Interesting lock/Monitor.Enter() behavior

[Jeff Gerber]

/*

This test program will give a "Value cannot be null" error.

If the lock in this code is removed (or Monitor.Enter()) the program will
run as expected.

I have found no explaination in lock() or Monitor.Enter() documentation as
to why this occurs. I suspect that it is by design of the behind-the-scenes
process that lock uses and is not a bug, however, it would be nice if there
was some documentation to illuminate this process.

If anyone knows otherwise the knowledge is greatly appreciated.

*/

using System;

using System.Threading;

namespace testdelegate

{

delegate void testDelegate();

class Class1

{

private static testDelegate myPrivateDelegate;

public static testDelegate myPublicDelegate

{

set

{

//Monitor.Enter(myPrivateDelegate);

lock(myPrivateDelegate)

{

myPrivateDelegate = value;

}

//Monitor.Exit(myPrivateDelegate);

}

}

[STAThread]

static void Main(string[] args)

{

myPublicDelegate = new testDelegate(DelegateMethod);

lock (myPrivateDelegate)

{

if (myPrivateDelegate != null)

myPrivateDelegate();

}

}

public static void DelegateMethod()

{

Console.WriteLine("executed");

}

}

}

[Keiji Oenoki]

Hi Jeff,
It is documented at:

http://msdn.microsoft.com/library/de...us/cpref/html/
frlrfsystemthreadingmonitorclassentertopic.asp

--
Keiji Oenoki
Visual C++ Team
This posting is provided AS IS with no warranties, and confers no rights.
--------------------

From: "Jeff Gerber" <jg******@tampabay.rr.com>
Newsgroups: microsoft.public.dotnet.languages.vc
Subject: Interesting lock/Monitor.Enter() behavior
/*

This test program will give a "Value cannot be null" error.

If the lock in this code is removed (or Monitor.Enter()) the program will
run as expected.

I have found no explaination in lock() or Monitor.Enter() documentation as
to why this occurs. I suspect that it is by design of the behind-the-scenes process that lock uses and is not a bug, however, it would be nice if there was some documentation to illuminate this process.

If anyone knows otherwise the knowledge is greatly appreciated.

*/

using System;

using System.Threading;

namespace testdelegate

{

delegate void testDelegate();

class Class1

{

private static testDelegate myPrivateDelegate;

public static testDelegate myPublicDelegate

{

set

{

//Monitor.Enter(myPrivateDelegate);

lock(myPrivateDelegate)

{

myPrivateDelegate = value;

}

//Monitor.Exit(myPrivateDelegate);

}

}

[STAThread]

static void Main(string[] args)

{

myPublicDelegate = new testDelegate(DelegateMethod);

lock (myPrivateDelegate)

{

if (myPrivateDelegate != null)

myPrivateDelegate();

}

}

public static void DelegateMethod()

{

Console.WriteLine("executed");

}

}

}