lib: Make timerwheel a passive component

This turns the timerwheel into a passive component since it is used by
application using the library. The user of the timerwheel now has to
call timerwheel_move to advance the timerwheel.

1 files changed, 8 insertions, 150 deletions

diff --git a/src/lib/timerwheel.c b/src/lib/timerwheel.c
index 76f0ab32..2952c5d3 100644
--- a/src/lib/timerwheel.c
+++ b/src/lib/timerwheel.c
@@ -39,12 +39,6 @@
 #define tw_free(tw) (tw_used(tw) + 1 < tw->elements)
 #define tw_empty(tw) (tw->head == tw->tail)
 
-enum tw_state {
-        TW_NULL = 0,
-        TW_RUNNING,
-        TW_DESTROY
-};
-
 struct tw_f {
         struct list_head next;
         void (* func)(void *);
@@ -63,19 +57,10 @@ struct timerwheel {
 
         size_t           pos;
 
-        struct list_head wq;
-
-        pthread_cond_t   work;
         pthread_mutex_t  lock;
 
-        int              resolution;
+        time_t           resolution;
         unsigned int     elements;
-
-        enum tw_state    state;
-        pthread_mutex_t  s_lock;
-
-        pthread_t        ticker;
-        pthread_t        worker;
 };
 
 static void tw_el_fini(struct tw_el * e)
@@ -89,72 +74,8 @@ static void tw_el_fini(struct tw_el * e)
         }
 }
 
-static enum tw_state tw_get_state(struct timerwheel * tw)
-{
-        enum tw_state state;
-
-        assert(tw);
-
-        pthread_mutex_lock(&tw->s_lock);
-
-        state = tw->state;
-
-        pthread_mutex_unlock(&tw->s_lock);
-
-        return state;
-}
-
-static void tw_set_state(struct timerwheel * tw, enum tw_state state)
-{
-        assert(tw);
-        assert(state != TW_NULL);
-
-        pthread_mutex_lock(&tw->s_lock);
-
-        tw->state = state;
-
-        pthread_mutex_unlock(&tw->s_lock);
-}
-
-static void * worker(void * o)
-{
-        struct list_head * p;
-        struct list_head * h;
-
-        struct timerwheel * tw = (struct timerwheel *) o;
-        struct timespec dl;
-        struct timespec now;
-
-        clock_gettime(PTHREAD_COND_CLOCK, &now);
-
-        ts_add(&now, &tw->intv, &dl);
-
-        pthread_mutex_lock(&tw->lock);
-
-        while (tw_get_state(tw) == TW_RUNNING) {
-                if (pthread_cond_timedwait(&tw->work, &tw->lock, &dl)
-                    == ETIMEDOUT)
-                        ts_add(&dl, &tw->intv, &dl);
-
-                list_for_each_safe(p, h, &tw->wq) {
-                        struct tw_f * f = list_entry(p, struct tw_f, next);
-                        list_del(&f->next);
-                        pthread_mutex_unlock(&tw->lock);
-                        f->func(f->arg);
-                        free(f);
-
-                        pthread_mutex_lock(&tw->lock);
-                }
-        }
-
-        pthread_mutex_unlock(&tw->lock);
-
-        return (void *) o;
-}
-
-static void * movement(void * o)
+void timerwheel_move(struct timerwheel * tw)
 {
-        struct timerwheel * tw = (struct timerwheel *) o;
         struct timespec now = {0, 0};
         long ms = tw->resolution * tw->elements;
         struct timespec total = {ms / 1000,
@@ -162,21 +83,16 @@ static void * movement(void * o)
         struct list_head * p;
         struct list_head * h;
 
-        while (tw_get_state(tw) == TW_RUNNING) {
-                clock_gettime(CLOCK_MONOTONIC, &now);
-
-                pthread_mutex_lock(&tw->lock);
+        clock_gettime(CLOCK_MONOTONIC, &now);
 
-                if (ts_diff_us(&tw->wheel[tw->pos].expiry, &now) < 0) {
-                        pthread_mutex_unlock(&tw->lock);
-                        nanosleep(&tw->intv, NULL);
-                        continue;
-                }
+        pthread_mutex_lock(&tw->lock);
 
+        while (ts_diff_us(&tw->wheel[tw->pos].expiry, &now) > 0) {
                 list_for_each_safe(p, h, &tw->wheel[tw->pos].funcs) {
                         struct tw_f * f = list_entry(p, struct tw_f, next);
                         list_del(&f->next);
-                        list_add(&f->next, &tw->wq);
+                        f->func(f->arg);
+                        free(f);
                 }
 
                 ts_add(&tw->wheel[tw->pos].expiry,
@@ -184,13 +100,9 @@ static void * movement(void * o)
                        &tw->wheel[tw->pos].expiry);
 
                 tw->pos = (tw->pos + 1) & (tw->elements - 1);
-
-                pthread_cond_signal(&tw->work);
-
-                pthread_mutex_unlock(&tw->lock);
         }
 
-        return (void *) 0;
+        pthread_mutex_unlock(&tw->lock);
 }
 
 struct timerwheel * timerwheel_create(time_t resolution,
@@ -203,8 +115,6 @@ struct timerwheel * timerwheel_create(time_t resolution,
 
         struct timerwheel * tw;
 
-        pthread_condattr_t cattr;
-
         assert(resolution != 0);
 
         tw = malloc(sizeof(*tw));
@@ -228,25 +138,10 @@ struct timerwheel * timerwheel_create(time_t resolution,
         tw->intv.tv_sec = (tw->resolution / FRAC) / 1000;
         tw->intv.tv_nsec = ((tw->resolution / FRAC) % 1000) * MILLION;
 
-        list_head_init(&tw->wq);
-
         if (pthread_mutex_init(&tw->lock, NULL))
                 goto fail_lock_init;
 
-        if (pthread_mutex_init(&tw->s_lock, NULL))
-                goto fail_s_lock_init;
-
-        if (pthread_condattr_init(&cattr))
-                goto fail_cond_init;
-
-#ifndef __APPLE__
-        pthread_condattr_setclock(&cattr, PTHREAD_COND_CLOCK);
-#endif
-        if (pthread_cond_init(&tw->work, &cattr))
-                goto fail_cond_init;
-
         tw->pos = 0;
-        tw->state = TW_RUNNING;
 
         clock_gettime(CLOCK_MONOTONIC, &now);
         now.tv_nsec -= (now.tv_nsec % MILLION);
@@ -257,24 +152,8 @@ struct timerwheel * timerwheel_create(time_t resolution,
                 ts_add(&now, &res_ts, &now);
         }
 
-        if (pthread_create(&tw->worker, NULL, worker, (void *) tw))
-                goto fail_worker_create;
-
-        if (pthread_create(&tw->ticker, NULL, movement, (void *) tw)) {
-                tw_set_state(tw, TW_DESTROY);
-                goto fail_ticker_create;
-        }
-
         return tw;
 
- fail_ticker_create:
-         pthread_join(tw->worker, NULL);
- fail_worker_create:
-         pthread_cond_destroy(&tw->work);
- fail_cond_init:
-         pthread_mutex_destroy(&tw->s_lock);
- fail_s_lock_init:
-         pthread_mutex_destroy(&tw->lock);
  fail_lock_init:
          free(tw->wheel);
  fail_wheel_malloc:
@@ -286,31 +165,10 @@ void timerwheel_destroy(struct timerwheel * tw)
 {
         unsigned long i;
 
-        struct list_head * p;
-        struct list_head * h;
-
-        tw_set_state(tw, TW_DESTROY);
-
-        pthread_join(tw->ticker, NULL);
-        pthread_join(tw->worker, NULL);
-
         for (i = 0; i < tw->elements; ++i)
                 tw_el_fini(&tw->wheel[i]);
 
-        pthread_mutex_lock(&tw->lock);
-
-        list_for_each_safe(p, h, &tw->wq) {
-                struct tw_f * f = list_entry(p, struct tw_f, next);
-                list_del(&f->next);
-                free(f);
-        }
-
-        pthread_mutex_unlock(&tw->lock);
-
-        pthread_cond_destroy(&tw->work);
         pthread_mutex_destroy(&tw->lock);
-        pthread_mutex_destroy(&tw->s_lock);
-
         free(tw->wheel);
         free(tw);
 }