The Tor Browser: gfx/layers/ipc/PLayer.ipdl@97036ab72558

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

     1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-

     2  * vim: sw=2 ts=8 et :

     3  */

     4 /* This Source Code Form is subject to the terms of the Mozilla Public

     5  * License, v. 2.0. If a copy of the MPL was not distributed with this

     6  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     8 include protocol PLayerTransaction;

    10 namespace mozilla {

    11 namespace layers {

    13 /**

    14  * PLayer represents a layer shared across thread contexts.

    15  */

    17 async protocol PLayer {

    18     manager PLayerTransaction;

    20     /**

    21      * OWNERSHIP MODEL

    22      *

    23      * Roughly speaking, the child side "actually owns" a Layer.  This

    24      * is because the parent side is the "shadow"; when the child

    25      * releases a Layer, the parent's shadow is no longer meaningful.

    26      *

    27      * To implement this model, the concrete PLayerParent keeps a

    28      * strong ref to its Layer, so the Layer's lifetime is bound to

    29      * the PLayerParent's.  Then, when the Layer's refcount hits 0 on

    30      * the child side, we send __delete__() from the child to parent.

    31      * The parent then releases its Layer, which results in the Layer

    32      * being deleted "soon" (usually immediately).

    33      */

    34 parent:

    35     async __delete__();

    36 };

    38 } // layers

    39 } // mozilla

The Tor Browser / file revision

gfx/layers/ipc/PLayer.ipdl@97036ab72558

gfx/layers/ipc/PLayer.ipdl