gcc/boehm-gc/malloc.c

486 lines
13 KiB
C

/*
* Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
* Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
* Copyright (c) 2000 by Hewlett-Packard Company. All rights reserved.
*
* THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
* OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
*
* Permission is hereby granted to use or copy this program
* for any purpose, provided the above notices are retained on all copies.
* Permission to modify the code and to distribute modified code is granted,
* provided the above notices are retained, and a notice that the code was
* modified is included with the above copyright notice.
*/
/* Boehm, February 7, 1996 4:32 pm PST */
#include <stdio.h>
#include "private/gc_priv.h"
extern ptr_t GC_clear_stack(); /* in misc.c, behaves like identity */
void GC_extend_size_map(); /* in misc.c. */
/* Allocate reclaim list for kind: */
/* Return TRUE on success */
GC_bool GC_alloc_reclaim_list(kind)
register struct obj_kind * kind;
{
struct hblk ** result = (struct hblk **)
GC_scratch_alloc((MAXOBJSZ+1) * sizeof(struct hblk *));
if (result == 0) return(FALSE);
BZERO(result, (MAXOBJSZ+1)*sizeof(struct hblk *));
kind -> ok_reclaim_list = result;
return(TRUE);
}
/* Allocate a large block of size lw words. */
/* The block is not cleared. */
/* Flags is 0 or IGNORE_OFF_PAGE. */
ptr_t GC_alloc_large(lw, k, flags)
word lw;
int k;
unsigned flags;
{
struct hblk * h;
word n_blocks = OBJ_SZ_TO_BLOCKS(lw);
ptr_t result;
if (!GC_is_initialized) GC_init_inner();
/* Do our share of marking work */
if(GC_incremental && !GC_dont_gc)
GC_collect_a_little_inner((int)n_blocks);
h = GC_allochblk(lw, k, flags);
# ifdef USE_MUNMAP
if (0 == h) {
GC_merge_unmapped();
h = GC_allochblk(lw, k, flags);
}
# endif
while (0 == h && GC_collect_or_expand(n_blocks, (flags != 0))) {
h = GC_allochblk(lw, k, flags);
}
if (h == 0) {
result = 0;
} else {
int total_bytes = BYTES_TO_WORDS(n_blocks * HBLKSIZE);
if (n_blocks > 1) {
GC_large_allocd_bytes += n_blocks * HBLKSIZE;
if (GC_large_allocd_bytes > GC_max_large_allocd_bytes)
GC_max_large_allocd_bytes = GC_large_allocd_bytes;
}
result = (ptr_t) (h -> hb_body);
GC_words_wasted += total_bytes - lw;
}
return result;
}
/* Allocate a large block of size lb bytes. Clear if appropriate. */
ptr_t GC_alloc_large_and_clear(lw, k, flags)
word lw;
int k;
unsigned flags;
{
ptr_t result = GC_alloc_large(lw, k, flags);
word n_blocks = OBJ_SZ_TO_BLOCKS(lw);
if (0 == result) return 0;
if (GC_debugging_started || GC_obj_kinds[k].ok_init) {
/* Clear the whole block, in case of GC_realloc call. */
BZERO(result, n_blocks * HBLKSIZE);
}
return result;
}
/* allocate lb bytes for an object of kind k. */
/* Should not be used to directly to allocate */
/* objects such as STUBBORN objects that */
/* require special handling on allocation. */
/* First a version that assumes we already */
/* hold lock: */
ptr_t GC_generic_malloc_inner(lb, k)
register word lb;
register int k;
{
register word lw;
register ptr_t op;
register ptr_t *opp;
if( SMALL_OBJ(lb) ) {
register struct obj_kind * kind = GC_obj_kinds + k;
# ifdef MERGE_SIZES
lw = GC_size_map[lb];
# else
lw = ALIGNED_WORDS(lb);
if (lw == 0) lw = MIN_WORDS;
# endif
opp = &(kind -> ok_freelist[lw]);
if( (op = *opp) == 0 ) {
# ifdef MERGE_SIZES
if (GC_size_map[lb] == 0) {
if (!GC_is_initialized) GC_init_inner();
if (GC_size_map[lb] == 0) GC_extend_size_map(lb);
return(GC_generic_malloc_inner(lb, k));
}
# else
if (!GC_is_initialized) {
GC_init_inner();
return(GC_generic_malloc_inner(lb, k));
}
# endif
if (kind -> ok_reclaim_list == 0) {
if (!GC_alloc_reclaim_list(kind)) goto out;
}
op = GC_allocobj(lw, k);
if (op == 0) goto out;
}
/* Here everything is in a consistent state. */
/* We assume the following assignment is */
/* atomic. If we get aborted */
/* after the assignment, we lose an object, */
/* but that's benign. */
/* Volatile declarations may need to be added */
/* to prevent the compiler from breaking things.*/
/* If we only execute the second of the */
/* following assignments, we lose the free */
/* list, but that should still be OK, at least */
/* for garbage collected memory. */
*opp = obj_link(op);
obj_link(op) = 0;
} else {
lw = ROUNDED_UP_WORDS(lb);
op = (ptr_t)GC_alloc_large_and_clear(lw, k, 0);
}
GC_words_allocd += lw;
out:
return op;
}
/* Allocate a composite object of size n bytes. The caller guarantees */
/* that pointers past the first page are not relevant. Caller holds */
/* allocation lock. */
ptr_t GC_generic_malloc_inner_ignore_off_page(lb, k)
register size_t lb;
register int k;
{
register word lw;
ptr_t op;
if (lb <= HBLKSIZE)
return(GC_generic_malloc_inner((word)lb, k));
lw = ROUNDED_UP_WORDS(lb);
op = (ptr_t)GC_alloc_large_and_clear(lw, k, IGNORE_OFF_PAGE);
GC_words_allocd += lw;
return op;
}
ptr_t GC_generic_malloc(lb, k)
register word lb;
register int k;
{
ptr_t result;
DCL_LOCK_STATE;
if (GC_have_errors) GC_print_all_errors();
GC_INVOKE_FINALIZERS();
if (SMALL_OBJ(lb)) {
DISABLE_SIGNALS();
LOCK();
result = GC_generic_malloc_inner((word)lb, k);
UNLOCK();
ENABLE_SIGNALS();
} else {
word lw;
word n_blocks;
GC_bool init;
lw = ROUNDED_UP_WORDS(lb);
n_blocks = OBJ_SZ_TO_BLOCKS(lw);
init = GC_obj_kinds[k].ok_init;
DISABLE_SIGNALS();
LOCK();
result = (ptr_t)GC_alloc_large(lw, k, 0);
if (0 != result) {
if (GC_debugging_started) {
BZERO(result, n_blocks * HBLKSIZE);
} else {
# ifdef THREADS
/* Clear any memory that might be used for GC descriptors */
/* before we release the lock. */
((word *)result)[0] = 0;
((word *)result)[1] = 0;
((word *)result)[lw-1] = 0;
((word *)result)[lw-2] = 0;
# endif
}
}
GC_words_allocd += lw;
UNLOCK();
ENABLE_SIGNALS();
if (init && !GC_debugging_started && 0 != result) {
BZERO(result, n_blocks * HBLKSIZE);
}
}
if (0 == result) {
return((*GC_oom_fn)(lb));
} else {
return(result);
}
}
#define GENERAL_MALLOC(lb,k) \
(GC_PTR)GC_clear_stack(GC_generic_malloc((word)lb, k))
/* We make the GC_clear_stack_call a tail call, hoping to get more of */
/* the stack. */
/* Allocate lb bytes of atomic (pointerfree) data */
# ifdef __STDC__
GC_PTR GC_malloc_atomic(size_t lb)
# else
GC_PTR GC_malloc_atomic(lb)
size_t lb;
# endif
{
register ptr_t op;
register ptr_t * opp;
register word lw;
DCL_LOCK_STATE;
if( EXPECT(SMALL_OBJ(lb), 1) ) {
# ifdef MERGE_SIZES
lw = GC_size_map[lb];
# else
lw = ALIGNED_WORDS(lb);
# endif
opp = &(GC_aobjfreelist[lw]);
FASTLOCK();
if( EXPECT(!FASTLOCK_SUCCEEDED() || (op = *opp) == 0, 0) ) {
FASTUNLOCK();
return(GENERAL_MALLOC((word)lb, PTRFREE));
}
/* See above comment on signals. */
*opp = obj_link(op);
GC_words_allocd += lw;
FASTUNLOCK();
return((GC_PTR) op);
} else {
return(GENERAL_MALLOC((word)lb, PTRFREE));
}
}
/* Allocate lb bytes of composite (pointerful) data */
# ifdef __STDC__
GC_PTR GC_malloc(size_t lb)
# else
GC_PTR GC_malloc(lb)
size_t lb;
# endif
{
register ptr_t op;
register ptr_t *opp;
register word lw;
DCL_LOCK_STATE;
if( EXPECT(SMALL_OBJ(lb), 1) ) {
# ifdef MERGE_SIZES
lw = GC_size_map[lb];
# else
lw = ALIGNED_WORDS(lb);
# endif
opp = &(GC_objfreelist[lw]);
FASTLOCK();
if( EXPECT(!FASTLOCK_SUCCEEDED() || (op = *opp) == 0, 0) ) {
FASTUNLOCK();
return(GENERAL_MALLOC((word)lb, NORMAL));
}
/* See above comment on signals. */
GC_ASSERT(0 == obj_link(op)
|| (word)obj_link(op)
<= (word)GC_greatest_plausible_heap_addr
&& (word)obj_link(op)
>= (word)GC_least_plausible_heap_addr);
*opp = obj_link(op);
obj_link(op) = 0;
GC_words_allocd += lw;
FASTUNLOCK();
return((GC_PTR) op);
} else {
return(GENERAL_MALLOC((word)lb, NORMAL));
}
}
# ifdef REDIRECT_MALLOC
# ifdef __STDC__
GC_PTR malloc(size_t lb)
# else
GC_PTR malloc(lb)
size_t lb;
# endif
{
/* It might help to manually inline the GC_malloc call here. */
/* But any decent compiler should reduce the extra procedure call */
/* to at most a jump instruction in this case. */
# if defined(I386) && defined(GC_SOLARIS_THREADS)
/*
* Thread initialisation can call malloc before
* we're ready for it.
* It's not clear that this is enough to help matters.
* The thread implementation may well call malloc at other
* inopportune times.
*/
if (!GC_is_initialized) return sbrk(lb);
# endif /* I386 && GC_SOLARIS_THREADS */
return((GC_PTR)REDIRECT_MALLOC(lb));
}
# ifdef __STDC__
GC_PTR calloc(size_t n, size_t lb)
# else
GC_PTR calloc(n, lb)
size_t n, lb;
# endif
{
return((GC_PTR)REDIRECT_MALLOC(n*lb));
}
#ifndef strdup
# include <string.h>
# ifdef __STDC__
char *strdup(const char *s)
# else
char *strdup(s)
char *s;
# endif
{
size_t len = strlen(s) + 1;
char * result = ((char *)REDIRECT_MALLOC(len+1));
BCOPY(s, result, len+1);
return result;
}
#endif /* !defined(strdup) */
/* If strdup is macro defined, we assume that it actually calls malloc, */
/* and thus the right thing will happen even without overriding it. */
/* This seems to be true on most Linux systems. */
# endif /* REDIRECT_MALLOC */
/* Explicitly deallocate an object p. */
# ifdef __STDC__
void GC_free(GC_PTR p)
# else
void GC_free(p)
GC_PTR p;
# endif
{
register struct hblk *h;
register hdr *hhdr;
register signed_word sz;
register ptr_t * flh;
register int knd;
register struct obj_kind * ok;
DCL_LOCK_STATE;
if (p == 0) return;
/* Required by ANSI. It's not my fault ... */
h = HBLKPTR(p);
hhdr = HDR(h);
GC_ASSERT(GC_base(p) == p);
# if defined(REDIRECT_MALLOC) && \
(defined(GC_SOLARIS_THREADS) || defined(GC_LINUX_THREADS) \
|| defined(__MINGW32__)) /* Should this be MSWIN32 in general? */
/* For Solaris, we have to redirect malloc calls during */
/* initialization. For the others, this seems to happen */
/* implicitly. */
/* Don't try to deallocate that memory. */
if (0 == hhdr) return;
# endif
knd = hhdr -> hb_obj_kind;
sz = hhdr -> hb_sz;
ok = &GC_obj_kinds[knd];
if (EXPECT((sz <= MAXOBJSZ), 1)) {
# ifdef THREADS
DISABLE_SIGNALS();
LOCK();
# endif
GC_mem_freed += sz;
/* A signal here can make GC_mem_freed and GC_non_gc_bytes */
/* inconsistent. We claim this is benign. */
if (IS_UNCOLLECTABLE(knd)) GC_non_gc_bytes -= WORDS_TO_BYTES(sz);
/* Its unnecessary to clear the mark bit. If the */
/* object is reallocated, it doesn't matter. O.w. the */
/* collector will do it, since it's on a free list. */
if (ok -> ok_init) {
BZERO((word *)p + 1, WORDS_TO_BYTES(sz-1));
}
flh = &(ok -> ok_freelist[sz]);
obj_link(p) = *flh;
*flh = (ptr_t)p;
# ifdef THREADS
UNLOCK();
ENABLE_SIGNALS();
# endif
} else {
DISABLE_SIGNALS();
LOCK();
GC_mem_freed += sz;
if (IS_UNCOLLECTABLE(knd)) GC_non_gc_bytes -= WORDS_TO_BYTES(sz);
GC_freehblk(h);
UNLOCK();
ENABLE_SIGNALS();
}
}
/* Explicitly deallocate an object p when we already hold lock. */
/* Only used for internally allocated objects, so we can take some */
/* shortcuts. */
#ifdef THREADS
void GC_free_inner(GC_PTR p)
{
register struct hblk *h;
register hdr *hhdr;
register signed_word sz;
register ptr_t * flh;
register int knd;
register struct obj_kind * ok;
DCL_LOCK_STATE;
h = HBLKPTR(p);
hhdr = HDR(h);
knd = hhdr -> hb_obj_kind;
sz = hhdr -> hb_sz;
ok = &GC_obj_kinds[knd];
if (sz <= MAXOBJSZ) {
GC_mem_freed += sz;
if (IS_UNCOLLECTABLE(knd)) GC_non_gc_bytes -= WORDS_TO_BYTES(sz);
if (ok -> ok_init) {
BZERO((word *)p + 1, WORDS_TO_BYTES(sz-1));
}
flh = &(ok -> ok_freelist[sz]);
obj_link(p) = *flh;
*flh = (ptr_t)p;
} else {
GC_mem_freed += sz;
if (IS_UNCOLLECTABLE(knd)) GC_non_gc_bytes -= WORDS_TO_BYTES(sz);
GC_freehblk(h);
}
}
#endif /* THREADS */
# if defined(REDIRECT_MALLOC) && !defined(REDIRECT_FREE)
# define REDIRECT_FREE GC_free
# endif
# ifdef REDIRECT_FREE
# ifdef __STDC__
void free(GC_PTR p)
# else
void free(p)
GC_PTR p;
# endif
{
# ifndef IGNORE_FREE
REDIRECT_FREE(p);
# endif
}
# endif /* REDIRECT_MALLOC */