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 file,
michael@0:  * You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #include "gfxReusableSharedImageSurfaceWrapper.h"
michael@0: #include "gfxSharedImageSurface.h"
michael@0: #include "mozilla/layers/ISurfaceAllocator.h"
michael@0: 
michael@0: using mozilla::ipc::Shmem;
michael@0: using mozilla::layers::ISurfaceAllocator;
michael@0: 
michael@0: gfxReusableSharedImageSurfaceWrapper::gfxReusableSharedImageSurfaceWrapper(ISurfaceAllocator* aAllocator,
michael@0:                                                                            gfxSharedImageSurface* aSurface)
michael@0:   : mAllocator(aAllocator)
michael@0:   , mSurface(aSurface)
michael@0: {
michael@0:   MOZ_COUNT_CTOR(gfxReusableSharedImageSurfaceWrapper);
michael@0:   ReadLock();
michael@0: }
michael@0: 
michael@0: gfxReusableSharedImageSurfaceWrapper::~gfxReusableSharedImageSurfaceWrapper()
michael@0: {
michael@0:   MOZ_COUNT_DTOR(gfxReusableSharedImageSurfaceWrapper);
michael@0:   ReadUnlock();
michael@0: }
michael@0: 
michael@0: void
michael@0: gfxReusableSharedImageSurfaceWrapper::ReadLock()
michael@0: {
michael@0:   NS_ASSERT_OWNINGTHREAD(gfxReusableSharedImageSurfaceWrapper);
michael@0:   mSurface->ReadLock();
michael@0: }
michael@0: 
michael@0: void
michael@0: gfxReusableSharedImageSurfaceWrapper::ReadUnlock()
michael@0: {
michael@0:   int32_t readCount = mSurface->ReadUnlock();
michael@0:   NS_ABORT_IF_FALSE(readCount >= 0, "Read count should not be negative");
michael@0: 
michael@0:   if (readCount == 0) {
michael@0:     mAllocator->DeallocShmem(mSurface->GetShmem());
michael@0:   }
michael@0: }
michael@0: 
michael@0: gfxReusableSurfaceWrapper*
michael@0: gfxReusableSharedImageSurfaceWrapper::GetWritable(gfxImageSurface** aSurface)
michael@0: {
michael@0:   NS_ASSERT_OWNINGTHREAD(gfxReusableSharedImageSurfaceWrapper);
michael@0: 
michael@0:   int32_t readCount = mSurface->GetReadCount();
michael@0:   NS_ABORT_IF_FALSE(readCount > 0, "A ReadLock must be held when calling GetWritable");
michael@0:   if (readCount == 1) {
michael@0:     *aSurface = mSurface;
michael@0:     return this;
michael@0:   }
michael@0: 
michael@0:   // Something else is reading the surface, copy it
michael@0:   nsRefPtr<gfxSharedImageSurface> copySurface =
michael@0:     gfxSharedImageSurface::CreateUnsafe(mAllocator.get(), mSurface->GetSize(), mSurface->Format());
michael@0:   copySurface->CopyFrom(mSurface);
michael@0:   *aSurface = copySurface;
michael@0: 
michael@0:   // We need to create a new wrapper since this wrapper has an external ReadLock
michael@0:   gfxReusableSurfaceWrapper* wrapper = new gfxReusableSharedImageSurfaceWrapper(mAllocator, copySurface);
michael@0: 
michael@0:   // No need to release the ReadLock on the surface, this will happen when
michael@0:   // the wrapper is destroyed.
michael@0: 
michael@0:   return wrapper;
michael@0: }
michael@0: 
michael@0: const unsigned char*
michael@0: gfxReusableSharedImageSurfaceWrapper::GetReadOnlyData() const
michael@0: {
michael@0:   NS_ABORT_IF_FALSE(mSurface->GetReadCount() > 0, "Should have read lock");
michael@0:   return mSurface->Data();
michael@0: }
michael@0: 
michael@0: gfxImageFormat
michael@0: gfxReusableSharedImageSurfaceWrapper::Format()
michael@0: {
michael@0:   return mSurface->Format();
michael@0: }
michael@0: 
michael@0: Shmem&
michael@0: gfxReusableSharedImageSurfaceWrapper::GetShmem()
michael@0: {
michael@0:   return mSurface->GetShmem();
michael@0: }
michael@0: 
michael@0: /* static */ already_AddRefed<gfxReusableSharedImageSurfaceWrapper>
michael@0: gfxReusableSharedImageSurfaceWrapper::Open(ISurfaceAllocator* aAllocator, const Shmem& aShmem)
michael@0: {
michael@0:   nsRefPtr<gfxSharedImageSurface> sharedImage = gfxSharedImageSurface::Open(aShmem);
michael@0:   nsRefPtr<gfxReusableSharedImageSurfaceWrapper> wrapper = new gfxReusableSharedImageSurfaceWrapper(aAllocator, sharedImage);
michael@0:   wrapper->ReadUnlock();
michael@0:   return wrapper.forget();
michael@0: }