michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
michael@0:  * You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef mozilla_ipc_backgroundchild_h__
michael@0: #define mozilla_ipc_backgroundchild_h__
michael@0: 
michael@0: #include "base/process.h"
michael@0: #include "mozilla/Attributes.h"
michael@0: #include "mozilla/ipc/Transport.h"
michael@0: 
michael@0: class nsIIPCBackgroundChildCreateCallback;
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace dom {
michael@0: 
michael@0: class ContentChild;
michael@0: class ContentParent;
michael@0: 
michael@0: } // namespace dom
michael@0: 
michael@0: namespace ipc {
michael@0: 
michael@0: class PBackgroundChild;
michael@0: 
michael@0: // This class allows access to the PBackground protocol. PBackground allows
michael@0: // communication between any thread (in the parent or a child process) and a
michael@0: // single background thread in the parent process. Each PBackgroundChild
michael@0: // instance is tied to the thread on which it is created and must not be shared
michael@0: // across threads. Each PBackgroundChild is unique and valid as long as its
michael@0: // designated thread lives.
michael@0: //
michael@0: // Creation of PBackground is asynchronous. GetForCurrentThread() will return
michael@0: // null until the sequence is complete. GetOrCreateForCurrentThread() will start
michael@0: // the creation sequence and will call back via the
michael@0: // nsIIPCBackgroundChildCreateCallback interface when completed. Thereafter
michael@0: // (assuming success) GetForCurrentThread() will return the same actor every
michael@0: // time.
michael@0: //
michael@0: // The PBackgroundChild actor and all its sub-protocol actors will be
michael@0: // automatically destroyed when its designated thread completes.
michael@0: class BackgroundChild MOZ_FINAL
michael@0: {
michael@0:   friend class mozilla::dom::ContentChild;
michael@0:   friend class mozilla::dom::ContentParent;
michael@0: 
michael@0:   typedef base::ProcessId ProcessId;
michael@0:   typedef mozilla::ipc::Transport Transport;
michael@0: 
michael@0: public:
michael@0:   // See above.
michael@0:   static PBackgroundChild*
michael@0:   GetForCurrentThread();
michael@0: 
michael@0:   // See above.
michael@0:   static bool
michael@0:   GetOrCreateForCurrentThread(nsIIPCBackgroundChildCreateCallback* aCallback);
michael@0: 
michael@0: private:
michael@0:   // Only called by ContentChild or ContentParent.
michael@0:   static void
michael@0:   Startup();
michael@0: 
michael@0:   // Only called by ContentChild.
michael@0:   static PBackgroundChild*
michael@0:   Alloc(Transport* aTransport, ProcessId aOtherProcess);
michael@0: };
michael@0: 
michael@0: } // namespace ipc
michael@0: } // namespace mozilla
michael@0: 
michael@0: #endif // mozilla_ipc_backgroundchild_h__