I've been looking out for ways to use ScriptCS in my day-to-day work lately. Each time I do, I am impressed by how much time it saves me.

So today I found myself needing to write some code with a named Mutex in C#. ScriptCS to the rescue!

Don't have ScriptCS?

Pop open a command window and run the following to install chocolatey then use that to install scriptcs.

@powershell -NoProfile -ExecutionPolicy unrestricted -Command "iex ((new-object net.webclient).DownloadString('https://chocolatey.org/install.ps1'))" && SET PATH=%PATH%;%systemdrive%\chocolatey\bin

cinst scriptcs

Done!
While you are there, why not install a few other chocolatey packages, I use it for node, git, mercurial, sourcetree, sublime, fiddler, console2, beyond compare, ravendb and more. I even use it for the SourceCodePro font. Seriously. It takes me just minutes to rebuild my dev machine from a base VM. Love it.

So how does it help?

Let's start with a basic Mutex pattern that I was adding to some code today.

using (var mutex = new Mutex(false, @"Global\MyTestApp-MyCriticalSection"))
{
    mutex.WaitOne();

    // Do some work

    mutex.ReleaseMutex();
}

After writing this code I wanted to run a few smoke tests over it. Make sure it was behaving in the ways I expected it to. The problem is that running two actual instances of this project isn't easy. Worse, synchronizing the two processes to hit the critical section together is even harder. Enter scriptcs.

c:\>scriptcs

> using System.Threading;
> var mutex = new Mutex(false, @"Global\MyTestApp-MyCriticalSection");

I now have a reference to the same Mutex sitting in my command window that I can WaitOne() or ReleaseMutex() at any time that suits me. So I simply fire up the application with debugging and step through the critical section a couple of times while retaining complete control of the other "process" with whom we are racing.

It's simple and fast. I don't need to create a new project or learn a new scripting language. I can literally copy and paste the lines I needed straight from my source.