diff options
Diffstat (limited to 'source/luametatex/source/libraries/mimalloc/src/alloc-aligned.c')
| -rw-r--r-- | source/luametatex/source/libraries/mimalloc/src/alloc-aligned.c | 70 |
1 files changed, 52 insertions, 18 deletions
diff --git a/source/luametatex/source/libraries/mimalloc/src/alloc-aligned.c b/source/luametatex/source/libraries/mimalloc/src/alloc-aligned.c index 9614aa092..9fe82890f 100644 --- a/source/luametatex/source/libraries/mimalloc/src/alloc-aligned.c +++ b/source/luametatex/source/libraries/mimalloc/src/alloc-aligned.c @@ -18,9 +18,9 @@ terms of the MIT license. A copy of the license can be found in the file static mi_decl_noinline void* mi_heap_malloc_zero_aligned_at_fallback(mi_heap_t* const heap, const size_t size, const size_t alignment, const size_t offset, const bool zero) mi_attr_noexcept { mi_assert_internal(size <= PTRDIFF_MAX); - mi_assert_internal(alignment!=0 && _mi_is_power_of_two(alignment) && alignment <= MI_ALIGNMENT_MAX); + mi_assert_internal(alignment != 0 && _mi_is_power_of_two(alignment)); - const uintptr_t align_mask = alignment-1; // for any x, `(x & align_mask) == (x % alignment)` + const uintptr_t align_mask = alignment - 1; // for any x, `(x & align_mask) == (x % alignment)` const size_t padsize = size + MI_PADDING_SIZE; // use regular allocation if it is guaranteed to fit the alignment constraints @@ -30,26 +30,59 @@ static mi_decl_noinline void* mi_heap_malloc_zero_aligned_at_fallback(mi_heap_t* return p; } - // otherwise over-allocate - const size_t oversize = size + alignment - 1; - void* p = _mi_heap_malloc_zero(heap, oversize, zero); - if (p == NULL) return NULL; + void* p; + size_t oversize; + if mi_unlikely(alignment > MI_ALIGNMENT_MAX) { + // use OS allocation for very large alignment and allocate inside a huge page (dedicated segment with 1 page) + // This can support alignments >= MI_SEGMENT_SIZE by ensuring the object can be aligned at a point in the + // first (and single) page such that the segment info is `MI_SEGMENT_SIZE` bytes before it (so it can be found by aligning the pointer down) + if mi_unlikely(offset != 0) { + // todo: cannot support offset alignment for very large alignments yet + #if MI_DEBUG > 0 + _mi_error_message(EOVERFLOW, "aligned allocation with a very large alignment cannot be used with an alignment offset (size %zu, alignment %zu, offset %zu)\n", size, alignment, offset); + #endif + return NULL; + } + oversize = (size <= MI_SMALL_SIZE_MAX ? MI_SMALL_SIZE_MAX + 1 /* ensure we use generic malloc path */ : size); + p = _mi_heap_malloc_zero_ex(heap, oversize, false, alignment); // the page block size should be large enough to align in the single huge page block + // zero afterwards as only the area from the aligned_p may be committed! + if (p == NULL) return NULL; + } + else { + // otherwise over-allocate + oversize = size + alignment - 1; + p = _mi_heap_malloc_zero(heap, oversize, zero); + if (p == NULL) return NULL; + } // .. and align within the allocation - uintptr_t adjust = alignment - (((uintptr_t)p + offset) & align_mask); - mi_assert_internal(adjust <= alignment); - void* aligned_p = (adjust == alignment ? p : (void*)((uintptr_t)p + adjust)); - if (aligned_p != p) mi_page_set_has_aligned(_mi_ptr_page(p), true); - mi_assert_internal(((uintptr_t)aligned_p + offset) % alignment == 0); + const uintptr_t poffset = ((uintptr_t)p + offset) & align_mask; + const uintptr_t adjust = (poffset == 0 ? 0 : alignment - poffset); + mi_assert_internal(adjust < alignment); + void* aligned_p = (void*)((uintptr_t)p + adjust); + if (aligned_p != p) { + mi_page_set_has_aligned(_mi_ptr_page(p), true); + } + + mi_assert_internal(mi_page_usable_block_size(_mi_ptr_page(p)) >= adjust + size); mi_assert_internal(p == _mi_page_ptr_unalign(_mi_ptr_segment(aligned_p), _mi_ptr_page(aligned_p), aligned_p)); + mi_assert_internal(((uintptr_t)aligned_p + offset) % alignment == 0); + mi_assert_internal(mi_page_usable_block_size(_mi_ptr_page(p)) >= adjust + size); + + // now zero the block if needed + if (zero && alignment > MI_ALIGNMENT_MAX) { + const ptrdiff_t diff = (uint8_t*)aligned_p - (uint8_t*)p; + const ptrdiff_t zsize = mi_page_usable_block_size(_mi_ptr_page(p)) - diff - MI_PADDING_SIZE; + if (zsize > 0) { _mi_memzero(aligned_p, zsize); } + } #if MI_TRACK_ENABLED if (p != aligned_p) { - mi_track_free(p); - mi_track_malloc(aligned_p,size,zero); + mi_track_free_size(p, oversize); + mi_track_malloc(aligned_p, size, zero); } else { - mi_track_resize(aligned_p,oversize,size); + mi_track_resize(aligned_p, oversize, size); } #endif return aligned_p; @@ -60,19 +93,21 @@ static void* mi_heap_malloc_zero_aligned_at(mi_heap_t* const heap, const size_t { // note: we don't require `size > offset`, we just guarantee that the address at offset is aligned regardless of the allocated size. mi_assert(alignment > 0); - if mi_unlikely(alignment==0 || !_mi_is_power_of_two(alignment)) { // require power-of-two (see <https://en.cppreference.com/w/c/memory/aligned_alloc>) + if mi_unlikely(alignment == 0 || !_mi_is_power_of_two(alignment)) { // require power-of-two (see <https://en.cppreference.com/w/c/memory/aligned_alloc>) #if MI_DEBUG > 0 _mi_error_message(EOVERFLOW, "aligned allocation requires the alignment to be a power-of-two (size %zu, alignment %zu)\n", size, alignment); #endif return NULL; } + /* if mi_unlikely(alignment > MI_ALIGNMENT_MAX) { // we cannot align at a boundary larger than this (or otherwise we cannot find segment headers) #if MI_DEBUG > 0 _mi_error_message(EOVERFLOW, "aligned allocation has a maximum alignment of %zu (size %zu, alignment %zu)\n", MI_ALIGNMENT_MAX, size, alignment); #endif return NULL; } - if mi_unlikely(size > PTRDIFF_MAX) { // we don't allocate more than PTRDIFF_MAX (see <https://sourceware.org/ml/libc-announce/2019/msg00001.html>) + */ + if mi_unlikely(size > PTRDIFF_MAX) { // we don't allocate more than PTRDIFF_MAX (see <https://sourceware.org/ml/libc-announce/2019/msg00001.html>) #if MI_DEBUG > 0 _mi_error_message(EOVERFLOW, "aligned allocation request is too large (size %zu, alignment %zu)\n", size, alignment); #endif @@ -82,7 +117,7 @@ static void* mi_heap_malloc_zero_aligned_at(mi_heap_t* const heap, const size_t const size_t padsize = size + MI_PADDING_SIZE; // note: cannot overflow due to earlier size > PTRDIFF_MAX check // try first if there happens to be a small block available with just the right alignment - if mi_likely(padsize <= MI_SMALL_SIZE_MAX) { + if mi_likely(padsize <= MI_SMALL_SIZE_MAX && alignment <= padsize) { mi_page_t* page = _mi_heap_get_free_small_page(heap, padsize); const bool is_aligned = (((uintptr_t)page->free+offset) & align_mask)==0; if mi_likely(page->free != NULL && is_aligned) @@ -269,4 +304,3 @@ mi_decl_nodiscard void* mi_recalloc_aligned_at(void* p, size_t newcount, size_t mi_decl_nodiscard void* mi_recalloc_aligned(void* p, size_t newcount, size_t size, size_t alignment) mi_attr_noexcept { return mi_heap_recalloc_aligned(mi_get_default_heap(), p, newcount, size, alignment); } - |