Hi Gibbi,
RTUseMutexOptimization refers to the "mutual exclusion algorithm" which stands for:
short: A
mutex ("mutual exclusion") is a mechanism to ensure integrity when
the same data or resource is accessed (in particular, changed) concurrently
from several threads. Usually when the term mutex is used, it refers to a
synchronisation primitive functionally identical to a binary semaphore.
Long: (copyright by Wikipedia) http://en.wikipedia.org/wiki/Mutual_exclusion
Mutual exclusion (often abbreviated to mutex) algorithms are used in concurrent programming to avoid the simultaneous use of a common resource, such as a global variable, by pieces of computer code called critical sections. A critical section is a piece of code in which a process or thread
accesses a common resource. The critical section by itself is not a
mechanism or algorithm for mutual exclusion. A program, process, or
thread can have the critical section in it without any mechanism or
algorithm which implements mutual exclusion.
Examples of such resources are fine-grained flags, counters or queues, used to communicate between code that runs concurrently, such as an application and its interrupt handlers. The synchronization of access to those resources is an acute problem because a thread can be stopped or started at any time.
To illustrate: suppose a section of code is altering a piece of data
over several program steps, when another thread, perhaps triggered by
some unpredictable event, starts executing. If this second thread reads
from the same piece of data, the data, which is in the process of being
overwritten, is in an inconsistent and unpredictable state. If the
second thread tries overwriting that data, the ensuing state will
probably be unrecoverable. These shared data being accessed by critical
sections of code must, therefore, be protected, so that other processes
which read from or write to the chunk of data are excluded from running.
I hope this helps you to understand the entry in the ni-rt.ini-file
Regards
Chris
). 
