[Beowulf] mpich2 mutex

[Ik Ben]

Hi,
I'm reading the book Using MPI-2 of William Gropp .
In the book they explains how to create a mutex for RMA using the
lock/unlock method.
They speek about the functions MPE_Counter_nxtval etc... to create the mutex.

I'm french and have it very difficult to merge the necessary pieces
together correctly.

Can someone please show an example of the minimum code for creating a
mutex using mpi-2 (planning to use Suse, but I don't think that this
matters...).

I know that this seems like I'm to lazy to do my own homework, but it's not.....

Thanks in advance; 
Gilles Roman.