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/*
* Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
* Copyright (c) 1991-1993 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 copy this garbage collector for any purpose,
* provided the above notices are retained on all copies.
*/
#include <stdio.h>
#include "gc_private.h"
extern void GC_clear_stack(); /* in misc.c */
# ifdef ALL_INTERIOR_POINTERS
# define SMALL_OBJ(bytes) ((bytes) < WORDS_TO_BYTES(MAXOBJSZ))
# define ADD_SLOP(bytes) ((bytes)+1)
# else
# define SMALL_OBJ(bytes) ((bytes) <= WORDS_TO_BYTES(MAXOBJSZ))
# define ADD_SLOP(bytes) (bytes)
# endif
/* 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) ) {
# ifdef MERGE_SIZES
lw = GC_size_map[lb];
# else
lw = ROUNDED_UP_WORDS(lb);
if (lw == 0) lw = 1;
# endif
opp = &(GC_obj_kinds[k].ok_freelist[lw]);
if( (op = *opp) == 0 ) {
if (!GC_is_initialized) {
GC_init_inner();
return(GC_generic_malloc_inner(lb, k));
}
GC_clear_stack();
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(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((int)n_blocks);
lw = ROUNDED_UP_WORDS(lb);
while ((h = GC_allochblk(lw, k)) == 0
&& GC_collect_or_expand(n_blocks));
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;
DISABLE_SIGNALS();
LOCK();
result = GC_generic_malloc_inner(lb, k);
UNLOCK();
ENABLE_SIGNALS();
return(result);
}
/* Analogous to the above, but assumes a small object size, and */
/* bypasses MERGE_SIZES mechanism. Used by gc_inline.h. */
ptr_t GC_generic_malloc_words_small(lw, k)
register word lw;
register int k;
{
register ptr_t op;
register ptr_t *opp;
DCL_LOCK_STATE;
DISABLE_SIGNALS();
LOCK();
opp = &(GC_obj_kinds[k].ok_freelist[lw]);
if( (op = *opp) == 0 ) {
if (!GC_is_initialized) {
GC_init_inner();
}
GC_clear_stack();
op = GC_allocobj(lw, k);
if (op == 0) goto out;
}
*opp = obj_link(op);
obj_link(op) = 0;
GC_words_allocd += lw;
out:
UNLOCK();
ENABLE_SIGNALS();
return((ptr_t)op);
}
/* Allocate lb bytes of atomic (pointerfree) data */
# ifdef __STDC__
extern_ptr_t GC_malloc_atomic(size_t lb)
# else
extern_ptr_t 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 = ROUNDED_UP_WORDS(lb);
# endif
opp = &(GC_aobjfreelist[lw]);
FASTLOCK();
if( !FASTLOCK_SUCCEEDED() || (op = *opp) == 0 ) {
FASTUNLOCK();
return(GC_generic_malloc((word)lb, PTRFREE));
}
/* See above comment on signals. */
*opp = obj_link(op);
GC_words_allocd += lw;
FASTUNLOCK();
return((extern_ptr_t) op);
} else {
return((extern_ptr_t)
GC_generic_malloc((word)lb, PTRFREE));
}
}
/* Allocate lb bytes of composite (pointerful) data */
# ifdef __STDC__
extern_ptr_t GC_malloc(size_t lb)
# else
extern_ptr_t 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 = ROUNDED_UP_WORDS(lb);
# endif
opp = &(GC_objfreelist[lw]);
FASTLOCK();
if( !FASTLOCK_SUCCEEDED() || (op = *opp) == 0 ) {
FASTUNLOCK();
return(GC_generic_malloc((word)lb, NORMAL));
}
/* See above comment on signals. */
*opp = obj_link(op);
obj_link(op) = 0;
GC_words_allocd += lw;
FASTUNLOCK();
return((extern_ptr_t) op);
} else {
return((extern_ptr_t)
GC_generic_malloc((word)lb, NORMAL));
}
}
/* Allocate lb bytes of pointerful, traced, but not collectable data */
# ifdef __STDC__
extern_ptr_t GC_malloc_uncollectable(size_t lb)
# else
extern_ptr_t GC_malloc_uncollectable(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 = ROUNDED_UP_WORDS(lb);
# endif
opp = &(GC_uobjfreelist[lw]);
FASTLOCK();
if( FASTLOCK_SUCCEEDED() && (op = *opp) != 0 ) {
/* See above comment on signals. */
*opp = obj_link(op);
obj_link(op) = 0;
GC_words_allocd += lw;
GC_set_mark_bit(op);
GC_non_gc_bytes += WORDS_TO_BYTES(lw);
FASTUNLOCK();
return((extern_ptr_t) op);
}
FASTUNLOCK();
op = (ptr_t)GC_generic_malloc((word)lb, UNCOLLECTABLE);
} else {
op = (ptr_t)GC_generic_malloc((word)lb, UNCOLLECTABLE);
}
/* We don't need the lock here, since we have an undisguised */
/* pointer. We do need to hold the lock while we adjust */
/* mark bits. */
{
register struct hblk * h;
h = HBLKPTR(op);
lw = HDR(h) -> hb_sz;
DISABLE_SIGNALS();
LOCK();
GC_set_mark_bit(op);
GC_non_gc_bytes += WORDS_TO_BYTES(lw);
UNLOCK();
ENABLE_SIGNALS();
return((extern_ptr_t) op);
}
}
extern_ptr_t 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 UNCOLLECTABLE:
return(GC_malloc_uncollectable((size_t)lb));
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__
extern_ptr_t GC_realloc(extern_ptr_t p, size_t lb)
# else
extern_ptr_t GC_realloc(p,lb)
extern_ptr_t p;
size_t lb;
# endif
{
register struct hblk * h;
register hdr * hhdr;
register signed_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 */
sz = (sz+HDR_BYTES+HBLKSIZE-1)
& (~HBLKMASK);
sz -= HDR_BYTES;
hhdr -> hb_sz = BYTES_TO_WORDS(sz);
if (obj_kind == UNCOLLECTABLE) 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(((char *)p) + lb, (int)(orig_sz - lb));
}
return(p);
} else {
/* shrink */
extern_ptr_t 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, (int)lb);
GC_free(p);
return(result);
}
} else {
/* grow */
extern_ptr_t result =
GC_generic_or_special_malloc((word)lb, obj_kind);
if (result == 0) return(0);
bcopy(p, result, (int)sz);
GC_free(p);
return(result);
}
}
/* Explicitly deallocate an object p. */
# ifdef __STDC__
void GC_free(extern_ptr_t p)
# else
void GC_free(p)
extern_ptr_t 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;
if (p == 0) return;
/* Required by ANSI. It's not my fault ... */
h = HBLKPTR(p);
hhdr = HDR(h);
knd = hhdr -> hb_obj_kind;
sz = hhdr -> hb_sz;
GC_mem_freed += sz;
ok = &GC_obj_kinds[knd];
if (knd == UNCOLLECTABLE) GC_non_gc_bytes -= sz;
if (sz > MAXOBJSZ) {
GC_freehblk(h);
} else {
ok = &GC_obj_kinds[hhdr -> hb_obj_kind];
if (ok -> ok_init) {
bzero((char *)((word *)p + 1), (int)(WORDS_TO_BYTES(sz-1)));
}
flh = &(ok -> ok_freelist[sz]);
obj_link(p) = *flh;
*flh = (ptr_t)p;
}
}
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