gecko/gfx/thebes/gfxReusableSurfaceWrapper.cpp

75 lines
2.0 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 "gfxReusableSurfaceWrapper.h"
#include "gfxImageSurface.h"
#include "pratom.h"
gfxReusableSurfaceWrapper::gfxReusableSurfaceWrapper(gfxImageSurface* aSurface)
: mSurface(aSurface)
, mFormat(aSurface->Format())
, mSurfaceData(aSurface->Data())
, mReadCount(0)
{
MOZ_COUNT_CTOR(gfxReusableSurfaceWrapper);
}
class DeleteImageOnMainThread : public nsRunnable {
public:
DeleteImageOnMainThread(gfxImageSurface *aImage)
: mImage(aImage)
{}
NS_IMETHOD Run()
{
return NS_OK;
}
private:
nsRefPtr<gfxImageSurface> mImage;
};
gfxReusableSurfaceWrapper::~gfxReusableSurfaceWrapper()
{
NS_ABORT_IF_FALSE(mReadCount == 0, "Should not be locked when released");
MOZ_COUNT_DTOR(gfxReusableSurfaceWrapper);
if (!NS_IsMainThread()) {
NS_DispatchToMainThread(new DeleteImageOnMainThread(mSurface));
}
}
void
gfxReusableSurfaceWrapper::ReadLock()
{
NS_CheckThreadSafe(_mOwningThread.GetThread(), "Only the owner thread can call ReadOnlyLock");
PR_ATOMIC_INCREMENT(&mReadCount);
}
void
gfxReusableSurfaceWrapper::ReadUnlock()
{
PR_ATOMIC_DECREMENT(&mReadCount);
NS_ABORT_IF_FALSE(mReadCount >= 0, "Should not be negative");
}
gfxReusableSurfaceWrapper*
gfxReusableSurfaceWrapper::GetWritable(gfxImageSurface** aSurface)
{
NS_CheckThreadSafe(_mOwningThread.GetThread(), "Only the owner thread can call GetWritable");
if (mReadCount == 0) {
*aSurface = mSurface;
return this;
}
// Something else is reading the surface, copy it
gfxImageSurface* copySurface = new gfxImageSurface(mSurface->GetSize(), mSurface->Format(), false);
copySurface->CopyFrom(mSurface);
*aSurface = copySurface;
// We need to create a new wrapper since this wrapper has a read only lock.
gfxReusableSurfaceWrapper* wrapper = new gfxReusableSurfaceWrapper(copySurface);
return wrapper;
}