1 /* Simple garbage collection for the GNU compiler.
2 Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008,
3 2009, 2010 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
21 /* Generic garbage collection (GC) functions and data, not specific to
22 any particular GC implementation. */
26 #include "coretypes.h"
29 #include "ggc-internal.h"
30 #include "diagnostic-core.h"
33 #include "hosthooks.h"
34 #include "hosthooks-def.h"
39 /* When set, ggc_collect will do collection. */
40 bool ggc_force_collect;
42 /* When true, protect the contents of the identifier hash table. */
43 bool ggc_protect_identifiers = true;
45 /* Statistics about the allocation. */
46 static ggc_statistics *ggc_stats;
48 struct traversal_state;
50 static int ggc_htab_delete (void **, void *);
51 static hashval_t saving_htab_hash (const void *);
52 static int saving_htab_eq (const void *, const void *);
53 static int call_count (void **, void *);
54 static int call_alloc (void **, void *);
55 static int compare_ptr_data (const void *, const void *);
56 static void relocate_ptrs (void *, void *);
57 static void write_pch_globals (const struct ggc_root_tab * const *tab,
58 struct traversal_state *state);
60 /* Maintain global roots that are preserved during GC. */
62 /* Process a slot of an htab by deleting it if it has not been marked. */
65 ggc_htab_delete (void **slot, void *info)
67 const struct ggc_cache_tab *r = (const struct ggc_cache_tab *) info;
69 if (! (*r->marked_p) (*slot))
70 htab_clear_slot (*r->base, slot);
78 /* This extra vector of dynamically registered root_tab-s is used by
79 ggc_mark_roots and gives the ability to dynamically add new GGC root
80 tables, for instance from some plugins; this vector is on the heap
81 since it is used by GGC internally. */
82 typedef const struct ggc_root_tab *const_ggc_root_tab_t;
83 DEF_VEC_P(const_ggc_root_tab_t);
84 DEF_VEC_ALLOC_P(const_ggc_root_tab_t, heap);
85 static VEC(const_ggc_root_tab_t, heap) *extra_root_vec;
87 /* Dynamically register a new GGC root table RT. This is useful for
91 ggc_register_root_tab (const struct ggc_root_tab* rt)
94 VEC_safe_push (const_ggc_root_tab_t, heap, extra_root_vec, rt);
97 /* This extra vector of dynamically registered cache_tab-s is used by
98 ggc_mark_roots and gives the ability to dynamically add new GGC cache
99 tables, for instance from some plugins; this vector is on the heap
100 since it is used by GGC internally. */
101 typedef const struct ggc_cache_tab *const_ggc_cache_tab_t;
102 DEF_VEC_P(const_ggc_cache_tab_t);
103 DEF_VEC_ALLOC_P(const_ggc_cache_tab_t, heap);
104 static VEC(const_ggc_cache_tab_t, heap) *extra_cache_vec;
106 /* Dynamically register a new GGC cache table CT. This is useful for
110 ggc_register_cache_tab (const struct ggc_cache_tab* ct)
113 VEC_safe_push (const_ggc_cache_tab_t, heap, extra_cache_vec, ct);
116 /* Scan a hash table that has objects which are to be deleted if they are not
120 ggc_scan_cache_tab (const_ggc_cache_tab_t ctp)
122 const struct ggc_cache_tab *cti;
124 for (cti = ctp; cti->base != NULL; cti++)
127 ggc_set_mark (*cti->base);
128 htab_traverse_noresize (*cti->base, ggc_htab_delete,
129 CONST_CAST (void *, (const void *)cti));
130 ggc_set_mark ((*cti->base)->entries);
134 /* Mark all the roots in the table RT. */
137 ggc_mark_root_tab (const_ggc_root_tab_t rt)
141 for ( ; rt->base != NULL; rt++)
142 for (i = 0; i < rt->nelt; i++)
143 (*rt->cb) (*(void **) ((char *)rt->base + rt->stride * i));
146 /* Iterate through all registered roots and mark each element. */
149 ggc_mark_roots (void)
151 const struct ggc_root_tab *const *rt;
152 const_ggc_root_tab_t rtp, rti;
153 const struct ggc_cache_tab *const *ct;
154 const_ggc_cache_tab_t ctp;
157 for (rt = gt_ggc_deletable_rtab; *rt; rt++)
158 for (rti = *rt; rti->base != NULL; rti++)
159 memset (rti->base, 0, rti->stride);
161 for (rt = gt_ggc_rtab; *rt; rt++)
162 ggc_mark_root_tab (*rt);
164 FOR_EACH_VEC_ELT (const_ggc_root_tab_t, extra_root_vec, i, rtp)
165 ggc_mark_root_tab (rtp);
167 if (ggc_protect_identifiers)
168 ggc_mark_stringpool ();
170 /* Now scan all hash tables that have objects which are to be deleted if
171 they are not already marked. */
172 for (ct = gt_ggc_cache_rtab; *ct; ct++)
173 ggc_scan_cache_tab (*ct);
175 FOR_EACH_VEC_ELT (const_ggc_cache_tab_t, extra_cache_vec, i, ctp)
176 ggc_scan_cache_tab (ctp);
178 if (! ggc_protect_identifiers)
179 ggc_purge_stringpool ();
181 /* Some plugins may call ggc_set_mark from here. */
182 invoke_plugin_callbacks (PLUGIN_GGC_MARKING, NULL);
185 /* Allocate a block of memory, then clear it. */
187 ggc_internal_cleared_alloc_stat (size_t size MEM_STAT_DECL)
189 void *buf = ggc_internal_alloc_stat (size PASS_MEM_STAT);
190 memset (buf, 0, size);
194 /* Resize a block of memory, possibly re-allocating it. */
196 ggc_realloc_stat (void *x, size_t size MEM_STAT_DECL)
202 return ggc_internal_alloc_stat (size PASS_MEM_STAT);
204 old_size = ggc_get_size (x);
206 if (size <= old_size)
208 /* Mark the unwanted memory as unaccessible. We also need to make
209 the "new" size accessible, since ggc_get_size returns the size of
210 the pool, not the size of the individually allocated object, the
211 size which was previously made accessible. Unfortunately, we
212 don't know that previously allocated size. Without that
213 knowledge we have to lose some initialization-tracking for the
214 old parts of the object. An alternative is to mark the whole
215 old_size as reachable, but that would lose tracking of writes
216 after the end of the object (by small offsets). Discard the
217 handle to avoid handle leak. */
218 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_NOACCESS ((char *) x + size,
220 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_DEFINED (x, size));
224 r = ggc_internal_alloc_stat (size PASS_MEM_STAT);
226 /* Since ggc_get_size returns the size of the pool, not the size of the
227 individually allocated object, we'd access parts of the old object
228 that were marked invalid with the memcpy below. We lose a bit of the
229 initialization-tracking since some of it may be uninitialized. */
230 VALGRIND_DISCARD (VALGRIND_MAKE_MEM_DEFINED (x, old_size));
232 memcpy (r, x, old_size);
234 /* The old object is not supposed to be used anymore. */
241 ggc_cleared_alloc_htab_ignore_args (size_t c ATTRIBUTE_UNUSED,
242 size_t n ATTRIBUTE_UNUSED)
244 gcc_assert (c * n == sizeof (struct htab));
245 return ggc_alloc_cleared_htab ();
248 /* TODO: once we actually use type information in GGC, create a new tag
249 gt_gcc_ptr_array and use it for pointer arrays. */
251 ggc_cleared_alloc_ptr_array_two_args (size_t c, size_t n)
253 gcc_assert (sizeof (PTR *) == n);
254 return ggc_internal_cleared_vec_alloc (sizeof (PTR *), c);
257 /* These are for splay_tree_new_ggc. */
259 ggc_splay_alloc (enum gt_types_enum obj_type ATTRIBUTE_UNUSED, int sz,
263 return ggc_internal_alloc (sz);
267 ggc_splay_dont_free (void * x ATTRIBUTE_UNUSED, void *nl)
272 /* Print statistics that are independent of the collector in use. */
273 #define SCALE(x) ((unsigned long) ((x) < 1024*10 \
275 : ((x) < 1024*1024*10 \
277 : (x) / (1024*1024))))
278 #define LABEL(x) ((x) < 1024*10 ? ' ' : ((x) < 1024*1024*10 ? 'k' : 'M'))
281 ggc_print_common_statistics (FILE *stream ATTRIBUTE_UNUSED,
282 ggc_statistics *stats)
284 /* Set the pointer so that during collection we will actually gather
288 /* Then do one collection to fill in the statistics. */
291 /* At present, we don't really gather any interesting statistics. */
293 /* Don't gather statistics any more. */
297 /* Functions for saving and restoring GCable memory to disk. */
299 static htab_t saving_htab;
304 void *note_ptr_cookie;
305 gt_note_pointers note_ptr_fn;
306 gt_handle_reorder reorder_fn;
309 enum gt_types_enum type;
312 #define POINTER_HASH(x) (hashval_t)((long)x >> 3)
314 /* Register an object in the hash table. */
317 gt_pch_note_object (void *obj, void *note_ptr_cookie,
318 gt_note_pointers note_ptr_fn,
319 enum gt_types_enum type)
321 struct ptr_data **slot;
323 if (obj == NULL || obj == (void *) 1)
326 slot = (struct ptr_data **)
327 htab_find_slot_with_hash (saving_htab, obj, POINTER_HASH (obj),
331 gcc_assert ((*slot)->note_ptr_fn == note_ptr_fn
332 && (*slot)->note_ptr_cookie == note_ptr_cookie);
336 *slot = XCNEW (struct ptr_data);
338 (*slot)->note_ptr_fn = note_ptr_fn;
339 (*slot)->note_ptr_cookie = note_ptr_cookie;
340 if (note_ptr_fn == gt_pch_p_S)
341 (*slot)->size = strlen ((const char *)obj) + 1;
343 (*slot)->size = ggc_get_size (obj);
344 (*slot)->type = type;
348 /* Register an object in the hash table. */
351 gt_pch_note_reorder (void *obj, void *note_ptr_cookie,
352 gt_handle_reorder reorder_fn)
354 struct ptr_data *data;
356 if (obj == NULL || obj == (void *) 1)
359 data = (struct ptr_data *)
360 htab_find_with_hash (saving_htab, obj, POINTER_HASH (obj));
361 gcc_assert (data && data->note_ptr_cookie == note_ptr_cookie);
363 data->reorder_fn = reorder_fn;
366 /* Hash and equality functions for saving_htab, callbacks for htab_create. */
369 saving_htab_hash (const void *p)
371 return POINTER_HASH (((const struct ptr_data *)p)->obj);
375 saving_htab_eq (const void *p1, const void *p2)
377 return ((const struct ptr_data *)p1)->obj == p2;
380 /* Handy state for the traversal functions. */
382 struct traversal_state
385 struct ggc_pch_data *d;
387 struct ptr_data **ptrs;
391 /* Callbacks for htab_traverse. */
394 call_count (void **slot, void *state_p)
396 struct ptr_data *d = (struct ptr_data *)*slot;
397 struct traversal_state *state = (struct traversal_state *)state_p;
399 ggc_pch_count_object (state->d, d->obj, d->size,
400 d->note_ptr_fn == gt_pch_p_S,
407 call_alloc (void **slot, void *state_p)
409 struct ptr_data *d = (struct ptr_data *)*slot;
410 struct traversal_state *state = (struct traversal_state *)state_p;
412 d->new_addr = ggc_pch_alloc_object (state->d, d->obj, d->size,
413 d->note_ptr_fn == gt_pch_p_S,
415 state->ptrs[state->ptrs_i++] = d;
419 /* Callback for qsort. */
422 compare_ptr_data (const void *p1_p, const void *p2_p)
424 const struct ptr_data *const p1 = *(const struct ptr_data *const *)p1_p;
425 const struct ptr_data *const p2 = *(const struct ptr_data *const *)p2_p;
426 return (((size_t)p1->new_addr > (size_t)p2->new_addr)
427 - ((size_t)p1->new_addr < (size_t)p2->new_addr));
430 /* Callbacks for note_ptr_fn. */
433 relocate_ptrs (void *ptr_p, void *state_p)
435 void **ptr = (void **)ptr_p;
436 struct traversal_state *state ATTRIBUTE_UNUSED
437 = (struct traversal_state *)state_p;
438 struct ptr_data *result;
440 if (*ptr == NULL || *ptr == (void *)1)
443 result = (struct ptr_data *)
444 htab_find_with_hash (saving_htab, *ptr, POINTER_HASH (*ptr));
446 *ptr = result->new_addr;
449 /* Write out, after relocation, the pointers in TAB. */
451 write_pch_globals (const struct ggc_root_tab * const *tab,
452 struct traversal_state *state)
454 const struct ggc_root_tab *const *rt;
455 const struct ggc_root_tab *rti;
458 for (rt = tab; *rt; rt++)
459 for (rti = *rt; rti->base != NULL; rti++)
460 for (i = 0; i < rti->nelt; i++)
462 void *ptr = *(void **)((char *)rti->base + rti->stride * i);
463 struct ptr_data *new_ptr;
464 if (ptr == NULL || ptr == (void *)1)
466 if (fwrite (&ptr, sizeof (void *), 1, state->f)
468 fatal_error ("can%'t write PCH file: %m");
472 new_ptr = (struct ptr_data *)
473 htab_find_with_hash (saving_htab, ptr, POINTER_HASH (ptr));
474 if (fwrite (&new_ptr->new_addr, sizeof (void *), 1, state->f)
476 fatal_error ("can%'t write PCH file: %m");
481 /* Hold the information we need to mmap the file back in. */
487 void *preferred_base;
490 /* Write out the state of the compiler to F. */
493 gt_pch_save (FILE *f)
495 const struct ggc_root_tab *const *rt;
496 const struct ggc_root_tab *rti;
498 struct traversal_state state;
499 char *this_object = NULL;
500 size_t this_object_size = 0;
501 struct mmap_info mmi;
502 const size_t mmap_offset_alignment = host_hooks.gt_pch_alloc_granularity();
504 gt_pch_save_stringpool ();
506 timevar_push (TV_PCH_PTR_REALLOC);
507 saving_htab = htab_create (50000, saving_htab_hash, saving_htab_eq, free);
509 for (rt = gt_ggc_rtab; *rt; rt++)
510 for (rti = *rt; rti->base != NULL; rti++)
511 for (i = 0; i < rti->nelt; i++)
512 (*rti->pchw)(*(void **)((char *)rti->base + rti->stride * i));
514 for (rt = gt_pch_cache_rtab; *rt; rt++)
515 for (rti = *rt; rti->base != NULL; rti++)
516 for (i = 0; i < rti->nelt; i++)
517 (*rti->pchw)(*(void **)((char *)rti->base + rti->stride * i));
519 /* Prepare the objects for writing, determine addresses and such. */
521 state.d = init_ggc_pch ();
523 htab_traverse (saving_htab, call_count, &state);
525 mmi.size = ggc_pch_total_size (state.d);
527 /* Try to arrange things so that no relocation is necessary, but
528 don't try very hard. On most platforms, this will always work,
529 and on the rest it's a lot of work to do better.
530 (The extra work goes in HOST_HOOKS_GT_PCH_GET_ADDRESS and
531 HOST_HOOKS_GT_PCH_USE_ADDRESS.) */
532 mmi.preferred_base = host_hooks.gt_pch_get_address (mmi.size, fileno (f));
534 ggc_pch_this_base (state.d, mmi.preferred_base);
536 state.ptrs = XNEWVEC (struct ptr_data *, state.count);
539 htab_traverse (saving_htab, call_alloc, &state);
540 timevar_pop (TV_PCH_PTR_REALLOC);
542 timevar_push (TV_PCH_PTR_SORT);
543 qsort (state.ptrs, state.count, sizeof (*state.ptrs), compare_ptr_data);
544 timevar_pop (TV_PCH_PTR_SORT);
546 /* Write out all the scalar variables. */
547 for (rt = gt_pch_scalar_rtab; *rt; rt++)
548 for (rti = *rt; rti->base != NULL; rti++)
549 if (fwrite (rti->base, rti->stride, 1, f) != 1)
550 fatal_error ("can%'t write PCH file: %m");
552 /* Write out all the global pointers, after translation. */
553 write_pch_globals (gt_ggc_rtab, &state);
554 write_pch_globals (gt_pch_cache_rtab, &state);
556 /* Pad the PCH file so that the mmapped area starts on an allocation
557 granularity (usually page) boundary. */
560 o = ftell (state.f) + sizeof (mmi);
562 fatal_error ("can%'t get position in PCH file: %m");
563 mmi.offset = mmap_offset_alignment - o % mmap_offset_alignment;
564 if (mmi.offset == mmap_offset_alignment)
568 if (fwrite (&mmi, sizeof (mmi), 1, state.f) != 1)
569 fatal_error ("can%'t write PCH file: %m");
571 && fseek (state.f, mmi.offset, SEEK_SET) != 0)
572 fatal_error ("can%'t write padding to PCH file: %m");
574 ggc_pch_prepare_write (state.d, state.f);
576 /* Actually write out the objects. */
577 for (i = 0; i < state.count; i++)
579 if (this_object_size < state.ptrs[i]->size)
581 this_object_size = state.ptrs[i]->size;
582 this_object = XRESIZEVAR (char, this_object, this_object_size);
584 memcpy (this_object, state.ptrs[i]->obj, state.ptrs[i]->size);
585 if (state.ptrs[i]->reorder_fn != NULL)
586 state.ptrs[i]->reorder_fn (state.ptrs[i]->obj,
587 state.ptrs[i]->note_ptr_cookie,
588 relocate_ptrs, &state);
589 state.ptrs[i]->note_ptr_fn (state.ptrs[i]->obj,
590 state.ptrs[i]->note_ptr_cookie,
591 relocate_ptrs, &state);
592 ggc_pch_write_object (state.d, state.f, state.ptrs[i]->obj,
593 state.ptrs[i]->new_addr, state.ptrs[i]->size,
594 state.ptrs[i]->note_ptr_fn == gt_pch_p_S);
595 if (state.ptrs[i]->note_ptr_fn != gt_pch_p_S)
596 memcpy (state.ptrs[i]->obj, this_object, state.ptrs[i]->size);
598 ggc_pch_finish (state.d, state.f);
599 gt_pch_fixup_stringpool ();
602 htab_delete (saving_htab);
605 /* Read the state of the compiler back in from F. */
608 gt_pch_restore (FILE *f)
610 const struct ggc_root_tab *const *rt;
611 const struct ggc_root_tab *rti;
613 struct mmap_info mmi;
616 /* Delete any deletable objects. This makes ggc_pch_read much
617 faster, as it can be sure that no GCable objects remain other
618 than the ones just read in. */
619 for (rt = gt_ggc_deletable_rtab; *rt; rt++)
620 for (rti = *rt; rti->base != NULL; rti++)
621 memset (rti->base, 0, rti->stride);
623 /* Read in all the scalar variables. */
624 for (rt = gt_pch_scalar_rtab; *rt; rt++)
625 for (rti = *rt; rti->base != NULL; rti++)
626 if (fread (rti->base, rti->stride, 1, f) != 1)
627 fatal_error ("can%'t read PCH file: %m");
629 /* Read in all the global pointers, in 6 easy loops. */
630 for (rt = gt_ggc_rtab; *rt; rt++)
631 for (rti = *rt; rti->base != NULL; rti++)
632 for (i = 0; i < rti->nelt; i++)
633 if (fread ((char *)rti->base + rti->stride * i,
634 sizeof (void *), 1, f) != 1)
635 fatal_error ("can%'t read PCH file: %m");
637 for (rt = gt_pch_cache_rtab; *rt; rt++)
638 for (rti = *rt; rti->base != NULL; rti++)
639 for (i = 0; i < rti->nelt; i++)
640 if (fread ((char *)rti->base + rti->stride * i,
641 sizeof (void *), 1, f) != 1)
642 fatal_error ("can%'t read PCH file: %m");
644 if (fread (&mmi, sizeof (mmi), 1, f) != 1)
645 fatal_error ("can%'t read PCH file: %m");
647 result = host_hooks.gt_pch_use_address (mmi.preferred_base, mmi.size,
648 fileno (f), mmi.offset);
650 fatal_error ("had to relocate PCH");
653 if (fseek (f, mmi.offset, SEEK_SET) != 0
654 || fread (mmi.preferred_base, mmi.size, 1, f) != 1)
655 fatal_error ("can%'t read PCH file: %m");
657 else if (fseek (f, mmi.offset + mmi.size, SEEK_SET) != 0)
658 fatal_error ("can%'t read PCH file: %m");
660 ggc_pch_read (f, mmi.preferred_base);
662 gt_pch_restore_stringpool ();
665 /* Default version of HOST_HOOKS_GT_PCH_GET_ADDRESS when mmap is not present.
666 Select no address whatsoever, and let gt_pch_save choose what it will with
667 malloc, presumably. */
670 default_gt_pch_get_address (size_t size ATTRIBUTE_UNUSED,
671 int fd ATTRIBUTE_UNUSED)
676 /* Default version of HOST_HOOKS_GT_PCH_USE_ADDRESS when mmap is not present.
677 Allocate SIZE bytes with malloc. Return 0 if the address we got is the
678 same as base, indicating that the memory has been allocated but needs to
679 be read in from the file. Return -1 if the address differs, to relocation
680 of the PCH file would be required. */
683 default_gt_pch_use_address (void *base, size_t size, int fd ATTRIBUTE_UNUSED,
684 size_t offset ATTRIBUTE_UNUSED)
686 void *addr = xmalloc (size);
687 return (addr == base) - 1;
690 /* Default version of HOST_HOOKS_GT_PCH_GET_ADDRESS. Return the
691 alignment required for allocating virtual memory. Usually this is the
695 default_gt_pch_alloc_granularity (void)
697 return getpagesize();
701 /* Default version of HOST_HOOKS_GT_PCH_GET_ADDRESS when mmap is present.
702 We temporarily allocate SIZE bytes, and let the kernel place the data
703 wherever it will. If it worked, that's our spot, if not we're likely
707 mmap_gt_pch_get_address (size_t size, int fd)
711 ret = mmap (NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
712 if (ret == (void *) MAP_FAILED)
715 munmap ((caddr_t) ret, size);
720 /* Default version of HOST_HOOKS_GT_PCH_USE_ADDRESS when mmap is present.
721 Map SIZE bytes of FD+OFFSET at BASE. Return 1 if we succeeded at
722 mapping the data at BASE, -1 if we couldn't.
724 This version assumes that the kernel honors the START operand of mmap
725 even without MAP_FIXED if START through START+SIZE are not currently
726 mapped with something. */
729 mmap_gt_pch_use_address (void *base, size_t size, int fd, size_t offset)
733 /* We're called with size == 0 if we're not planning to load a PCH
734 file at all. This allows the hook to free any static space that
735 we might have allocated at link time. */
739 addr = mmap ((caddr_t) base, size, PROT_READ | PROT_WRITE, MAP_PRIVATE,
742 return addr == base ? 1 : -1;
744 #endif /* HAVE_MMAP_FILE */
746 #if !defined ENABLE_GC_CHECKING && !defined ENABLE_GC_ALWAYS_COLLECT
748 /* Modify the bound based on rlimits. */
750 ggc_rlimit_bound (double limit)
752 #if defined(HAVE_GETRLIMIT)
754 # if defined (RLIMIT_AS)
755 /* RLIMIT_AS is what POSIX says is the limit on mmap. Presumably
756 any OS which has RLIMIT_AS also has a working mmap that GCC will use. */
757 if (getrlimit (RLIMIT_AS, &rlim) == 0
758 && rlim.rlim_cur != (rlim_t) RLIM_INFINITY
759 && rlim.rlim_cur < limit)
760 limit = rlim.rlim_cur;
761 # elif defined (RLIMIT_DATA)
762 /* ... but some older OSs bound mmap based on RLIMIT_DATA, or we
763 might be on an OS that has a broken mmap. (Others don't bound
764 mmap at all, apparently.) */
765 if (getrlimit (RLIMIT_DATA, &rlim) == 0
766 && rlim.rlim_cur != (rlim_t) RLIM_INFINITY
767 && rlim.rlim_cur < limit
768 /* Darwin has this horribly bogus default setting of
769 RLIMIT_DATA, to 6144Kb. No-one notices because RLIMIT_DATA
770 appears to be ignored. Ignore such silliness. If a limit
771 this small was actually effective for mmap, GCC wouldn't even
773 && rlim.rlim_cur >= 8 * 1024 * 1024)
774 limit = rlim.rlim_cur;
775 # endif /* RLIMIT_AS or RLIMIT_DATA */
776 #endif /* HAVE_GETRLIMIT */
781 /* Heuristic to set a default for GGC_MIN_EXPAND. */
783 ggc_min_expand_heuristic (void)
785 double min_expand = physmem_total();
787 /* Adjust for rlimits. */
788 min_expand = ggc_rlimit_bound (min_expand);
790 /* The heuristic is a percentage equal to 30% + 70%*(RAM/1GB), yielding
791 a lower bound of 30% and an upper bound of 100% (when RAM >= 1GB). */
792 min_expand /= 1024*1024*1024;
794 min_expand = MIN (min_expand, 70);
800 /* Heuristic to set a default for GGC_MIN_HEAPSIZE. */
802 ggc_min_heapsize_heuristic (void)
804 double phys_kbytes = physmem_total();
805 double limit_kbytes = ggc_rlimit_bound (phys_kbytes * 2);
807 phys_kbytes /= 1024; /* Convert to Kbytes. */
808 limit_kbytes /= 1024;
810 /* The heuristic is RAM/8, with a lower bound of 4M and an upper
811 bound of 128M (when RAM >= 1GB). */
814 #if defined(HAVE_GETRLIMIT) && defined (RLIMIT_RSS)
815 /* Try not to overrun the RSS limit while doing garbage collection.
816 The RSS limit is only advisory, so no margin is subtracted. */
819 if (getrlimit (RLIMIT_RSS, &rlim) == 0
820 && rlim.rlim_cur != (rlim_t) RLIM_INFINITY)
821 phys_kbytes = MIN (phys_kbytes, rlim.rlim_cur / 1024);
825 /* Don't blindly run over our data limit; do GC at least when the
826 *next* GC would be within 20Mb of the limit or within a quarter of
827 the limit, whichever is larger. If GCC does hit the data limit,
828 compilation will fail, so this tries to be conservative. */
829 limit_kbytes = MAX (0, limit_kbytes - MAX (limit_kbytes / 4, 20 * 1024));
830 limit_kbytes = (limit_kbytes * 100) / (110 + ggc_min_expand_heuristic ());
831 phys_kbytes = MIN (phys_kbytes, limit_kbytes);
833 phys_kbytes = MAX (phys_kbytes, 4 * 1024);
834 phys_kbytes = MIN (phys_kbytes, 128 * 1024);
841 init_ggc_heuristics (void)
843 #if !defined ENABLE_GC_CHECKING && !defined ENABLE_GC_ALWAYS_COLLECT
844 set_default_param_value (GGC_MIN_EXPAND, ggc_min_expand_heuristic ());
845 set_default_param_value (GGC_MIN_HEAPSIZE, ggc_min_heapsize_heuristic ());
849 #ifdef GATHER_STATISTICS
851 /* Datastructure used to store per-call-site statistics. */
852 struct loc_descriptor
856 const char *function;
864 /* Hashtable used for statistics. */
865 static htab_t loc_hash;
867 /* Hash table helpers functions. */
869 hash_descriptor (const void *p)
871 const struct loc_descriptor *const d = (const struct loc_descriptor *) p;
873 return htab_hash_pointer (d->function) | d->line;
877 eq_descriptor (const void *p1, const void *p2)
879 const struct loc_descriptor *const d = (const struct loc_descriptor *) p1;
880 const struct loc_descriptor *const d2 = (const struct loc_descriptor *) p2;
882 return (d->file == d2->file && d->line == d2->line
883 && d->function == d2->function);
886 /* Hashtable converting address of allocated field to loc descriptor. */
887 static htab_t ptr_hash;
888 struct ptr_hash_entry
891 struct loc_descriptor *loc;
895 /* Hash table helpers functions. */
897 hash_ptr (const void *p)
899 const struct ptr_hash_entry *const d = (const struct ptr_hash_entry *) p;
901 return htab_hash_pointer (d->ptr);
905 eq_ptr (const void *p1, const void *p2)
907 const struct ptr_hash_entry *const p = (const struct ptr_hash_entry *) p1;
909 return (p->ptr == p2);
912 /* Return descriptor for given call site, create new one if needed. */
913 static struct loc_descriptor *
914 loc_descriptor (const char *name, int line, const char *function)
916 struct loc_descriptor loc;
917 struct loc_descriptor **slot;
921 loc.function = function;
923 loc_hash = htab_create (10, hash_descriptor, eq_descriptor, NULL);
925 slot = (struct loc_descriptor **) htab_find_slot (loc_hash, &loc, INSERT);
928 *slot = XCNEW (struct loc_descriptor);
929 (*slot)->file = name;
930 (*slot)->line = line;
931 (*slot)->function = function;
935 /* Record ALLOCATED and OVERHEAD bytes to descriptor NAME:LINE (FUNCTION). */
937 ggc_record_overhead (size_t allocated, size_t overhead, void *ptr,
938 const char *name, int line, const char *function)
940 struct loc_descriptor *loc = loc_descriptor (name, line, function);
941 struct ptr_hash_entry *p = XNEW (struct ptr_hash_entry);
946 p->size = allocated + overhead;
948 ptr_hash = htab_create (10, hash_ptr, eq_ptr, NULL);
949 slot = htab_find_slot_with_hash (ptr_hash, ptr, htab_hash_pointer (ptr), INSERT);
954 loc->allocated+=allocated;
955 loc->overhead+=overhead;
958 /* Helper function for prune_overhead_list. See if SLOT is still marked and
959 remove it from hashtable if it is not. */
961 ggc_prune_ptr (void **slot, void *b ATTRIBUTE_UNUSED)
963 struct ptr_hash_entry *p = (struct ptr_hash_entry *) *slot;
964 if (!ggc_marked_p (p->ptr))
966 p->loc->collected += p->size;
967 htab_clear_slot (ptr_hash, slot);
973 /* After live values has been marked, walk all recorded pointers and see if
974 they are still live. */
976 ggc_prune_overhead_list (void)
978 htab_traverse (ptr_hash, ggc_prune_ptr, NULL);
981 /* Notice that the pointer has been freed. */
983 ggc_free_overhead (void *ptr)
985 PTR *slot = htab_find_slot_with_hash (ptr_hash, ptr, htab_hash_pointer (ptr),
987 struct ptr_hash_entry *p;
988 /* The pointer might be not found if a PCH read happened between allocation
989 and ggc_free () call. FIXME: account memory properly in the presence of
993 p = (struct ptr_hash_entry *) *slot;
994 p->loc->freed += p->size;
995 htab_clear_slot (ptr_hash, slot);
999 /* Helper for qsort; sort descriptors by amount of memory consumed. */
1001 final_cmp_statistic (const void *loc1, const void *loc2)
1003 const struct loc_descriptor *const l1 =
1004 *(const struct loc_descriptor *const *) loc1;
1005 const struct loc_descriptor *const l2 =
1006 *(const struct loc_descriptor *const *) loc2;
1008 diff = ((long)(l1->allocated + l1->overhead - l1->freed) -
1009 (l2->allocated + l2->overhead - l2->freed));
1010 return diff > 0 ? 1 : diff < 0 ? -1 : 0;
1013 /* Helper for qsort; sort descriptors by amount of memory consumed. */
1015 cmp_statistic (const void *loc1, const void *loc2)
1017 const struct loc_descriptor *const l1 =
1018 *(const struct loc_descriptor *const *) loc1;
1019 const struct loc_descriptor *const l2 =
1020 *(const struct loc_descriptor *const *) loc2;
1023 diff = ((long)(l1->allocated + l1->overhead - l1->freed - l1->collected) -
1024 (l2->allocated + l2->overhead - l2->freed - l2->collected));
1026 return diff > 0 ? 1 : diff < 0 ? -1 : 0;
1027 diff = ((long)(l1->allocated + l1->overhead - l1->freed) -
1028 (l2->allocated + l2->overhead - l2->freed));
1029 return diff > 0 ? 1 : diff < 0 ? -1 : 0;
1032 /* Collect array of the descriptors from hashtable. */
1033 static struct loc_descriptor **loc_array;
1035 add_statistics (void **slot, void *b)
1038 loc_array[*n] = (struct loc_descriptor *) *slot;
1043 /* Dump per-site memory statistics. */
1046 dump_ggc_loc_statistics (bool final ATTRIBUTE_UNUSED)
1048 #ifdef GATHER_STATISTICS
1051 size_t collected = 0, freed = 0, allocated = 0, overhead = 0, times = 0;
1054 ggc_force_collect = true;
1057 loc_array = XCNEWVEC (struct loc_descriptor *, loc_hash->n_elements);
1058 fprintf (stderr, "-------------------------------------------------------\n");
1059 fprintf (stderr, "\n%-48s %10s %10s %10s %10s %10s\n",
1060 "source location", "Garbage", "Freed", "Leak", "Overhead", "Times");
1061 fprintf (stderr, "-------------------------------------------------------\n");
1062 htab_traverse (loc_hash, add_statistics, &nentries);
1063 qsort (loc_array, nentries, sizeof (*loc_array),
1064 final ? final_cmp_statistic : cmp_statistic);
1065 for (i = 0; i < nentries; i++)
1067 struct loc_descriptor *d = loc_array[i];
1068 allocated += d->allocated;
1071 collected += d->collected;
1072 overhead += d->overhead;
1074 for (i = 0; i < nentries; i++)
1076 struct loc_descriptor *d = loc_array[i];
1079 const char *s1 = d->file;
1081 while ((s2 = strstr (s1, "gcc/")))
1083 sprintf (s, "%s:%i (%s)", s1, d->line, d->function);
1085 fprintf (stderr, "%-48s %10li:%4.1f%% %10li:%4.1f%% %10li:%4.1f%% %10li:%4.1f%% %10li\n", s,
1087 (d->collected) * 100.0 / collected,
1089 (d->freed) * 100.0 / freed,
1090 (long)(d->allocated + d->overhead - d->freed - d->collected),
1091 (d->allocated + d->overhead - d->freed - d->collected) * 100.0
1092 / (allocated + overhead - freed - collected),
1094 d->overhead * 100.0 / overhead,
1098 fprintf (stderr, "%-48s %10ld %10ld %10ld %10ld %10ld\n",
1099 "Total", (long)collected, (long)freed,
1100 (long)(allocated + overhead - freed - collected), (long)overhead,
1102 fprintf (stderr, "%-48s %10s %10s %10s %10s %10s\n",
1103 "source location", "Garbage", "Freed", "Leak", "Overhead", "Times");
1104 fprintf (stderr, "-------------------------------------------------------\n");
1105 ggc_force_collect = false;