On 06/16/2010 04:22 PM, Jamie Lokier wrote:
Paolo Bonzini wrote:
These should be (at least for now) block-obj-$(CONFIG_POSIX).
+ while (QTAILQ_EMPTY(&(queue->request_list))&&
+ (ret != ETIMEDOUT)) {
+ ret = qemu_cond_timedwait(&(queue->cond),
+ &(queue->lock), 10*100000);
+ }
Using qemu_cond_timedwait is a hack for not properly broadcasting the
condvar in flush_threadlet_queue.
Are you sure? It looks like it also expires idle threads after a
fixed amount of idle time.
Unnecessary idle threads are immediately expired as soon as the
threadlet exits if ncecessary, since here
+ queue->idle_threads++;
+
+check_exit:
+ if (queue->exit || ((queue->idle_threads > 0) &&
+ (queue->cur_threads > queue->min_threads))) {
+ /* We exit the queue or we retain minimum number of threads */
+ break;
+ }
queue->idle_threads > 0 will always be true (so maybe that should be
changed into an assertion: "this thread is idle, so there must be idle
threads").
The min/max_threads parameters of the queue are currently immutable, so
it can never happen that a thread has to be expired while it's waiting.
It may well become true in the future, in which case the condvar will
have to be broadcast when min_threads changes.
I may well be wrong of course. :)
Paolo
