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

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 * 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 protocol PGrallocBuffer;
include protocol PImageContainer;

using ImageHandle;

namespace mozilla {
namespace layers {

/**
 * The PImageBridge protocol is used to allow isolated threads or processes to push
 * frames directly to the compositor thread/process without relying on the main thread
 * which might be too busy dealing with content script.
 */
/*FIXME: sync*/rpc protocol PImageBridge
{
  manages PImageContainer;
  manages PGrallocBuffer;

parent:

  // Allocates a gralloc buffer that may not suitable to use with
  // gfxImageSurface but allows hardware decoder to write to the
  // buffer directly. The format is a enum defined in
  // system/graphics.h and the usage is the GraphicBuffer usage
  // flag. See GraphicBuffer.h and gralloc.h.
  sync PGrallocBuffer(gfxIntSize size, uint32_t format, uint32_t usage)
    returns (MaybeMagicGrallocBufferHandle handle);
  
  // First step of the destruction sequence. This puts all the ImageContainerParents
  // in a state in which they can't send asynchronous messages to their child 
  // counterpart so as to not race with the upcomming __delete__ message. 
  // In the child side, the __delete__ messages are not sent right after Stop,
  // they are scheduled in the ImageBridgeChild's message queue in order to ensure 
  // that all the messages from the parent side have been received and processed
  // before sending __delete__.
  sync Stop();

  sync PImageContainer() returns (uint64_t id);
};


} // namespace
} // namespace