Problem about QTimer

[pawer]

I have several classes in my program, one of them is the main GUI and other is an XML-RPC (from XML-RPC for C/C++) class that have several methods. All thinks goes ok, but when I start the QTimer in the GUI class from the XMLRPC clas it says "QTimer can't be stop/started from other thread". If I put signals and slots does nothing. WTF?

cambiaTimer::cambiaTimer ( rssani_lite *rss, QObject *parent ) :  QObject ( parent ),rpc_ani ( rss )  {
	connect ( this,SIGNAL ( cambiarTimer ( int ) ), rss, SLOT ( cambiaTimer ( int ) ) );
}
 
void cambiaTimer::execute ( xmlrpc_c::paramList const& paramList,xmlrpc_c::value *   const  retvalP ) {
 
	emit cambiarTimer ( 1 );
	std::cerr << "RPC llamada" << std::endl;
	*retvalP = xmlrpc_c::value_int ( 0 ) ;
}

cambiaTimer::cambiaTimer ( rssani_lite *rss, QObject *parent ) :  QObject ( parent ),rpc_ani ( rss )  {
	connect ( this,SIGNAL ( cambiarTimer ( int ) ), rss, SLOT ( cambiaTimer ( int ) ) );
}

void cambiaTimer::execute ( xmlrpc_c::paramList const& paramList,xmlrpc_c::value *   const  retvalP ) {

	emit cambiarTimer ( 1 );
	std::cerr << "RPC llamada" << std::endl;
	*retvalP = xmlrpc_c::value_int ( 0 ) ;
}

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void rssani_lite::cambiaTimer(int tiempo) {
	qDebug() << "Timer cambiado a : " << tiempo << endl; 
	this->tiempo = tiempo;
	timer.start ( tiempo * 60 * 1000 );
}

void rssani_lite::cambiaTimer(int tiempo) {
	qDebug() << "Timer cambiado a : " << tiempo << endl; 
	this->tiempo = tiempo;
	timer.start ( tiempo * 60 * 1000 );
}

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class rssani_lite : public QObject {
	Q_OBJECT
 
public:
	rssani_lite ( QObject* parent = 0);
	~rssani_lite();
 
public slots:
	void cambiaTimer(int tiempo);
        ....
}

class rssani_lite : public QObject {
	Q_OBJECT

public:
	rssani_lite ( QObject* parent = 0);
	~rssani_lite();

public slots:
	void cambiaTimer(int tiempo);
        ....
}

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Thanks in advance.

[jpn]

Are you using QThread somewhere in your app?

[pawer]

No, I create 2 classes in main function:

int main ( int argc, char **argv ) {
	QCoreApplication app(argc, argv);
	.....	
	rssani_lite *rss = new rssani_lite();
	new rssxmlrpc(rss);
}

int main ( int argc, char **argv ) {
	QCoreApplication app(argc, argv);
	.....	
	rssani_lite *rss = new rssani_lite();
	new rssxmlrpc(rss);
}

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rssxmlrpc::	rssxmlrpc ( rssani_lite *rss ) {
        ....
	xmlrpc_c::methodPtr const cambiaTimerP ( new cambiaTimer ( rss ) );
        ....
	myRegistry.addMethod ( "rssani.cambiaTimer", cambiaTimerP );
 
	xmlrpc_c::serverAbyss myAbyssServer (
	  myRegistry,
	  8080,              // TCP port on which to listen
	  "/tmp/xmlrpc_log"  // Log file
	);
 
	myAbyssServer.run();
	assert ( false );
}

rssxmlrpc::	rssxmlrpc ( rssani_lite *rss ) {
        ....
	xmlrpc_c::methodPtr const cambiaTimerP ( new cambiaTimer ( rss ) );
        ....
	myRegistry.addMethod ( "rssani.cambiaTimer", cambiaTimerP );

	xmlrpc_c::serverAbyss myAbyssServer (
	  myRegistry,
	  8080,              // TCP port on which to listen
	  "/tmp/xmlrpc_log"  // Log file
	);

	myAbyssServer.run();
	assert ( false );
}

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[wysota]

Maybe one of these two classes:

rssani_lite *rss = new rssani_lite();
new rssxmlrpc(rss);

rssani_lite *rss = new rssani_lite();
new rssxmlrpc(rss);

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starts a new thread? The effect you observe suggests rssani_lite is the one. The timer object is a member of the rssani_lite class but it does not live in the thread spawned by that class.

[pawer]

$ ./rssani_lite
RPC llamada
Timer cambiado a :  1
 
QObject::killTimer: timers cannot be stopped from another thread
QObject::startTimer: timers cannot be started from another thread
QObject::killTimer: timers cannot be stopped from another thread
QObject::startTimer: timers cannot be started from another thread

$ ./rssani_lite
RPC llamada
Timer cambiado a :  1

QObject::killTimer: timers cannot be stopped from another thread
QObject::startTimer: timers cannot be started from another thread
QObject::killTimer: timers cannot be stopped from another thread
QObject::startTimer: timers cannot be started from another thread

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This is the output if I call the method directly. I don't know the signal behaviour, because the slot is not called.

Thanks for your answers.

[wysota]

Signals and slots have nothing to do with it. You just have to start the timer from within the proper thread.