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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at */
#include "VolatileBuffer.h"
#include "mozilla/Assertions.h"
#include "mozilla/mozalloc.h"
int posix_memalign(void** memptr, size_t alignment, size_t size);
namespace mozilla {
: mMutex("VolatileBuffer"), mBuf(nullptr), mSize(0), mLockCount(0) {}
bool VolatileBuffer::Init(size_t aSize, size_t aAlignment) {
MOZ_ASSERT(!mSize && !mBuf, "Init called twice");
MOZ_ASSERT(!(aAlignment % sizeof(void*)),
"Alignment must be multiple of pointer size");
mSize = aSize;
#if defined(MOZ_MEMORY) || defined(HAVE_POSIX_MEMALIGN)
if (posix_memalign(&mBuf, aAlignment, aSize) != 0) {
return false;
# error "No memalign implementation found"
return !!mBuf;
VolatileBuffer::~VolatileBuffer() {
MOZ_ASSERT(mLockCount == 0, "Being destroyed with non-zero lock count?");
bool VolatileBuffer::Lock(void** aBuf) {
MutexAutoLock lock(mMutex);
MOZ_ASSERT(mBuf, "Attempting to lock an uninitialized VolatileBuffer");
*aBuf = mBuf;
return true;
void VolatileBuffer::Unlock() {
MutexAutoLock lock(mMutex);
MOZ_ASSERT(mLockCount >= 0, "VolatileBuffer unlocked too many times!");
bool VolatileBuffer::OnHeap() const { return true; }
size_t VolatileBuffer::HeapSizeOfExcludingThis(
MallocSizeOf aMallocSizeOf) const {
return aMallocSizeOf(mBuf);
size_t VolatileBuffer::NonHeapSizeOfExcludingThis() const { return 0; }
} // namespace mozilla