public void using_child_locks__avoids_deadlock_situations()
{
// Lock_1 (more coarse than Lock_2)
// Lock_2 (child of Lock_1, more granual)
// Thread_1 accesses Lock_1 then Lock_2
// Thread_2 accesses Lock_2 only
var l1 = new ReaderWriterLockSlimEx(LockRecursionPolicy.NoRecursion);
var l2 = new ReaderWriterLockSlimEx(LockRecursionPolicy.NoRecursion);
l1.AddChild(l2);
bool oh_no = false;
var t1 = Task.Run(() =>
{
using (l1.AcquireWriteLockIfNotHeld())
{
Trace.WriteLine("t1 acquired l1");
Thread.Sleep(1000);
using (l2.AcquireReadLockIfNotHeld())
{
if (oh_no)
Assert.Fail(":(");
}
}
});
var t2 = Task.Run(() =>
{
Thread.Sleep(100);
using (l2.AcquireWriteLock())
{
oh_no = true;
Trace.WriteLine("t2 acquired l2");
}
});
Task.WaitAll(new[] { t1, t2 });
}
