Generalized signal handling. Now handling SIGHUP in addition

to SIGINT and SIGTERM.  Setup SIGHUP to reload the server's
configuration.

cmd/synergyc/synergyc.cpp

@@ -358,6 +358,13 @@ static
 int
 mainLoop()
 {
+	// create socket multiplexer.  this must happen after daemonization
+	// on unix because threads evaporate across a fork().
+	CSocketMultiplexer multiplexer;
+
+	// create the event queue
+	CEventQueue eventQueue;
+
 	// start the client.  if this return false then we've failed and
 	// we shouldn't retry.
 	LOG((CLOG_DEBUG1 "starting client"));
@@ -416,8 +423,6 @@ int
 run(int argc, char** argv, ILogOutputter* outputter, StartupFunc startup)
 {
 	// general initialization
-	CSocketMultiplexer multiplexer;
-	CEventQueue eventQueue;
 	ARG->m_serverAddress = new CNetworkAddress;
 	ARG->m_pname         = ARCH->getBasename(argv[0]);
 

cmd/synergys/synergys.cpp

@@ -68,6 +68,7 @@
 
 typedef int (*StartupFunc)(int, char**);
 static void parse(int argc, const char* const* argv);
+static bool loadConfig(const CString& pathname);
 static void loadConfig();
 
 //
@@ -83,7 +84,7 @@ public:
 		m_backend(false),
 		m_restartable(true),
 		m_daemon(true),
-		m_configFile(NULL),
+		m_configFile(),
 		m_logFilter(NULL)
 		{ s_instance = this; }
 	~CArgs() { s_instance = NULL; }
@@ -94,7 +95,7 @@ public:
 	bool				m_backend;
 	bool				m_restartable;
 	bool				m_daemon;
-	const char* 		m_configFile;
+	CString		 		m_configFile;
 	const char* 		m_logFilter;
 	CString 			m_name;
 	CNetworkAddress*	m_synergyAddress;
@@ -141,6 +142,7 @@ static CScreen*					s_serverScreen    = NULL;
 static CPrimaryClient*			s_primaryClient     = NULL;
 static CClientListener*			s_listener          = NULL;
 static CServerTaskBarReceiver*	s_taskBarReceiver   = NULL;
+static CEvent::Type				s_reloadConfigEvent = CEvent::kUnknown;
 
 static
 void
@@ -389,10 +391,38 @@ stopServer()
 	s_serverScreen  = NULL;
 }
 
+static
+void
+reloadSignalHandler(CArch::ESignal, void*)
+{
+	EVENTQUEUE->addEvent(CEvent(s_reloadConfigEvent,
+							IEventQueue::getSystemTarget()));
+}
+
+static
+void
+reloadConfig(const CEvent&, void*)
+{
+	LOG((CLOG_DEBUG "reload configuration"));
+	if (loadConfig(ARG->m_configFile)) {
+		if (s_server != NULL) {
+			s_server->setConfig(*ARG->m_config);
+		}
+		LOG((CLOG_NOTE "reloaded configuration"));
+	}
+}
+
 static
 int
 mainLoop()
 {
+	// create socket multiplexer.  this must happen after daemonization
+	// on unix because threads evaporate across a fork().
+	CSocketMultiplexer multiplexer;
+
+	// create the event queue
+	CEventQueue eventQueue;
+
 	// if configuration has no screens then add this system
 	// as the default
 	if (ARG->m_config->begin() == ARG->m_config->end()) {
@@ -423,6 +453,13 @@ mainLoop()
 		return kExitFailed;
 	}
 
+	// handle hangup signal by reloading the server's configuration
+	CEvent::registerTypeOnce(s_reloadConfigEvent, "reloadConfig");
+	ARCH->setSignalHandler(CArch::kHANGUP, &reloadSignalHandler, NULL);
+	EVENTQUEUE->adoptHandler(s_reloadConfigEvent,
+							IEventQueue::getSystemTarget(),
+							new CFunctionEventJob(&reloadConfig));
+
 	// run event loop.  if startServer() failed we're supposed to retry
 	// later.  the timer installed by startServer() will take care of
 	// that.
@@ -438,6 +475,8 @@ mainLoop()
 
 	// close down
 	LOG((CLOG_DEBUG1 "stopping server"));
+	EVENTQUEUE->removeHandler(s_reloadConfigEvent,
+							IEventQueue::getSystemTarget());
 	stopServer();
 	updateStatus();
 	LOG((CLOG_NOTE "stopped server"));
@@ -477,8 +516,6 @@ int
 run(int argc, char** argv, ILogOutputter* outputter, StartupFunc startup)
 {
 	// general initialization
-	CSocketMultiplexer multiplexer;
-	CEventQueue eventQueue;
 	ARG->m_synergyAddress = new CNetworkAddress;
 	ARG->m_config         = new CConfig;
 	ARG->m_pname          = ARCH->getBasename(argv[0]);
@@ -759,14 +796,12 @@ parse(int argc, const char* const* argv)
 
 static
 bool
-loadConfig(const char* pathname)
+loadConfig(const CString& pathname)
 {
-	assert(pathname != NULL);
-
 	try {
 		// load configuration
-		LOG((CLOG_DEBUG "opening configuration \"%s\"", pathname));
+		LOG((CLOG_DEBUG "opening configuration \"%s\"", pathname.c_str()));
-		std::ifstream configStream(pathname);
+		std::ifstream configStream(pathname.c_str());
 		if (!configStream) {
 			throw XConfigRead("cannot open file");
 		}
@@ -776,7 +811,7 @@ loadConfig(const char* pathname)
 	}
 	catch (XConfigRead& e) {
 		LOG((CLOG_DEBUG "cannot read configuration \"%s\": %s",
-								pathname, e.what()));
+								pathname.c_str(), e.what()));
 	}
 	return false;
 }
@@ -788,7 +823,7 @@ loadConfig()
 	bool loaded = false;
 
 	// load the config file, if specified
-	if (ARG->m_configFile != NULL) {
+	if (!ARG->m_configFile.empty()) {
 		loaded = loadConfig(ARG->m_configFile);
 	}
 
@@ -801,14 +836,20 @@ loadConfig()
 			path = ARCH->concatPath(path, USR_CONFIG_NAME);
 
 			// now try loading the user's configuration
-			loaded = loadConfig(path.c_str());
+			if (loadConfig(path)) {
+				loaded            = true;
+				ARG->m_configFile = path;
+			}
 		}
 		if (!loaded) {
 			// try the system-wide config file
 			path = ARCH->getSystemDirectory();
 			if (!path.empty()) {
 				path = ARCH->concatPath(path, SYS_CONFIG_NAME);
-				loaded = loadConfig(path.c_str());
+				if (loadConfig(path)) {
+					loaded            = true;
+					ARG->m_configFile = path;
+				}
 			}
 		}
 	}

lib/arch/CArch.cpp

@@ -376,15 +376,15 @@ CArch::getIDOfThread(CArchThread thread)
 }
 
 void
-CArch::setInterruptHandler(InterruptFunc func, void* userData)
+CArch::setSignalHandler(ESignal signal, SignalFunc func, void* userData)
 {
-	m_mt->setInterruptHandler(func, userData);
+	m_mt->setSignalHandler(signal, func, userData);
 }
 
 void
-CArch::interrupt()
+CArch::raiseSignal(ESignal signal)
 {
-	m_mt->interrupt();
+	m_mt->raiseSignal(signal);
 }
 
 CArchSocket

lib/arch/CArch.h

@@ -120,8 +120,8 @@ public:
 	virtual bool		isExitedThread(CArchThread);
 	virtual void*		getResultOfThread(CArchThread);
 	virtual ThreadID	getIDOfThread(CArchThread);
-	virtual void		setInterruptHandler(InterruptFunc, void*);
+	virtual void		setSignalHandler(ESignal, SignalFunc, void*);
-	virtual void		interrupt();
+	virtual void		raiseSignal(ESignal);
 
 	// IArchNetwork overrides
 	virtual CArchSocket	newSocket(EAddressFamily, ESocketType);

lib/arch/CArchConsoleWindows.cpp

@@ -108,9 +108,20 @@ CArchConsoleWindows::getNewlineForConsole()
 }
 
 BOOL WINAPI
-CArchConsoleWindows::signalHandler(DWORD)
+CArchConsoleWindows::signalHandler(DWORD ctrlType)
 {
 	// terminate app and skip remaining handlers
-	ARCH->interrupt();
+	switch (ctrlType) {
+	case CTRL_C_EVENT:
+		ARCH->raiseSignal(CArch::kINTERRUPT);
 		return TRUE;
+
+	case CTRL_BREAK_EVENT:
+		ARCH->raiseSignal(CArch::kTERMINATE);
+		return TRUE;
+
+	default:
+		ARCH->raiseSignal(CArch::kINTERRUPT);
+		return TRUE;
+	}
 }

lib/arch/CArchMultithreadPosix.cpp

@@ -41,6 +41,16 @@
 #	define HAVE_POSIX_SIGWAIT 1
 #endif
 
+static
+void
+setSignalSet(sigset_t* sigset)
+{
+	sigemptyset(sigset);
+	sigaddset(sigset, SIGHUP);
+	sigaddset(sigset, SIGINT);
+	sigaddset(sigset, SIGTERM);
+}
+
 //
 // CArchThreadImpl
 //
@@ -83,14 +93,18 @@ CArchMultithreadPosix*	CArchMultithreadPosix::s_instance = NULL;
 
 CArchMultithreadPosix::CArchMultithreadPosix() :
 	m_newThreadCalled(false),
-	m_nextID(0),
+	m_nextID(0)
-	m_signalFunc(NULL),
-	m_signalUserData(NULL)
 {
 	assert(s_instance == NULL);
 
 	s_instance = this;
 
+	// no signal handlers
+	for (size_t i = 0; i < kNUM_SIGNALS; ++i) {
+		m_signalFunc[i]     = NULL;
+		m_signalUserData[i] = NULL;
+	}
+
 	// create mutex for thread list
 	m_threadMutex = newMutex();
 
@@ -353,13 +367,6 @@ CArchMultithreadPosix::newThread(ThreadFunc func, void* data)
 	thread->m_func          = func;
 	thread->m_userData      = data;
 
-	// mask some signals in all threads except the main thread
-	sigset_t sigset, oldsigset;
-	sigemptyset(&sigset);
-	sigaddset(&sigset, SIGINT);
-	sigaddset(&sigset, SIGTERM);
-	pthread_sigmask(SIG_BLOCK, &sigset, &oldsigset);
-
 	// create the thread.  pthread_create() on RedHat 7.2 smp fails
 	// if passed a NULL attr so use a default attr.
 	pthread_attr_t attr;
@@ -370,9 +377,6 @@ CArchMultithreadPosix::newThread(ThreadFunc func, void* data)
 		pthread_attr_destroy(&attr);
 	}
 
-	// restore signals
-	pthread_sigmask(SIG_SETMASK, &oldsigset, NULL);
-
 	// check if thread was started
 	if (status != 0) {
 		// failed to start thread so clean up
@@ -560,23 +564,24 @@ CArchMultithreadPosix::getIDOfThread(CArchThread thread)
 }
 
 void
-CArchMultithreadPosix::setInterruptHandler(InterruptFunc func, void* userData)
+CArchMultithreadPosix::setSignalHandler(
+				ESignal signal, SignalFunc func, void* userData)
 {
 	lockMutex(m_threadMutex);
-	m_signalFunc     = func;
+	m_signalFunc[signal]     = func;
-	m_signalUserData = userData;
+	m_signalUserData[signal] = userData;
 	unlockMutex(m_threadMutex);
 }
 
 void
-CArchMultithreadPosix::interrupt() 
+CArchMultithreadPosix::raiseSignal(ESignal signal) 
 {
 	lockMutex(m_threadMutex);
-	if (m_signalFunc != NULL) {
+	if (m_signalFunc[signal] != NULL) {
-		m_signalFunc(m_signalUserData);
+		m_signalFunc[signal](signal, m_signalUserData[signal]);
 		unblockThread(m_mainThread);
 	}
-	else {
+	else if (signal == kINTERRUPT || signal == kTERMINATE) {
 		ARCH->cancelThread(m_mainThread);
 	}
 	unlockMutex(m_threadMutex);
@@ -587,11 +592,9 @@ CArchMultithreadPosix::startSignalHandler()
 {
 	// set signal mask.  the main thread blocks these signals and
 	// the signal handler thread will listen for them.
-	sigset_t sigset;
+	sigset_t sigset, oldsigset;
-	sigemptyset(&sigset);
+	setSignalSet(&sigset);
-	sigaddset(&sigset, SIGINT);
+	pthread_sigmask(SIG_BLOCK, &sigset, &oldsigset);
-	sigaddset(&sigset, SIGTERM);
-	pthread_sigmask(SIG_BLOCK, &sigset, NULL);
 
 	// fire up the INT and TERM signal handler thread.  we could
 	// instead arrange to catch and handle these signals but
@@ -608,10 +611,7 @@ CArchMultithreadPosix::startSignalHandler()
 	if (status != 0) {
 		// can't create thread to wait for signal so don't block
 		// the signals.
-		sigemptyset(&sigset);
+		pthread_sigmask(SIG_UNBLOCK, &oldsigset, NULL);
-		sigaddset(&sigset, SIGINT);
-		sigaddset(&sigset, SIGTERM);
-		pthread_sigmask(SIG_UNBLOCK, &sigset, NULL);
 	}
 }
 
@@ -766,9 +766,7 @@ CArchMultithreadPosix::threadSignalHandler(void*)
 
 	// add signal to mask
 	sigset_t sigset;
-	sigemptyset(&sigset);
+	setSignalSet(&sigset);
-	sigaddset(&sigset, SIGINT);
-	sigaddset(&sigset, SIGTERM);
 
 	// also wait on SIGABRT.  on linux (others?) this thread (process)
 	// will persist after all the other threads evaporate due to an
@@ -791,6 +789,22 @@ CArchMultithreadPosix::threadSignalHandler(void*)
 #endif
 
 		// if we get here then the signal was raised
-		ARCH->interrupt();
+		switch (signal) {
+		case SIGINT:
+			ARCH->raiseSignal(kINTERRUPT);
+			break;
+
+		case SIGTERM:
+			ARCH->raiseSignal(kTERMINATE);
+			break;
+
+		case SIGHUP:
+			ARCH->raiseSignal(kHANGUP);
+			break;
+
+		default:
+			// ignore
+			break;
+		}
 	}
 }

lib/arch/CArchMultithreadPosix.h

@@ -72,8 +72,8 @@ public:
 	virtual bool		isExitedThread(CArchThread);
 	virtual void*		getResultOfThread(CArchThread);
 	virtual ThreadID	getIDOfThread(CArchThread);
-	virtual void		setInterruptHandler(InterruptFunc, void*);
+	virtual void		setSignalHandler(ESignal, SignalFunc, void*);
-	virtual void		interrupt();
+	virtual void		raiseSignal(ESignal);
 
 private:
 	void				startSignalHandler();
@@ -104,8 +104,8 @@ private:
 	ThreadID			m_nextID;
 
 	pthread_t			m_signalThread;
-	InterruptFunc		m_signalFunc;
+	SignalFunc			m_signalFunc[kNUM_SIGNALS];
-	void*				m_signalUserData;
+	void*				m_signalUserData[kNUM_SIGNALS];
 };
 
 #endif

lib/arch/CArchMultithreadWindows.cpp

@@ -80,13 +80,17 @@ CArchThreadImpl::~CArchThreadImpl()
 
 CArchMultithreadWindows*	CArchMultithreadWindows::s_instance = NULL;
 
-CArchMultithreadWindows::CArchMultithreadWindows() :
+CArchMultithreadWindows::CArchMultithreadWindows()
-	m_signalFunc(NULL),
-	m_signalUserData(NULL)
 {
 	assert(s_instance == NULL);
 	s_instance = this;
 
+	// no signal handlers
+	for (size_t i = 0; i < kNUM_SIGNALS; ++i) {
+		m_signalFunc[i]     = NULL;
+		m_signalUserData[i] = NULL;
+	}
+
 	// create mutex for thread list
 	m_threadMutex = newMutex();
 
@@ -529,23 +533,24 @@ CArchMultithreadWindows::getIDOfThread(CArchThread thread)
 }
 
 void
-CArchMultithreadWindows::setInterruptHandler(InterruptFunc func, void* userData)
+CArchMultithreadWindows::setSignalHandler(
+				ESignal signal, SignalFunc func, void* userData)
 {
 	lockMutex(m_threadMutex);
-	m_signalFunc     = func;
+	m_signalFunc[signal]     = func;
-	m_signalUserData = userData;
+	m_signalUserData[signal] = userData;
 	unlockMutex(m_threadMutex);
 }
 
 void
-CArchMultithreadWindows::interrupt() 
+CArchMultithreadWindows::raiseSignal(ESignal signal)
 {
 	lockMutex(m_threadMutex);
-	if (m_signalFunc != NULL) {
+	if (m_signalFunc[signal] != NULL) {
-		m_signalFunc(m_signalUserData);
+		m_signalFunc[signal](signal, m_signalUserData[signal]);
 		ARCH->unblockPollSocket(m_mainThread);
 	}
-	else {
+	else if (signal == kINTERRUPT || signal == kTERMINATE) {
 		ARCH->cancelThread(m_mainThread);
 	}
 	unlockMutex(m_threadMutex);

lib/arch/CArchMultithreadWindows.h

@@ -81,8 +81,8 @@ public:
 	virtual bool		isExitedThread(CArchThread);
 	virtual void*		getResultOfThread(CArchThread);
 	virtual ThreadID	getIDOfThread(CArchThread);
-	virtual void		setInterruptHandler(InterruptFunc, void*);
+	virtual void		setSignalHandler(ESignal, SignalFunc, void*);
-	virtual void		interrupt();
+	virtual void		raiseSignal(ESignal);
 
 private:
 	CArchThreadImpl*	find(DWORD id);
@@ -107,8 +107,8 @@ private:
 	CThreadList			m_threadList;
 	CArchThread			m_mainThread;
 
-	InterruptFunc		m_signalFunc;
+	SignalFunc			m_signalFunc[kNUM_SIGNALS];
-	void*				m_signalUserData;
+	void*				m_signalUserData[kNUM_SIGNALS];
 };
 
 #endif

lib/arch/IArchMultithread.h

@@ -71,6 +71,19 @@ public:
 	typedef void* (*ThreadFunc)(void*);
 	//! Type of thread identifier
 	typedef unsigned int ThreadID;
+	//! Types of signals
+	/*!
+	Not all platforms support all signals.  Unsupported signals are
+	ignored.
+	*/
+	enum ESignal {
+		kINTERRUPT,		//!< Interrupt (e.g. Ctrl+C)
+		kTERMINATE,		//!< Terminate (e.g. Ctrl+Break)
+		kHANGUP,		//!< Hangup (SIGHUP)
+		kNUM_SIGNALS
+	};
+	//! Type of signal handler function
+	typedef void		(*SignalFunc)(ESignal, void* userData);
 
 	//! @name manipulators
 	//@{
@@ -242,12 +255,16 @@ public:
 	Sets the function to call on receipt of an external interrupt.
 	By default and when \p func is NULL, the main thread is cancelled.
 	*/
-	typedef void		(*InterruptFunc)(void*);
+	virtual void		setSignalHandler(ESignal, SignalFunc func,
-	virtual void		setInterruptHandler(InterruptFunc func,
 							void* userData) = 0;
 
-	//! Invoke the interrupt handler
+	//! Invoke the signal handler
-	virtual void		interrupt() = 0;
+	/*!
+	Invokes the signal handler for \p signal, if any.  If no handler
+	cancels the main thread for \c kINTERRUPT and \c kTERMINATE and
+	ignores the call otherwise.
+	*/
+	virtual void		raiseSignal(ESignal signal) = 0;
 
 	//@}
 };

lib/base/CEventQueue.cpp

@@ -1,4 +1,4 @@
-/*
+;/*
  * synergy -- mouse and keyboard sharing utility
  * Copyright (C) 2004 Chris Schoeneman
  * 
@@ -22,7 +22,7 @@
 // interrupt handler.  this just adds a quit event to the queue.
 static
 void
-interrupt(void*)
+interrupt(CArch::ESignal, void*)
 {
 	EVENTQUEUE->addEvent(CEvent(CEvent::kQuit));
 }
@@ -37,14 +37,16 @@ CEventQueue::CEventQueue() :
 {
 	setInstance(this);
 	m_mutex = ARCH->newMutex();
-	ARCH->setInterruptHandler(&interrupt, NULL);
+	ARCH->setSignalHandler(CArch::kINTERRUPT, &interrupt, NULL);
+	ARCH->setSignalHandler(CArch::kTERMINATE, &interrupt, NULL);
 	m_buffer = new CSimpleEventQueueBuffer;
 }
 
 CEventQueue::~CEventQueue()
 {
 	delete m_buffer;
-	ARCH->setInterruptHandler(NULL, NULL);
+	ARCH->setSignalHandler(CArch::kINTERRUPT, NULL, NULL);
+	ARCH->setSignalHandler(CArch::kTERMINATE, NULL, NULL);
 	ARCH->closeMutex(m_mutex);
 	setInstance(NULL);
 }