Socket::select and SocketReactor improvements

Net/include/Poco/Net/Socket.h

@@ -1,7 +1,7 @@
 //
 // Socket.h
 //
-// $Id: //poco/svn/Net/include/Poco/Net/Socket.h#3 $
+// $Id: //poco/1.3/Net/include/Poco/Net/Socket.h#3 $
 //
 // Library: Net
 // Package: Sockets
@@ -129,6 +129,10 @@ public:
 		///   * readList contains those sockets ready for reading,
 		///   * writeList contains those sockets ready for writing,
 		///   * exceptList contains those sockets with a pending error.
+		///
+		/// If the total number of sockets passed in readList, writeList and
+		/// exceptList is zero, select() will return immediately and the
+		/// return value will be 0.
 
 	bool poll(const Poco::Timespan& timeout, int mode) const;
 		/// Determines the status of the socket, using a 

Net/include/Poco/Net/SocketNotification.h

@@ -1,7 +1,7 @@
 //
 // SocketNotification.h
 //
-// $Id: //poco/svn/Net/include/Poco/Net/SocketNotification.h#2 $
+// $Id: //poco/1.3/Net/include/Poco/Net/SocketNotification.h#2 $
 //
 // Library: Net
 // Package: Reactor
@@ -128,6 +128,19 @@ public:
 };
 
 
+class Net_API IdleNotification: public SocketNotification
+	/// This notification is sent when the SocketReactor does
+	/// not have any sockets to react to.
+{
+public:
+	IdleNotification(SocketReactor* pReactor);
+		/// Creates the IdleNotification for the given SocketReactor.
+
+	~IdleNotification();
+		/// Destroys the IdleNotification.
+};
+
+
 class Net_API ShutdownNotification: public SocketNotification
 	/// This notification is sent when the SocketReactor is
 	/// about to shut down.

Net/include/Poco/Net/SocketReactor.h

@@ -1,7 +1,7 @@
 //
 // SocketReactor.h
 //
-// $Id: //poco/svn/Net/include/Poco/Net/SocketReactor.h#2 $
+// $Id: //poco/1.3/Net/include/Poco/Net/SocketReactor.h#2 $
 //
 // Library: Net
 // Package: Reactor
@@ -90,7 +90,8 @@ class Net_API SocketReactor: public Poco::Runnable
 	/// If an event is detected, the corresponding event handler
 	/// is invoked. There are five event types (and corresponding
 	/// notification classes) defined: ReadableNotification, WritableNotification,
-	/// ErrorNotification, TimeoutNotification and ShutdownNotification.
+	/// ErrorNotification, TimeoutNotification, IdleNotification and 
+	/// ShutdownNotification.
 	/// 
 	/// The ReadableNotification will be dispatched if a socket becomes
 	/// readable. The WritableNotification will be dispatched if a socket
@@ -100,9 +101,17 @@ class Net_API SocketReactor: public Poco::Runnable
 	/// If the timeout expires and no event has occured, a
 	/// TimeoutNotification will be dispatched to all event handlers
 	/// registered for it. This is done in the onTimeout() method
-	/// which can be overridded by subclasses to perform custom
+	/// which can be overridden by subclasses to perform custom
 	/// timeout processing.
 	///
+	/// If there are no sockets for the SocketReactor to pass to
+	/// Socket::select(), an IdleNotification will be dispatched to
+	/// all event handlers registered for it. This is done in the
+	/// onIdle() method which can be overridden by subclasses
+	/// to perform custom idle processing. Since onIdle() will be
+	/// called repeatedly in a loop, it is recommended to do a
+	/// short sleep or yield in the event handler.
+	///
 	/// Finally, when the SocketReactor is about to shut down (as a result 
 	/// of stop() being called), it dispatches a ShutdownNotification
 	/// to all event handlers. This is done in the onShutdown() method
@@ -174,6 +183,13 @@ protected:
 		/// Can be overridden by subclasses. The default implementation
 		/// dispatches the TimeoutNotification and thus should be called by overriding
 		/// implementations.
+		
+	virtual void onIdle();
+		/// Called if no sockets are available to call select() on.
+		///
+		/// Can be overridden by subclasses. The default implementation
+		/// dispatches the IdleNotification and thus should be called by overriding
+		/// implementations.
 
 	virtual void onShutdown();
 		/// Called when the SocketReactor is about to terminate.
@@ -208,6 +224,7 @@ private:
 	NotificationPtr _pWritableNotification;
 	NotificationPtr _pErrorNotification;
 	NotificationPtr _pTimeoutNotification;
+	NotificationPtr _pIdleNotification;
 	NotificationPtr _pShutdownNotification;
 	Poco::FastMutex _mutex;
 	

Net/src/Socket.cpp

@@ -1,7 +1,7 @@
 //
 // Socket.cpp
 //
-// $Id: //poco/svn/Net/src/Socket.cpp#2 $
+// $Id: //poco/1.3/Net/src/Socket.cpp#4 $
 //
 // Library: Net
 // Package: Sockets
@@ -112,6 +112,7 @@ int Socket::select(SocketList& readList, SocketList& writeList, SocketList& exce
 			nfd = int(it->sockfd());
 		FD_SET(it->sockfd(), &fdExcept);
 	}
+	if (nfd == 0) return 0;
 	Poco::Timespan remainingTime(timeout);
 	int rc;
 	do

Net/src/SocketNotification.cpp

@@ -1,7 +1,7 @@
 //
 // SocketNotification.cpp
 //
-// $Id: //poco/svn/Net/src/SocketNotification.cpp#2 $
+// $Id: //poco/1.3/Net/src/SocketNotification.cpp#2 $
 //
 // Library: Net
 // Package: Reactor
@@ -102,6 +102,17 @@ TimeoutNotification::~TimeoutNotification()
 }
 
 
+IdleNotification::IdleNotification(SocketReactor* pReactor): 
+	SocketNotification(pReactor)
+{
+}
+
+
+IdleNotification::~IdleNotification()
+{
+}
+
+
 ShutdownNotification::ShutdownNotification(SocketReactor* pReactor): 
 	SocketNotification(pReactor)
 {

Net/src/SocketReactor.cpp

@@ -1,7 +1,7 @@
 //
 // SocketReactor.cpp
 //
-// $Id: //poco/svn/Net/src/SocketReactor.cpp#2 $
+// $Id: //poco/1.3/Net/src/SocketReactor.cpp#2 $
 //
 // Library: Net
 // Package: Reactor
@@ -38,6 +38,7 @@
 #include "Poco/Net/SocketNotification.h"
 #include "Poco/Net/SocketNotifier.h"
 #include "Poco/ErrorHandler.h"
+#include "Poco/Thread.h"
 #include "Poco/Exception.h"
 
 
@@ -57,6 +58,7 @@ SocketReactor::SocketReactor():
 	_pWritableNotification(new WritableNotification(this)),
 	_pErrorNotification(new ErrorNotification(this)),
 	_pTimeoutNotification(new TimeoutNotification(this)),
+	_pIdleNotification(new IdleNotification(this)),
 	_pShutdownNotification(new ShutdownNotification(this))
 {
 }
@@ -69,6 +71,7 @@ SocketReactor::SocketReactor(const Poco::Timespan& timeout):
 	_pWritableNotification(new WritableNotification(this)),
 	_pErrorNotification(new ErrorNotification(this)),
 	_pTimeoutNotification(new TimeoutNotification(this)),
+	_pIdleNotification(new IdleNotification(this)),
 	_pShutdownNotification(new ShutdownNotification(this))
 {
 }
@@ -87,31 +90,60 @@ void SocketReactor::run()
 	
 	while (!_stop)
 	{
-		readable.clear();
+		try
-		writable.clear();
-		except.clear();
 		{
-			FastMutex::ScopedLock lock(_mutex);
+			readable.clear();
-			for (EventHandlerMap::iterator it = _handlers.begin(); it != _handlers.end(); ++it)
+			writable.clear();
+			except.clear();
+			int nSockets = 0;
 			{
-				if (it->second->accepts(_pReadableNotification))
+				FastMutex::ScopedLock lock(_mutex);
-					readable.push_back(it->first);
+				for (EventHandlerMap::iterator it = _handlers.begin(); it != _handlers.end(); ++it)
-				if (it->second->accepts(_pWritableNotification))
+				{
-					writable.push_back(it->first);
+					if (it->second->accepts(_pReadableNotification))
-				if (it->second->accepts(_pErrorNotification))
+					{
-					except.push_back(it->first);
+						readable.push_back(it->first);
+						nSockets++;
+					}
+					if (it->second->accepts(_pWritableNotification))
+					{
+						writable.push_back(it->first);
+						nSockets++;
+					}
+					if (it->second->accepts(_pErrorNotification))
+					{
+						except.push_back(it->first);
+						nSockets++;
+					}
+				}
 			}
+			if (nSockets == 0)
+			{
+				onIdle();
+			}
+			else if (Socket::select(readable, writable, except, _timeout))
+			{
+				for (Socket::SocketList::iterator it = readable.begin(); it != readable.end(); ++it)
+					dispatch(*it, _pReadableNotification);
+				for (Socket::SocketList::iterator it = writable.begin(); it != writable.end(); ++it)
+					dispatch(*it, _pWritableNotification);
+				for (Socket::SocketList::iterator it = except.begin(); it != except.end(); ++it)
+					dispatch(*it, _pErrorNotification);
+			}
+			else onTimeout();
 		}
-		if (Socket::select(readable, writable, except, _timeout))
+		catch (Exception& exc)
 		{
-			for (Socket::SocketList::iterator it = readable.begin(); it != readable.end(); ++it)
+			ErrorHandler::handle(exc);
-				dispatch(*it, _pReadableNotification);
+		}
-			for (Socket::SocketList::iterator it = writable.begin(); it != writable.end(); ++it)
+		catch (std::exception& exc)
-				dispatch(*it, _pWritableNotification);
+		{
-			for (Socket::SocketList::iterator it = except.begin(); it != except.end(); ++it)
+			ErrorHandler::handle(exc);
-				dispatch(*it, _pErrorNotification);
+		}
+		catch (...)
+		{
+			ErrorHandler::handle();
 		}
-		else onTimeout();
 	}
 	onShutdown();
 }
@@ -172,6 +204,12 @@ void SocketReactor::onTimeout()
 }
 
 
+void SocketReactor::onIdle()
+{
+	dispatch(_pIdleNotification);
+}
+
+
 void SocketReactor::onShutdown()
 {
 	dispatch(_pShutdownNotification);

Net/testsuite/src/SocketTest.cpp

@@ -1,7 +1,7 @@
 //
 // SocketTest.cpp
 //
-// $Id: //poco/svn/Net/testsuite/src/SocketTest.cpp#2 $
+// $Id: //poco/1.3/Net/testsuite/src/SocketTest.cpp#2 $
 //
 // Copyright (c) 2005-2006, Applied Informatics Software Engineering GmbH.
 // and Contributors.
@@ -425,6 +425,18 @@ void SocketTest::testSelect2()
 }
 
 
+void SocketTest::testSelect3()
+{
+	Socket::SocketList readList;
+	Socket::SocketList writeList;
+	Socket::SocketList exceptList;
+	Timespan timeout(1000);
+
+	int rc = Socket::select(readList, writeList, exceptList, timeout);
+	assert (rc == 0);
+}
+
+
 void SocketTest::setUp()
 {
 }
@@ -452,6 +464,7 @@ CppUnit::Test* SocketTest::suite()
 	CppUnit_addTest(pSuite, SocketTest, testOptions);
 	CppUnit_addTest(pSuite, SocketTest, testSelect);
 	CppUnit_addTest(pSuite, SocketTest, testSelect2);
+	CppUnit_addTest(pSuite, SocketTest, testSelect3);
 
 	return pSuite;
 }

Net/testsuite/src/SocketTest.h

@@ -1,7 +1,7 @@
 //
 // SocketTest.h
 //
-// $Id: //poco/svn/Net/testsuite/src/SocketTest.h#2 $
+// $Id: //poco/1.3/Net/testsuite/src/SocketTest.h#2 $
 //
 // Definition of the SocketTest class.
 //
@@ -59,6 +59,7 @@ public:
 	void testOptions();
 	void testSelect();
 	void testSelect2();
+	void testSelect3();
 
 	void setUp();
 	void tearDown();