MultyThreading in C#: Communication between threads
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Hi! May be yo can help me with this problem: I need to create a new instance of class (DLL or Windows Class file) that part of the project in a separate thread. Then I need to communicate with that class by passing some varibales or calling function/methods in this class. So question is: How I can do that (with multythreading) ? I appreciate if you write me some code too - thanks "I have not failed. I've just found 10,000 ways that won't work." - Thomas Alva Edison (1847-1931)
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Hi! May be yo can help me with this problem: I need to create a new instance of class (DLL or Windows Class file) that part of the project in a separate thread. Then I need to communicate with that class by passing some varibales or calling function/methods in this class. So question is: How I can do that (with multythreading) ? I appreciate if you write me some code too - thanks "I have not failed. I've just found 10,000 ways that won't work." - Thomas Alva Edison (1847-1931)
Jasper4C# wrote: Then I need to communicate with that class by passing some varibales or calling function/methods in this class. So question is: How I can do that (with multythreading) ? That's bit vague, so here goes: 1. look at the "lock" keyword in C# for preventing multiple threads from writing to a variable at the same time. 2. Look at the Mutex class for synchronizing between threads and blocking one thread while another thread is calling a method you want protected from simultaneous execution. 3. Look at AutoResetEvent and ManualResetEvent for signalling between threads. Hope that helps! Marc Latest AAL Article My blog Join my forum!
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Jasper4C# wrote: Then I need to communicate with that class by passing some varibales or calling function/methods in this class. So question is: How I can do that (with multythreading) ? That's bit vague, so here goes: 1. look at the "lock" keyword in C# for preventing multiple threads from writing to a variable at the same time. 2. Look at the Mutex class for synchronizing between threads and blocking one thread while another thread is calling a method you want protected from simultaneous execution. 3. Look at AutoResetEvent and ManualResetEvent for signalling between threads. Hope that helps! Marc Latest AAL Article My blog Join my forum!
10x for information but what I mean was - for example: -------------------------------------------------------- using .... ; //doesn't matter namespace DllClass { public class ClassA { private string m_message; public ClassA() { //Empty constr (??) } public void ThreadEntrancePoint() { //This method will be called when creating //a new thread //TODO: Should I put here infinity loop ??? } //This method will chande variable in this class public string SetMessage { set { if (value != null) m_message = value; } } } } // End of DLL file --------------------------------------------------------- using ....; //All the other using System.Threading; using DllClass; //need to create class namespace MyFormNameSpace { public class MyForm: Windows.Form { public int Main (...) { //Doesn't matter for now } //This function will be called when user want's //to create a new thread public void btn_CreateThread(...) { Thread t = new Thread (new ThreadStart DllClass.ClassA.ThreadEntrancePoint); t.Start(); } //This function will be called when user want //to send a new messge to the class that inside //thread public void SendNewMessageToThread (string msg) { //TODO: What code should I put here to send //message to ClassA.SetMessage ?? } }//class close }//namespace close --------------------------------------------------------- You see - in this example I want to completly run ClassA in new thread and also pass some variables to this class and may be receive some inforamtion from it. How I can do that ? "I have not failed. I've just found 10,000 ways that won't work." - Thomas Alva Edison (1847-1931)
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10x for information but what I mean was - for example: -------------------------------------------------------- using .... ; //doesn't matter namespace DllClass { public class ClassA { private string m_message; public ClassA() { //Empty constr (??) } public void ThreadEntrancePoint() { //This method will be called when creating //a new thread //TODO: Should I put here infinity loop ??? } //This method will chande variable in this class public string SetMessage { set { if (value != null) m_message = value; } } } } // End of DLL file --------------------------------------------------------- using ....; //All the other using System.Threading; using DllClass; //need to create class namespace MyFormNameSpace { public class MyForm: Windows.Form { public int Main (...) { //Doesn't matter for now } //This function will be called when user want's //to create a new thread public void btn_CreateThread(...) { Thread t = new Thread (new ThreadStart DllClass.ClassA.ThreadEntrancePoint); t.Start(); } //This function will be called when user want //to send a new messge to the class that inside //thread public void SendNewMessageToThread (string msg) { //TODO: What code should I put here to send //message to ClassA.SetMessage ?? } }//class close }//namespace close --------------------------------------------------------- You see - in this example I want to completly run ClassA in new thread and also pass some variables to this class and may be receive some inforamtion from it. How I can do that ? "I have not failed. I've just found 10,000 ways that won't work." - Thomas Alva Edison (1847-1931)
Ok, first off, you can't call ThreadStart() the way you described because you need an instance of the class or the method you're calling has to be static. If it's static, then anything it manipulates has to be static as well, and that means anything outside of the thread can access it as well, as long as it's static. If you made all the data and methods in ClassA static, then you could simply call ClassA.SetMessage from any thread--main application thread included. If it's not static, then you need an instance of the object to pass along to the delegate. Since you have the instance, you can also call the SetMessage method from the application thread. For example:
ClassA myClassA=new ClassA();
ThreadStart threadDelegate=new ThreadStart(myClassA.ThreadEntrancePoint);
Thread newThread=new Thread(threadDelegate);
newThread.Start();// in my main application:
myClassA.SetMessage="foobar";
...I hope that helps. Note that you probably would want a "lock" statement to bracket the setter. Marc Latest AAL Article My blog Join my forum!