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