Date: 2007nov6 Q. A critical section is too strong for my application. I only want other threads excluded when changes are made to the shared data. A. You want a read-write lock. In Linux/Unix check the man page for pthread_rwlock_rdlock Windows does not have native support for read-write locks. We have succesfully used KReadWriteLock by Ivan Krivyakov http://www.codeguru.com/cpp/w-p/system/misc/article.php/c5679/