Reminder to self:
ThreadStaticAttribute only works with static fields!
Here is why:
public class TestingTLS
{
[ThreadStatic]
public static int value = 0;
[ThreadStatic]
public int value2 = 0;
}
public class MyClass
{
public static void TLSTest()
{
TestingTLS tls = new TestingTLS();
Dictionary<int, Thread> threads = new Dictionary<int, Thread>();
Semaphore sem = new Semaphore(100, 100);
long count = 0;
for ( int i = 0 ; i < 100 ; i ++ )
{
Thread t = new Thread(state => {
int tid = Thread.CurrentThread.ManagedThreadId;
TestingTLS.value = tid;
Thread.Sleep(0);
if ( tid != TestingTLS.value )
{
Console.Error.WriteLine( "Value 1: {0} read {1}", tid, TestingTLS.value );
Interlocked.Increment(ref count);
}
tls.value2 = tid;
Thread.Sleep(0);
if ( tid != tls.value2 )
{
Console.Error.WriteLine( "Value 2: {0} read {1}", tid, tls.value2);
Interlocked.Increment(ref count);
}
threads.Remove(tid);
if ( threads.Count == 0 )
sem.Release();
});
threads.Add(t.ManagedThreadId, t);
sem.WaitOne();
t.Start();
}
Console.WriteLine("Waiting for all threads to finish...");
sem.WaitOne();
Console.WriteLine("Total races: " + count);
}
}
You will see races for value2 but not for value.
Update: The code snippet was updated, since the previous example had a race where the Total Race count would reach before all threads have finished reporting the wrong number of total races in cases where there were large number of races.
