1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/layers/ipc/PLayer.ipdl Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,39 @@
1.4 +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
1.5 + * vim: sw=2 ts=8 et :
1.6 + */
1.7 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.8 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.9 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.10 +
1.11 +include protocol PLayerTransaction;
1.12 +
1.13 +namespace mozilla {
1.14 +namespace layers {
1.15 +
1.16 +/**
1.17 + * PLayer represents a layer shared across thread contexts.
1.18 + */
1.19 +
1.20 +async protocol PLayer {
1.21 + manager PLayerTransaction;
1.22 +
1.23 + /**
1.24 + * OWNERSHIP MODEL
1.25 + *
1.26 + * Roughly speaking, the child side "actually owns" a Layer. This
1.27 + * is because the parent side is the "shadow"; when the child
1.28 + * releases a Layer, the parent's shadow is no longer meaningful.
1.29 + *
1.30 + * To implement this model, the concrete PLayerParent keeps a
1.31 + * strong ref to its Layer, so the Layer's lifetime is bound to
1.32 + * the PLayerParent's. Then, when the Layer's refcount hits 0 on
1.33 + * the child side, we send __delete__() from the child to parent.
1.34 + * The parent then releases its Layer, which results in the Layer
1.35 + * being deleted "soon" (usually immediately).
1.36 + */
1.37 +parent:
1.38 + async __delete__();
1.39 +};
1.40 +
1.41 +} // layers
1.42 +} // mozilla
