From ca9b91886d763fed3bdc32530cd052ff0b7fef6b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Axel=20D=C3=B6rfler?= <axeld@pinc-software.de>
Date: Thu, 25 Jan 2007 17:08:16 +0000
Subject: [PATCH] * Added a Dano extension to BMessageQueue: IsNextMessage(). *
 BLooper::AddMessage() is now using this method to determine wether or not to 
  update its looper thread.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@19956 a95241bf-73f2-0310-859d-f6bbb57e9c96
---
 headers/os/app/MessageQueue.h |  3 ++-
 src/kits/app/Looper.cpp       | 15 ++++++++++-----
 src/kits/app/MessageQueue.cpp | 14 +++++++++++++-
 3 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/headers/os/app/MessageQueue.h b/headers/os/app/MessageQueue.h
index ef36ed3e72..eeea3eb23e 100644
--- a/headers/os/app/MessageQueue.h
+++ b/headers/os/app/MessageQueue.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2005, Haiku, Inc. All Rights Reserved.
+ * Copyright 2001-2007, Haiku, Inc. All Rights Reserved.
  * Distributed under the terms of the MIT License.
  */
 #ifndef	_MESSAGE_QUEUE_H
@@ -30,6 +30,7 @@ class BMessageQueue {
 		bool IsLocked() const;
 
 		BMessage *NextMessage();
+		bool IsNextMessage(const BMessage* message) const;
 
 	private:
 		// Reserved space in the vtable for future changes to BMessageQueue
diff --git a/src/kits/app/Looper.cpp b/src/kits/app/Looper.cpp
index b4bffb58cb..4012fe6f41 100644
--- a/src/kits/app/Looper.cpp
+++ b/src/kits/app/Looper.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2005, Haiku.
+ * Copyright 2001-2007, Haiku.
  * Distributed under the terms of the MIT License.
  *
  * Authors:
@@ -9,7 +9,7 @@
  *		Axel Dörfler, axeld@pinc-software.de
  */
 
-/**	BLooper class spawns a thread that runs a message loop. */
+/*!	BLooper class spawns a thread that runs a message loop. */
 
 /**
 	@note	Although I'm implementing "by the book" for now, I would like to
@@ -1076,11 +1076,16 @@ BLooper::InitData(const char *name, int32 priority, int32 portCapacity)
 
 
 void
-BLooper::AddMessage(BMessage* msg)
+BLooper::AddMessage(BMessage* message)
 {
-	_AddMessagePriv(msg);
+	_AddMessagePriv(message);
 
-	// ToDo: if called from a different thread, we need to wake up the looper
+	// wakeup looper when being called from other threads if necessary
+	if (find_thread(NULL) != Thread()
+		&& fQueue->IsNextMessage(message) && port_count(fMsgPort) <= 0) {
+		// there is currently no message waiting, and we need to wakeup the looper
+		write_port_etc(fMsgPort, 0, NULL, 0, B_RELATIVE_TIMEOUT, 0);
+	}
 }
 
 
diff --git a/src/kits/app/MessageQueue.cpp b/src/kits/app/MessageQueue.cpp
index 20cd219bc9..e9917adda8 100644
--- a/src/kits/app/MessageQueue.cpp
+++ b/src/kits/app/MessageQueue.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright 2001-2005, Haiku, Inc. All Rights Reserved.
+ * Copyright 2001-2007, Haiku, Inc. All Rights Reserved.
  * Distributed under the terms of the MIT License.
  *
  * Authors:
@@ -262,6 +262,18 @@ BMessageQueue::NextMessage()
 }
 
 
+/*!
+	\brief Checks wether or not the specified \a message is the message
+		you would get when calling NextMessage().
+*/
+bool
+BMessageQueue::IsNextMessage(const BMessage* message) const
+{
+	BAutolock _(fLock);
+	return fHead == message;
+}
+
+
 /*!
 	\brief This method is only here for R5 binary compatibility!
 		It should be dropped as soon as possible (it misses the const qualifier).