michael@0: // Copyright (c) 2009 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_HOST_H_
michael@0: #define CHROME_COMMON_CHILD_PROCESS_HOST_H_
michael@0: 
michael@0: #include "build/build_config.h"
michael@0: 
michael@0: #include <list>
michael@0: 
michael@0: #include "base/basictypes.h"
michael@0: #include "base/scoped_ptr.h"
michael@0: #include "base/waitable_event_watcher.h"
michael@0: #include "chrome/common/child_process_info.h"
michael@0: #include "chrome/common/ipc_channel.h"
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace ipc {
michael@0: class FileDescriptor;
michael@0: }
michael@0: }
michael@0: 
michael@0: class NotificationType;
michael@0: 
michael@0: // Plugins/workers and other child processes that live on the IO thread should
michael@0: // derive from this class.
michael@0: class ChildProcessHost :
michael@0:                          public IPC::Message::Sender,
michael@0:                          public ChildProcessInfo,
michael@0:                          public base::WaitableEventWatcher::Delegate,
michael@0:                          public IPC::Channel::Listener {
michael@0:  public:
michael@0:   virtual ~ChildProcessHost();
michael@0: 
michael@0:   // ResourceDispatcherHost::Receiver implementation:
michael@0:   virtual bool Send(IPC::Message* msg);
michael@0: 
michael@0:   // The Iterator class allows iteration through either all child processes, or
michael@0:   // ones of a specific type, depending on which constructor is used.  Note that
michael@0:   // this should be done from the IO thread and that the iterator should not be
michael@0:   // kept around as it may be invalidated on subsequent event processing in the
michael@0:   // event loop.
michael@0:   class Iterator {
michael@0:    public:
michael@0:     Iterator();
michael@0:     Iterator(ProcessType type);
michael@0:     ChildProcessHost* operator->() { return *iterator_; }
michael@0:     ChildProcessHost* operator*() { return *iterator_; }
michael@0:     ChildProcessHost* operator++();
michael@0:     bool Done();
michael@0: 
michael@0:    private:
michael@0:     bool all_;
michael@0:     ProcessType type_;
michael@0:     std::list<ChildProcessHost*>::iterator iterator_;
michael@0:   };
michael@0: 
michael@0:  protected:
michael@0:   explicit ChildProcessHost(ProcessType type);
michael@0: 
michael@0:   // Derived classes return true if it's ok to shut down the child process.
michael@0:   virtual bool CanShutdown() = 0;
michael@0: 
michael@0:   // Creates the IPC channel.  Returns true iff it succeeded.
michael@0:   bool CreateChannel();
michael@0: 
michael@0:   bool CreateChannel(mozilla::ipc::FileDescriptor& aFileDescriptor);
michael@0: 
michael@0:   // Once the subclass gets a handle to the process, it needs to tell
michael@0:   // ChildProcessHost using this function.
michael@0:   void SetHandle(base::ProcessHandle handle);
michael@0: 
michael@0:   // Notifies us that an instance has been created on this child process.
michael@0:   void InstanceCreated();
michael@0: 
michael@0:   // IPC::Channel::Listener implementation:
michael@0:   virtual void OnMessageReceived(const IPC::Message& msg) { }
michael@0:   virtual void OnChannelConnected(int32_t peer_pid) { }
michael@0:   virtual void OnChannelError() { }
michael@0: 
michael@0:   bool opening_channel() { return opening_channel_; }
michael@0:   const std::wstring& channel_id() { return channel_id_; }
michael@0: 
michael@0:   base::WaitableEvent* GetProcessEvent() { return process_event_.get(); }
michael@0: 
michael@0:   const IPC::Channel& channel() const { return *channel_; }
michael@0:   IPC::Channel* channelp() const { return channel_.get(); }
michael@0: 
michael@0:  private:
michael@0:   // Sends the given notification to the notification service on the UI thread.
michael@0:   void Notify(NotificationType type);
michael@0: 
michael@0:  protected:
michael@0:   // WaitableEventWatcher::Delegate implementation:
michael@0:   virtual void OnWaitableEventSignaled(base::WaitableEvent *event);
michael@0: 
michael@0:  private:
michael@0:   // By using an internal class as the IPC::Channel::Listener, we can intercept
michael@0:   // OnMessageReceived/OnChannelConnected and do our own processing before
michael@0:   // calling the subclass' implementation.
michael@0:   class ListenerHook : public IPC::Channel::Listener {
michael@0:    public:
michael@0:     ListenerHook(ChildProcessHost* host);
michael@0:     virtual void OnMessageReceived(const IPC::Message& msg);
michael@0:     virtual void OnChannelConnected(int32_t peer_pid);
michael@0:     virtual void OnChannelError();
michael@0:     virtual void GetQueuedMessages(std::queue<IPC::Message>& queue);
michael@0:    private:
michael@0:     ChildProcessHost* host_;
michael@0:   };
michael@0: 
michael@0:   ListenerHook listener_;
michael@0: 
michael@0:   // True while we're waiting the channel to be opened.
michael@0:   bool opening_channel_;
michael@0: 
michael@0:   // The IPC::Channel.
michael@0:   scoped_ptr<IPC::Channel> channel_;
michael@0: 
michael@0:   // IPC Channel's id.
michael@0:   std::wstring channel_id_;
michael@0: 
michael@0:   // Used to watch the child process handle.
michael@0:   base::WaitableEventWatcher watcher_;
michael@0: 
michael@0:   scoped_ptr<base::WaitableEvent> process_event_;
michael@0: };
michael@0: 
michael@0: #endif  // CHROME_COMMON_CHILD_PROCESS_HOST_H_