On Fri, Jul 12, 2002 at 01:40:42AM +0200, Peter Hanappe wrote: > [EMAIL PROTECTED] wrote: > > > > > For example, in RTLinux, fifos shared > > between Linux (non-rt) processes and RT threads are asymmetric: the > > RT thread never blocks, the non-RT thread blocks. In many cases > > it is best to optimize the data operations and perform them under > > a spin_lock with interrupts disabled. In RTLinux pthread_spin_lock > > disables irqs and, in SMP also sets the lock > > pthread_spin_lock(&myq.spin); > > myq.tail->next = new; > > new->next = 0; > > myq.tail= next; > > if(!myq.head)myq.head = new; > > pthread_spin_unlock(&myq.spin); > > How do you tell a blocking non-RT thread that new data is available?
It's done automatically by a write: a write does sends a soft interrupt to Linux and the interrupt handler does a standard wakeup on flagged fifos. -- --------------------------------------------------------- Victor Yodaiken Finite State Machine Labs: The RTLinux Company. www.fsmlabs.com www.rtlinux.com
