updated Signals package

git-svn-id: svn://ultimatepp.org/upp/trunk@588 f0d560ea-af0d-0410-9eb7-867de7ffcac7

bazaar/Signals/Signals.cpp

@@ -17,6 +17,8 @@ void _SignalHandler(int sig, siginfo_t *info, void *v)
 // constructor
 TSignals::TSignals()
 {
+	// not(yet) stored instance on file
+	StoredInstance = false;
 	
 } // END Constructor TSignals
 		
@@ -37,6 +39,11 @@ TSignals::~TSignals()
 	// empties the map
 	CallbackMap.Clear();
 	
+	// if process had stored instance on file, removes it
+	if(StoredInstance)
+		FileDelete(CreateLockName());
+	StoredInstance = false;
+	
 } // END Destructor class TSignals
 	
 ////////////////////////////////////////////////////////////////////////////////////
@@ -53,6 +60,17 @@ void TSignals::Dispatch(int sig, siginfo_t *info, void *v)
 	
 } // END TSignals::Dispatcher()
 		
+////////////////////////////////////////////////////////////////////////////////////
+// creates lock file name based on user name, app name and display
+String TSignals::CreateLockName(void)
+{
+	if(LockName == "")
+		LockName = "/tmp/" + Environment().Get("USER") + "_" + GetExeTitle() + "_" + Environment().Get("DISPLAY") + ".lck";
+	
+	return LockName;
+
+} // END TSignals::CreateLockName()
+
 ////////////////////////////////////////////////////////////////////////////////////
 // add a signal handler
 bool TSignals::Handle(int sig, Callback const &cb)
@@ -107,6 +125,76 @@ bool TSignals::Unhandle(int sig)
 	
 } // END TSignals::Unhandle()
 
+////////////////////////////////////////////////////////////////////////////////////
+// stores process info on filesystem
+// allowing other process to communicate with it
+bool TSignals::StoreInstance(void)
+{
+	// if already stored, does nothing
+	if(StoredInstance)
+		return true;
+	
+	// first, checks if another instance is running
+	// if yes returns false (can't store more than 1 instance)
+	if(IsOtherInstanceRunning())
+		return false;
+	
+	// creates lock file
+	FileOut f(CreateLockName());
+	
+	// stores current process id on lock file
+	f.PutLine(AsString(getpid()));
+	f.Close();
+	
+	// marks instance as already stored
+	StoredInstance = true;
+	
+	// all ok
+	return true;
+	
+} // END TSignals::StoreInstance()
+
+////////////////////////////////////////////////////////////////////////////////////
+// checks whether another instance of this process is running
+bool TSignals::IsOtherInstanceRunning(void)
+{
+	// if we stored THIS instance, no other is running
+	if(StoredInstance)
+		return false;
+	
+	// otherwise, check the lock file
+	if(FileExists(CreateLockName()))
+		return true;
+	return false;
+	
+} // END TSignals::IsOtherInstanceRunning()
+
+////////////////////////////////////////////////////////////////////////////////////
+// sends a signal to another process
+bool TSignals::Send(int sig, int procId)
+{
+	return (kill(procId, sig) == 0);
+	
+} // END TSignals::Send()
+
+////////////////////////////////////////////////////////////////////////////////////
+// sends a signal to another running instance of this app
+bool TSignals::Send(int sig)
+{
+	// if no other instance running, returns false
+	if(!IsOtherInstanceRunning())
+		return false;
+	
+	// gets pid of other instance
+	FileIn f(CreateLockName());
+	int pid = atoi(f.GetLine());
+	f.Close();
+	
+	// sends the signal to process
+	return Send(sig, pid); 
+	
+} // END TSignals::Send()
+
 ////////////////////////////////////////////////////////////////////////////////////
 // Global signals access
 TSignals &Signals(void)

bazaar/Signals/Signals.h

@@ -11,6 +11,11 @@ class TSignals
 	friend void ::_SignalHandler(int, siginfo_t *, void *);
 	
 	private:
+	
+		// flag indicating that the process instance has been stored on file
+		bool StoredInstance;
+		String LockName;
+		
 		// signal/handlers map
 		ArrayMap<int, Callback> CallbackMap;
 		
@@ -20,6 +25,9 @@ class TSignals
 		// dispatch signals
 		void Dispatch(int sig, siginfo_t *info, void *v);
 		
+		// creates lock file name based on user name, app name and display
+		String CreateLockName(void);
+		
 	public:
 
 		// distruttore
@@ -30,7 +38,20 @@ class TSignals
 
 		// removes a signal handler
 		bool Unhandle(int sig);
+		
+		// stores process info on filesystem
+		// allowing other process to communicate with it
+		bool StoreInstance(void);
+		
+		// checks whether another instance of this process is running
+		bool IsOtherInstanceRunning(void); 
 
+		// sends a signal to another process
+		bool Send(int sig, int procId);
+		
+		// sends a signal to another running instance of this app
+		bool Send(int sig);
+		
 }; // END Class TSignals
 
 ////////////////////////////////////////////////////////////////////////////////////

bazaar/Signals/src.tpp/TSignals$en-us.tpp

@@ -126,6 +126,13 @@ behaviour:&]
 :: [s0; [2 File size limit exceeded]]}}&]
 [s0; &]
 [s4;%- &]
+[s5;:Signals`(void`):%- [_^TSignals^ TSignals]_`&[* Signals]([@(0.0.255) void])&]
+[s2; &]
+[s2; Returns global TSignals object  Used to acceass all package 
+functions&]
+[s2; &]
+[s4;%- &]
+[s3;%- &]
 [s5;:TSignals`:`:Handle`(int`,Callback const`&`):%- [@(0.0.255) bool]_[* Handle]([@(0.0.255) i
 nt]_[*@3 sig], [_^Callback^ Callback]_[@(0.0.255) const]_`&[*@3 cb])&]
 [s0;%- &]
@@ -153,4 +160,44 @@ handle the signal&]
 [s2; Example usage:&]
 [s0; &]
 [s2; -|-|Signals().Unhandle(SIGHUP);&]
+[s4;%- &]
+[s5;:TSignals`:`:StoreInstance`(void`):%- [@(0.0.255) bool]_[* StoreInstance]([@(0.0.255) v
+oid])&]
+[s2; &]
+[s2; Stores current process info on file allowing check for other 
+instances&]
+[s3;%- &]
+[s6; [*/ Return value]-|boolean, true if the call succeeded&]
+[s0; &]
+[s2; Example usage:&]
+[s0; &]
+[s2; -|-|Signals().StoreInstance();&]
+[s4;%- &]
+[s5;:TSignals`:`:IsOtherInstanceRunning`(void`):%- [@(0.0.255) bool]_[* IsOtherInstanceRu
+nning]([@(0.0.255) void])&]
+[s2; &]
+[s2; Checks wether another instance of this app is already running&]
+[s3;%- &]
+[s6; [*/ Return value]-|boolean, true another instance is running&]
+[s0; &]
+[s2; Example usage:&]
+[s0; &]
+[s2; -|-|Signals().IsOtherInstanceRunning();&]
+[s3;%- &]
+[s4;%- &]
+[s5;:TSignals`:`:Send`(int`,int`):%- [@(0.0.255) bool]_[* Send]([@(0.0.255) int]_[*@3 sig], 
+[@(0.0.255) int]_[*@3 procId])&]
+[s2; &]
+[s2; Sends a signal to another process&]
+[s0; &]
+[s2;  [%-*@3 sig] ..................................Posix signal number&]
+[s2; [%-*@3  procId].............................Process id of target 
+process&]
+[s3; &]
+[s4;%- &]
+[s5;:TSignals`:`:Send`(int`):%- [@(0.0.255) bool]_[* Send]([@(0.0.255) int]_[*@3 sig])&]
+[s2; &]
+[s2; Sends a signal to another instance of this application&]
+[s0; &]
+[s2;  [%-*@3 sig] ..................................Posix signal number&]
 [s0; ]

bazaar/TestSignals/main.cpp

@@ -39,6 +39,20 @@ TestSignals::TestSignals()
 
 GUI_APP_MAIN
 {
+	// first checks if another app instance is running
+	if(Signals().IsOtherInstanceRunning())
+	{
+		// sends to other instance a SIGHUP signal
+		Signals().Send(SIGHUP);
+		
+		// prompt and exit
+		PromptOK("Another app instance is already running!!!");
+		return;
+	}
+	
+	// ok, no other instance, signals this one
+	Signals().StoreInstance();
+	
+	// runs the application
 	TestSignals().Run();
 }
-