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* malloc/arena.c (grow_heap): Split out code to shrink heap into...

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(shrink_heap): ... this new function.
	(heap_trim): Call shrink_heap instead of grow_heap.
This commit is contained in:
Ulrich Drepper 2007-12-12 00:11:49 +00:00
parent 17edb30c62
commit cbf5760e62
2 changed files with 51 additions and 33 deletions
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4
ChangeLog
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@ -1,5 +1,9 @@
2007-12-11 Ulrich Drepper <drepper@redhat.com>
* malloc/arena.c (grow_heap): Split out code to shrink heap into...
(shrink_heap): ... this new function.
(heap_trim): Call shrink_heap instead of grow_heap.
* malloc/malloc.c (_int_malloc): sYSMALLOc might fail, in this
case don't call alloc_perturb.

80
malloc/arena.c
View File

@ -704,8 +704,8 @@ new_heap(size, top_pad) size_t size, top_pad;
return h;
}
/* Grow or shrink a heap. size is automatically rounded up to a
multiple of the page size if it is positive. */
/* Grow a heap. size is automatically rounded up to a
multiple of the page size. */
static int
#if __STD_C
@ -717,41 +717,55 @@ grow_heap(h, diff) heap_info *h; long diff;
size_t page_mask = malloc_getpagesize - 1;
long new_size;
if(diff >= 0) {
diff = (diff + page_mask) & ~page_mask;
new_size = (long)h->size + diff;
if((unsigned long) new_size > (unsigned long) HEAP_MAX_SIZE)
return -1;
if((unsigned long) new_size > h->mprotect_size) {
if (mprotect((char *)h + h->mprotect_size,
(unsigned long) new_size - h->mprotect_size,
PROT_READ|PROT_WRITE) != 0)
diff = (diff + page_mask) & ~page_mask;
new_size = (long)h->size + diff;
if((unsigned long) new_size > (unsigned long) HEAP_MAX_SIZE)
return -1;
if((unsigned long) new_size > h->mprotect_size) {
if (mprotect((char *)h + h->mprotect_size,
(unsigned long) new_size - h->mprotect_size,
PROT_READ|PROT_WRITE) != 0)
return -2;
h->mprotect_size = new_size;
}
h->size = new_size;
return 0;
}
/* Shrink a heap. */
static int
#if __STD_C
shrink_heap(heap_info *h, long diff)
#else
shrink_heap(h, diff) heap_info *h; long diff;
#endif
{
long new_size;
new_size = (long)h->size - diff;
if(new_size < (long)sizeof(*h))
return -1;
/* Try to re-map the extra heap space freshly to save memory, and
make it inaccessible. */
#ifdef _LIBC
if (__builtin_expect (__libc_enable_secure, 0))
#else
if (1)
#endif
{
if((char *)MMAP((char *)h + new_size, diff, PROT_NONE,
MAP_PRIVATE|MAP_FIXED) == (char *) MAP_FAILED)
return -2;
h->mprotect_size = new_size;
}
} else {
new_size = (long)h->size + diff;
if(new_size < (long)sizeof(*h))
return -1;
/* Try to re-map the extra heap space freshly to save memory, and
make it inaccessible. */
#ifdef _LIBC
if (__builtin_expect (__libc_enable_secure, 0))
#else
if (1)
else
madvise ((char *)h + new_size, diff, MADV_DONTNEED);
#endif
{
if((char *)MMAP((char *)h + new_size, -diff, PROT_NONE,
MAP_PRIVATE|MAP_FIXED) == (char *) MAP_FAILED)
return -2;
h->mprotect_size = new_size;
}
#ifdef _LIBC
else
madvise ((char *)h + new_size, -diff, MADV_DONTNEED);
#endif
/*fprintf(stderr, "shrink %p %08lx\n", h, new_size);*/
}
/*fprintf(stderr, "shrink %p %08lx\n", h, new_size);*/
h->size = new_size;
return 0;
}
@ -811,7 +825,7 @@ heap_trim(heap, pad) heap_info *heap; size_t pad;
if(extra < (long)pagesz)
return 0;
/* Try to shrink. */
if(grow_heap(heap, -extra) != 0)
if(shrink_heap(heap, extra) != 0)
return 0;
ar_ptr->system_mem -= extra;
arena_mem -= extra;