Moved common parts of ChildProcessHost into chrome/common and created a Brows...

chrome/common/child_process_host.h

-// Copyright (c) 2009 The Chromium Authors. All rights reserved.
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROME_BROWSER_CHILD_PROCESS_HOST_H_
-#define CHROME_BROWSER_CHILD_PROCESS_HOST_H_
+#ifndef CHROME_COMMON_CHILD_PROCESS_HOST_H_
+#define CHROME_COMMON_CHILD_PROCESS_HOST_H_
 
 #include <list>
 #include <string>
 
 // Must be included early (e.g. before chrome/common/plugin_messages.h)
 #include "ipc/ipc_logging.h"
 
 #include "base/basictypes.h"
+#include "base/file_path.h"
 #include "base/scoped_ptr.h"
-#include "chrome/browser/child_process_launcher.h"
-#include "chrome/browser/renderer_host/resource_dispatcher_host.h"
+#include "chrome/common/notification_type.h"
 #include "ipc/ipc_channel.h"
 
 class CommandLine;
-class NotificationType;
 
-// Plugins/workers and other child processes that live on the IO thread should
-// derive from this class.
+// Provides common functionality for hosting a child process and processing IPC
+// messages between the host and the child process. Subclasses are responsible
+// for the actual launching and terminating of the child processes.
 //
-// [Browser]RenderProcessHost is the main exception that doesn't derive from
-// this class. That project lives on the UI thread.
-class ChildProcessHost : public ResourceDispatcherHost::Receiver,
-                         public IPC::Channel::Listener,
-                         public ChildProcessLauncher::Client {
+class ChildProcessHost : public IPC::Channel::Listener {
  public:
   virtual ~ChildProcessHost();
 
   // Returns the pathname to be used for a child process.  If a subprocess
   // pathname was specified on the command line, that will be used.  Otherwise,
   // the default child process pathname will be returned.  On most platforms,
   // this will be the same as the currently-executing process.
   //
   // The argument allow_self is used on Linux to indicate that we allow us to
   // fork from /proc/self/exe rather than using the "real" app path. This
   // prevents autoupdate from confusing us if it changes the file out from
   // under us. You will generally want to set this to true, except when there
   // is an override to the command line (for example, we're forking a renderer
   // in gdb). In this case, you'd use GetChildPath to get the real executable
   // file name, and then prepend the GDB command to the command line.
   //
   // On failure, returns an empty FilePath.
   static FilePath GetChildPath(bool allow_self);
 
-  // Prepares command_line for crash reporting as appropriate.  On Linux and
-  // Mac, a command-line flag to enable crash reporting in the child process
-  // will be appended if needed, because the child process may not have access
-  // to the data that determines the status of crash reporting in the
-  // currently-executing process.  This function is a no-op on Windows.
-  static void SetCrashReporterCommandLine(CommandLine* command_line);
+ protected:
+  ChildProcessHost();
 
-  // Terminates all child processes and deletes each ChildProcessHost instance.
-  static void TerminateAll();
-
-  // ResourceDispatcherHost::Receiver implementation:
-  virtual bool Send(IPC::Message* msg);
-
-  // The Iterator class allows iteration through either all child processes, or
-  // ones of a specific type, depending on which constructor is used.  Note that
-  // this should be done from the IO thread and that the iterator should not be
-  // kept around as it may be invalidated on subsequent event processing in the
-  // event loop.
-  class Iterator {
-   public:
-    Iterator();
-    explicit Iterator(ProcessType type);
-    ChildProcessHost* operator->() { return *iterator_; }
-    ChildProcessHost* operator*() { return *iterator_; }
-    ChildProcessHost* operator++();
-    bool Done();
-
-   private:
-    bool all_;
-    ProcessType type_;
-    std::list<ChildProcessHost*>::iterator iterator_;
-  };
-
- protected:
-  // The resource_dispatcher_host may be NULL to indicate none is needed for
-  // this process type.
-  ChildProcessHost(ProcessType type,
-                   ResourceDispatcherHost* resource_dispatcher_host);
-
-  // Derived classes call this to launch the child process asynchronously.
-  void Launch(
-#if defined(OS_WIN)
-      const FilePath& exposed_dir,
-#elif defined(OS_POSIX)
-      bool use_zygote,
-      const base::environment_vector& environ,
-#endif
-      CommandLine* cmd_line);
+  // A helper method to send an IPC message to the child on the channel.
+  // It behavies just like IPC::Message::Sender::Send. The implementor takes
+  // ownership of the given Message regardless of whether or not this method
+  // succeeds. This class does not implement IPC::Message::Sender to prevent
+  // conflicts with subclasses which indirectly could inherit from
+  // IPC::Message::Sender.
+  bool SendOnChannel(IPC::Message* msg);
 
   // Derived classes return true if it's ok to shut down the child process.
   virtual bool CanShutdown() = 0;
 
-  // Send the shutdown message to the child process, and remove this host from
-  // the host list. Does not check if CanShutdown is true.
-  void ForceShutdown();
+  // Send the shutdown message to the child process.
+  // Does not check if CanShutdown is true.
+  virtual void ForceShutdown();
 
   // Creates the IPC channel.  Returns true iff it succeeded.
-  bool CreateChannel();
+  virtual bool CreateChannel();
 
   // Notifies us that an instance has been created on this child process.
-  void InstanceCreated();
+  virtual void InstanceCreated();
 
   // IPC::Channel::Listener implementation:
   virtual void OnMessageReceived(const IPC::Message& msg) { }
   virtual void OnChannelConnected(int32 peer_pid) { }
   virtual void OnChannelError() { }
 
-  // ChildProcessLauncher::Client implementation.
-  virtual void OnProcessLaunched() {}
-
-  // Derived classes can override this to know if the process crashed.
-  virtual void OnProcessCrashed() {}
-
   bool opening_channel() { return opening_channel_; }
   const std::string& channel_id() { return channel_id_; }
-
-  virtual bool DidChildCrash();
+  IPC::Channel* channel() { return channel_.get(); }
 
   // Called when the child process goes away.
   virtual void OnChildDied();
+  // Allows the derived implementation to intercept a message before it is
+  // handed to the IPC::Channel::Listener::OnMessageReceived implementation.
+  virtual bool InterceptMessageFromChild(const IPC::Message& msg) {
+    return false;
+  }
+  // Subclasses can implement specific notification methods.
+  virtual void Notify(NotificationType type) { }
 
  private:
-  // Sends the given notification to the notification service on the UI thread.
-  void Notify(NotificationType type);
-
   // By using an internal class as the IPC::Channel::Listener, we can intercept
   // OnMessageReceived/OnChannelConnected and do our own processing before
   // calling the subclass' implementation.
-  class ListenerHook : public IPC::Channel::Listener,
-                       public ChildProcessLauncher::Client {
+  class ListenerHook : public IPC::Channel::Listener {
    public:
     explicit ListenerHook(ChildProcessHost* host);
     virtual void OnMessageReceived(const IPC::Message& msg);
     virtual void OnChannelConnected(int32 peer_pid);
     virtual void OnChannelError();
-    virtual void OnProcessLaunched();
    private:
     ChildProcessHost* host_;
   };
 
   ListenerHook listener_;
 
-  // May be NULL if this current process has no resource dispatcher host.
-  ResourceDispatcherHost* resource_dispatcher_host_;
-
   bool opening_channel_;  // True while we're waiting the channel to be opened.
   scoped_ptr<IPC::Channel> channel_;
   std::string channel_id_;
-  scoped_ptr<ChildProcessLauncher> child_process_;
 };
 
-#endif  // CHROME_BROWSER_CHILD_PROCESS_HOST_H_
+#endif  // CHROME_COMMON_CHILD_PROCESS_HOST_H_
+