michael@0: // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #ifndef CHROME_COMMON_CHILD_PROCESS_H__
michael@0: #define CHROME_COMMON_CHILD_PROCESS_H__
michael@0: 
michael@0: #include <string>
michael@0: #include <vector>
michael@0: #include "base/basictypes.h"
michael@0: #include "base/message_loop.h"
michael@0: #include "base/scoped_ptr.h"
michael@0: #include "base/waitable_event.h"
michael@0: 
michael@0: class ChildThread;
michael@0: 
michael@0: 
michael@0: // Base class for child processes of the browser process (i.e. renderer and
michael@0: // plugin host). This is a singleton object for each child process.
michael@0: class ChildProcess {
michael@0:  public:
michael@0:   // Child processes should have an object that derives from this class.  The
michael@0:   // constructor will return once ChildThread has started.
michael@0:   ChildProcess(ChildThread* child_thread);
michael@0:   virtual ~ChildProcess();
michael@0: 
michael@0:   // Getter for this process' main thread.
michael@0:   ChildThread* child_thread() { return child_thread_.get(); }
michael@0: 
michael@0:   // A global event object that is signalled when the main thread's message
michael@0:   // loop exits.  This gives background threads a way to observe the main
michael@0:   // thread shutting down.  This can be useful when a background thread is
michael@0:   // waiting for some information from the browser process.  If the browser
michael@0:   // process goes away prematurely, the background thread can at least notice
michael@0:   // the child processes's main thread exiting to determine that it should give
michael@0:   // up waiting.
michael@0:   // For example, see the renderer code used to implement
michael@0:   // webkit_glue::GetCookies.
michael@0:   base::WaitableEvent* GetShutDownEvent();
michael@0: 
michael@0:   // These are used for ref-counting the child process.  The process shuts
michael@0:   // itself down when the ref count reaches 0.
michael@0:   // For example, in the renderer process, generally each tab managed by this
michael@0:   // process will hold a reference to the process, and release when closed.
michael@0:   void AddRefProcess();
michael@0:   void ReleaseProcess();
michael@0: 
michael@0:   // Getter for the one ChildProcess object for this process.
michael@0:   static ChildProcess* current() { return child_process_; }
michael@0: 
michael@0:  private:
michael@0:   // NOTE: make sure that child_thread_ is listed before shutdown_event_, since
michael@0:   // it depends on it (indirectly through IPC::SyncChannel).
michael@0:   scoped_ptr<ChildThread> child_thread_;
michael@0: 
michael@0:   int ref_count_;
michael@0: 
michael@0:   // An event that will be signalled when we shutdown.
michael@0:   base::WaitableEvent shutdown_event_;
michael@0: 
michael@0:   // The singleton instance for this process.
michael@0:   static ChildProcess* child_process_;
michael@0: 
michael@0:   DISALLOW_EVIL_CONSTRUCTORS(ChildProcess);
michael@0: };
michael@0: 
michael@0: #endif  // CHROME_COMMON_CHILD_PROCESS_H__