If the VM/OS observes that the same thread that called yield() is still eligible to run, it is quite likely to simply reschedule it as the best candidate. Depending on the level in the code where this happens in a particular VM or OS implementation, yield() can therefore be a no-op, or a very short break. sleep() on the other hand makes the thread ineligible to run for a period, forcing a context switch to always happen. -- Andrew Thompson ____________________________________________________________________________________ Need Mail bonding? Go to the Yahoo! Mail Q&A for great tips from Yahoo! Answers users. http://answers.yahoo.com/dir/?link=list&sid=396546091