diff options
Diffstat (limited to 'src/os.c')
| -rw-r--r-- | src/os.c | 68 |
1 files changed, 32 insertions, 36 deletions
@@ -67,7 +67,8 @@ terms of the MIT license. A copy of the license can be found in the file On windows initializes support for aligned allocation and large OS pages (if MIMALLOC_LARGE_OS_PAGES is true). ----------------------------------------------------------- */ -bool _mi_os_decommit(void* addr, size_t size, mi_stats_t* stats); +bool _mi_os_decommit(void* addr, size_t size, mi_stats_t* stats); +bool _mi_os_commit(void* addr, size_t size, bool* is_zero, mi_stats_t* tld_stats); static void* mi_align_up_ptr(void* p, size_t alignment) { return (void*)_mi_align_up((uintptr_t)p, alignment); @@ -294,9 +295,23 @@ static bool mi_os_mem_free(void* addr, size_t size, bool was_committed, mi_stats if (addr == NULL || size == 0) return true; // || _mi_os_is_huge_reserved(addr) bool err = false; #if defined(_WIN32) + DWORD errcode = 0; err = (VirtualFree(addr, 0, MEM_RELEASE) == 0); - if (err) { - _mi_warning_message("unable to release OS memory: error code 0x%x, addr: %p, size: %zu\n", GetLastError(), addr, size); + if (err) { errcode = GetLastError(); } + if (errcode == ERROR_INVALID_ADDRESS) { + // In mi_os_mem_alloc_aligned the fallback path may have returned a pointer inside + // the memory region returned by VirtualAlloc; in that case we need to free using + // the start of the region. + MEMORY_BASIC_INFORMATION info = { 0, 0 }; + VirtualQuery(addr, &info, sizeof(info)); + if (info.AllocationBase < addr) { + errcode = 0; + err = (VirtualFree(info.AllocationBase, 0, MEM_RELEASE) == 0); + if (err) { errcode = GetLastError(); } + } + } + if (errcode != 0) { + _mi_warning_message("unable to release OS memory: error code 0x%x, addr: %p, size: %zu\n", errcode, addr, size); } #elif defined(MI_USE_SBRK) || defined(__wasi__) err = false; // sbrk heap cannot be shrunk @@ -728,46 +743,27 @@ static void* mi_os_mem_alloc_aligned(size_t size, size_t alignment, bool commit, // try first with a hint (this will be aligned directly on Win 10+ or BSD) void* p = mi_os_mem_alloc(size, alignment, commit, allow_large, is_large, stats); if (p == NULL) return NULL; - + // if not aligned, free it, overallocate, and unmap around it if (((uintptr_t)p % alignment != 0)) { - _mi_warning_message("unable to allocate aligned OS memory directly, fall back to over-allocation (%zu bytes, address: %p, commit: %d, is_large: %d)\n", size, p, commit, *is_large); mi_os_mem_free(p, size, commit, stats); + _mi_warning_message("unable to allocate aligned OS memory directly, fall back to over-allocation (%zu bytes, address: %p, commit: %d, is_large: %d)\n", size, p, commit, *is_large); if (size >= (SIZE_MAX - alignment)) return NULL; // overflow const size_t over_size = size + alignment; #if _WIN32 - // over-allocate and than re-allocate exactly at an aligned address in there. - // this may fail due to threads allocating at the same time so we - // retry this at most 3 times before giving up. - // (we can not decommit around the overallocation on Windows, because we can only - // free the original pointer, not one pointing inside the area) - int flags = MEM_RESERVE; - if (commit) flags |= MEM_COMMIT; - for (int tries = 0; tries < 3; tries++) { - // over-allocate to determine a virtual memory range - p = mi_os_mem_alloc(over_size, alignment, commit, false, is_large, stats); - if (p == NULL) return NULL; // error - if (((uintptr_t)p % alignment) == 0) { - // if p happens to be aligned, just decommit the left-over area - _mi_os_decommit((uint8_t*)p + size, over_size - size, stats); - break; - } - else { - // otherwise free and allocate at an aligned address in there - mi_os_mem_free(p, over_size, commit, stats); - void* aligned_p = mi_align_up_ptr(p, alignment); - p = mi_win_virtual_alloc(aligned_p, size, alignment, flags, false, allow_large, is_large); - if (p != NULL) { - _mi_stat_increase(&stats->reserved, size); - if (commit) { _mi_stat_increase(&stats->committed, size); } - } - if (p == aligned_p) break; // success! - if (p != NULL) { // should not happen? - mi_os_mem_free(p, size, commit, stats); - p = NULL; - } - } + // over-allocate uncommitted (virtual) memory + p = mi_os_mem_alloc(over_size, 0 /*alignment*/, false /* commit? */, false /* allow_large */, is_large, stats); + if (p == NULL) return NULL; + + // set p to the aligned part in the full region + // note: this is dangerous on Windows as VirtualFree needs the actual region pointer + // but in mi_os_mem_free we handle this (hopefully exceptional) situation. + p = mi_align_up_ptr(p, alignment); + + // explicitly commit only the aligned part + if (commit) { + _mi_os_commit(p, size, NULL, stats); } #else // overallocate... |