gecko-dev/gfx/layers/ipc/PCompositor.ipdl

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * vim: sw=2 ts=8 et :
 */
/* 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 LayersSurfaces;
include LayersMessages;
include protocol PLayerTransaction;
include "mozilla/GfxMessageUtils.h";
include "nsRegion.h";

using struct mozilla::null_t from "ipc/IPCMessageUtils.h";
using struct mozilla::layers::TextureFactoryIdentifier from "mozilla/layers/CompositorTypes.h";
using struct mozilla::layers::FrameMetrics from "FrameMetrics.h";
using mozilla::layers::FrameMetrics::ViewID from "FrameMetrics.h";
using mozilla::layers::LayersBackend from "mozilla/layers/LayersTypes.h";
using mozilla::CrossProcessMutexHandle from "mozilla/ipc/CrossProcessMutex.h";
using mozilla::ipc::SharedMemoryBasic::Handle from "mozilla/ipc/SharedMemoryBasic.h";
using class mozilla::TimeStamp from "mozilla/TimeStamp.h";

namespace mozilla {
namespace layers {


/**
 * The PCompositor protocol is used to manage communication between
 * the main thread and the compositor thread context. It's primary
 * purpose is to manage the PLayerTransaction sub protocol.
 */
sync protocol PCompositor
{
  // A Compositor manages a single Layer Manager (PLayerTransaction)
  manages PLayerTransaction;

child:
  // The child should invalidate everything so that the whole window is redrawn.
  async InvalidateAll();

  // The compositor completed a layers transaction. id is the layers id
  // of the child layer tree that was composited (or 0 when notifying
  // the root layer tree).
  async DidComposite(uint64_t id, uint64_t transactionId);

  // The parent sends the child the requested fill ratio numbers.
  async Overfill(uint32_t aOverfill);

  /**
   * Parent informs the child that the graphics objects are ready for
   * compositing.  This usually means that the graphics objects (textures
   * and the like) are available on the GPU.  This is used for chrome UI.
   * @see RequestNotifyAfterRemotePaint
   * @see PBrowser
   */
  async RemotePaintIsReady();

  /**
   * Bounce plugin widget configurations over to the main thread for
   * application on the widgets. Used on Windows and Linux in managing
   * plugin widgets.
   */
  async UpdatePluginConfigurations(IntPoint aContentOffset,
                                   nsIntRegion aVisibleRegion,
                                   PluginWindowData[] aPlugins);

  /**
   * Sets the list of currently visible plugin windows based on a
   * list of plugin window ids.
   */
  async UpdatePluginVisibility(uintptr_t[] aVisibleIdList);

  /**
   * Drop any buffers that might be retained on the child compositor
   * side.
   */
  async ClearCachedResources(uint64_t id);

parent:
  // Child sends the parent a request for fill ratio numbers.
  async RequestOverfill();

  // The child is about to be destroyed, so perform any necessary cleanup.
  sync WillStop();

  // Clean up in preparation for own destruction.
  sync Stop();

  // Pause/resume the compositor. These are intended to be used on mobile, when
  // the compositor needs to pause/resume in lockstep with the application.
  sync Pause();
  sync Resume();

  // The child layer tree is hidden. id is the layers id of the child
  // layer tree.
  async NotifyHidden(uint64_t id);

  // The child layer tree is visible. id is the layers id of the child
  // layer tree.
  async NotifyVisible(uint64_t id);

  async NotifyChildCreated(uint64_t id);
  async AdoptChild(uint64_t id);

  // Make a snapshot of the content that would have been drawn to our
  // render target at the time this message is received.  If the size
  // or format of |inSnapshot| doesn't match our render target,
  // results are undefined.
  //
  // NB: this message will result in animations, transforms, effects,
  // and so forth being interpolated.  That's what we want to happen.
  sync MakeSnapshot(SurfaceDescriptor inSnapshot, IntRect dirtyRect);

  // Same as Makesnapshot(), except the snapshot is read from the underlying
  // operating system desktop rather than the compositor's backbuffer. This
  // is intended for testing whether hardware acceleration works.
  //
  // This call is part of IPDL, even though it simply wraps an nsIWidget
  // call, to make sure it does not occur in the middle of a composite.
  sync MakeWidgetSnapshot(SurfaceDescriptor inSnapshot);

  // Make sure any pending composites are started immediately and
  // block until they are completed.
  sync FlushRendering();

  // Get the size of the tiles. This number should not change at runtime.
  sync GetTileSize()
    returns (int32_t tileWidth, int32_t tileHeight);

  sync StartFrameTimeRecording(int32_t bufferSize)
    returns (uint32_t startIndex);

  sync StopFrameTimeRecording(uint32_t startIndex)
    returns (float[] intervals);

  // layersBackendHints is an ordered list of preffered backends where
  // layersBackendHints[0] is the best backend. If any hints are LayersBackend::LAYERS_NONE
  // that hint is ignored.
  sync PLayerTransaction(LayersBackend[] layersBackendHints, uint64_t id)
    returns (TextureFactoryIdentifier textureFactoryIdentifier, bool success);

  // Notify the compositor that a region of the screen has been invalidated.
  async NotifyRegionInvalidated(nsIntRegion region);

  /**
   * The child (content/chrome thread) requests that the parent inform it when
   * the graphics objects are ready to display.
   * @see PBrowser
   * @see RemotePaintIsReady
   */
  async RequestNotifyAfterRemotePaint();

child:
  // Send back Compositor Frame Metrics from APZCs so tiled layers can
  // update progressively.
  async SharedCompositorFrameMetrics(Handle metrics, CrossProcessMutexHandle mutex, uint64_t aLayersId, uint32_t aAPZCId);
  async ReleaseSharedCompositorFrameMetrics(ViewID aId, uint32_t aAPZCId);
};

} // layers
} // mozilla