Multithreading

[havij000]

if I want to inform one thread from another thread how should I do it?
Can I call the run function of the thread that I want to call from the thread that the process is being run in it?

[karankumar1609]

run() method of QThread will automatically called whenever "start()" method of QThread called.

void Dialog::on_pushButton_Start_clicked()
    {
    //Started
 
 
    if(rThread->Stop == true)
    rThread->Stop = false;
 
    rThread->start(QThread::HighPriority);
 
 
 
    //My_Initializer();
 
    if(rcvThread->Stop == true)
    rcvThread->Stop = false;
 
    // data_child should passed before starting of thread
    rcvThread->setChildData(data_child); 
    rcvThread->start(QThread::HighestPriority);
    // rcvThread->run(data_child);
 
 
 
 
 
    if(prcsThread->Stop == true)
    prcsThread->Stop = false;
 
    // data_child should passed before starting of thread
    prcsThread->setChildData(data_child);
    prcsThread->start(QThread::HighPriority);
    // prcsThread->run(data_child);
 
 
    }

void Dialog::on_pushButton_Start_clicked()
    {
    //Started
     
     
    if(rThread->Stop == true)
    rThread->Stop = false;
     
    rThread->start(QThread::HighPriority);
     
     
     
    //My_Initializer();
     
    if(rcvThread->Stop == true)
    rcvThread->Stop = false;
    
    // data_child should passed before starting of thread
    rcvThread->setChildData(data_child); 
    rcvThread->start(QThread::HighestPriority);
    // rcvThread->run(data_child);
     
     
     
     
     
    if(prcsThread->Stop == true)
    prcsThread->Stop = false;
    
    // data_child should passed before starting of thread
    prcsThread->setChildData(data_child);
    prcsThread->start(QThread::HighPriority);
    // prcsThread->run(data_child);
     
     
    }

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Hope this will help you

[anda_skoa]

if I want to inform one thread from another thread how should I do it?

Wel, in Qt the easiest way of course is signal/slots, assuming the receiver thread is running its event loop.

Aside from that you can use all object communication options that C++ offers, like calling a method on the other object, etc.

Cheers,
_

[havij000]

Dear buddy,

Thanks for your response.
I have already 5 thread which consist the main thread (or the ui thread).
I want all threads that I have work concurrently and continously giving data from ui and do their tasks without stop until I push the stop button.
Also I have a common data class between them and I need that each thread inform other when it do its duty and its own processes on this common data!

one the code is so long and the site don't let me to upload it or copy it in the response.

But I really dont know how should I manage them.

:confused:
regards

[havij000]

Dear karankumar1609's,
thanks for your reply.

would you please put the complete code here, I really do not understand what is the

prcsThread->setChildData(data_child);

is what should it do!

thanks

regards,

[anda_skoa]

Both of your threads are missing the implementation of QThread::run()

You probably want to call your run functions from it.

Cheers,
_

[havij000]

Dear buddy,
thanks for your response.

Both of your threads are missing the implementation of QThread::run()

would you please explain it more about it?

Isn't it enough to implement the run function?

void Recive_Thread::run(Data_Class *data_rcv_child)

void Recive_Thread::run(Data_Class *data_rcv_child)

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[anda_skoa]

Dear buddy,
Isn't it enough to implement the run function?

void Recive_Thread::run(Data_Class *data_rcv_child)

void Recive_Thread::run(Data_Class *data_rcv_child)

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Yes, implementing the run function is enough. But as I said, you are not implementing the run function. Or rather you are implementing another function called run that does not match the override requirements for QThread::run().

Look at QThread's documentation. Its run method looks like this

void run();

void run();

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Now look at your run function

void run(Data_Class *data_rcv_child);

void run(Data_Class *data_rcv_child);

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Don't they look different?

"Blimey", you say, "indeed, one of the has a function argument!"

So if you want to execute run(Data_Class*) in a thread, what do you do?
Easy, right?

You add run() to your class and let it calls run(Data_Class*)

Cheers,
_

[havij000]

yes I got it.
you mean that I should emplement the run function:

void run();

void run();

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and define another function to get and set the values that I need to set!?

[karankumar1609]

prcsThread->setChildData(data_child);

It is just the replacement of your code

prcsThread->run(data_child);

You are calling run function with some arguments.
In case of QThread run() is the virtual function which we reimplement in our derived class.

so on calling start function run will autometically executed.
The implementation of run() in thread should be without parameters.

rcvThread->start(QThread::HighestPriority);

rcvThread->start(QThread::HighestPriority);

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ex

class myThread : public QThread
{
  myThread() {}
 
  void setChildData(YourDataType value) {
  value_ = value
  }
 
protected:
  void run()
  {  
  // DO SOMETHING 
  }
 
private:
  yourDataType value_;
};

class myThread : public QThread
{
  myThread() {}

  void setChildData(YourDataType value) {
  value_ = value
  }

protected:
  void run()
  {  
  // DO SOMETHING 
  }

private:
  yourDataType value_;
};

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you can use this thread

int myValue_say = 5;
myThread *thread = new myThread();
thread->setChildData(myValue_say);
thread->start(QThread::HighestPriority);

int myValue_say = 5;
myThread *thread = new myThread();
thread->setChildData(myValue_say);
thread->start(QThread::HighestPriority);

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For more basic info about QThread:
http://qt-project.org/doc/qt-4.8/threads-starting.html

[havij000]

where should I use these parts of code:

myThread *thread = new myThread();

myThread *thread = new myThread();

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well in fact I have a common header as a class and I want to share this header between the threads.
and also I need threads to inform each others about the changes that they have made in the shared data.

[karankumar1609]

where should I use these parts of code:

myThread *thread = new myThread();

myThread *thread = new myThread();

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well in fact I have a common header as a class and I want to share this header between the threads.
and also I need threads to inform each others about the changes that they have made in the shared data.

you can initialize thread in constructor of your window,
that was just for your understanding about QThread.

for basic information about threads, use Google, it will surely help you.

For data sharing between threads, you can use Global variables , static variables., or you can use a class which is derived with QObject.
Both threads can use the same class.

Use SIGNAL, and SLOTS for notification of data change.