gecko-dev/gfx/thebes/gfxReusableSharedImageSurfaceWrapper.cpp

99 lines
3.0 KiB
C++

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