Changeset 53f68fd in mainline

Timestamp:

2014-07-08T21:42:35Z (10 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

8f0dc26

Parents:

df2e621c

Message:

fibril_timer_func() must examine timer state each time it reacquires timer lock after cv_wait.

Location:

uspace/lib/c

Files:

• generic/fibril_synch.c (modified) (3 diffs)
• include/fibril_synch.h (modified) (1 diff)

uspace/lib/c/generic/fibril_synch.c

@@ -450 +450 @@
         fibril_mutex_lock(&timer->lock);
 
-        while (true) {
-                while (timer->state != fts_active &&
-                    timer->state != fts_cleanup) {
-
-                        if (timer->state == fts_cleanup)
-                                break;
-
+        while (timer->state != fts_cleanup) {
+                switch (timer->state) {
+                case fts_not_set:
+                case fts_fired:
                         fibril_condvar_wait(&timer->cv, &timer->lock);
+                        break;
+                case fts_active:
+                        rc = fibril_condvar_wait_timeout(&timer->cv,
+                            &timer->lock, timer->delay);
+                        if (rc == ETIMEOUT && timer->state == fts_active) {
+                                timer->state = fts_fired;
+                                fibril_mutex_unlock(&timer->lock);
+                                timer->fun(timer->arg);
+                                fibril_mutex_lock(&timer->lock);
+                        }
+                        break;
+                case fts_cleanup:
+                case fts_clean:
+                        assert(false);
+                        break;
                 }
-
-                if (timer->state == fts_cleanup)
-                        break;
-
-                rc = fibril_condvar_wait_timeout(&timer->cv, &timer->lock,
-                    timer->delay);
-                if (rc == ETIMEOUT) {
-                        timer->state = fts_fired;
-                        fibril_mutex_unlock(&timer->lock);
-                        timer->fun(timer->arg);
-                        fibril_mutex_lock(&timer->lock);
-                }
-        }
-
+        }
+
+        /* Acknowledge timer fibril has finished cleanup. */
+        timer->state = fts_clean;
         fibril_mutex_unlock(&timer->lock);
+
         return 0;
 }
@@ -514 +517 @@
 {
         fibril_mutex_lock(&timer->lock);
-        assert(timer->state != fts_active);
+        assert(timer->state == fts_not_set || timer->state == fts_fired);
+
+        /* Request timer fibril to terminate. */
         timer->state = fts_cleanup;
         fibril_condvar_broadcast(&timer->cv);
+
+        /* Wait for timer fibril to acknowledge. */
+        while (timer->state != fts_clean)
+                fibril_condvar_wait(&timer->cv, &timer->lock);
+
         fibril_mutex_unlock(&timer->lock);
 }
@@ -534 +544 @@
 {
         fibril_mutex_lock(&timer->lock);
+        assert(timer->state == fts_not_set || timer->state == fts_fired);
         timer->state = fts_active;
         timer->delay = delay;

uspace/lib/c/include/fibril_synch.h

@@ -116 +116 @@
         /** Timer has fired and has not been cleared since */
         fts_fired,
-        /** Timer is being destroyed */
-        fts_cleanup
+        /** Timer fibril is requested to terminate */
+        fts_cleanup,
+        /** Timer fibril acknowledged termination */
+        fts_clean
 } fibril_timer_state_t;