Is Thread Detection already running in C # .net?

Question

I am using the following code.

public void runThread(){ if (System.Diagnostics.Process.GetProcessesByName("myThread").Length == 0) { Thread t = new Thread(new ThreadStart(go)); t.IsBackground = true; t.Name = "myThread"; t.Start(); } else { System.Diagnostics.Debug.WriteLine("myThreadis already Running."); } } public void go() { //My work goes here } 

I call the runThread () function many times, but I want the thread to start only when the thread is not running. How is this possible?

Answer 1

GetProcessesByName will not search for threads in your application, but for processes on your computer. Actually there is no good way to get a request for threads in your own application (the question aside is the debugger).

Why can you create a wrapper class for your threads so that you can query if they are running. Or track the topics themselves in other ways .

You can also think about having a Lazy<Thread> field, which will be initialized if necessary, and you can ask if the thread will burn out. After testing, Lazy<Thread> not a good idea.

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Received from Simon's answer :

 private int running; public void runThread() { if (Interlocked.CompareExchange(ref running, 1, 0) == 0) { Thread t = new Thread ( () => { try { go(); } catch { //Without the catch any exceptions will be unhandled //(Maybe that what you want, maybe not*) } finally { //Regardless of exceptions, we need this to happen: running = 0; } } ); t.IsBackground = true; t.Name = "myThread"; t.Start(); } else { System.Diagnostics.Debug.WriteLine("myThreadis already Running."); } } public void go() { //My work goes here } 

*: Gotta catch'em all

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Wajid and Segey are right. You may have a Thread field. Let me give an example:

 private Thread _thread; public void runThread() { var thread = _thread; //Prevent optimization from not using the local variable Thread.MemoryBarrier(); if ( thread == null || thread.ThreadState == System.Threading.ThreadState.Stopped ) { var newThread = new Thread(go); newThread.IsBackground = true; newThread.Name = "myThread"; newThread.Start(); //Prevent optimization from setting the field before calling Start Thread.MemoryBarrier(); _thread = newThread; } else { System.Diagnostics.Debug.WriteLine("myThreadis already Running."); } } public void go() { //My work goes here } 

Note It’s better to use the first alternative (obtained from Simon’s answer), since it is thread safe. That is, if there are several threads calling the runThread method at the same time, there is no risk of creating more than one thread.

Answer 2

One simple way is that you can have a flag indicating whether it works or not. You may need to use some lock if these are conflicts.

 public static bool isThreadRunning = false; public void runThread() { if (!isThreadRunning) { Thread t = new Thread(new ThreadStart(go)); t.IsBackground = true; t.Name = "myThread"; t.Start(); } else { System.Diagnostics.Debug.WriteLine("myThreadis already Running."); } } public void go() { isThreadRunning = true; //My work goes here isThreadRunning = false; } 

Answer 3

You can use Thread.IsAlive to check if the prevoius thread is working or not. This should provide thread status. You can put this check before mythread.Start().

Answer 4

Do you only create a thread in the run thread method? If he holds it like that, as a class field that contains the runThread method and requests t.IsAlive.

Answer 5

Maybe this will help you

 static bool isRunning = false; public void RunThread(){ if (!isRunning) { Thread t = new Thread(()=> { go(); isRunning = true;}); t.IsBackground = true; t.Name = "myThread"; t.Start(); } else { System.Diagnostics.Debug.WriteLine("myThread is already Running."); } } public void go() { //My work goes here }