gecko/gfx/layers/ipc/PImageContainer.ipdl

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/* -*- 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 PImageBridge;
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.
*
* PImageContainer is the sub protocol of PImageBridge that takes place on the
* ImageContainer level. There is basically one pair ImageContainerChild/Parent
* for each ImageContainer that uses the protocol. ImageContainerChild (content
* side) is responsible for sending images to the ImageContainerParent (compositor
* side) by using SendPublishImage. Once received on the content side, shared
* images are stored in a global map (see ImageContainerParent.cpp) accessible to
* the image layers. Once a shared image is not usefull to the compositor anymore,
* it is sent back to the child side (ReturnImage).
*/
sync protocol PImageContainer
{
manager PImageBridge;
manages PGrallocBuffer;
child:
// Give back the child thread/process ownership to a SharedImage
async ReturnImage(SharedImage image);
parent:
sync PGrallocBuffer(gfxIntSize size, gfxContentType content)
returns (MaybeMagicGrallocBufferHandle handle);
// Send a SharedImage to the compositor giving to the compositor ownership
// of the image.
async PublishImage(SharedImage image);
// Tells the parent side to dispose of its shared images (most likely because the
// video element is still alive but will not be displayed for a moment).
async Flush();
// After receiving this message, the ImageContainerParent will not return images
// back to the child side (to avoid a race between ReturnImage and __delete__)
sync Stop();
sync __delete__();
};
} // namespace
} // namespace