Subj : Re: recursive mutexes
To   : comp.programming.threads
From : Uenal Mutlu
Date : Wed May 18 2005 10:10 pm

"Torsten Robitzki" wrote
> Uenal Mutlu wrote:
>
> > "Torsten Robitzki" wrote
> >
> >>Uenal Mutlu wrote:
> >>>
> >>>It is really basic stuff. Ask yourself how you would extend a non-recursive
> >>>locking method to make it recursive? Recursivity starts with the 2nd Lock()
> >>>call on the same object within the same thread, true?
> >>
> >>First one have to check if this lock request comes from the thread
> >>holding the mutex or not. This can not be implemented by a simple
> >>increment.
> >
> >
> > I can only repeat: The code which increments the counter cannot be
> > executed by anyone else but the current lock holding thread.
>
> What will a thread that does not hold the lock prevent it from
> incrementing the counter if not by checking if it's holding the lock or
> not?

What about a policy?
FYI: in reply to doug I've posted a code-snippet to show this.

> > For which OS and using which threading pkg do you develop?
>
> OpenVMS/Alpha with some C++ wrapper around pthread.

Do you know or believe that your OS makes no use recursive mutexes?
I personally cannot believe that any complex system of nowadays like an
OS or any server application can be developed without recursive mutices.

.