1 files changed, 99 insertions, 0 deletions
diff --git a/ipc/glue/BackgroundChild.h b/ipc/glue/BackgroundChild.h
new file mode 100644
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+++ b/ipc/glue/BackgroundChild.h
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+#ifndef mozilla_ipc_backgroundchild_h__
+#define mozilla_ipc_backgroundchild_h__
+
+#include "base/process.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/ipc/Transport.h"
+
+class nsIDOMBlob;
+class nsIIPCBackgroundChildCreateCallback;
+
+namespace mozilla {
+namespace dom {
+
+class BlobImpl;
+class ContentChild;
+class ContentParent;
+class PBlobChild;
+
+} // namespace dom
+
+namespace ipc {
+
+class PBackgroundChild;
+
+// This class allows access to the PBackground protocol. PBackground allows
+// communication between any thread (in the parent or a child process) and a
+// single background thread in the parent process. Each PBackgroundChild
+// instance is tied to the thread on which it is created and must not be shared
+// across threads. Each PBackgroundChild is unique and valid as long as its
+// designated thread lives.
+//
+// Creation of PBackground is asynchronous. GetForCurrentThread() will return
+// null until the sequence is complete. GetOrCreateForCurrentThread() will start
+// the creation sequence and will call back via the
+// nsIIPCBackgroundChildCreateCallback interface when completed. Thereafter
+// (assuming success) GetForCurrentThread() will return the same actor every
+// time. SynchronouslyCreateForCurrentThread() will spin the event loop until
+// the BackgroundChild until the creation sequence is complete.
+//
+// CloseForCurrentThread() will close the current PBackground actor.  Subsequent
+// calls to GetForCurrentThread will return null.  CloseForCurrentThread() may
+// only be called exactly once for each thread-specific actor.  Currently it is
+// illegal to call this before the PBackground actor has been created.
+//
+// The PBackgroundChild actor and all its sub-protocol actors will be
+// automatically destroyed when its designated thread completes.
+class BackgroundChild final
+{
+  friend class mozilla::dom::ContentChild;
+  friend class mozilla::dom::ContentParent;
+
+  typedef base::ProcessId ProcessId;
+  typedef mozilla::ipc::Transport Transport;
+
+public:
+  // See above.
+  static PBackgroundChild*
+  GetForCurrentThread();
+
+  // See above.
+  static bool
+  GetOrCreateForCurrentThread(nsIIPCBackgroundChildCreateCallback* aCallback);
+
+  // See above.
+  static PBackgroundChild*
+  SynchronouslyCreateForCurrentThread();
+
+  static mozilla::dom::PBlobChild*
+  GetOrCreateActorForBlob(PBackgroundChild* aBackgroundActor,
+                          nsIDOMBlob* aBlob);
+
+  static mozilla::dom::PBlobChild*
+  GetOrCreateActorForBlobImpl(PBackgroundChild* aBackgroundActor,
+                              mozilla::dom::BlobImpl* aBlobImpl);
+
+  // See above.
+  static void
+  CloseForCurrentThread();
+
+private:
+  // Only called by ContentChild or ContentParent.
+  static void
+  Startup();
+
+  // Only called by ContentChild.
+  static PBackgroundChild*
+  Alloc(Transport* aTransport, ProcessId aOtherProcess);
+};
+
+} // namespace ipc
+} // namespace mozilla
+
+#endif // mozilla_ipc_backgroundchild_h__