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pass page to block_zero_init and extend to block_size

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daan 2019-09-03 10:11:24 -07:00
parent 739d11313c
commit 7a91368108
4 changed files with 46 additions and 31 deletions
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15
src/alloc-aligned.c
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@ -33,7 +33,7 @@ static void* mi_heap_malloc_zero_aligned_at(mi_heap_t* heap, size_t size, size_t
void* p = _mi_page_malloc(heap,page,size);
mi_assert_internal(p != NULL);
mi_assert_internal(((uintptr_t)p + offset) % alignment == 0);
if (zero) _mi_block_zero_init(p,size);
if (zero) _mi_block_zero_init(page,p,size);
return p;
}
}
@ -117,9 +117,16 @@ static void* mi_heap_realloc_zero_aligned_at(mi_heap_t* heap, void* p, size_t ne
void* newp = mi_heap_malloc_aligned_at(heap,newsize,alignment,offset);
if (newp != NULL) {
if (zero && newsize > size) {
// also set last word in the previous allocation to zero to ensure any padding is zero-initialized
size_t start = (size >= sizeof(intptr_t) ? size - sizeof(intptr_t) : 0);
memset((uint8_t*)newp + start, 0, newsize - start);
const mi_page_t* page = _mi_ptr_page(newp);
if (page->flags.is_zero) {
// already zero initialized
mi_assert_expensive(mi_mem_is_zero(newp,newsize));
}
else {
// also set last word in the previous allocation to zero to ensure any padding is zero-initialized
size_t start = (size >= sizeof(intptr_t) ? size - sizeof(intptr_t) : 0);
memset((uint8_t*)newp + start, 0, newsize - start);
}
}
memcpy(newp, p, (newsize > size ? size : newsize));
mi_free(p); // only free if successful

33
src/alloc.c
View file

@ -89,31 +89,28 @@ extern inline void* mi_malloc(size_t size) mi_attr_noexcept {
return mi_heap_malloc(mi_get_default_heap(), size);
}
void _mi_block_zero_init(void* p, size_t size) {
void _mi_block_zero_init(const mi_page_t* page, void* p, size_t size) {
// note: we need to initialize the whole block to zero, not just size
// or the recalloc/rezalloc functions cannot safely expand in place (see issue #63)
UNUSED(size);
mi_assert_internal(p != NULL);
// already zero initialized memory?
if (size > 4*sizeof(void*)) { // don't bother for small sizes
mi_page_t* page = _mi_ptr_page(p);
if (page->flags.is_zero) {
((mi_block_t*)p)->next = 0;
#if MI_DEBUG>0
for (size_t i = 0; i < (page->block_size/sizeof(uintptr_t)); i++) {
if (((uintptr_t*)p)[i] != 0) {
_mi_assert_fail("page not zero", __FILE__, __LINE__, "_mi_block_zero_init");
}
}
#endif
return; // and done
}
mi_assert_internal(size > 0 && page->block_size >= size);
mi_assert_internal(_mi_ptr_page(p)==page);
if (page->flags.is_zero) {
// already zero initialized memory?
((mi_block_t*)p)->next = 0; // clear the free list pointer
mi_assert_expensive(mi_mem_is_zero(p,page->block_size));
}
else {
// otherwise memset
memset(p, 0, page->block_size);
}
// otherwise memset
memset(p, 0, size);
}
void* _mi_heap_malloc_zero(mi_heap_t* heap, size_t size, bool zero) {
void* p = mi_heap_malloc(heap,size);
if (zero && p != NULL) {
_mi_block_zero_init(p,size);
_mi_block_zero_init(_mi_ptr_page(p),p,size); // todo: can we avoid getting the page again?
}
return p;
}

8
src/page.c
View file

@ -81,14 +81,10 @@ static bool mi_page_is_valid_init(mi_page_t* page) {
mi_assert_internal(mi_page_list_is_valid(page,page->free));
mi_assert_internal(mi_page_list_is_valid(page,page->local_free));
#if 0
#if MI_DEBUG>3 // generally too expensive to check this
if (page->flags.is_zero) {
for(mi_block_t* block = page->free; block != NULL; mi_block_next(page,block)) {
for (size_t i = 1; i < (page->block_size/sizeof(uintptr_t)); i++) {
if (((uintptr_t*)block)[i] != 0) {
return false;
}
}
mi_assert_expensive(mi_mem_is_zero(block + 1, page->block_size - sizeof(mi_block_t)));
}
}
#endif