site_archiver@lists.apple.com Delivered-To: darwin-kernel@lists.apple.com Basically you are on the right track. Godfrey On 2008-04-19, at 5:03 , Duane Murphy wrote: Scenario - An IOKit kext that uses a separate background thread to process data independent of any other outside influence. When the kext is signaled to stop this thread, how does the kext stop the thread and wait for it to exit? (The following code is uncompiled, untested, & unproven) void myKext::startThread() { me->_threadComplete = false; IOCreateThread( threadMain, this ); } /* static */ void myKext::threadMain( myKext* me ) { while ( me->_keepWorking ) { doWork(); // ... } // _threadComplete is from OSMemberFunctionCast me->_commandGate->runAction( _threadComplete, ... ); } void myKext::threadComplete() { me->_commandGate->commandWakeup( &me->_threadComplete, true /* one thread */ ); } void myKext::stopThread() { _commandGate->runAction( _reallyStopThread, ... ); } void myKext::reallyStopThread() { _keepWorking = false; while( ! _threadComplete ) _commandGate->commandSleep( *_threadComplete ); } The important point seems to be that one must be in the gate to sleep and wake in order to be on the workloop. Hence the indirection through IOCommandGate::runAction(). Assuming the rest of the driver hierarchy is similarly using the workloop and command gate, this seems like it will work. Did I get this right? Is there a better way? Are there other ways? Thanks for the lesson, ...Duane _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/gvdl%40mac.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Darwin-kernel mailing list (Darwin-kernel@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/darwin-kernel/site_archiver%40lists.a... Basically you are on the right track. Use the commandGate to put your main thread to sleep waiting for your worker to get its act together. You should synchronise with the IOWorkLoop in the driver stack, i.e. the work loop returned by provider->getWorkLoop(). One thing you can try out though is a poorly documented, what isn't in the kernel, service routines the osmk/kern/thread_call.h package. This is a general purpose pool of threads that the mach kernel provides for exactly these sort of short term on the side processing. The best thing about it is that you don't have to do any of the usual clean up and accounting. Another thing I like the ability to preallocate a call/data pair and use it repeatedly. As suggested, I'd should be using IOCommandGate to wait for a worker thread to complete. I've not found any documentation or notes for how to do this, so I am writing this up in order to document and determine if this is the correct way to do this. This email sent to gvdl@mac.com This email sent to site_archiver@lists.apple.com