clearing 16 MB of
4024 * memory at startup if the page size is 4 KB and the size of
4025 * dynamic space is 4 GB.
4026 * FREE_PAGE_FLAG must be 0 for this to work correctly which is
4027 * asserted below: */
4029 /* Compile time assertion: If triggered, declares an array
4030 * of dimension -1 forcing a syntax error. The intent of the
4031 * assignment is to avoid an "unused variable" warning. */
4032 char assert_free_page_flag_0[(FREE_PAGE_FLAG) ? -1 : 1];
4033 assert_free_page_flag_0[0] = assert_free_page_flag_0[0];
4036 bytes_allocated = 0;
4038 /* Initialize the generations.
4040 * FIXME: very similar to code in gc_free_heap(), should be shared */
4041 for (i = 0; i < NUM_GENERATIONS; i++) {
4042 generations[i].alloc_start_page = 0;
4043 generations[i].alloc_unboxed_start_page = 0;
4044 generations[i].alloc_large_start_page = 0;
4045 generations[i].alloc_large_unboxed_start_page = 0;
4046 generations[i].bytes_allocated = 0;
4047 generations[i].gc_trigger = 2000000;
4048 generations[i].num_gc = 0;
4049 generations[i].cum_sum_bytes_allocated = 0;
4050 /* the tune-able parameters */
4051 generations[i].bytes_consed_between_gc = bytes_consed_between_gcs;
4052 generations[i].number_of_gcs_before_promotion = 1;
4053 generations[i].minimum_age_before_gc = 0.75;
4056 /* Initialize gc_alloc. */
4057 gc_alloc_generation = 0;
4058 gc_set_region_empty(&boxed_region);
4059 gc_set_region_empty(&unboxed_region);
4064 /* Pick up the dynamic space from after a core load.
4066 * The ALLOCATION_POINTER points to the end of the dynamic space.
4070 gencgc_pickup_dynamic(void)
4072 page_index_t page = 0;
4073 void *alloc_ptr = (void *)get_alloc_pointer();
4074 lispobj *prev=(lispobj *)page_address(page);
4075 generation_index_t gen = PSEUDO_STATIC_GENERATION;
4077 lispobj *first,*ptr= (lispobj *)page_address(page);
4079 if (!gencgc_partial_pickup || page_allocated_p(page)) {
4080 /* It is possible, though rare, for the saved page table
4081 * to contain free pages below alloc_ptr. */
4082 page_table[page].gen = gen;
4083 page_table[page].bytes_used = GENCGC_CARD_BYTES;
4084 page_table[page].large_object = 0;
4085 page_table[page].write_protected = 0;
4086 page_table[page].write_protected_cleared = 0;
4087 page_table[page].dont_move = 0;
4088 page_table[page].need_to_zero = 1;
4091 if (!gencgc_partial_pickup) {
4092 page_table[page].allocated = BOXED_PAGE_FLAG;
4093 first=gc_search_space(prev,(ptr+2)-prev,ptr);
4096 page_table[page].region_start_offset =
4097 page_address(page) - (void *)prev;
4100 } while (page_address(page) < alloc_ptr);
4102 last_free_page = page;
4104 generations[gen].bytes_allocated = npage_bytes(page);
4105 bytes_allocated = npage_bytes(page);
4107 gc_alloc_update_all_page_tables();
4108 write_protect_generation_pages(gen);
4112 gc_initialize_pointers(void)
4114 gencgc_pickup_dynamic();
4118 /* alloc(..) is the external interface for memory allocation. It
4119 * allocates to generation 0. It is not called from within the garbage
4120 * collector as it is only external uses that need the check for heap
4121 * size (GC trigger) and to disable the interrupts (interrupts are
4122 * always disabled during a GC).
4124 * The vops that call alloc(..) assume that the returned space is zero-filled.
4125 * (E.g. the most significant word of a 2-word bignum in MOVE-FROM-UNSIGNED.)
4127 * The check for a GC trigger is only performed when the current
4128 * region is full, so in most cases it's not needed. */
4130 static inline lispobj *
4131 general_alloc_internal(long nbytes, int page_type_flag, struct alloc_region *region,
4132 struct thread *thread)
4134 #ifndef LISP_FEATURE_WIN32
4135 lispobj alloc_signal;
4138 void *new_free_pointer;
4140 gc_assert(nbytes>0);
4142 /* Check for alignment allocation problems. */
4143 gc_assert((((unsigned long)region->free_pointer & LOWTAG_MASK) == 0)
4144 && ((nbytes & LOWTAG_MASK) == 0));
4146 /* Must be inside a PA section. */
4147 gc_assert(get_pseudo_atomic_atomic(thread));
4149 /* maybe we can do this quickly ... */
4150 new_free_pointer = region->free_pointer + nbytes;
4151 if (new_free_pointer <= region->end_addr) {
4152 new_obj = (void*)(region->free_pointer);
4153 region->free_pointer = new_free_pointer;
4154 return(new_obj); /* yup */
4157 /* we have to go the long way around, it seems. Check whether we
4158 * should GC in the near future
4160 if (auto_gc_trigger && bytes_allocated > auto_gc_trigger) {
4161 /* Don't flood the system with interrupts if the need to gc is
4162 * already noted. This can happen for example when SUB-GC
4163 * allocates or after a gc triggered in a WITHOUT-GCING. */
4164 if (SymbolValue(GC_PENDING,thread) == NIL) {
4165 /* set things up so that GC happens when we finish the PA
4167 SetSymbolValue(GC_PENDING,T,thread);
4168 if (SymbolValue(GC_INHIBIT,thread) == NIL) {
4169 set_pseudo_atomic_interrupted(thread);
4170 #ifdef LISP_FEATURE_PPC
4171 /* PPC calls alloc() from a trap or from pa_alloc(),
4172 * look up the most context if it's from a trap. */
4174 os_context_t *context =
4175 thread->interrupt_data->allocation_trap_context;
4176 maybe_save_gc_mask_and_block_deferrables
4177 (context ? os_context_sigmask_addr(context) : NULL);
4180 maybe_save_gc_mask_and_block_deferrables(NULL);
4185 new_obj = gc_alloc_with_region(nbytes, page_type_flag, region, 0);
4187 #ifndef LISP_FEATURE_WIN32
4188 alloc_signal = SymbolValue(ALLOC_SIGNAL,thread);
4189 if ((alloc_signal & FIXNUM_TAG_MASK) == 0) {
4190 if ((signed long) alloc_signal <= 0) {
4191 SetSymbolValue(ALLOC_SIGNAL, T, thread);
4194 SetSymbolValue(ALLOC_SIGNAL,
4195 alloc_signal - (1 << N_FIXNUM_TAG_BITS),
4205 general_alloc(long nbytes, int page_type_flag)
4207 struct thread *thread = arch_os_get_current_thread();
4208 /* Select correct region, and call general_alloc_internal with it.
4209 * For other then boxed allocation we must lock first, since the
4210 * region is shared. */
4211 if (BOXED_PAGE_FLAG & page_type_flag) {
4212 #ifdef LISP_FEATURE_SB_THREAD
4213 struct alloc_region *region = (thread ? &(thread->alloc_region) : &boxed_region);
4215 struct alloc_region *region = &boxed_region;
4217 return general_alloc_internal(nbytes, page_type_flag, region, thread);
4218 } else if (UNBOXED_PAGE_FLAG == page_type_flag) {
4220 gc_assert(0 == thread_mutex_lock(&allocation_lock));
4221 obj = general_alloc_internal(nbytes, page_type_flag, &unboxed_region, thread);
4222 gc_assert(0 == thread_mutex_unlock(&allocation_lock));
4225 lose("bad page type flag: %d", page_type_flag);
4232 gc_assert(get_pseudo_atomic_atomic(arch_os_get_current_thread()));
4233 return general_alloc(nbytes, BOXED_PAGE_FLAG);
4237 * shared support for the OS-dependent signal handlers which
4238 * catch GENCGC-related write-protect violations
4240 void unhandled_sigmemoryfault(void* addr);
4242 /* Depending on which OS we're running under, different signals might
4243 * be raised for a violation of write protection in the heap. This
4244 * function factors out the common generational GC magic which needs
4245 * to invoked in this case, and should be called from whatever signal
4246 * handler is appropriate for the OS we're running under.
4248 * Return true if this signal is a normal generational GC thing that
4249 * we were able to handle, or false if it was abnormal and control
4250 * should fall through to the general SIGSEGV/SIGBUS/whatever logic.
4252 * We have two control flags for this: one causes us to ignore faults
4253 * on unprotected pages completely, and the second complains to stderr
4254 * but allows us to continue without losing.
4256 extern boolean ignore_memoryfaults_on_unprotected_pages;
4257 boolean ignore_memoryfaults_on_unprotected_pages = 0;
4259 extern boolean continue_after_memoryfault_on_unprotected_pages;
4260 boolean continue_after_memoryfault_on_unprotected_pages = 0;
4263 gencgc_handle_wp_violation(void* fault_addr)
4265 page_index_t page_index = find_page_index(fault_addr);
4268 FSHOW((stderr, "heap WP violation? fault_addr=%x, page_index=%d\n",
4269 fault_addr, page_index));
4272 /* Check whether the fault is within the dynamic space. */
4273 if (page_index == (-1)) {
4275 /* It can be helpful to be able to put a breakpoint on this
4276 * case to help diagnose low-level problems. */
4277 unhandled_sigmemoryfault(fault_addr);
4279 /* not within the dynamic space -- not our responsibility */
4284 ret = thread_mutex_lock(&free_pages_lock);
4285 gc_assert(ret == 0);
4286 if (page_table[page_index].write_protected) {
4287 /* Unprotect the page. */
4288 os_protect(page_address(page_index), GENCGC_CARD_BYTES, OS_VM_PROT_ALL);
4289 page_table[page_index].write_protected_cleared = 1;
4290 page_table[page_index].write_protected = 0;
4291 } else if (!ignore_memoryfaults_on_unprotected_pages) {
4292 /* The only acceptable reason for this signal on a heap
4293 * access is that GENCGC write-protected the page.
4294 * However, if two CPUs hit a wp page near-simultaneously,
4295 * we had better not have the second one lose here if it
4296 * does this test after the first one has already set wp=0
4298 if(page_table[page_index].write_protected_cleared != 1) {
4299 void lisp_backtrace(int frames);
4302 "Fault @ %p, page %"PAGE_INDEX_FMT" not marked as write-protected:\n"
4303 " boxed_region.first_page: %"PAGE_INDEX_FMT","
4304 " boxed_region.last_page %"PAGE_INDEX_FMT"\n"
4305 " page.region_start_offset: %"OS_VM_SIZE_FMT"\n"
4306 " page.bytes_used: %"PAGE_BYTES_FMT"\n"
4307 " page.allocated: %d\n"
4308 " page.write_protected: %d\n"
4309 " page.write_protected_cleared: %d\n"
4310 " page.generation: %d\n",
4313 boxed_region.first_page,
4314 boxed_region.last_page,
4315 page_table[page_index].region_start_offset,
4316 page_table[page_index].bytes_used,
4317 page_table[page_index].allocated,
4318 page_table[page_index].write_protected,
4319 page_table[page_index].write_protected_cleared,
4320 page_table[page_index].gen);
4321 if (!continue_after_memoryfault_on_unprotected_pages)
4325 ret = thread_mutex_unlock(&free_pages_lock);
4326 gc_assert(ret == 0);
4327 /* Don't worry, we can handle it. */
4331 /* This is to be called when we catch a SIGSEGV/SIGBUS, determine that
4332 * it's not just a case of the program hitting the write barrier, and
4333 * are about to let Lisp deal with it. It's basically just a
4334 * convenient place to set a gdb breakpoint. */
4336 unhandled_sigmemoryfault(void *addr)
4339 void gc_alloc_update_all_page_tables(void)
4341 /* Flush the alloc regions updating the tables. */
4344 gc_alloc_update_page_tables(BOXED_PAGE_FLAG, &th->alloc_region);
4345 gc_alloc_update_page_tables(UNBOXED_PAGE_FLAG, &unboxed_region);
4346 gc_alloc_update_page_tables(BOXED_PAGE_FLAG, &boxed_region);
4350 gc_set_region_empty(struct alloc_region *region)
4352 region->first_page = 0;
4353 region->last_page = -1;
4354 region->start_addr = page_address(0);
4355 region->free_pointer = page_address(0);
4356 region->end_addr = page_address(0);
4360 zero_all_free_pages()
4364 for (i = 0; i < last_free_page; i++) {
4365 if (page_free_p(i)) {
4366 #ifdef READ_PROTECT_FREE_PAGES
4367 os_protect(page_address(i),
4376 /* Things to do before doing a final GC before saving a core (without
4379 * + Pages in large_object pages aren't moved by the GC, so we need to
4380 * unset that flag from all pages.
4381 * + The pseudo-static generation isn't normally collected, but it seems
4382 * reasonable to collect it at least when saving a core. So move the
4383 * pages to a normal generation.
4386 prepare_for_final_gc ()
4389 for (i = 0; i < last_free_page; i++) {
4390 page_table[i].large_object = 0;
4391 if (page_table[i].gen == PSEUDO_STATIC_GENERATION) {
4392 int used = page_table[i].bytes_used;
4393 page_table[i].gen = HIGHEST_NORMAL_GENERATION;
4394 generations[PSEUDO_STATIC_GENERATION].bytes_allocated -= used;
4395 generations[HIGHEST_NORMAL_GENERATION].bytes_allocated += used;
4401 /* Do a non-conservative GC, and then save a core with the initial
4402 * function being set to the value of the static symbol
4403 * SB!VM:RESTART-LISP-FUNCTION */
4405 gc_and_save(char *filename, boolean prepend_runtime,
4406 boolean save_runtime_options,
4407 boolean compressed, int compression_level)
4410 void *runtime_bytes = NULL;
4411 size_t runtime_size;
4413 file = prepare_to_save(filename, prepend_runtime, &runtime_bytes,
4418 conservative_stack = 0;
4420 /* The filename might come from Lisp, and be moved by the now
4421 * non-conservative GC. */
4422 filename = strdup(filename);
4424 /* Collect twice: once into relatively high memory, and then back
4425 * into low memory. This compacts the retained data into the lower
4426 * pages, minimizing the size of the core file.
4428 prepare_for_final_gc();
4429 gencgc_alloc_start_page = last_free_page;
4430 collect_garbage(HIGHEST_NORMAL_GENERATION+1);
4432 prepare_for_final_gc();
4433 gencgc_alloc_start_page = -1;
4434 collect_garbage(HIGHEST_NORMAL_GENERATION+1);
4436 if (prepend_runtime)
4437 save_runtime_to_filehandle(file, runtime_bytes, runtime_size);
4439 /* The dumper doesn't know that pages need to be zeroed before use. */
4440 zero_all_free_pages();
4441 save_to_filehandle(file, filename, SymbolValue(RESTART_LISP_FUNCTION,0),
4442 prepend_runtime, save_runtime_options,
4443 compressed ? compression_level : COMPRESSION_LEVEL_NONE);
4444 /* Oops. Save still managed to fail. Since we've mangled the stack
4445 * beyond hope, there's not much we can do.
4446 * (beyond FUNCALLing RESTART_LISP_FUNCTION, but I suspect that's
4447 * going to be rather unsatisfactory too... */
4448 lose("Attempt to save core after non-conservative GC failed.\n");