Edit: internal.h
/* ---------------------------------------------------------------------------- Copyright (c) 2018-2023, Microsoft Research, Daan Leijen This is free software; you can redistribute it and/or modify it under the terms of the MIT license. A copy of the license can be found in the file "LICENSE" at the root of this distribution. -----------------------------------------------------------------------------*/ #pragma once #ifndef MIMALLOC_INTERNAL_H #define MIMALLOC_INTERNAL_H // -------------------------------------------------------------------------- // This file contains the interal API's of mimalloc and various utility // functions and macros. // -------------------------------------------------------------------------- #include "types.h" #include "track.h" #if (MI_DEBUG>0) #define mi_trace_message(...) _mi_trace_message(__VA_ARGS__) #else #define mi_trace_message(...) #endif #if defined(__EMSCRIPTEN__) && !defined(__wasi__) #define __wasi__ #endif #if defined(__cplusplus) #define mi_decl_externc extern "C" #else #define mi_decl_externc #endif // pthreads #if !defined(_WIN32) && !defined(__wasi__) #define MI_USE_PTHREADS #include <pthread.h> #endif // "options.c" void _mi_fputs(mi_output_fun* out, void* arg, const char* prefix, const char* message); void _mi_fprintf(mi_output_fun* out, void* arg, const char* fmt, ...); void _mi_warning_message(const char* fmt, ...); void _mi_verbose_message(const char* fmt, ...); void _mi_trace_message(const char* fmt, ...); void _mi_options_init(void); void _mi_error_message(int err, const char* fmt, ...); // random.c void _mi_random_init(mi_random_ctx_t* ctx); void _mi_random_init_weak(mi_random_ctx_t* ctx); void _mi_random_reinit_if_weak(mi_random_ctx_t * ctx); void _mi_random_split(mi_random_ctx_t* ctx, mi_random_ctx_t* new_ctx); uintptr_t _mi_random_next(mi_random_ctx_t* ctx); uintptr_t _mi_heap_random_next(mi_heap_t* heap); uintptr_t _mi_os_random_weak(uintptr_t extra_seed); static inline uintptr_t _mi_random_shuffle(uintptr_t x); // init.c extern mi_decl_cache_align mi_stats_t _mi_stats_main; extern mi_decl_cache_align const mi_page_t _mi_page_empty; bool _mi_is_main_thread(void); size_t _mi_current_thread_count(void); bool _mi_preloading(void); // true while the C runtime is not initialized yet mi_threadid_t _mi_thread_id(void) mi_attr_noexcept; mi_heap_t* _mi_heap_main_get(void); // statically allocated main backing heap void _mi_thread_done(mi_heap_t* heap); void _mi_thread_data_collect(void); void _mi_tld_init(mi_tld_t* tld, mi_heap_t* bheap); // os.c void _mi_os_init(void); // called from process init void* _mi_os_alloc(size_t size, mi_memid_t* memid, mi_stats_t* stats); void _mi_os_free(void* p, size_t size, mi_memid_t memid, mi_stats_t* stats); void _mi_os_free_ex(void* p, size_t size, bool still_committed, mi_memid_t memid, mi_stats_t* stats); size_t _mi_os_page_size(void); size_t _mi_os_good_alloc_size(size_t size); bool _mi_os_has_overcommit(void); bool _mi_os_has_virtual_reserve(void); bool _mi_os_purge(void* p, size_t size, mi_stats_t* stats); bool _mi_os_reset(void* addr, size_t size, mi_stats_t* tld_stats); bool _mi_os_commit(void* p, size_t size, bool* is_zero, mi_stats_t* stats); bool _mi_os_decommit(void* addr, size_t size, mi_stats_t* stats); bool _mi_os_protect(void* addr, size_t size); bool _mi_os_unprotect(void* addr, size_t size); bool _mi_os_purge(void* p, size_t size, mi_stats_t* stats); bool _mi_os_purge_ex(void* p, size_t size, bool allow_reset, mi_stats_t* stats); void* _mi_os_alloc_aligned(size_t size, size_t alignment, bool commit, bool allow_large, mi_memid_t* memid, mi_stats_t* stats); void* _mi_os_alloc_aligned_at_offset(size_t size, size_t alignment, size_t align_offset, bool commit, bool allow_large, mi_memid_t* memid, mi_stats_t* tld_stats); void* _mi_os_get_aligned_hint(size_t try_alignment, size_t size); bool _mi_os_use_large_page(size_t size, size_t alignment); size_t _mi_os_large_page_size(void); void* _mi_os_alloc_huge_os_pages(size_t pages, int numa_node, mi_msecs_t max_secs, size_t* pages_reserved, size_t* psize, mi_memid_t* memid); // arena.c mi_arena_id_t _mi_arena_id_none(void); void _mi_arena_free(void* p, size_t size, size_t still_committed_size, mi_memid_t memid, mi_stats_t* stats); void* _mi_arena_alloc(size_t size, bool commit, bool allow_large, mi_arena_id_t req_arena_id, mi_memid_t* memid, mi_os_tld_t* tld); void* _mi_arena_alloc_aligned(size_t size, size_t alignment, size_t align_offset, bool commit, bool allow_large, mi_arena_id_t req_arena_id, mi_memid_t* memid, mi_os_tld_t* tld); bool _mi_arena_memid_is_suitable(mi_memid_t memid, mi_arena_id_t request_arena_id); bool _mi_arena_contains(const void* p); void _mi_arena_collect(bool force_purge, mi_stats_t* stats); void _mi_arena_unsafe_destroy_all(mi_stats_t* stats); // "segment-map.c" void _mi_segment_map_allocated_at(const mi_segment_t* segment); void _mi_segment_map_freed_at(const mi_segment_t* segment); // "segment.c" extern mi_abandoned_pool_t _mi_abandoned_default; // global abandoned pool mi_page_t* _mi_segment_page_alloc(mi_heap_t* heap, size_t block_size, size_t page_alignment, mi_segments_tld_t* tld, mi_os_tld_t* os_tld); void _mi_segment_page_free(mi_page_t* page, bool force, mi_segments_tld_t* tld); void _mi_segment_page_abandon(mi_page_t* page, mi_segments_tld_t* tld); bool _mi_segment_try_reclaim_abandoned( mi_heap_t* heap, bool try_all, mi_segments_tld_t* tld); void _mi_segment_thread_collect(mi_segments_tld_t* tld); bool _mi_abandoned_pool_visit_blocks(mi_abandoned_pool_t* pool, uint8_t page_tag, bool visit_blocks, mi_block_visit_fun* visitor, void* arg); #if MI_HUGE_PAGE_ABANDON void _mi_segment_huge_page_free(mi_segment_t* segment, mi_page_t* page, mi_block_t* block); #else void _mi_segment_huge_page_reset(mi_segment_t* segment, mi_page_t* page, mi_block_t* block); #endif uint8_t* _mi_segment_page_start(const mi_segment_t* segment, const mi_page_t* page, size_t* page_size); // page start for any page void _mi_abandoned_reclaim_all(mi_heap_t* heap, mi_segments_tld_t* tld); void _mi_abandoned_await_readers(mi_abandoned_pool_t *pool); void _mi_abandoned_collect(mi_heap_t* heap, bool force, mi_segments_tld_t* tld); // "page.c" void* _mi_malloc_generic(mi_heap_t* heap, size_t size, bool zero, size_t huge_alignment) mi_attr_noexcept mi_attr_malloc; void _mi_page_retire(mi_page_t* page) mi_attr_noexcept; // free the page if there are no other pages with many free blocks void _mi_page_unfull(mi_page_t* page); void _mi_page_free(mi_page_t* page, mi_page_queue_t* pq, bool force); // free the page void _mi_page_abandon(mi_page_t* page, mi_page_queue_t* pq); // abandon the page, to be picked up by another thread... void _mi_heap_delayed_free_all(mi_heap_t* heap); bool _mi_heap_delayed_free_partial(mi_heap_t* heap); void _mi_heap_collect_retired(mi_heap_t* heap, bool force); void _mi_page_use_delayed_free(mi_page_t* page, mi_delayed_t delay, bool override_never); bool _mi_page_try_use_delayed_free(mi_page_t* page, mi_delayed_t delay, bool override_never); size_t _mi_page_queue_append(mi_heap_t* heap, mi_page_queue_t* pq, mi_page_queue_t* append); void _mi_deferred_free(mi_heap_t* heap, bool force); void _mi_page_free_collect(mi_page_t* page,bool force); void _mi_page_reclaim(mi_heap_t* heap, mi_page_t* page); // callback from segments size_t _mi_bin_size(uint8_t bin); // for stats uint8_t _mi_bin(size_t size); // for stats // "heap.c" void _mi_heap_init_ex(mi_heap_t* heap, mi_tld_t* tld, mi_arena_id_t arena_id, bool no_reclaim, uint8_t tag); void _mi_heap_destroy_pages(mi_heap_t* heap); void _mi_heap_collect_abandon(mi_heap_t* heap); void _mi_heap_set_default_direct(mi_heap_t* heap); bool _mi_heap_memid_is_suitable(mi_heap_t* heap, mi_memid_t memid); void _mi_heap_unsafe_destroy_all(void); void _mi_heap_area_init(mi_heap_area_t* area, mi_page_t* page); bool _mi_heap_area_visit_blocks(const mi_heap_area_t* area, mi_page_t *page, mi_block_visit_fun* visitor, void* arg); // "stats.c" void _mi_stats_done(mi_stats_t* stats); mi_msecs_t _mi_clock_now(void); mi_msecs_t _mi_clock_end(mi_msecs_t start); mi_msecs_t _mi_clock_start(void); // "alloc.c" void* _mi_page_malloc(mi_heap_t* heap, mi_page_t* page, size_t size, bool zero) mi_attr_noexcept; // called from `_mi_malloc_generic` void* _mi_heap_malloc_zero(mi_heap_t* heap, size_t size, bool zero) mi_attr_noexcept; void* _mi_heap_malloc_zero_ex(mi_heap_t* heap, size_t size, bool zero, size_t huge_alignment) mi_attr_noexcept; // called from `_mi_heap_malloc_aligned` void* _mi_heap_realloc_zero(mi_heap_t* heap, void* p, size_t newsize, bool zero) mi_attr_noexcept; mi_block_t* _mi_page_ptr_unalign(const mi_segment_t* segment, const mi_page_t* page, const void* p); bool _mi_free_delayed_block(mi_block_t* block); void _mi_free_generic(const mi_segment_t* segment, mi_page_t* page, bool is_local, void* p) mi_attr_noexcept; // for runtime integration void _mi_padding_shrink(const mi_page_t* page, const mi_block_t* block, const size_t min_size); // option.c, c primitives char _mi_toupper(char c); int _mi_strnicmp(const char* s, const char* t, size_t n); void _mi_strlcpy(char* dest, const char* src, size_t dest_size); void _mi_strlcat(char* dest, const char* src, size_t dest_size); size_t _mi_strlen(const char* s); size_t _mi_strnlen(const char* s, size_t max_len); #if MI_DEBUG>1 bool _mi_page_is_valid(mi_page_t* page); #endif // ------------------------------------------------------ // Branches // ------------------------------------------------------ #if defined(__GNUC__) || defined(__clang__) #define mi_unlikely(x) (__builtin_expect(!!(x),false)) #define mi_likely(x) (__builtin_expect(!!(x),true)) #elif (defined(__cplusplus) && (__cplusplus >= 202002L)) || (defined(_MSVC_LANG) && _MSVC_LANG >= 202002L) #define mi_unlikely(x) (x) [[unlikely]] #define mi_likely(x) (x) [[likely]] #else #define mi_unlikely(x) (x) #define mi_likely(x) (x) #endif #ifndef __has_builtin #define __has_builtin(x) 0 #endif /* ----------------------------------------------------------- Error codes passed to `_mi_fatal_error` All are recoverable but EFAULT is a serious error and aborts by default in secure mode. For portability define undefined error codes using common Unix codes: <https://www-numi.fnal.gov/offline_software/srt_public_context/WebDocs/Errors/unix_system_errors.html> ----------------------------------------------------------- */ #include <errno.h> #ifndef EAGAIN // double free #define EAGAIN (11) #endif #ifndef ENOMEM // out of memory #define ENOMEM (12) #endif #ifndef EFAULT // corrupted free-list or meta-data #define EFAULT (14) #endif #ifndef EINVAL // trying to free an invalid pointer #define EINVAL (22) #endif #ifndef EOVERFLOW // count*size overflow #define EOVERFLOW (75) #endif /* ----------------------------------------------------------- Inlined definitions ----------------------------------------------------------- */ #define MI_UNUSED(x) (void)(x) #if (MI_DEBUG>0) #define MI_UNUSED_RELEASE(x) #else #define MI_UNUSED_RELEASE(x) MI_UNUSED(x) #endif #define MI_INIT4(x) x(),x(),x(),x() #define MI_INIT8(x) MI_INIT4(x),MI_INIT4(x) #define MI_INIT16(x) MI_INIT8(x),MI_INIT8(x) #define MI_INIT32(x) MI_INIT16(x),MI_INIT16(x) #define MI_INIT64(x) MI_INIT32(x),MI_INIT32(x) #define MI_INIT128(x) MI_INIT64(x),MI_INIT64(x) #define MI_INIT256(x) MI_INIT128(x),MI_INIT128(x) #include <string.h> // initialize a local variable to zero; use memset as compilers optimize constant sized memset's #define _mi_memzero_var(x) memset(&x,0,sizeof(x)) // Is `x` a power of two? (0 is considered a power of two) static inline bool _mi_is_power_of_two(uintptr_t x) { return ((x & (x - 1)) == 0); } // Is a pointer aligned? static inline bool _mi_is_aligned(void* p, size_t alignment) { mi_assert_internal(alignment != 0); return (((uintptr_t)p % alignment) == 0); } // Align upwards static inline uintptr_t _mi_align_up(uintptr_t sz, size_t alignment) { mi_assert_internal(alignment != 0); uintptr_t mask = alignment - 1; if ((alignment & mask) == 0) { // power of two? return ((sz + mask) & ~mask); } else { return (((sz + mask)/alignment)*alignment); } } // Align downwards static inline uintptr_t _mi_align_down(uintptr_t sz, size_t alignment) { mi_assert_internal(alignment != 0); uintptr_t mask = alignment - 1; if ((alignment & mask) == 0) { // power of two? return (sz & ~mask); } else { return ((sz / alignment) * alignment); } } // Divide upwards: `s <= _mi_divide_up(s,d)*d < s+d`. static inline uintptr_t _mi_divide_up(uintptr_t size, size_t divider) { mi_assert_internal(divider != 0); return (divider == 0 ? size : ((size + divider - 1) / divider)); } // Is memory zero initialized? static inline bool mi_mem_is_zero(const void* p, size_t size) { for (size_t i = 0; i < size; i++) { if (((uint8_t*)p)[i] != 0) return false; } return true; } // Align a byte size to a size in _machine words_, // i.e. byte size == `wsize*sizeof(void*)`. static inline size_t _mi_wsize_from_size(size_t size) { mi_assert_internal(size <= SIZE_MAX - sizeof(uintptr_t)); return (size + sizeof(uintptr_t) - 1) / sizeof(uintptr_t); } // Overflow detecting multiply #if __has_builtin(__builtin_umul_overflow) || (defined(__GNUC__) && (__GNUC__ >= 5)) #include <limits.h> // UINT_MAX, ULONG_MAX #if defined(_CLOCK_T) // for Illumos #undef _CLOCK_T #endif static inline bool mi_mul_overflow(size_t count, size_t size, size_t* total) { #if (SIZE_MAX == ULONG_MAX) return __builtin_umull_overflow(count, size, (unsigned long *)total); #elif (SIZE_MAX == UINT_MAX) return __builtin_umul_overflow(count, size, (unsigned int *)total); #else return __builtin_umulll_overflow(count, size, (unsigned long long *)total); #endif } #else /* __builtin_umul_overflow is unavailable */ static inline bool mi_mul_overflow(size_t count, size_t size, size_t* total) { #define MI_MUL_NO_OVERFLOW ((size_t)1 << (4*sizeof(size_t))) // sqrt(SIZE_MAX) *total = count * size; // note: gcc/clang optimize this to directly check the overflow flag return ((size >= MI_MUL_NO_OVERFLOW || count >= MI_MUL_NO_OVERFLOW) && size > 0 && (SIZE_MAX / size) < count); } #endif // Safe multiply `count*size` into `total`; return `true` on overflow. static inline bool mi_count_size_overflow(size_t count, size_t size, size_t* total) { if (count==1) { // quick check for the case where count is one (common for C++ allocators) *total = size; return false; } else if mi_unlikely(mi_mul_overflow(count, size, total)) { #if MI_DEBUG > 0 _mi_error_message(EOVERFLOW, "allocation request is too large (%zu * %zu bytes)\n", count, size); #endif *total = SIZE_MAX; return true; } else return false; } /*---------------------------------------------------------------------------------------- Heap functions ------------------------------------------------------------------------------------------- */ extern const mi_heap_t _mi_heap_empty; // read-only empty heap, initial value of the thread local default heap static inline bool mi_heap_is_backing(const mi_heap_t* heap) { return (heap->tld->heap_backing == heap); } static inline bool mi_heap_is_initialized(mi_heap_t* heap) { mi_assert_internal(heap != NULL); return (heap != &_mi_heap_empty); } static inline uintptr_t _mi_ptr_cookie(const void* p) { extern mi_heap_t _mi_heap_main; mi_assert_internal(_mi_heap_main.cookie != 0); return ((uintptr_t)p ^ _mi_heap_main.cookie); } /* ----------------------------------------------------------- Pages ----------------------------------------------------------- */ static inline mi_page_t* _mi_heap_get_free_small_page(mi_heap_t* heap, size_t size) { mi_assert_internal(size <= (MI_SMALL_SIZE_MAX + MI_PADDING_SIZE)); const size_t idx = _mi_wsize_from_size(size); mi_assert_internal(idx < MI_PAGES_DIRECT); return heap->pages_free_direct[idx]; } // Segment that contains the pointer // Large aligned blocks may be aligned at N*MI_SEGMENT_SIZE (inside a huge segment > MI_SEGMENT_SIZE), // and we need align "down" to the segment info which is `MI_SEGMENT_SIZE` bytes before it; // therefore we align one byte before `p`. static inline mi_segment_t* _mi_ptr_segment(const void* p) { mi_assert_internal(p != NULL); return (mi_segment_t*)(((uintptr_t)p - 1) & ~MI_SEGMENT_MASK); } static inline mi_page_t* mi_slice_to_page(mi_slice_t* s) { mi_assert_internal(s->slice_offset== 0 && s->slice_count > 0); return (mi_page_t*)(s); } static inline mi_slice_t* mi_page_to_slice(mi_page_t* p) { mi_assert_internal(p->slice_offset== 0 && p->slice_count > 0); return (mi_slice_t*)(p); } // Segment belonging to a page static inline mi_segment_t* _mi_page_segment(const mi_page_t* page) { mi_segment_t* segment = _mi_ptr_segment(page); mi_assert_internal(segment == NULL || ((mi_slice_t*)page >= segment->slices && (mi_slice_t*)page < segment->slices + segment->slice_entries)); return segment; } static inline mi_slice_t* mi_slice_first(const mi_slice_t* slice) { mi_slice_t* start = (mi_slice_t*)((uint8_t*)slice - slice->slice_offset); mi_assert_internal(start >= _mi_ptr_segment(slice)->slices); mi_assert_internal(start->slice_offset == 0); mi_assert_internal(start + start->slice_count > slice); return start; } // Get the page containing the pointer (performance critical as it is called in mi_free) static inline mi_page_t* _mi_segment_page_of(const mi_segment_t* segment, const void* p) { mi_assert_internal(p > (void*)segment); ptrdiff_t diff = (uint8_t*)p - (uint8_t*)segment; mi_assert_internal(diff > 0 && diff <= (ptrdiff_t)MI_SEGMENT_SIZE); size_t idx = (size_t)diff >> MI_SEGMENT_SLICE_SHIFT; mi_assert_internal(idx <= segment->slice_entries); mi_slice_t* slice0 = (mi_slice_t*)&segment->slices[idx]; mi_slice_t* slice = mi_slice_first(slice0); // adjust to the block that holds the page data mi_assert_internal(slice->slice_offset == 0); mi_assert_internal(slice >= segment->slices && slice < segment->slices + segment->slice_entries); return mi_slice_to_page(slice); } // Quick page start for initialized pages static inline uint8_t* _mi_page_start(const mi_segment_t* segment, const mi_page_t* page, size_t* page_size) { return _mi_segment_page_start(segment, page, page_size); } // Get the page containing the pointer static inline mi_page_t* _mi_ptr_page(void* p) { return _mi_segment_page_of(_mi_ptr_segment(p), p); } // Get the block size of a page (special case for huge objects) static inline size_t mi_page_block_size(const mi_page_t* page) { const size_t bsize = page->xblock_size; mi_assert_internal(bsize > 0); if mi_likely(bsize < MI_HUGE_BLOCK_SIZE) { return bsize; } else { size_t psize; _mi_segment_page_start(_mi_page_segment(page), page, &psize); return psize; } } static inline bool mi_page_is_huge(const mi_page_t* page) { return (_mi_page_segment(page)->kind == MI_SEGMENT_HUGE); } // Get the usable block size of a page without fixed padding. // This may still include internal padding due to alignment and rounding up size classes. static inline size_t mi_page_usable_block_size(const mi_page_t* page) { return mi_page_block_size(page) - MI_PADDING_SIZE; } // size of a segment static inline size_t mi_segment_size(mi_segment_t* segment) { return segment->segment_slices * MI_SEGMENT_SLICE_SIZE; } static inline uint8_t* mi_segment_end(mi_segment_t* segment) { return (uint8_t*)segment + mi_segment_size(segment); } // Thread free access static inline mi_block_t* mi_page_thread_free(const mi_page_t* page) { return (mi_block_t*)(mi_atomic_load_relaxed(&((mi_page_t*)page)->xthread_free) & ~3); } static inline mi_delayed_t mi_page_thread_free_flag(const mi_page_t* page) { return (mi_delayed_t)(mi_atomic_load_relaxed(&((mi_page_t*)page)->xthread_free) & 3); } // Heap access static inline mi_heap_t* mi_page_heap(const mi_page_t* page) { return (mi_heap_t*)(mi_atomic_load_relaxed(&((mi_page_t*)page)->xheap)); } static inline void mi_page_set_heap(mi_page_t* page, mi_heap_t* heap) { mi_assert_internal(mi_page_thread_free_flag(page) != MI_DELAYED_FREEING); mi_atomic_store_release(&page->xheap,(uintptr_t)heap); } // Thread free flag helpers static inline mi_block_t* mi_tf_block(mi_thread_free_t tf) { return (mi_block_t*)(tf & ~0x03); } static inline mi_delayed_t mi_tf_delayed(mi_thread_free_t tf) { return (mi_delayed_t)(tf & 0x03); } static inline mi_thread_free_t mi_tf_make(mi_block_t* block, mi_delayed_t delayed) { return (mi_thread_free_t)((uintptr_t)block | (uintptr_t)delayed); } static inline mi_thread_free_t mi_tf_set_delayed(mi_thread_free_t tf, mi_delayed_t delayed) { return mi_tf_make(mi_tf_block(tf),delayed); } static inline mi_thread_free_t mi_tf_set_block(mi_thread_free_t tf, mi_block_t* block) { return mi_tf_make(block, mi_tf_delayed(tf)); } // are all blocks in a page freed? // note: needs up-to-date used count, (as the `xthread_free` list may not be empty). see `_mi_page_collect_free`. static inline bool mi_page_all_free(const mi_page_t* page) { mi_assert_internal(page != NULL); return (page->used == 0); } // are there any available blocks? static inline bool mi_page_has_any_available(const mi_page_t* page) { mi_assert_internal(page != NULL && page->reserved > 0); return (page->used < page->reserved || (mi_page_thread_free(page) != NULL)); } // are there immediately available blocks, i.e. blocks available on the free list. static inline bool mi_page_immediate_available(const mi_page_t* page) { mi_assert_internal(page != NULL); return (page->free != NULL); } // is more than 7/8th of a page in use? static inline bool mi_page_mostly_used(const mi_page_t* page) { if (page==NULL) return true; uint16_t frac = page->reserved / 8U; return (page->reserved - page->used <= frac); } static inline mi_page_queue_t* mi_page_queue(const mi_heap_t* heap, size_t size) { return &((mi_heap_t*)heap)->pages[_mi_bin(size)]; } //----------------------------------------------------------- // Page flags //----------------------------------------------------------- static inline bool mi_page_is_in_full(const mi_page_t* page) { return page->flags.x.in_full; } static inline void mi_page_set_in_full(mi_page_t* page, bool in_full) { page->flags.x.in_full = in_full; } static inline bool mi_page_has_aligned(const mi_page_t* page) { return page->flags.x.has_aligned; } static inline void mi_page_set_has_aligned(mi_page_t* page, bool has_aligned) { page->flags.x.has_aligned = has_aligned; } /* ------------------------------------------------------------------- Encoding/Decoding the free list next pointers This is to protect against buffer overflow exploits where the free list is mutated. Many hardened allocators xor the next pointer `p` with a secret key `k1`, as `p^k1`. This prevents overwriting with known values but might be still too weak: if the attacker can guess the pointer `p` this can reveal `k1` (since `p^k1^p == k1`). Moreover, if multiple blocks can be read as well, the attacker can xor both as `(p1^k1) ^ (p2^k1) == p1^p2` which may reveal a lot about the pointers (and subsequently `k1`). Instead mimalloc uses an extra key `k2` and encodes as `((p^k2)<<<k1)+k1`. Since these operations are not associative, the above approaches do not work so well any more even if the `p` can be guesstimated. For example, for the read case we can subtract two entries to discard the `+k1` term, but that leads to `((p1^k2)<<<k1) - ((p2^k2)<<<k1)` at best. We include the left-rotation since xor and addition are otherwise linear in the lowest bit. Finally, both keys are unique per page which reduces the re-use of keys by a large factor. We also pass a separate `null` value to be used as `NULL` or otherwise `(k2<<<k1)+k1` would appear (too) often as a sentinel value. ------------------------------------------------------------------- */ static inline bool mi_is_in_same_segment(const void* p, const void* q) { return (_mi_ptr_segment(p) == _mi_ptr_segment(q)); } static inline bool mi_is_in_same_page(const void* p, const void* q) { mi_segment_t* segment = _mi_ptr_segment(p); if (_mi_ptr_segment(q) != segment) return false; // assume q may be invalid // return (_mi_segment_page_of(segment, p) == _mi_segment_page_of(segment, q)); mi_page_t* page = _mi_segment_page_of(segment, p); size_t psize; uint8_t* start = _mi_segment_page_start(segment, page, &psize); return (start <= (uint8_t*)q && (uint8_t*)q < start + psize); } static inline uintptr_t mi_rotl(uintptr_t x, uintptr_t shift) { shift %= MI_INTPTR_BITS; return (shift==0 ? x : ((x << shift) | (x >> (MI_INTPTR_BITS - shift)))); } static inline uintptr_t mi_rotr(uintptr_t x, uintptr_t shift) { shift %= MI_INTPTR_BITS; return (shift==0 ? x : ((x >> shift) | (x << (MI_INTPTR_BITS - shift)))); } static inline void* mi_ptr_decode(const void* null, const mi_encoded_t x, const uintptr_t* keys) { void* p = (void*)(mi_rotr(x - keys[0], keys[0]) ^ keys[1]); return (p==null ? NULL : p); } static inline mi_encoded_t mi_ptr_encode(const void* null, const void* p, const uintptr_t* keys) { uintptr_t x = (uintptr_t)(p==NULL ? null : p); return mi_rotl(x ^ keys[1], keys[0]) + keys[0]; } static inline mi_block_t* mi_block_nextx( const void* null, const mi_block_t* block, const uintptr_t* keys ) { mi_track_mem_defined(block,sizeof(mi_block_t)); mi_block_t* next; #ifdef MI_ENCODE_FREELIST next = (mi_block_t*)mi_ptr_decode(null, mi_atomic_load_relaxed((_Atomic(mi_encoded_t)*)&block->next), keys); #else MI_UNUSED(keys); MI_UNUSED(null); next = (mi_block_t*)mi_atomic_load_relaxed((_Atomic(mi_encoded_t)*)&block->next); #endif mi_track_mem_noaccess(block,sizeof(mi_block_t)); return next; } static inline void mi_block_set_nextx(const void* null, mi_block_t* block, const mi_block_t* next, const uintptr_t* keys) { mi_track_mem_undefined(block,sizeof(mi_block_t)); #ifdef MI_ENCODE_FREELIST mi_atomic_store_relaxed(&block->next, mi_ptr_encode(null, next, keys)); #else MI_UNUSED(keys); MI_UNUSED(null); mi_atomic_store_relaxed(&block->next, (mi_encoded_t)next); #endif mi_track_mem_noaccess(block,sizeof(mi_block_t)); } static inline mi_block_t* mi_block_next(const mi_page_t* page, const mi_block_t* block) { #ifdef MI_ENCODE_FREELIST mi_block_t* next = mi_block_nextx(page,block,page->keys); // check for free list corruption: is `next` at least in the same page? // TODO: check if `next` is `page->block_size` aligned? if mi_unlikely(next!=NULL && !mi_is_in_same_page(block, next)) { _mi_error_message(EFAULT, "corrupted free list entry of size %zub at %p: value 0x%zx\n", mi_page_block_size(page), block, (uintptr_t)next); next = NULL; } return next; #else MI_UNUSED(page); return mi_block_nextx(page,block,NULL); #endif } static inline void mi_block_set_next(const mi_page_t* page, mi_block_t* block, const mi_block_t* next) { #ifdef MI_ENCODE_FREELIST mi_block_set_nextx(page,block,next, page->keys); #else MI_UNUSED(page); mi_block_set_nextx(page,block,next,NULL); #endif } // ------------------------------------------------------------------- // commit mask // ------------------------------------------------------------------- static inline void mi_commit_mask_create_empty(mi_commit_mask_t* cm) { for (size_t i = 0; i < MI_COMMIT_MASK_FIELD_COUNT; i++) { cm->mask[i] = 0; } } static inline void mi_commit_mask_create_full(mi_commit_mask_t* cm) { for (size_t i = 0; i < MI_COMMIT_MASK_FIELD_COUNT; i++) { cm->mask[i] = ~((size_t)0); } } static inline bool mi_commit_mask_is_empty(const mi_commit_mask_t* cm) { for (size_t i = 0; i < MI_COMMIT_MASK_FIELD_COUNT; i++) { if (cm->mask[i] != 0) return false; } return true; } static inline bool mi_commit_mask_is_full(const mi_commit_mask_t* cm) { for (size_t i = 0; i < MI_COMMIT_MASK_FIELD_COUNT; i++) { if (cm->mask[i] != ~((size_t)0)) return false; } return true; } // defined in `segment.c`: size_t _mi_commit_mask_committed_size(const mi_commit_mask_t* cm, size_t total); size_t _mi_commit_mask_next_run(const mi_commit_mask_t* cm, size_t* idx); #define mi_commit_mask_foreach(cm,idx,count) \ idx = 0; \ while ((count = _mi_commit_mask_next_run(cm,&idx)) > 0) { #define mi_commit_mask_foreach_end() \ idx += count; \ } /* ----------------------------------------------------------- memory id's ----------------------------------------------------------- */ static inline mi_memid_t _mi_memid_create(mi_memkind_t memkind) { mi_memid_t memid; _mi_memzero_var(memid); memid.memkind = memkind; return memid; } static inline mi_memid_t _mi_memid_none(void) { return _mi_memid_create(MI_MEM_NONE); } static inline mi_memid_t _mi_memid_create_os(bool committed, bool is_zero, bool is_large) { mi_memid_t memid = _mi_memid_create(MI_MEM_OS); memid.initially_committed = committed; memid.initially_zero = is_zero; memid.is_pinned = is_large; return memid; } // ------------------------------------------------------------------- // Fast "random" shuffle // ------------------------------------------------------------------- static inline uintptr_t _mi_random_shuffle(uintptr_t x) { if (x==0) { x = 17; } // ensure we don't get stuck in generating zeros #if (MI_INTPTR_SIZE==8) // by Sebastiano Vigna, see: <http://xoshiro.di.unimi.it/splitmix64.c> x ^= x >> 30; x *= 0xbf58476d1ce4e5b9UL; x ^= x >> 27; x *= 0x94d049bb133111ebUL; x ^= x >> 31; #elif (MI_INTPTR_SIZE==4) // by Chris Wellons, see: <https://nullprogram.com/blog/2018/07/31/> x ^= x >> 16; x *= 0x7feb352dUL; x ^= x >> 15; x *= 0x846ca68bUL; x ^= x >> 16; #endif return x; } // ------------------------------------------------------------------- // Optimize numa node access for the common case (= one node) // ------------------------------------------------------------------- int _mi_os_numa_node_get(mi_os_tld_t* tld); size_t _mi_os_numa_node_count_get(void); extern _Atomic(size_t) _mi_numa_node_count; static inline int _mi_os_numa_node(mi_os_tld_t* tld) { if mi_likely(mi_atomic_load_relaxed(&_mi_numa_node_count) == 1) { return 0; } else return _mi_os_numa_node_get(tld); } static inline size_t _mi_os_numa_node_count(void) { const size_t count = mi_atomic_load_relaxed(&_mi_numa_node_count); if mi_likely(count > 0) { return count; } else return _mi_os_numa_node_count_get(); } // ----------------------------------------------------------------------- // Count bits: trailing or leading zeros (with MI_INTPTR_BITS on all zero) // ----------------------------------------------------------------------- #if defined(__GNUC__) #include <limits.h> // LONG_MAX #define MI_HAVE_FAST_BITSCAN static inline size_t mi_clz(uintptr_t x) { if (x==0) return MI_INTPTR_BITS; #if (INTPTR_MAX == LONG_MAX) return __builtin_clzl(x); #else return __builtin_clzll(x); #endif } static inline size_t mi_ctz(uintptr_t x) { if (x==0) return MI_INTPTR_BITS; #if (INTPTR_MAX == LONG_MAX) return __builtin_ctzl(x); #else return __builtin_ctzll(x); #endif } #elif defined(_MSC_VER) #include <limits.h> // LONG_MAX #include <intrin.h> // BitScanReverse64 #define MI_HAVE_FAST_BITSCAN static inline size_t mi_clz(uintptr_t x) { if (x==0) return MI_INTPTR_BITS; unsigned long idx; #if (INTPTR_MAX == LONG_MAX) _BitScanReverse(&idx, x); #else _BitScanReverse64(&idx, x); #endif return ((MI_INTPTR_BITS - 1) - idx); } static inline size_t mi_ctz(uintptr_t x) { if (x==0) return MI_INTPTR_BITS; unsigned long idx; #if (INTPTR_MAX == LONG_MAX) _BitScanForward(&idx, x); #else _BitScanForward64(&idx, x); #endif return idx; } #else static inline size_t mi_ctz32(uint32_t x) { // de Bruijn multiplication, see <http://supertech.csail.mit.edu/papers/debruijn.pdf> static const unsigned char debruijn[32] = { 0, 1, 28, 2, 29, 14, 24, 3, 30, 22, 20, 15, 25, 17, 4, 8, 31, 27, 13, 23, 21, 19, 16, 7, 26, 12, 18, 6, 11, 5, 10, 9 }; if (x==0) return 32; return debruijn[((x & -(int32_t)x) * 0x077CB531UL) >> 27]; } static inline size_t mi_clz32(uint32_t x) { // de Bruijn multiplication, see <http://supertech.csail.mit.edu/papers/debruijn.pdf> static const uint8_t debruijn[32] = { 31, 22, 30, 21, 18, 10, 29, 2, 20, 17, 15, 13, 9, 6, 28, 1, 23, 19, 11, 3, 16, 14, 7, 24, 12, 4, 8, 25, 5, 26, 27, 0 }; if (x==0) return 32; x |= x >> 1; x |= x >> 2; x |= x >> 4; x |= x >> 8; x |= x >> 16; return debruijn[(uint32_t)(x * 0x07C4ACDDUL) >> 27]; } static inline size_t mi_clz(uintptr_t x) { if (x==0) return MI_INTPTR_BITS; #if (MI_INTPTR_BITS <= 32) return mi_clz32((uint32_t)x); #else size_t count = mi_clz32((uint32_t)(x >> 32)); if (count < 32) return count; return (32 + mi_clz32((uint32_t)x)); #endif } static inline size_t mi_ctz(uintptr_t x) { if (x==0) return MI_INTPTR_BITS; #if (MI_INTPTR_BITS <= 32) return mi_ctz32((uint32_t)x); #else size_t count = mi_ctz32((uint32_t)x); if (count < 32) return count; return (32 + mi_ctz32((uint32_t)(x>>32))); #endif } #endif // "bit scan reverse": Return index of the highest bit (or MI_INTPTR_BITS if `x` is zero) static inline size_t mi_bsr(uintptr_t x) { return (x==0 ? MI_INTPTR_BITS : MI_INTPTR_BITS - 1 - mi_clz(x)); } // --------------------------------------------------------------------------------- // Provide our own `_mi_memcpy` for potential performance optimizations. // // For now, only on Windows with msvc/clang-cl we optimize to `rep movsb` if // we happen to run on x86/x64 cpu's that have "fast short rep movsb" (FSRM) support // (AMD Zen3+ (~2020) or Intel Ice Lake+ (~2017). See also issue #201 and pr #253. // --------------------------------------------------------------------------------- #if !MI_TRACK_ENABLED && defined(_WIN32) && (defined(_M_IX86) || defined(_M_X64)) #include <intrin.h> extern bool _mi_cpu_has_fsrm; static inline void _mi_memcpy(void* dst, const void* src, size_t n) { if (_mi_cpu_has_fsrm) { __movsb((unsigned char*)dst, (const unsigned char*)src, n); } else { memcpy(dst, src, n); } } static inline void _mi_memzero(void* dst, size_t n) { if (_mi_cpu_has_fsrm) { __stosb((unsigned char*)dst, 0, n); } else { memset(dst, 0, n); } } #else static inline void _mi_memcpy(void* dst, const void* src, size_t n) { memcpy(dst, src, n); } static inline void _mi_memzero(void* dst, size_t n) { memset(dst, 0, n); } #endif // ------------------------------------------------------------------------------- // The `_mi_memcpy_aligned` can be used if the pointers are machine-word aligned // This is used for example in `mi_realloc`. // ------------------------------------------------------------------------------- #if (defined(__GNUC__) && (__GNUC__ >= 4)) || defined(__clang__) // On GCC/CLang we provide a hint that the pointers are word aligned. static inline void _mi_memcpy_aligned(void* dst, const void* src, size_t n) { mi_assert_internal(((uintptr_t)dst % MI_INTPTR_SIZE == 0) && ((uintptr_t)src % MI_INTPTR_SIZE == 0)); void* adst = __builtin_assume_aligned(dst, MI_INTPTR_SIZE); const void* asrc = __builtin_assume_aligned(src, MI_INTPTR_SIZE); _mi_memcpy(adst, asrc, n); } static inline void _mi_memzero_aligned(void* dst, size_t n) { mi_assert_internal((uintptr_t)dst % MI_INTPTR_SIZE == 0); void* adst = __builtin_assume_aligned(dst, MI_INTPTR_SIZE); _mi_memzero(adst, n); } #else // Default fallback on `_mi_memcpy` static inline void _mi_memcpy_aligned(void* dst, const void* src, size_t n) { mi_assert_internal(((uintptr_t)dst % MI_INTPTR_SIZE == 0) && ((uintptr_t)src % MI_INTPTR_SIZE == 0)); _mi_memcpy(dst, src, n); } static inline void _mi_memzero_aligned(void* dst, size_t n) { mi_assert_internal((uintptr_t)dst % MI_INTPTR_SIZE == 0); _mi_memzero(dst, n); } #endif #endif
Cancel