Hi, I've been trying to use tsleep() and wakeup() in a kernel extension, but it isn't obvious to me how to enforce synchronization of these calls. (Likely, this isn't the right mechanism for what I want. But, since I'm not sure what I need to use, I'm bringing it up here.) My goal is to put a thread Y to sleep until a condition is met or a time out occurs. Thread Z is manipulating the condition, then calling wakeup on Thread Y when it changes. But if thread Z's timing is just right (or should I say wrong) thread Y may call tsleep after thread Z has decided whether or not to wake it up. Searching for a condition lock, I came to this page: <http://developer.apple.com/documentation/Darwin/Conceptual/KernelProgrammin g/synchronization/chapter_15_section_3.html#//apple_ref/doc/uid/TP30000905-C H218-TPXREF109> Which says:

The BSD portion of Mac OS X provides tsleep, wakeup, and wakeup_one, which are

equivalent to condition variables with the addition of an optional time-out.

Since they are more commonly used for waiting a predetermined period of time,

these calls are discussed in more detail in the section 3Using tsleep2 as part

of the 3Miscellaneous Kernel Services2 chapter.

In my case, I'm not waiting for a predetermined amount of time. In fact, I may not need to wait at all, if the other thread has changed the value, and ultimately I only want to sleep until the value has changed or we time-out and give up waiting for the change. What's the best way to do this in the kernel? Thanks, Eric _______________________________________________ darwin-kernel mailing list | darwin-kernel@lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.