diff options
| -rw-r--r-- | kern/sleepq.c | 6 | ||||
| -rw-r--r-- | kern/sleepq.h | 8 |
2 files changed, 6 insertions, 8 deletions
diff --git a/kern/sleepq.c b/kern/sleepq.c index bd0e363e..0d04c6ea 100644 --- a/kern/sleepq.c +++ b/kern/sleepq.c @@ -492,11 +492,13 @@ sleepq_signal(struct sleepq *sleepq) { struct sleepq_waiter *waiter; - if (list_empty(&sleepq->waiters)) { + waiter = sleepq->oldest_waiter; + + if (!waiter) { return; } - waiter = list_last_entry(&sleepq->waiters, struct sleepq_waiter, node); + sleepq_shift_oldest_waiter(sleepq); sleepq_waiter_set_pending_wakeup(waiter); sleepq_waiter_wakeup(waiter); } diff --git a/kern/sleepq.h b/kern/sleepq.h index 827d0436..007e3f2f 100644 --- a/kern/sleepq.h +++ b/kern/sleepq.h @@ -105,8 +105,6 @@ bool sleepq_empty(const struct sleepq *sleepq); * released, e.g. if a single thread is waiting and another signals * the queue, the queue is not immediately considered empty. * - * Threads are queued in FIFO order. - * * When bounding the duration of the wait, the caller must pass an absolute * time in ticks, and ERROR_TIMEDOUT is returned if that time is reached * before the sleep queue is signalled. @@ -124,10 +122,8 @@ int sleepq_timedwait(struct sleepq *sleepq, const char *wchan, uint64_t ticks); * acquired) when waiting, and acquired in order to signal it, * wake-ups are serialized and cannot be missed. * - * Threads are queued in FIFO order, which means signalling a sleep - * queue multiple times always awakens the same thread, regardless - * of new waiters, as long as that thread didn't reacquire the - * sleep queue. + * At least one thread is awaken if any threads are waiting on the sleep + * queue. * * A broadcast differs only by also making all currently waiting threads * pending for wake-up. As with sleepq_signal, a single thread may be |