iokit/Kernel/IOWorkLoop.cpp

172     if ( workThread == NULL ) {
177         if (KERN_SUCCESS != kernel_thread_start(cptr, this, &workThread))
181     (void) thread_set_tag(workThread, THREAD_TAG_IOWORKLOOP);
220     if (workThread) {
239     else /* !workThread */ {
259 	// or the workThread itself is performing hari-kari.
418 	thread_t thread = workThread;
419     workThread = 0;	// Say we don't have a loop and free ourselves
428     return workThread;
433     return (IOThreadSelf() == workThread);