diff options
| -rw-r--r-- | lib/thread.c | 57 |
1 files changed, 41 insertions, 16 deletions
diff --git a/lib/thread.c b/lib/thread.c index af52b057..fb6fe375 100644 --- a/lib/thread.c +++ b/lib/thread.c @@ -903,6 +903,24 @@ thread_timer_process (struct thread_list *list, struct timeval *timenow) return ready; } +/* process a list en masse, e.g. for event thread lists */ +static unsigned int +thread_process (struct thread_list *list) +{ + struct thread *thread; + unsigned int ready = 0; + + for (thread = list->head; thread; thread = thread->next) + { + thread_list_delete (list, thread); + thread->type = THREAD_READY; + thread_list_add (&thread->master->ready, thread); + ready++; + } + return ready; +} + + /* Fetch next ready thread. */ struct thread * thread_fetch (struct thread_master *m, struct thread *fetch) @@ -911,41 +929,48 @@ thread_fetch (struct thread_master *m, struct thread *fetch) fd_set readfd; fd_set writefd; fd_set exceptfd; - struct timeval timer_val; + struct timeval timer_val = { .tv_sec = 0, .tv_usec = 0 }; struct timeval timer_val_bg; - struct timeval *timer_wait; + struct timeval *timer_wait = &timer_val; struct timeval *timer_wait_bg; while (1) { int num = 0; - /* Signals are highest priority */ + /* Signals pre-empt everything */ quagga_sigevent_process (); - /* Normal event are the next highest priority. */ - if ((thread = thread_trim_head (&m->event)) != NULL) - return thread_run (m, thread, fetch); - - /* If there are any ready threads from previous scheduler runs, - * process top of them. + /* Drain the ready queue of already scheduled jobs, before scheduling + * more. */ if ((thread = thread_trim_head (&m->ready)) != NULL) return thread_run (m, thread, fetch); + /* To be fair to all kinds of threads, and avoid starvation, we + * need to be careful to consider all thread types for scheduling + * in each quanta. I.e. we should not return early from here on. + */ + + /* Normal event are the next highest priority. */ + thread_process (&m->event); + /* Structure copy. */ readfd = m->readfd; writefd = m->writefd; exceptfd = m->exceptfd; /* Calculate select wait timer if nothing else to do */ - quagga_get_relative (NULL); - timer_wait = thread_timer_wait (&m->timer, &timer_val); - timer_wait_bg = thread_timer_wait (&m->background, &timer_val_bg); - - if (timer_wait_bg && - (!timer_wait || (timeval_cmp (*timer_wait, *timer_wait_bg) > 0))) - timer_wait = timer_wait_bg; + if (m->ready.count == 0) + { + quagga_get_relative (NULL); + timer_wait = thread_timer_wait (&m->timer, &timer_val); + timer_wait_bg = thread_timer_wait (&m->background, &timer_val_bg); + + if (timer_wait_bg && + (!timer_wait || (timeval_cmp (*timer_wait, *timer_wait_bg) > 0))) + timer_wait = timer_wait_bg; + } num = select (FD_SETSIZE, &readfd, &writefd, &exceptfd, timer_wait); |