The AutoResetEvent Class

The AutoResetEvent Class

The AutoResetEvent class works in a similar way to the ManualResetEvent class. It waits for the timeout to take place or the event to be signaled and then notifies the waiting threads about the event. One important difference between ManualResetEvent and AutoResetEvent is that AutoResetEvent changes state at the WaitOne( method. The following listing shows the usage of the AutoResetEvent class:

using System;
using System.Threading;

namespace AutoReset

The output from AutoReset is the same as that from the ManualReset example shown earlier:

Before First WaitOne
After First WaitOne True
After Second WaitOne False

In AutoReset, the differences between the AutoResetEvent and ManualResetEvent are clear. The state of the event object changes from signaled to non-signaled at the first WaitOne( , and then it changes state again from non-signaled to signaled at the second WaitOne() method. As a result, the thread does not wait at the first WaitOne( method and has to wait at the second WaitOne() method until the time expires.