How do I wait until a console application is idle?

Question

I have a console application that starts up, hosts a bunch of services (long-running startup), and then waits for clients to call into it. I have integration tests that start this console application and make "client" calls. How do I wait for the console application to complete its startup before making the client calls?

I want to avoid doing Thread.Sleep(int) because that's dependent on the startup time (which may change) and I waste time if the startup is faster.

Process.WaitForInputIdle works only on applications with a UI (and I confirmed that it does throw an exception in this case).

I'm open to awkward solutions like, have the console application write a temp file when it's ready.

Answer 1

One option would be to create a named EventWaitHandle. This creates a synchronization object that you can use across processes. Then you have your 'client' applications wait until the event is signalled before proceeding. Once the main console application has completed the startup it can signal the event.

http://msdn.microsoft.com/en-us/library/41acw8ct(VS.80).aspx

As an example, your "Server" console application might have the following. This is not compiled so it is just a starting point :)

using System.Threading;
static EventWaitHandle _startedEvent;
static void main()
{  
  _startedEvent = new EventWaitHandle(false, EventResetMode.ManualReset, @"Global\ConServerStarted");

  DoLongRunnningInitialization();

  // Signal the event so that all the waiting clients can proceed
  _startedEvent.Set();
}

The clients would then be doing something like this

using System.Threading;
static void main()
{  
  EventWaitHandle startedEvent = new EventWaitHandle(false, EventResetMode.ManualReset, @"Global\ConServerStarted");

  // Wait for the event to be signaled, if it is already signalled then this will fall throught immediately.
  startedEvent.WaitOne();    

//  ... continue communicating with the server console app now ...
}

Answer 2

What about setting a mutex, and removing it once start up is done. Have the client app wait until it can grab the mutex before it starts doing things.