Split the IPC code into ipc/

This splits the ipc code from the common project.  The 'common' project pulls in
all of webkit, the v8 bindings, skia, googleurl, and a number of other projects
which makes it very difficult to deal with especially for external projects
wanting just to use some of Chromium's infrastructure.  This puts the ipc code
into its top-level ipc/ directory with a dependency only on base.  The common
project depends on the new ipc/ipc.gyp:ipc target so that all projects currently
pulling common in to get the IPC code still have it available.  This mostly
follows agl's pre-gyp attempt to do this which was r13062.

Known issues:
- Currently a number of projects depend on chrome/chrome.gyp:common in order to
use the IPC infrastructure.  Rather than fixing all of these dependencies I have
made common depend on ipc/ipc.gyp:ipc and added "ipc" to the include_rules
section of DEPS so that checkdeps.py doesn't complain.  Over time projects that
need IPC should depend on the IPC project themselves and dependencies on common
removed, although I don't think many projects that need IPC will be able to get
away without common currently.
- ipc/ipc_message_macros.h still has #include "chrome/common/..." inside of a
ipc/ should not refer to files in chrome/... now.  I'm not sure how to resolve
this since it's really an IDE bug
- the named pipe name (windows+linux) and the logging event name (all) + env
variable (posix) refer explicitly to 'Chrome' which somewhat hurts the illusion
of ipc/ being an independent library.  I think this should be examined in a
subsequent, much smaller patch.
- I've eliminated the IPC.SendMsgCount counter since it was implemented in a way
to create a dependency from ipc/ to chrome/common/chrome_counters. This is the
same approach that r13062 took.

http://codereview.chromium.org/155905

(Patch from James Robinson)


git-svn-id: svn://svn.chromium.org/chrome/trunk/src@21342 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 162 insertions, 0 deletions

diff --git a/ipc/ipc_sync_channel.h b/ipc/ipc_sync_channel.h
new file mode 100644
index 0000000..f5d2add
--- /dev/null
+++ b/ipc/ipc_sync_channel.h
@@ -0,0 +1,162 @@
+// Copyright (c) 2006-2008 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 IPC_IPC_SYNC_SENDER_H__
+#define IPC_IPC_SYNC_SENDER_H__
+
+#include <string>
+#include <deque>
+
+#include "base/basictypes.h"
+#include "base/lock.h"
+#include "base/ref_counted.h"
+#include "base/waitable_event_watcher.h"
+#include "ipc/ipc_channel_proxy.h"
+
+namespace base {
+class WaitableEvent;
+};
+
+namespace IPC {
+
+class SyncMessage;
+class MessageReplyDeserializer;
+
+// This is similar to IPC::ChannelProxy, with the added feature of supporting
+// sending synchronous messages.
+// Note that care must be taken that the lifetime of the ipc_thread argument
+// is more than this object.  If the message loop goes away while this object
+// is running and it's used to send a message, then it will use the invalid
+// message loop pointer to proxy it to the ipc thread.
+class SyncChannel : public ChannelProxy,
+                    public base::WaitableEventWatcher::Delegate {
+ public:
+  SyncChannel(const std::string& channel_id, Channel::Mode mode,
+              Channel::Listener* listener, MessageFilter* filter,
+              MessageLoop* ipc_message_loop, bool create_pipe_now,
+              base::WaitableEvent* shutdown_event);
+  ~SyncChannel();
+
+  virtual bool Send(Message* message);
+  virtual bool SendWithTimeout(Message* message, int timeout_ms);
+
+  // Whether we allow sending messages with no time-out.
+  void set_sync_messages_with_no_timeout_allowed(bool value) {
+    sync_messages_with_no_timeout_allowed_ = value;
+  }
+
+ protected:
+  class ReceivedSyncMsgQueue;
+  friend class ReceivedSyncMsgQueue;
+
+  // SyncContext holds the per object data for SyncChannel, so that SyncChannel
+  // can be deleted while it's being used in a different thread.  See
+  // ChannelProxy::Context for more information.
+  class SyncContext : public Context,
+                      public base::WaitableEventWatcher::Delegate {
+   public:
+    SyncContext(Channel::Listener* listener,
+                MessageFilter* filter,
+                MessageLoop* ipc_thread,
+                base::WaitableEvent* shutdown_event);
+
+    ~SyncContext();
+
+    // Adds information about an outgoing sync message to the context so that
+    // we know how to deserialize the reply.
+    void Push(IPC::SyncMessage* sync_msg);
+
+    // Cleanly remove the top deserializer (and throw it away).  Returns the
+    // result of the Send call for that message.
+    bool Pop();
+
+    // Returns an event that's set when the send is complete, timed out or the
+    // process shut down.
+    base::WaitableEvent* GetSendDoneEvent();
+
+    // Returns an event that's set when an incoming message that's not the reply
+    // needs to get dispatched (by calling SyncContext::DispatchMessages).
+    base::WaitableEvent* GetDispatchEvent();
+
+    void DispatchMessages();
+
+    // Checks if the given message is blocking the listener thread because of a
+    // synchronous send.  If it is, the thread is unblocked and true is
+    // returned. Otherwise the function returns false.
+    bool TryToUnblockListener(const Message* msg);
+
+    // Called on the IPC thread when a sync send that runs a nested message loop
+    // times out.
+    void OnSendTimeout(int message_id);
+
+    base::WaitableEvent* shutdown_event() { return shutdown_event_; }
+
+   private:
+    // IPC::ChannelProxy methods that we override.
+
+    // Called on the listener thread.
+   virtual void Clear();
+
+    // Called on the IPC thread.
+    virtual void OnMessageReceived(const Message& msg);
+    virtual void OnChannelError();
+    virtual void OnChannelOpened();
+    virtual void OnChannelClosed();
+
+    // Cancels all pending Send calls.
+    void CancelPendingSends();
+
+    // WaitableEventWatcher::Delegate implementation.
+    virtual void OnWaitableEventSignaled(base::WaitableEvent* arg);
+
+    // When sending a synchronous message, this structure contains an object
+    // that knows how to deserialize the response.
+    struct PendingSyncMsg {
+      PendingSyncMsg(int id, IPC::MessageReplyDeserializer* d,
+                     base::WaitableEvent* e) :
+          id(id), deserializer(d), done_event(e), send_result(false) { }
+      int id;
+      IPC::MessageReplyDeserializer* deserializer;
+      base::WaitableEvent* done_event;
+      bool send_result;
+    };
+
+    typedef std::deque<PendingSyncMsg> PendingSyncMessageQueue;
+    PendingSyncMessageQueue deserializers_;
+    Lock deserializers_lock_;
+
+    scoped_refptr<ReceivedSyncMsgQueue> received_sync_msgs_;
+
+    base::WaitableEvent* shutdown_event_;
+    base::WaitableEventWatcher shutdown_watcher_;
+  };
+
+ private:
+  // WaitableEventWatcher::Delegate implementation.
+  virtual void OnWaitableEventSignaled(base::WaitableEvent* arg);
+
+  SyncContext* sync_context() {
+    return reinterpret_cast<SyncContext*>(context());
+  }
+
+  // Both these functions wait for a reply, timeout or process shutdown.  The
+  // latter one also runs a nested message loop in the meantime.
+  void WaitForReply(base::WaitableEvent* pump_messages_event);
+
+  // Runs a nested message loop until a reply arrives, times out, or the process
+  // shuts down.
+  void WaitForReplyWithNestedMessageLoop();
+
+  bool sync_messages_with_no_timeout_allowed_;
+
+  // Used to signal events between the IPC and listener threads.
+  base::WaitableEventWatcher send_done_watcher_;
+  base::WaitableEventWatcher dispatch_watcher_;
+
+  DISALLOW_EVIL_CONSTRUCTORS(SyncChannel);
+};
+
+}  // namespace IPC
+
+#endif  // IPC_IPC_SYNC_SENDER_H__