shaka-packager/base/allocator/win_allocator.cc

74 lines
1.9 KiB
C++

// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// This is a simple allocator based on the windows heap.
extern "C" {
HANDLE win_heap;
bool win_heap_init(bool use_lfh) {
win_heap = HeapCreate(0, 0, 0);
if (win_heap == NULL)
return false;
if (use_lfh) {
ULONG enable_lfh = 2;
HeapSetInformation(win_heap, HeapCompatibilityInformation,
&enable_lfh, sizeof(enable_lfh));
// NOTE: Setting LFH may fail. Vista already has it enabled.
// And under the debugger, it won't use LFH. So we
// ignore any errors.
}
return true;
}
void* win_heap_malloc(size_t size) {
return HeapAlloc(win_heap, 0, size);
}
void win_heap_free(void* size) {
HeapFree(win_heap, 0, size);
}
void* win_heap_realloc(void* ptr, size_t size) {
if (!ptr)
return win_heap_malloc(size);
if (!size) {
win_heap_free(ptr);
return NULL;
}
return HeapReAlloc(win_heap, 0, ptr, size);
}
size_t win_heap_msize(void* ptr) {
return HeapSize(win_heap, 0, ptr);
}
void* win_heap_memalign(size_t alignment, size_t size) {
// Reserve enough space to ensure we can align and set aligned_ptr[-1] to the
// original allocation for use with win_heap_memalign_free() later.
size_t allocation_size = size + (alignment - 1) + sizeof(void*);
// Check for overflow. Alignment and size are checked in allocator_shim.
DCHECK_LT(size, allocation_size);
DCHECK_LT(alignment, allocation_size);
void* ptr = win_heap_malloc(allocation_size);
char* aligned_ptr = static_cast<char*>(ptr) + sizeof(void*);
aligned_ptr +=
alignment - reinterpret_cast<uintptr_t>(aligned_ptr) & (alignment - 1);
reinterpret_cast<void**>(aligned_ptr)[-1] = ptr;
return aligned_ptr;
}
void win_heap_memalign_free(void* ptr) {
if (ptr)
win_heap_free(static_cast<void**>(ptr)[-1]);
}
} // extern "C"