third_party/WebKit/Source/platform/graphics/AcceleratedStaticBitmapImage.h

// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef AcceleratedStaticBitmapImage_h
#define AcceleratedStaticBitmapImage_h

#include "base/threading/thread_checker.h"
#include "platform/geometry/IntSize.h"
#include "platform/graphics/StaticBitmapImage.h"
#include "third_party/skia/include/core/SkRefCnt.h"

#include <memory>

class GrContext;

namespace cc {
class SingleReleaseCallback;
}

namespace blink {
class WebThread;

class PLATFORM_EXPORT AcceleratedStaticBitmapImage final : public StaticBitmapImage {
public:
    // SkImage with a texture backing that is assumed to be from the shared context of the current thread.
    static PassRefPtr<AcceleratedStaticBitmapImage> createFromSharedContextImage(sk_sp<SkImage>);
    // Can specify the GrContext that created the texture backing the for the given SkImage. Ideally all callers would use this option.
    // The |mailbox| is a name for the texture backing the SkImage, allowing other contexts to use the same backing.
    static PassRefPtr<AcceleratedStaticBitmapImage> createFromWebGLContextImage(sk_sp<SkImage>, const gpu::Mailbox&, const gpu::SyncToken&);

    ~AcceleratedStaticBitmapImage() override;

    // StaticBitmapImage overrides.
    sk_sp<SkImage> imageForCurrentFrame() override;
    void copyToTexture(WebGraphicsContext3DProvider*, GLuint destTextureId, GLenum destInternalFormat, GLenum destType, bool flipY) override;

    // Image overrides.
    void draw(SkCanvas*, const SkPaint&, const FloatRect& dstRect, const FloatRect& srcRect, RespectImageOrientationEnum, ImageClampingMode) override;

    // To be called on sender thread before performing a transfer
    void transfer() final;

    void ensureMailbox() final;
    gpu::Mailbox getMailbox() final { return m_mailbox; }
    gpu::SyncToken getSyncToken() final { return m_syncToken; }

private:
    AcceleratedStaticBitmapImage(sk_sp<SkImage>);
    AcceleratedStaticBitmapImage(sk_sp<SkImage>, const gpu::Mailbox&, const gpu::SyncToken&);

    void createImageFromMailboxIfNeeded();
    void checkThread();
    void waitSyncTokenIfNeeded();
    bool isValid();
    void releaseImageThreadSafe();
    bool imageBelongsToSharedContext();

    // Id of the shared context where m_image was created
    unsigned m_sharedContextId;
    // True when the below mailbox and sync token are valid for getting at the texture backing the object's SkImage.
    bool m_hasMailbox = false;
    // A mailbox referring to the texture id backing the SkImage. The mailbox is valid as long as the SkImage is held alive.
    gpu::Mailbox m_mailbox;
    // This token must be waited for before using the mailbox.
    gpu::SyncToken m_syncToken;
    // Thread that m_image belongs to. Set to null when m_image belong to the same thread
    // as this AcceleratedStaticBitmapImage.  Should only be non-null after a transfer.
    WebThread* m_imageThread = nullptr;

    base::ThreadChecker m_threadChecker;
    bool m_detachThreadAtNextCheck = false;
};

} // namespace blink

#endif