Shorten function with bool variable?

[doanhquang2005]

Ex: bool IsProcess; void function(){ if(IsProcess) return; IsProcess = true; // TODO IsProcess = false; }

Do we have any shorthand for this case? I have many such commands in my project

[jnm2]

That's pretty dangerous. If the method throws an exception, you'll be stuck with IsProcess being true forever.

This is the usual pattern:

private bool isProcessing;

private void Function()
{
    if (isProcessing) return;
    isProcessing = true;
    try
    {
        // ...
    }
    finally
    {
        isProcessing = false;
    }
}

This can be encapsulated in various ways to avoid repetition of the full pattern.

[huoyaoyuan]

And to be thread safe, you need lock, Semaphore or CompareExchange. The library may contain some encapsulation for the patterns, but they are too complex for language.

[jnm2]

Very good point. Here's the thread-safe version of the same code, actually not requiring CompareExchange:

private int isProcessing;

private void Function()
{
    if (Interlocked.Exchange(ref isProcessing, 1) != 0) return;
    try
    {
        // ...
    }
    finally
    {
        Volatile.Write(ref isProcessing, 0);
    }
}