note BrowserUk <blockquote><i> Now I wonder: Could there be cases, where a process gets killed while being in the critical region, BUT the lock is not being released (and therefore all other processes would be locked out forever)? </i></blockquote> <p>In a nutshell: No, that cannot happen. <p>However, if a process terminates whilst holding a lock, it may be some time before the OS gets around to releasing the lock -- dependent upon the availability of suitable system resources -- so attempts to acquire the lock should be programmed to retry, <i>without tight loop polling</i>, as a tight polling loop can itself be the cause of the unavailability of those system resources. <p>(For more info, see the "Remarks" under [http://msdn.microsoft.com/en-us/library/windows/desktop/aa365203(v=vs.85).aspx|LockFile(Ex)()], which is the system call that underlies perl's emulation of flock() on Windows.) <div class="pmsig"><div class="pmsig-171588"> <hr /> <font size=1 > <div>With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'</div> <div>Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.</div> <div>"Science is about questioning the status quo. Questioning authority". </div> <div>In the absence of evidence, opinion is indistinguishable from prejudice. <p align=right> [http://thebottomline.cpaaustralia.com.au/|RIP Neil Armstrong]</p></div> </font> </div></div> 1008652 1008652