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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 */
#include <stdint.h> // for uint64_t
#include <map> // for map
#include <vector> // for vector
#include "mozilla/Assertions.h" // for MOZ_CRASH
#include "mozilla/DataMutex.h"
#include "mozilla/RefPtr.h" // for already_AddRefed, RefCounted
#include "mozilla/gfx/Types.h" // for SurfaceFormat
#include "mozilla/layers/CompositorTypes.h"
#include "mozilla/layers/LayersTypes.h" // for LayersBackend, TextureDumpMode
#include "mozilla/layers/TextureClient.h" // for TextureClient
#include "mozilla/webrender/WebRenderTypes.h" // for RenderRoot
#include "nsISupportsImpl.h" // for MOZ_COUNT_CTOR, etc
namespace mozilla {
namespace layers {
class CompositableClient;
class ImageBridgeChild;
class ImageContainer;
class CompositableForwarder;
class CompositableChild;
class TextureClientRecycleAllocator;
class ContentClientRemoteBuffer;
* CompositableClient manages the texture-specific logic for composite layers,
* independently of the layer. It is the content side of a CompositableClient/
* CompositableHost pair.
* CompositableClient's purpose is to send texture data to the compositor side
* along with any extra information about how the texture is to be composited.
* Things like opacity or transformation belong to layer and not compositable.
* Since Compositables are independent of layers it is possible to create one,
* connect it to the compositor side, and start sending images to it. This alone
* is arguably not very useful, but it means that as long as a shadow layer can
* do the proper magic to find a reference to the right CompositableHost on the
* Compositor side, a Compositable client can be used outside of the main
* shadow layer forwarder machinery that is used on the main thread.
* The first step is to create a Compositable client and call Connect().
* Connect() creates the underlying IPDL actor (see CompositableChild) and the
* corresponding CompositableHost on the other side.
* To do async texture transfer (like async-video), the CompositableClient
* should be created with a different CompositableForwarder (like
* ImageBridgeChild) and attachment is done with
* CompositableForwarder::AttachAsyncCompositable that takes an identifier
* instead of a CompositableChild, since the CompositableClient is not managed
* by this layer forwarder (the matching uses a global map on the compositor
* side, see CompositableMap in ImageBridgeParent.cpp)
* Subclasses: Painted layers use ContentClients, ImageLayers use ImageClients,
* Canvas layers use CanvasClients (but ImageHosts). We have a different
* subclass where we have a different way of interfacing with the textures - in
* terms of drawing into the compositable and/or passing its contents to the
* compostior.
class CompositableClient {
virtual ~CompositableClient();
explicit CompositableClient(CompositableForwarder* aForwarder,
TextureFlags aFlags = TextureFlags::NO_FLAGS);
virtual void Dump(std::stringstream& aStream, const char* aPrefix = "",
bool aDumpHtml = false,
TextureDumpMode aCompress = TextureDumpMode::Compress){};
virtual TextureInfo GetTextureInfo() const = 0;
LayersBackend GetCompositorBackendType() const;
already_AddRefed<TextureClient> CreateBufferTextureClient(
gfx::SurfaceFormat aFormat, gfx::IntSize aSize,
gfx::BackendType aMoz2dBackend = gfx::BackendType::NONE,
TextureFlags aFlags = TextureFlags::DEFAULT);
already_AddRefed<TextureClient> CreateTextureClientForDrawing(
gfx::SurfaceFormat aFormat, gfx::IntSize aSize, BackendSelector aSelector,
TextureFlags aTextureFlags,
TextureAllocationFlags aAllocFlags = ALLOC_DEFAULT);
already_AddRefed<TextureClient> CreateTextureClientFromSurface(
gfx::SourceSurface* aSurface, BackendSelector aSelector,
TextureFlags aTextureFlags,
TextureAllocationFlags aAllocFlags = ALLOC_DEFAULT);
* Establishes the connection with compositor side through IPDL
virtual bool Connect(ImageContainer* aImageContainer = nullptr);
void Destroy();
bool IsConnected() const;
CompositableForwarder* GetForwarder() const { return mForwarder; }
* This identifier is what lets us attach async compositables with a shadow
* layer. It is not used if the compositable is used with the regular shadow
* layer forwarder.
* If this returns empty, it means the compositable is not async (it is used
* on the main thread).
CompositableHandle GetAsyncHandle() const;
* Handle for IPDL communication.
CompositableHandle GetIPCHandle() const { return mHandle; }
* Tells the Compositor to create a TextureHost for this TextureClient.
virtual bool AddTextureClient(TextureClient* aClient);
* A hook for the when the Compositable is detached from it's layer.
virtual void OnDetach() {}
* Clear any resources that are not immediately necessary. This may be called
* in low-memory conditions.
virtual void ClearCachedResources();
* Shrink memory usage.
* Called when "memory-pressure" is observed.
virtual void HandleMemoryPressure();
* Should be called when deataching a TextureClient from a Compositable,
* because some platforms need to do some extra book keeping when this
* happens.
* See AutoRemoveTexture to automatically invoke this at the end of a scope.
virtual void RemoveTexture(TextureClient* aTexture);
void InitIPDL(const CompositableHandle& aHandle);
TextureFlags GetTextureFlags() const { return mTextureFlags; }
TextureClientRecycleAllocator* GetTextureClientRecycler();
bool HasTextureClientRecycler() {
auto lock = mTextureClientRecycler.Lock();
return !!(*lock);
static void DumpTextureClient(std::stringstream& aStream,
TextureClient* aTexture,
TextureDumpMode aCompress);
RefPtr<CompositableForwarder> mForwarder;
// Some layers may want to enforce some flags to all their textures
// (like disallowing tiling)
Atomic<TextureFlags> mTextureFlags;
DataMutex<RefPtr<TextureClientRecycleAllocator>> mTextureClientRecycler;
// Only ever accessed via mTextureClientRecycler's Lock
CompositableHandle mHandle;
bool mIsAsync;
friend class CompositableChild;
* Helper to call RemoveTexture at the end of a scope.
struct AutoRemoveTexture {
explicit AutoRemoveTexture(CompositableClient* aCompositable,
TextureClient* aTexture = nullptr)
: mTexture(aTexture), mCompositable(aCompositable) {}
RefPtr<TextureClient> mTexture;
CompositableClient* mCompositable;
} // namespace layers
} // namespace mozilla