ipc/glue/BackgroundChild.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
   5  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_ipc_backgroundchild_h__
   8 #define mozilla_ipc_backgroundchild_h__
   9
  10 #include "mozilla/Attributes.h"
  11 #include "mozilla/ipc/Transport.h"
  12
  13 class nsIEventTarget;
  14
  15 namespace mozilla {
  16 namespace dom {
  17
  18 class BlobImpl;
  19 class ContentChild;
  20 class ContentParent;
  21
  22 }  // namespace dom
  23
  24 namespace net {
  25
  26 class SocketProcessImpl;
  27 class SocketProcessChild;
  28
  29 }  // namespace net
  30
  31 namespace ipc {
  32
  33 class PBackgroundChild;
  34
  35 // This class allows access to the PBackground protocol. PBackground allows
  36 // communication between any thread (in the parent or a child process) and a
  37 // single background thread in the parent process. Each PBackgroundChild
  38 // instance is tied to the thread on which it is created and must not be shared
  39 // across threads. Each PBackgroundChild is unique and valid as long as its
  40 // designated thread lives.
  41 //
  42 // Creation of PBackground is synchronous. GetOrCreateForCurrentThread will
  43 // create the actor if it doesn't exist yet. Thereafter (assuming success)
  44 // GetForCurrentThread() will return the same actor every time.
  45 //
  46 // GetOrCreateSocketActorForCurrentThread, which is like
  47 // GetOrCreateForCurrentThread, is used to get or create PBackground actor
  48 // between child process and socket process.
  49 //
  50 // CloseForCurrentThread() will close the current PBackground actor.  Subsequent
  51 // calls to GetForCurrentThread will return null.  CloseForCurrentThread() may
  52 // only be called exactly once for each thread-specific actor.  Currently it is
  53 // illegal to call this before the PBackground actor has been created.
  54 //
  55 // The PBackgroundChild actor and all its sub-protocol actors will be
  56 // automatically destroyed when its designated thread completes.
  57 class BackgroundChild final {
  58   friend class mozilla::dom::ContentChild;
  59   friend class mozilla::dom::ContentParent;
  60   friend class mozilla::net::SocketProcessImpl;
  61   friend class mozilla::net::SocketProcessChild;
  62
  63   typedef mozilla::ipc::Transport Transport;
  64
  65  public:
  66   // See above.
  67   static PBackgroundChild* GetForCurrentThread();
  68
  69   // See above.
  70   static PBackgroundChild* GetOrCreateForCurrentThread(
  71       nsIEventTarget* aMainEventTarget = nullptr);
  72
  73   // See above.
  74   static void CloseForCurrentThread();
  75
  76   // See above.
  77   static PBackgroundChild* GetOrCreateSocketActorForCurrentThread(
  78       nsIEventTarget* aMainEventTarget = nullptr);
  79
  80   // See above.
  81   static PBackgroundChild* GetOrCreateForSocketParentBridgeForCurrentThread(
  82       nsIEventTarget* aMainEventTarget = nullptr);
  83
  84  private:
  85   // Only called by ContentChild or ContentParent.
  86   static void Startup();
  87 };
  88
  89 }  // namespace ipc
  90 }  // namespace mozilla
  91
  92 #endif  // mozilla_ipc_backgroundchild_h__