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add sized deallocation support

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This commit is contained in:
Daniel Micay 2018-09-18 17:28:52 -04:00
parent 82314f4471
commit cf449b3df4
2 changed files with 29 additions and 6 deletions
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32
malloc.c
View File

@ -402,11 +402,14 @@ static void enqueue_free_slab(struct size_class *c, struct slab_metadata *metada
c->free_slabs_tail = metadata; c->free_slabs_tail = metadata;
} }
static inline void deallocate_small(void *p) { static inline void deallocate_small(void *p, size_t *expected_size) {
size_t class = slab_size_class(p); size_t class = slab_size_class(p);
struct size_class *c = &size_class_metadata[class]; struct size_class *c = &size_class_metadata[class];
size_t size = size_classes[class]; size_t size = size_classes[class];
if (expected_size && size != *expected_size) {
fatal_error("sized deallocation mismatch");
}
bool is_zero_size = size == 0; bool is_zero_size = size == 0;
if (is_zero_size) { if (is_zero_size) {
size = 16; size = 16;
@ -751,7 +754,7 @@ static void *allocate(size_t size) {
return p; return p;
} }
static void deallocate_large(void *p) { static void deallocate_large(void *p, size_t *expected_size) {
enforce_init(); enforce_init();
mutex_lock(&regions_lock); mutex_lock(&regions_lock);
@ -760,6 +763,9 @@ static void deallocate_large(void *p) {
fatal_error("invalid free"); fatal_error("invalid free");
} }
size_t size = region->size; size_t size = region->size;
if (expected_size && size != *expected_size) {
fatal_error("sized deallocation mismatch");
}
size_t guard_size = region->guard_size; size_t guard_size = region->guard_size;
regions_delete(region); regions_delete(region);
mutex_unlock(&regions_lock); mutex_unlock(&regions_lock);
@ -894,9 +900,9 @@ EXPORT void *h_realloc(void *old, size_t size) {
} }
memcpy(new, old, copy_size); memcpy(new, old, copy_size);
if (old_size <= max_slab_size_class) { if (old_size <= max_slab_size_class) {
deallocate_small(old); deallocate_small(old, NULL);
} else { } else {
deallocate_large(old); deallocate_large(old, NULL);
} }
return new; return new;
} }
@ -987,15 +993,29 @@ EXPORT void h_free(void *p) {
} }
if (p >= ro.slab_region_start && p < ro.slab_region_end) { if (p >= ro.slab_region_start && p < ro.slab_region_end) {
deallocate_small(p); deallocate_small(p, NULL);
return; return;
} }
deallocate_large(p); deallocate_large(p, NULL);
} }
EXPORT void h_cfree(void *ptr) ALIAS(h_free); EXPORT void h_cfree(void *ptr) ALIAS(h_free);
EXPORT void h_free_sized(void *p, size_t expected_size) {
if (p == NULL) {
return;
}
if (p >= ro.slab_region_start && p < ro.slab_region_end) {
expected_size = get_size_info(adjust_size_for_canaries(expected_size)).size;
deallocate_small(p, &expected_size);
return;
}
deallocate_large(p, &expected_size);
}
EXPORT size_t h_malloc_usable_size(void *p) { EXPORT size_t h_malloc_usable_size(void *p) {
if (p == NULL) { if (p == NULL) {
return 0; return 0;

3
malloc.h
View File

@ -34,6 +34,7 @@
#define h_malloc_object_size malloc_object_size #define h_malloc_object_size malloc_object_size
#define h_malloc_object_size_fast malloc_object_size_fast #define h_malloc_object_size_fast malloc_object_size_fast
#define h_free_sized free_sized
#endif #endif
// C standard // C standard
@ -84,4 +85,6 @@ size_t h_malloc_object_size(void *ptr);
// similar to malloc_object_size, but avoiding locking so the results are much more limited // similar to malloc_object_size, but avoiding locking so the results are much more limited
size_t h_malloc_object_size_fast(void *ptr); size_t h_malloc_object_size_fast(void *ptr);
void h_free_sized(void *ptr, size_t expected_size);
#endif #endif