michael@0: /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0: /* vim: set sw=2 ts=8 et ft=cpp : */
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_PreallocatedProcessManager_h
michael@0: #define mozilla_PreallocatedProcessManager_h
michael@0: 
michael@0: #include "base/basictypes.h"
michael@0: #include "nsCOMPtr.h"
michael@0: #include "nsIObserver.h"
michael@0: 
michael@0: class nsIRunnable;
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace dom {
michael@0: class ContentParent;
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * This class manages a ContentParent that it starts up ahead of any particular
michael@0:  * need.  You can then call Take() to get this process and use it.  Since we
michael@0:  * already started it up, it should be ready for use faster than if you'd
michael@0:  * created the process when you needed it.
michael@0:  *
michael@0:  * This class watches the dom.ipc.processPrelaunch.enabled pref.  If it changes
michael@0:  * from false to true, it preallocates a process.  If it changes from true to
michael@0:  * false, it kills the preallocated process, if any.
michael@0:  *
michael@0:  * We don't expect this pref to flip between true and false in production, but
michael@0:  * flipping the pref is important for tests.
michael@0:  *
michael@0:  * The static methods here are implemented by forwarding calls on to a
michael@0:  * PreallocatedProcessManagerImpl singleton class, so if you add a new static
michael@0:  * method here, you'll need to write a corresponding public method on the
michael@0:  * singleton.
michael@0:  */
michael@0: class PreallocatedProcessManager MOZ_FINAL
michael@0: {
michael@0:   typedef mozilla::dom::ContentParent ContentParent;
michael@0: 
michael@0: public:
michael@0:   /**
michael@0:    * Create a process after a delay.  We wait for a period of time (specified
michael@0:    * by the dom.ipc.processPrelaunch.delayMs pref), then wait for this process
michael@0:    * to go idle, then allocate the new process.
michael@0:    *
michael@0:    * If the dom.ipc.processPrelaunch.enabled pref is false, or if we already
michael@0:    * have a preallocated process, this function does nothing.
michael@0:    */
michael@0:   static void AllocateAfterDelay();
michael@0: 
michael@0:   /**
michael@0:    * Create a process once this process goes idle.
michael@0:    *
michael@0:    * If the dom.ipc.processPrelaunch.enabled pref is false, or if we already
michael@0:    * have a preallocated process, this function does nothing.
michael@0:    */
michael@0:   static void AllocateOnIdle();
michael@0: 
michael@0:   /**
michael@0:    * Create a process right now.
michael@0:    *
michael@0:    * If the dom.ipc.processPrelaunch.enabled pref is false, or if we already
michael@0:    * have a preallocated process, this function does nothing.
michael@0:    */
michael@0:   static void AllocateNow();
michael@0: 
michael@0:   /**
michael@0:    * Take the preallocated process, if we have one.  If we don't have one, this
michael@0:    * returns null.
michael@0:    *
michael@0:    * If you call Take() twice in a row, the second call is guaranteed to return
michael@0:    * null.
michael@0:    *
michael@0:    * After you Take() the preallocated process, you need to call one of the
michael@0:    * Allocate* functions (or change the dom.ipc.processPrelaunch pref from
michael@0:    * false to true) before we'll create a new process.
michael@0:    */
michael@0:   static already_AddRefed<ContentParent> Take();
michael@0: 
michael@0: #ifdef MOZ_NUWA_PROCESS
michael@0:   static void PublishSpareProcess(ContentParent* aContent);
michael@0:   static void MaybeForgetSpare(ContentParent* aContent);
michael@0:   static void OnNuwaReady();
michael@0:   static bool PreallocatedProcessReady();
michael@0:   static void RunAfterPreallocatedProcessReady(nsIRunnable* aRunnable);
michael@0: #endif
michael@0: 
michael@0: private:
michael@0:   PreallocatedProcessManager();
michael@0:   DISALLOW_EVIL_CONSTRUCTORS(PreallocatedProcessManager);
michael@0: };
michael@0: 
michael@0: } // namespace mozilla
michael@0: 
michael@0: #endif // defined mozilla_PreallocatedProcessManager_h