Hi,

I'd like to know if the Thread.start() method does acquire any locks during its execution.

My problem is that sometimes my multi-threading application freezes because a call to Thread.start() does not return.

The parts of the code that are involved are similar to the code below(considering synchronization and thread execution)

			

			import java.util.*;
			

			

			public class Test
			

			{
			

			public static ThreadContainer threadContainer = new ThreadContainer();
			

			public static boolean stop = false;
			

			

			private static class ThreadA extends Thread
			

			{
			

			public void run ()
			

			{
			

			for (int i = 0; i
			< 35; i++)
			

			{
			

			ThreadC threadC=threadContainer.createThread();
			

			} // for
			

			threadContainer.startThreads();
			

			stop = true;
			

			}
			

			}
			

			

			private static class ThreadB extends Thread
			

			{
			

			

			public void run ()
			

			{
			

			Random random = new Random();
			

			while ( !stop )
			

			{
			

			try
			

			{
			

			// wait a bit so threadA already has the lock
			

			Thread.sleep(random.nextInt(300)+150);
			

			} // try
			

			catch (InterruptedException e )
			

			{
			

			} // try-catch
			

			threadContainer.createThread();
			

			} // while
			

			}
			

			}
			

			

			private static class ThreadC extends Thread
			

			{
			

			

			public void run ()
			

			{
			

			while ( !stop )
			

			{
			

			//do something
			

			} // while
			

			}
			

			}
			

			

			private static class ThreadContainer
			

			{
			

			private transient final Object threadListLock = new Object ();
			

			private LinkedList threadList = new LinkedList();
			

			

			public ThreadC createThread ()
			

			{
			

			synchronized(threadListLock)
			

			{
			

			ThreadC threadC=new ThreadC();
			

			threadList.add(threadC);
			

			return threadC;
			

			}
			

			}
			

			

			public void startThreads()
			

			{
			

			synchronized (threadListLock)
			

			{
			

			Iterator iter=threadList.iterator();
			

			while ( iter.hasNext() )
			

			{
			

			ThreadC threadC=(ThreadC)iter.next();
			

			threadC.start();
			

			} // while
			

			}
			

			}
			

			}
			

			

			public static void main (String[] args)
			

			{
			

			ThreadA a = new ThreadA();
			

			ThreadB b = new ThreadB();
			

			

			b.start();
			

			a.start();
			

			Thread.yield();
			

			} // main ()
			

			}
			

		

The problem is that while ThreadA is in the start-loop in method startThreads ThreadB tries to enter method createThread and in that situation it sometimes happens that the Thread.start() method does not return...

Regards,

Carsten

PS: Note however that this problem does not occur (for some reason I don't understand) in the code above which is much simpler than my original code...