Subj : Re: Lockable objects
To   : comp.programming.threads
From : Giancarlo Niccolai
Date : Sat May 21 2005 03:12 pm

Uenal Mutlu wrote:

> 
> void f()
> { // requires that object must be locked before calling this func
>   assert(!m.IsLocked());
>   //...
> }
> 

So you are serious. Ok.

However, got a better one:

void f()
{
        lock( &x );
        // it's locked here.
        unlock( &x );
}

IsLocked() suggests that you may call a function with or without a mutex
locked. A well designed application NEVER calls a function while holding a
mutex, unless very very special cases. 
In a few words, you should NOT call any function between a lock() and an
unlock(). That because mutexes protect data, and function calls are not
data to protect.

If you need to, then you must use a condition wait; they are meant to wait
for something to relevant to happen, i.e. for the data you want to use to
be ready. You are confusing too much the two things, I am afraid.

Oh, but there aren't condition waits in Windows... sorry...

However, someone created them for you.

Giancarlo.

.