/*
* Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers
* Copyright (c) 1991-1994 by Xerox Corporation. All rights reserved.
* Copyright (c) 1999-2004 Hewlett-Packard Development Company, L.P.
*
* 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.
*/
#include "private/gc_priv.h"
#include "gc_inline.h" /* for GC_malloc_kind */
#include <stdio.h>
#include <string.h>
/* Allocate reclaim list for kind: */
/* Return TRUE on success */
STATIC GC_bool GC_alloc_reclaim_list(struct obj_kind *kind)
{
struct hblk ** result = (struct hblk **)
GC_scratch_alloc((MAXOBJGRANULES+1) * sizeof(struct hblk *));
if (result == 0) return(FALSE);
BZERO(result, (MAXOBJGRANULES+1)*sizeof(struct hblk *));
kind -> ok_reclaim_list = result;
return(TRUE);
}
/* Allocate a large block of size lb bytes. The block is not cleared. */
/* flags argument should be 0 or IGNORE_OFF_PAGE. EXTRA_BYTES value */
/* was already added to lb. */
GC_INNER ptr_t GC_alloc_large(size_t lb, int k, unsigned flags)
{
struct hblk * h;
word n_blocks;
ptr_t result;
GC_bool retry = FALSE;
GC_ASSERT(I_HOLD_LOCK());
lb = ROUNDUP_GRANULE_SIZE(lb);
n_blocks = OBJ_SZ_TO_BLOCKS_CHECKED(lb);
if (!EXPECT(GC_is_initialized, TRUE)) {
DCL_LOCK_STATE;
UNLOCK(); /* just to unset GC_lock_holder */
GC_init();
LOCK();
}
/* Do our share of marking work */
if (GC_incremental && !GC_dont_gc) {
ENTER_GC();
GC_collect_a_little_inner((int)n_blocks);
EXIT_GC();
}
h = GC_allochblk(lb, k, flags);
# ifdef USE_MUNMAP
if (0 == h) {
GC_merge_unmapped();
h = GC_allochblk(lb, k, flags);
}
# endif
while (0 == h && GC_collect_or_expand(n_blocks, flags != 0, retry)) {
h = GC_allochblk(lb, k, flags);
retry = TRUE;
}
if (h == 0) {
result = 0;
} else {
size_t total_bytes = n_blocks * HBLKSIZE;
if (n_blocks > 1) {
GC_large_allocd_bytes += total_bytes;
if (GC_large_allocd_bytes > GC_max_large_allocd_bytes)
GC_max_large_allocd_bytes = GC_large_allocd_bytes;
}
/* FIXME: Do we need some way to reset GC_max_large_allocd_bytes? */
result = h -> hb_body;
}
return result;
}
/* Allocate a large block of size lb bytes. Clear if appropriate. */
/* EXTRA_BYTES were already added to lb. */
STATIC ptr_t GC_alloc_large_and_clear(size_t lb, int k, unsigned flags)
{
ptr_t result;
GC_ASSERT(I_HOLD_LOCK());
result = GC_alloc_large(lb, k, flags);
if (result != NULL
&& (GC_debugging_started || GC_obj_kinds[k].ok_init)) {
word n_blocks = OBJ_SZ_TO_BLOCKS(lb);
/* Clear the whole block, in case of GC_realloc call. */
BZERO(result, n_blocks * HBLKSIZE);
}
return result;
}
/* Fill in additional entries in GC_size_map, including the i-th one. */
/* Note that a filled in section of the array ending at n always */
/* has the length of at least n/4. */
STATIC void GC_extend_size_map(size_t i)
{
size_t orig_granule_sz = ROUNDED_UP_GRANULES(i);
size_t granule_sz;
size_t byte_sz = GRANULES_TO_BYTES(orig_granule_sz);
/* The size we try to preserve. */
/* Close to i, unless this would */
/* introduce too many distinct sizes. */
size_t smaller_than_i = byte_sz - (byte_sz >> 3);
size_t low_limit; /* The lowest indexed entry we initialize. */
size_t number_of_objs;
GC_ASSERT(I_HOLD_LOCK());
GC_ASSERT(0 == GC_size_map[i]);
if (0 == GC_size_map[smaller_than_i]) {
low_limit = byte_sz - (byte_sz >> 2); /* much smaller than i */
granule_sz = orig_granule_sz;
while (GC_size_map[low_limit] != 0)
low_limit++;
} else {
low_limit = smaller_than_i + 1;
while (GC_size_map[low_limit] != 0)
low_limit++;
/* For these larger sizes, we use an even number of granules. */
/* This makes it easier to, e.g., construct a 16-byte-aligned */
/* allocator even if GRANULE_BYTES is 8. */
granule_sz = (granule_sz + 1) & ~(size_t)1;
if (granule_sz > MAXOBJGRANULES)
granule_sz = MAXOBJGRANULES;
/* If we can fit the same number of larger objects in a block, do so. */
number_of_objs = HBLK_GRANULES / granule_sz;
GC_ASSERT(number_of_objs != 0);
granule_sz = (HBLK_GRANULES / number_of_objs) & ~(size_t)1;
byte_sz = GRANULES_TO_BYTES(granule_sz) - EXTRA_BYTES;
/* We may need one extra byte; do not always */
/* fill in GC_size_map[byte_sz]. */
for (; low_limit <= byte_sz; low_limit++)
GC_size_map[low_limit] = granule_sz;
}
/* Allocate lb bytes for an object of kind k. */
/* Should not be used to directly allocate objects */
/* that require special handling on allocation. */
GC_INNER void * GC_generic_malloc_inner(size_t lb, int k)
{
void *op;
GC_ASSERT(I_HOLD_LOCK());
GC_ASSERT(k < MAXOBJKINDS);
if (SMALL_OBJ(lb)) {
struct obj_kind * kind = GC_obj_kinds + k;
size_t lg = GC_size_map[lb];
void ** opp = &(kind -> ok_freelist[lg]);
op = *opp;
if (EXPECT(0 == op, FALSE)) {
if (lg == 0) {
if (!EXPECT(GC_is_initialized, TRUE)) {
DCL_LOCK_STATE;
UNLOCK(); /* just to unset GC_lock_holder */
GC_init();
LOCK();
lg = GC_size_map[lb];
}
if (0 == lg) {
GC_extend_size_map(lb);
lg = GC_size_map[lb];
GC_ASSERT(lg != 0);
}
/* Retry */
opp = &(kind -> ok_freelist[lg]);
op = *opp;
}
if (0 == op) {
if (0 == kind -> ok_reclaim_list &&
!GC_alloc_reclaim_list(kind))
return NULL;
op = GC_allocobj(lg, k);
if (0 == op)
return NULL;
}
}
*opp = obj_link(op);
obj_link(op) = 0;
GC_bytes_allocd += GRANULES_TO_BYTES((word)lg);
} else {
size_t lb_adjusted = ADD_SLOP(lb);
op = (ptr_t)GC_alloc_large_and_clear(lb_adjusted, k, 0 /* flags */);
if (op != NULL)
GC_bytes_allocd += lb_adjusted;
}
return op;
}
#if defined(DBG_HDRS_ALL) || defined(GC_GCJ_SUPPORT) \
|| !defined(GC_NO_FINALIZATION)
/* Allocate a composite object of size n bytes. The caller */
/* guarantees that pointers past the first hblk are not relevant. */
GC_INNER void * GC_generic_malloc_inner_ignore_off_page(size_t lb, int k)
{
size_t lb_adjusted;
void * op;
GC_ASSERT(I_HOLD_LOCK());
if (lb <= HBLKSIZE)
return GC_generic_malloc_inner(lb, k);
GC_ASSERT(k < MAXOBJKINDS);
lb_adjusted = ADD_SLOP(lb);
op = GC_alloc_large_and_clear(lb_adjusted, k, IGNORE_OFF_PAGE);
if (op != NULL)
GC_bytes_allocd += lb_adjusted;
return op;
}
#endif
#ifdef GC_COLLECT_AT_MALLOC
/* Parameter to force GC at every malloc of size greater or equal to */
/* the given value. This might be handy during debugging. */
# if defined(CPPCHECK)
size_t GC_dbg_collect_at_malloc_min_lb = 16*1024; /* e.g. */
# else
size_t GC_dbg_collect_at_malloc_min_lb = (GC_COLLECT_AT_MALLOC);
# endif
#endif
GC_ASSERT(k < MAXOBJKINDS);
if (SMALL_OBJ(lb)) {
void **opp;
size_t lg;
GC_DBG_COLLECT_AT_MALLOC(lb);
if (EXTRA_BYTES != 0 && lb != 0) lb--;
/* We don't need the extra byte, since this won't be */
/* collected anyway. */
LOCK();
lg = GC_size_map[lb];
opp = &GC_obj_kinds[k].ok_freelist[lg];
op = *opp;
if (EXPECT(op != NULL, TRUE)) {
*opp = obj_link(op);
obj_link(op) = 0;
GC_bytes_allocd += GRANULES_TO_BYTES((word)lg);
/* Mark bit was already set on free list. It will be */
/* cleared only temporarily during a collection, as a */
/* result of the normal free list mark bit clearing. */
GC_non_gc_bytes += GRANULES_TO_BYTES((word)lg);
UNLOCK();
} else {
UNLOCK();
op = GC_generic_malloc(lb, k);
/* For small objects, the free lists are completely marked. */
}
GC_ASSERT(0 == op || GC_is_marked(op));
} else {
op = GC_generic_malloc(lb, k);
if (op /* != NULL */) { /* CPPCHECK */
hdr * hhdr = HDR(op);
GC_ASSERT(((word)op & (HBLKSIZE - 1)) == 0); /* large block */
/* 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. */
LOCK();
set_mark_bit_from_hdr(hhdr, 0); /* Only object. */
# ifndef THREADS
GC_ASSERT(hhdr -> hb_n_marks == 0);
/* This is not guaranteed in the multi-threaded case */
/* because the counter could be updated before locking. */
# endif
hhdr -> hb_n_marks = 1;
UNLOCK();
}
}
return op;
}
/* Allocate lb bytes of pointerful, traced, but not collectible data. */
GC_API GC_ATTR_MALLOC void * GC_CALL GC_malloc_uncollectable(size_t lb)
{
return GC_generic_malloc_uncollectable(lb, UNCOLLECTABLE);
}
#ifdef GC_ATOMIC_UNCOLLECTABLE
/* Allocate lb bytes of pointer-free, untraced, uncollectible data */
/* This is normally roughly equivalent to the system malloc. */
/* But it may be useful if malloc is redefined. */
GC_API GC_ATTR_MALLOC void * GC_CALL
GC_malloc_atomic_uncollectable(size_t lb)
{
return GC_generic_malloc_uncollectable(lb, AUNCOLLECTABLE);
}
#endif /* GC_ATOMIC_UNCOLLECTABLE */
/* Avoid unnecessary nested procedure calls here, by #defining some */
/* malloc replacements. Otherwise we end up saving a meaningless */
/* return address in the object. It also speeds things up, but it is */
/* admittedly quite ugly. */
# define GC_debug_malloc_replacement(lb) GC_debug_malloc(lb, GC_DBG_EXTRAS)
# if defined(CPPCHECK)
# define REDIRECT_MALLOC_F GC_malloc /* e.g. */
# else
# define REDIRECT_MALLOC_F REDIRECT_MALLOC
# endif
void * malloc(size_t lb)
{
/* 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 initialization can call malloc before we are ready for. */
/* It is not clear that this is enough to help matters. */
/* The thread implementation may well call malloc at other */
/* inopportune times. */
if (!EXPECT(GC_is_initialized, TRUE)) return sbrk(lb);
# endif
return (void *)REDIRECT_MALLOC_F(lb);
}
/* This test does not need to ensure memory visibility, since */
/* the bounds will be set when/if we create another thread. */
if (EXPECT(lib_bounds_set, TRUE)) return;
DISABLE_CANCEL(cancel_state);
GC_init(); /* if not called yet */
# if defined(GC_ASSERTIONS) && defined(GC_ALWAYS_MULTITHREADED)
LOCK(); /* just to set GC_lock_holder */
# endif
if (!GC_text_mapping("libpthread-",
&GC_libpthread_start, &GC_libpthread_end)) {
/* Some libc implementations like bionic, musl and glibc 2.34 */
/* do not have libpthread.so because the pthreads-related code */
/* is located in libc.so, thus potential calloc calls from such */
/* code are forwarded to real (libc) calloc without any special */
/* handling on the libgc side. Checking glibc version at */
/* compile time to turn off the warning seems to be fine. */
/* TODO: Remove GC_text_mapping() call for this case. */
# if defined(__GLIBC__) \
&& (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ < 34))
WARN("Failed to find libpthread.so text mapping: Expect crash\n", 0);
/* This might still work with some versions of libpthread, */
/* so we do not abort. */
# endif
}
if (!GC_text_mapping("ld-", &GC_libld_start, &GC_libld_end)) {
WARN("Failed to find ld.so text mapping: Expect crash\n", 0);
}
# if defined(GC_ASSERTIONS) && defined(GC_ALWAYS_MULTITHREADED)
UNLOCK();
# endif
RESTORE_CANCEL(cancel_state);
lib_bounds_set = TRUE;
}
# endif /* GC_LINUX_THREADS */
void * calloc(size_t n, size_t lb)
{
if ((lb | n) > GC_SQRT_SIZE_MAX /* fast initial test */
&& lb && n > GC_SIZE_MAX / lb)
return (*GC_get_oom_fn())(GC_SIZE_MAX); /* n*lb overflow */
# if defined(GC_LINUX_THREADS)
/* libpthread allocated some memory that is only pointed to by */
/* mmapped thread stacks. Make sure it is not collectible. */
{
ptr_t caller = (ptr_t)__builtin_return_address(0);
GC_init_lib_bounds();
if (((word)caller >= (word)GC_libpthread_start
&& (word)caller < (word)GC_libpthread_end)
|| ((word)caller >= (word)GC_libld_start
&& (word)caller < (word)GC_libld_end))
return GC_generic_malloc_uncollectable(n * lb, UNCOLLECTABLE);
/* The two ranges are actually usually adjacent, so there may */
/* be a way to speed this up. */
}
# endif
return (void *)REDIRECT_MALLOC_F(n * lb);
}
# ifndef strdup
char *strdup(const char *s)
{
size_t lb = strlen(s) + 1;
char *result = (char *)REDIRECT_MALLOC_F(lb);
if (result == 0) {
errno = ENOMEM;
return 0;
}
BCOPY(s, result, lb);
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. */
# ifndef strndup
/* This is similar to strdup(). */
char *strndup(const char *str, size_t size)
{
char *copy;
size_t len = strlen(str);
if (len > size)
len = size;
copy = (char *)REDIRECT_MALLOC_F(len + 1);
if (copy == NULL) {
errno = ENOMEM;
return NULL;
}
if (EXPECT(len > 0, TRUE))
BCOPY(str, copy, len);
copy[len] = '\0';
return copy;
}
# endif /* !strndup */
# undef GC_debug_malloc_replacement
#endif /* REDIRECT_MALLOC */
/* Explicitly deallocate an object p. */
GC_API void GC_CALL GC_free(void * p)
{
struct hblk *h;
hdr *hhdr;
size_t sz; /* In bytes */
size_t ngranules; /* sz in granules */
int knd;
struct obj_kind * ok;
DCL_LOCK_STATE;
if (p /* != NULL */) {
/* CPPCHECK */
} else {
/* Required by ANSI. It's not my fault ... */
return;
}
# ifdef LOG_ALLOCS
GC_log_printf("GC_free(%p) after GC #%lu\n",
p, (unsigned long)GC_gc_no);
# endif
h = HBLKPTR(p);
hhdr = HDR(h);
# if defined(REDIRECT_MALLOC) && \
((defined(NEED_CALLINFO) && defined(GC_HAVE_BUILTIN_BACKTRACE)) \
|| defined(GC_SOLARIS_THREADS) || defined(GC_LINUX_THREADS) \
|| defined(MSWIN32))
/* This might be called indirectly by GC_print_callers to free */
/* the result of backtrace_symbols. */
/* 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
GC_ASSERT(GC_base(p) == p);
sz = (size_t)hhdr->hb_sz;
ngranules = BYTES_TO_GRANULES(sz);
knd = hhdr -> hb_obj_kind;
ok = &GC_obj_kinds[knd];
if (EXPECT(ngranules <= MAXOBJGRANULES, TRUE)) {
void **flh;
LOCK();
GC_bytes_freed += sz;
if (IS_UNCOLLECTABLE(knd)) GC_non_gc_bytes -= sz;
/* It's 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 && EXPECT(sz > sizeof(word), TRUE)) {
BZERO((word *)p + 1, sz-sizeof(word));
}
flh = &(ok -> ok_freelist[ngranules]);
obj_link(p) = *flh;
*flh = (ptr_t)p;
UNLOCK();
} else {
size_t nblocks = OBJ_SZ_TO_BLOCKS(sz);
/* Explicitly deallocate an object p when we already hold lock. */
/* Only used for internally allocated objects, so we can take some */
/* shortcuts. */
#ifdef THREADS
GC_INNER void GC_free_inner(void * p)
{
struct hblk *h;
hdr *hhdr;
size_t sz; /* bytes */
size_t ngranules; /* sz in granules */
int knd;
struct obj_kind * ok;
h = HBLKPTR(p);
hhdr = HDR(h);
knd = hhdr -> hb_obj_kind;
sz = (size_t)hhdr->hb_sz;
ngranules = BYTES_TO_GRANULES(sz);
ok = &GC_obj_kinds[knd];
if (ngranules <= MAXOBJGRANULES) {
void ** flh;
# if defined(CPPCHECK)
# define REDIRECT_FREE_F GC_free /* e.g. */
# else
# define REDIRECT_FREE_F REDIRECT_FREE
# endif
void free(void * p GC_ATTR_UNUSED)
{
# ifndef IGNORE_FREE
# if defined(GC_LINUX_THREADS) && !defined(USE_PROC_FOR_LIBRARIES)
/* Don't bother with initialization checks. If nothing */
/* has been initialized, the check fails, and that's safe, */
/* since we have not allocated uncollectible objects neither. */
ptr_t caller = (ptr_t)__builtin_return_address(0);
/* This test does not need to ensure memory visibility, since */
/* the bounds will be set when/if we create another thread. */
if (((word)caller >= (word)GC_libpthread_start
&& (word)caller < (word)GC_libpthread_end)
|| ((word)caller >= (word)GC_libld_start
&& (word)caller < (word)GC_libld_end)) {
GC_free(p);
return;
}
# endif
REDIRECT_FREE_F(p);
# endif
}
#endif /* REDIRECT_FREE */
