| /* Simple garbage collection for the GNU compiler. |
| Copyright (C) 1999, 2000, 2001, 2002 Free Software Foundation, Inc. |
| |
| This file is part of GCC. |
| |
| GCC is free software; you can redistribute it and/or modify it under |
| the terms of the GNU General Public License as published by the Free |
| Software Foundation; either version 2, or (at your option) any later |
| version. |
| |
| GCC is distributed in the hope that it will be useful, but WITHOUT ANY |
| WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GCC; see the file COPYING. If not, write to the Free |
| Software Foundation, 59 Temple Place - Suite 330, Boston, MA |
| 02111-1307, USA. */ |
| |
| /* Generic garbage collection (GC) functions and data, not specific to |
| any particular GC implementation. */ |
| |
| #include "config.h" |
| #include "system.h" |
| #include "rtl.h" |
| #include "tree.h" |
| #include "tm_p.h" |
| #include "hashtab.h" |
| #include "varray.h" |
| #include "ggc.h" |
| #include "langhooks.h" |
| #include "params.h" |
| #ifdef HAVE_SYS_RESOURCE_H |
| # include <sys/resource.h> |
| #endif |
| #ifdef ENABLE_VALGRIND_CHECKING |
| #include <valgrind.h> |
| #else |
| /* Avoid #ifdef:s when we can help it. */ |
| #define VALGRIND_DISCARD(x) |
| #endif |
| |
| /* Statistics about the allocation. */ |
| static ggc_statistics *ggc_stats; |
| |
| static int ggc_htab_delete PARAMS ((void **, void *)); |
| static double ggc_rlimit_bound PARAMS ((double)); |
| |
| /* Maintain global roots that are preserved during GC. */ |
| |
| /* Global roots that are preserved during calls to gc. */ |
| |
| struct ggc_root |
| { |
| struct ggc_root *next; |
| void *base; |
| int nelt; |
| int size; |
| void (*cb) PARAMS ((void *)); |
| }; |
| |
| static struct ggc_root *roots; |
| |
| /* Add BASE as a new garbage collection root. It is an array of |
| length NELT with each element SIZE bytes long. CB is a |
| function that will be called with a pointer to each element |
| of the array; it is the intention that CB call the appropriate |
| routine to mark gc-able memory for that element. */ |
| |
| void |
| ggc_add_root (base, nelt, size, cb) |
| void *base; |
| int nelt, size; |
| void (*cb) PARAMS ((void *)); |
| { |
| struct ggc_root *x = (struct ggc_root *) xmalloc (sizeof (*x)); |
| |
| x->next = roots; |
| x->base = base; |
| x->nelt = nelt; |
| x->size = size; |
| x->cb = cb; |
| |
| roots = x; |
| } |
| |
| /* Process a slot of an htab by deleting it if it has not been marked. */ |
| |
| static int |
| ggc_htab_delete (slot, info) |
| void **slot; |
| void *info; |
| { |
| const struct ggc_cache_tab *r = (const struct ggc_cache_tab *) info; |
| |
| if (! (*r->marked_p) (*slot)) |
| htab_clear_slot (*r->base, slot); |
| else |
| (*r->cb) (*slot); |
| |
| return 1; |
| } |
| |
| /* Iterate through all registered roots and mark each element. */ |
| |
| void |
| ggc_mark_roots () |
| { |
| struct ggc_root *x; |
| const struct ggc_root_tab *const *rt; |
| const struct ggc_root_tab *rti; |
| const struct ggc_cache_tab *const *ct; |
| const struct ggc_cache_tab *cti; |
| size_t i; |
| |
| for (rt = gt_ggc_deletable_rtab; *rt; rt++) |
| for (rti = *rt; rti->base != NULL; rti++) |
| memset (rti->base, 0, rti->stride); |
| |
| for (rt = gt_ggc_rtab; *rt; rt++) |
| for (rti = *rt; rti->base != NULL; rti++) |
| for (i = 0; i < rti->nelt; i++) |
| (*rti->cb)(*(void **)((char *)rti->base + rti->stride * i)); |
| |
| for (x = roots; x != NULL; x = x->next) |
| { |
| char *elt = x->base; |
| int s = x->size, n = x->nelt; |
| void (*cb) PARAMS ((void *)) = x->cb; |
| int i; |
| |
| for (i = 0; i < n; ++i, elt += s) |
| (*cb)(elt); |
| } |
| |
| /* Now scan all hash tables that have objects which are to be deleted if |
| they are not already marked. */ |
| for (ct = gt_ggc_cache_rtab; *ct; ct++) |
| for (cti = *ct; cti->base != NULL; cti++) |
| if (*cti->base) |
| htab_traverse (*cti->base, ggc_htab_delete, (PTR) cti); |
| } |
| |
| /* Allocate a block of memory, then clear it. */ |
| void * |
| ggc_alloc_cleared (size) |
| size_t size; |
| { |
| void *buf = ggc_alloc (size); |
| memset (buf, 0, size); |
| return buf; |
| } |
| |
| /* Resize a block of memory, possibly re-allocating it. */ |
| void * |
| ggc_realloc (x, size) |
| void *x; |
| size_t size; |
| { |
| void *r; |
| size_t old_size; |
| |
| if (x == NULL) |
| return ggc_alloc (size); |
| |
| old_size = ggc_get_size (x); |
| if (size <= old_size) |
| { |
| /* Mark the unwanted memory as unaccessible. We also need to make |
| the "new" size accessible, since ggc_get_size returns the size of |
| the pool, not the size of the individually allocated object, the |
| size which was previously made accessible. Unfortunately, we |
| don't know that previously allocated size. Without that |
| knowledge we have to lose some initialization-tracking for the |
| old parts of the object. An alternative is to mark the whole |
| old_size as reachable, but that would lose tracking of writes |
| after the end of the object (by small offsets). Discard the |
| handle to avoid handle leak. */ |
| VALGRIND_DISCARD (VALGRIND_MAKE_NOACCESS ((char *) x + size, |
| old_size - size)); |
| VALGRIND_DISCARD (VALGRIND_MAKE_READABLE (x, size)); |
| return x; |
| } |
| |
| r = ggc_alloc (size); |
| |
| /* Since ggc_get_size returns the size of the pool, not the size of the |
| individually allocated object, we'd access parts of the old object |
| that were marked invalid with the memcpy below. We lose a bit of the |
| initialization-tracking since some of it may be uninitialized. */ |
| VALGRIND_DISCARD (VALGRIND_MAKE_READABLE (x, old_size)); |
| |
| memcpy (r, x, old_size); |
| |
| /* The old object is not supposed to be used anymore. */ |
| VALGRIND_DISCARD (VALGRIND_MAKE_NOACCESS (x, old_size)); |
| |
| return r; |
| } |
| |
| /* Like ggc_alloc_cleared, but performs a multiplication. */ |
| void * |
| ggc_calloc (s1, s2) |
| size_t s1, s2; |
| { |
| return ggc_alloc_cleared (s1 * s2); |
| } |
| |
| /* Print statistics that are independent of the collector in use. */ |
| #define SCALE(x) ((unsigned long) ((x) < 1024*10 \ |
| ? (x) \ |
| : ((x) < 1024*1024*10 \ |
| ? (x) / 1024 \ |
| : (x) / (1024*1024)))) |
| #define LABEL(x) ((x) < 1024*10 ? ' ' : ((x) < 1024*1024*10 ? 'k' : 'M')) |
| |
| void |
| ggc_print_common_statistics (stream, stats) |
| FILE *stream; |
| ggc_statistics *stats; |
| { |
| int code; |
| |
| /* Set the pointer so that during collection we will actually gather |
| the statistics. */ |
| ggc_stats = stats; |
| |
| /* Then do one collection to fill in the statistics. */ |
| ggc_collect (); |
| |
| /* Total the statistics. */ |
| for (code = 0; code < MAX_TREE_CODES; ++code) |
| { |
| stats->total_num_trees += stats->num_trees[code]; |
| stats->total_size_trees += stats->size_trees[code]; |
| } |
| for (code = 0; code < NUM_RTX_CODE; ++code) |
| { |
| stats->total_num_rtxs += stats->num_rtxs[code]; |
| stats->total_size_rtxs += stats->size_rtxs[code]; |
| } |
| |
| /* Print the statistics for trees. */ |
| fprintf (stream, "\n%-17s%10s %16s %10s\n", "Tree", |
| "Number", "Bytes", "% Total"); |
| for (code = 0; code < MAX_TREE_CODES; ++code) |
| if (ggc_stats->num_trees[code]) |
| { |
| fprintf (stream, "%-17s%10u%16ld%c %10.3f\n", |
| tree_code_name[code], |
| ggc_stats->num_trees[code], |
| SCALE (ggc_stats->size_trees[code]), |
| LABEL (ggc_stats->size_trees[code]), |
| (100 * ((double) ggc_stats->size_trees[code]) |
| / ggc_stats->total_size_trees)); |
| } |
| fprintf (stream, |
| "%-17s%10u%16ld%c\n", "Total", |
| ggc_stats->total_num_trees, |
| SCALE (ggc_stats->total_size_trees), |
| LABEL (ggc_stats->total_size_trees)); |
| |
| /* Print the statistics for RTL. */ |
| fprintf (stream, "\n%-17s%10s %16s %10s\n", "RTX", |
| "Number", "Bytes", "% Total"); |
| for (code = 0; code < NUM_RTX_CODE; ++code) |
| if (ggc_stats->num_rtxs[code]) |
| { |
| fprintf (stream, "%-17s%10u%16ld%c %10.3f\n", |
| rtx_name[code], |
| ggc_stats->num_rtxs[code], |
| SCALE (ggc_stats->size_rtxs[code]), |
| LABEL (ggc_stats->size_rtxs[code]), |
| (100 * ((double) ggc_stats->size_rtxs[code]) |
| / ggc_stats->total_size_rtxs)); |
| } |
| fprintf (stream, |
| "%-17s%10u%16ld%c\n", "Total", |
| ggc_stats->total_num_rtxs, |
| SCALE (ggc_stats->total_size_rtxs), |
| LABEL (ggc_stats->total_size_rtxs)); |
| |
| /* Don't gather statistics any more. */ |
| ggc_stats = NULL; |
| } |
| |
| /* Modify the bound based on rlimits. Keep the smallest number found. */ |
| static double |
| ggc_rlimit_bound (limit) |
| double limit; |
| { |
| #if defined(HAVE_GETRLIMIT) |
| struct rlimit rlim; |
| # ifdef RLIMIT_RSS |
| if (getrlimit (RLIMIT_RSS, &rlim) == 0 |
| && rlim.rlim_cur != (rlim_t) RLIM_INFINITY |
| && rlim.rlim_cur < limit) |
| limit = rlim.rlim_cur; |
| # endif |
| # ifdef RLIMIT_DATA |
| if (getrlimit (RLIMIT_DATA, &rlim) == 0 |
| && rlim.rlim_cur != (rlim_t) RLIM_INFINITY |
| && rlim.rlim_cur < limit) |
| limit = rlim.rlim_cur; |
| # endif |
| # ifdef RLIMIT_AS |
| if (getrlimit (RLIMIT_AS, &rlim) == 0 |
| && rlim.rlim_cur != (rlim_t) RLIM_INFINITY |
| && rlim.rlim_cur < limit) |
| limit = rlim.rlim_cur; |
| # endif |
| #endif /* HAVE_GETRLIMIT */ |
| |
| return limit; |
| } |
| |
| /* Heuristic to set a default for GGC_MIN_EXPAND. */ |
| int |
| ggc_min_expand_heuristic() |
| { |
| double min_expand = physmem_total(); |
| |
| /* Adjust for rlimits. */ |
| min_expand = ggc_rlimit_bound (min_expand); |
| |
| /* The heuristic is a percentage equal to 30% + 70%*(RAM/1GB), yielding |
| a lower bound of 30% and an upper bound of 100% (when RAM >= 1GB). */ |
| min_expand /= 1024*1024*1024; |
| min_expand *= 70; |
| min_expand = MIN (min_expand, 70); |
| min_expand += 30; |
| |
| return min_expand; |
| } |
| |
| /* Heuristic to set a default for GGC_MIN_HEAPSIZE. */ |
| int |
| ggc_min_heapsize_heuristic() |
| { |
| double min_heap_kbytes = physmem_total(); |
| |
| /* Adjust for rlimits. */ |
| min_heap_kbytes = ggc_rlimit_bound (min_heap_kbytes); |
| |
| min_heap_kbytes /= 1024; /* convert to Kbytes. */ |
| |
| /* The heuristic is RAM/8, with a lower bound of 4M and an upper |
| bound of 128M (when RAM >= 1GB). */ |
| min_heap_kbytes /= 8; |
| min_heap_kbytes = MAX (min_heap_kbytes, 4 * 1024); |
| min_heap_kbytes = MIN (min_heap_kbytes, 128 * 1024); |
| |
| return min_heap_kbytes; |
| } |
| |
| void |
| init_ggc_heuristics () |
| { |
| #ifndef ENABLE_GC_ALWAYS_COLLECT |
| set_param_value ("ggc-min-expand", ggc_min_expand_heuristic()); |
| set_param_value ("ggc-min-heapsize", ggc_min_heapsize_heuristic()); |
| #endif |
| } |