pjs/gc/boehm/malloc.c

436 строки
11 KiB
C

/*
* Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
* Copyright (c) 1991-1994 by Xerox Corporation. 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 "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 lb bytes for an object of kind. */
/* 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 = 1;
# 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.*/
*opp = obj_link(op);
obj_link(op) = 0;
} else {
register struct hblk * h;
register word n_blocks = divHBLKSZ(ADD_SLOP(lb)
+ HDR_BYTES + HBLKSIZE-1);
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);
lw = ROUNDED_UP_WORDS(lb);
while ((h = GC_allochblk(lw, k, 0)) == 0
&& GC_collect_or_expand(n_blocks, FALSE));
if (h == 0) {
op = 0;
} else {
op = (ptr_t) (h -> hb_body);
GC_words_wasted += BYTES_TO_WORDS(n_blocks * HBLKSIZE) - lw;
}
}
GC_words_allocd += lw;
out:
return((ptr_t)op);
}
ptr_t GC_generic_malloc(lb, k)
register word lb;
register int k;
{
ptr_t result;
DCL_LOCK_STATE;
GC_INVOKE_FINALIZERS();
DISABLE_SIGNALS();
LOCK();
result = GC_generic_malloc_inner(lb, k);
UNLOCK();
ENABLE_SIGNALS();
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( SMALL_OBJ(lb) ) {
# ifdef MERGE_SIZES
lw = GC_size_map[lb];
# else
lw = ALIGNED_WORDS(lb);
# endif
opp = &(GC_aobjfreelist[lw]);
FASTLOCK();
if( !FASTLOCK_SUCCEEDED() || (op = *opp) == 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( SMALL_OBJ(lb) ) {
# ifdef MERGE_SIZES
lw = GC_size_map[lb];
# else
lw = ALIGNED_WORDS(lb);
# endif
opp = &(GC_objfreelist[lw]);
FASTLOCK();
if( !FASTLOCK_SUCCEEDED() || (op = *opp) == 0 ) {
FASTUNLOCK();
return(GENERAL_MALLOC((word)lb, NORMAL));
}
/* See above comment on signals. */
*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(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 && SOLARIS_THREADS */
return(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(REDIRECT_MALLOC(n*lb));
}
# endif /* REDIRECT_MALLOC */
GC_PTR GC_generic_or_special_malloc(lb,knd)
word lb;
int knd;
{
switch(knd) {
# ifdef STUBBORN_ALLOC
case STUBBORN:
return(GC_malloc_stubborn((size_t)lb));
# endif
case PTRFREE:
return(GC_malloc_atomic((size_t)lb));
case NORMAL:
return(GC_malloc((size_t)lb));
case UNCOLLECTABLE:
return(GC_malloc_uncollectable((size_t)lb));
# ifdef ATOMIC_UNCOLLECTABLE
case AUNCOLLECTABLE:
return(GC_malloc_atomic_uncollectable((size_t)lb));
# endif /* ATOMIC_UNCOLLECTABLE */
default:
return(GC_generic_malloc(lb,knd));
}
}
/* Change the size of the block pointed to by p to contain at least */
/* lb bytes. The object may be (and quite likely will be) moved. */
/* The kind (e.g. atomic) is the same as that of the old. */
/* Shrinking of large blocks is not implemented well. */
# ifdef __STDC__
GC_PTR GC_realloc(GC_PTR p, size_t lb)
# else
GC_PTR GC_realloc(p,lb)
GC_PTR p;
size_t lb;
# endif
{
register struct hblk * h;
register hdr * hhdr;
register word sz; /* Current size in bytes */
register word orig_sz; /* Original sz in bytes */
int obj_kind;
if (p == 0) return(GC_malloc(lb)); /* Required by ANSI */
h = HBLKPTR(p);
hhdr = HDR(h);
sz = hhdr -> hb_sz;
obj_kind = hhdr -> hb_obj_kind;
sz = WORDS_TO_BYTES(sz);
orig_sz = sz;
if (sz > WORDS_TO_BYTES(MAXOBJSZ)) {
/* Round it up to the next whole heap block */
register word descr;
sz = (sz+HDR_BYTES+HBLKSIZE-1)
& (~HBLKMASK);
sz -= HDR_BYTES;
hhdr -> hb_sz = BYTES_TO_WORDS(sz);
descr = GC_obj_kinds[obj_kind].ok_descriptor;
if (GC_obj_kinds[obj_kind].ok_relocate_descr) descr += sz;
hhdr -> hb_descr = descr;
if (IS_UNCOLLECTABLE(obj_kind)) GC_non_gc_bytes += (sz - orig_sz);
/* Extra area is already cleared by allochblk. */
}
if (ADD_SLOP(lb) <= sz) {
if (lb >= (sz >> 1)) {
# ifdef STUBBORN_ALLOC
if (obj_kind == STUBBORN) GC_change_stubborn(p);
# endif
if (orig_sz > lb) {
/* Clear unneeded part of object to avoid bogus pointer */
/* tracing. */
/* Safe for stubborn objects. */
BZERO(((ptr_t)p) + lb, orig_sz - lb);
}
return(p);
} else {
/* shrink */
GC_PTR result =
GC_generic_or_special_malloc((word)lb, obj_kind);
if (result == 0) return(0);
/* Could also return original object. But this */
/* gives the client warning of imminent disaster. */
BCOPY(p, result, lb);
# ifndef IGNORE_FREE
GC_free(p);
# endif
return(result);
}
} else {
/* grow */
GC_PTR result =
GC_generic_or_special_malloc((word)lb, obj_kind);
if (result == 0) return(0);
BCOPY(p, result, sz);
# ifndef IGNORE_FREE
GC_free(p);
# endif
return(result);
}
}
# ifdef REDIRECT_MALLOC
# ifdef __STDC__
GC_PTR realloc(GC_PTR p, size_t lb)
# else
GC_PTR realloc(p,lb)
GC_PTR p;
size_t lb;
# endif
{
return(GC_realloc(p, lb));
}
# 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);
# if defined(REDIRECT_MALLOC) && \
(defined(SOLARIS_THREADS) || defined(LINUX_THREADS))
/* We have to redirect malloc calls during initialization. */
/* 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 (sz <= MAXOBJSZ) {
# 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();
}
}
# ifdef REDIRECT_MALLOC
# ifdef __STDC__
void free(GC_PTR p)
# else
void free(p)
GC_PTR p;
# endif
{
# ifndef IGNORE_FREE
GC_free(p);
# endif
}
# endif /* REDIRECT_MALLOC */