GNUNET_SCHEDULER_do_work: always check if shutdown is necessary and update wakeup

time

1 files changed, 86 insertions, 76 deletions

diff --git a/src/util/scheduler.c b/src/util/scheduler.c
index 014288944..5d3836639 100644
--- a/src/util/scheduler.c
+++ b/src/util/scheduler.c
@@ -2022,99 +2022,109 @@ GNUNET_SCHEDULER_do_work (struct GNUNET_SCHEDULER_Handle *sh)
     if (timeout.abs_value_us > now.abs_value_us)
     {
       /**
-       * The driver called this function before the current timeout was
-       * reached (and no FD tasks are ready). This can happen in the
-       * rare case when the system time is changed while the driver is
-       * waiting for the timeout, so we handle this gracefully. It might
-       * also be a programming error in the driver though.
+       * The event loop called this function before the current timeout was
+       * reached (and no FD tasks are ready). This is acceptable if
+       *
+       * - the system time was changed while the driver was waiting for
+       *   the timeout
+       * - an external event loop called GNUnet API functions outside of
+       *   the callbacks called in GNUNET_SCHEDULER_do_work and thus 
+       *   wasn't notified about the new timeout
+       *
+       * It might also mean we are busy-waiting because of a programming
+       * error in the external event loop.
        */
       LOG (GNUNET_ERROR_TYPE_DEBUG,
            "GNUNET_SCHEDULER_do_work did not find any ready "
            "tasks and timeout has not been reached yet.\n");
-      return GNUNET_NO;
     }
-    /**
-     * the current timeout was reached but no ready tasks were found,
-     * internal scheduler error!
-     */
-    GNUNET_assert (0);
-  }
-
-  /* find out which task priority level we are going to
-     process this time */
-  max_priority_added = GNUNET_SCHEDULER_PRIORITY_KEEP;
-  GNUNET_assert (NULL == ready_head[GNUNET_SCHEDULER_PRIORITY_KEEP]);
-  /* yes, p>0 is correct, 0 is "KEEP" which should
-   * always be an empty queue (see assertion)! */
-  for (p = GNUNET_SCHEDULER_PRIORITY_COUNT - 1; p > 0; p--)
-  {
-    pos = ready_head[p];
-    if (NULL != pos)
-      break;
+    else
+    {
+      /**
+       * the current timeout was reached but no ready tasks were found,
+       * internal scheduler error!
+       */
+      GNUNET_assert (0);
+    }
   }
-  GNUNET_assert (NULL != pos);        /* ready_count wrong? */
-
-  /* process all tasks at this priority level, then yield */
-  while (NULL != (pos = ready_head[p]))
+  else
   {
-    GNUNET_CONTAINER_DLL_remove (ready_head[p],
-         ready_tail[p],
-         pos);
-    ready_count--;
-    current_priority = pos->priority;
-    current_lifeness = pos->lifeness;
-    active_task = pos;
-#if PROFILE_DELAYS
-    if (GNUNET_TIME_absolute_get_duration (pos->start_time).rel_value_us >
-        DELAY_THRESHOLD.rel_value_us)
+    /* find out which task priority level we are going to
+       process this time */
+    max_priority_added = GNUNET_SCHEDULER_PRIORITY_KEEP;
+    GNUNET_assert (NULL == ready_head[GNUNET_SCHEDULER_PRIORITY_KEEP]);
+    /* yes, p>0 is correct, 0 is "KEEP" which should
+     * always be an empty queue (see assertion)! */
+    for (p = GNUNET_SCHEDULER_PRIORITY_COUNT - 1; p > 0; p--)
     {
-      LOG (GNUNET_ERROR_TYPE_DEBUG,
-           "Task %p took %s to be scheduled\n",
-           pos,
-           GNUNET_STRINGS_relative_time_to_string (GNUNET_TIME_absolute_get_duration (pos->start_time),
-                                                   GNUNET_YES));
+      pos = ready_head[p];
+      if (NULL != pos)
+        break;
     }
-#endif
-    tc.reason = pos->reason;
-    GNUNET_NETWORK_fdset_zero (sh->rs);
-    GNUNET_NETWORK_fdset_zero (sh->ws);
-    // FIXME: do we have to remove FdInfos from fds if they are not ready?
-    tc.fds_len = pos->fds_len;
-    tc.fds = pos->fds;
-    for (unsigned int i = 0; i != pos->fds_len; ++i)
+    GNUNET_assert (NULL != pos);        /* ready_count wrong? */
+
+    /* process all tasks at this priority level, then yield */
+    while (NULL != (pos = ready_head[p]))
     {
-      struct GNUNET_SCHEDULER_FdInfo *fdi = &pos->fds[i];
-      if (0 != (GNUNET_SCHEDULER_ET_IN & fdi->et))
+      GNUNET_CONTAINER_DLL_remove (ready_head[p],
+           ready_tail[p],
+           pos);
+      ready_count--;
+      current_priority = pos->priority;
+      current_lifeness = pos->lifeness;
+      active_task = pos;
+#if PROFILE_DELAYS
+      if (GNUNET_TIME_absolute_get_duration (pos->start_time).rel_value_us >
+          DELAY_THRESHOLD.rel_value_us)
       {
-        GNUNET_NETWORK_fdset_set_native (sh->rs,
-                                         fdi->sock);
+        LOG (GNUNET_ERROR_TYPE_DEBUG,
+             "Task %p took %s to be scheduled\n",
+             pos,
+             GNUNET_STRINGS_relative_time_to_string (GNUNET_TIME_absolute_get_duration (pos->start_time),
+                                                     GNUNET_YES));
       }
-      if (0 != (GNUNET_SCHEDULER_ET_OUT & fdi->et))
+#endif
+      tc.reason = pos->reason;
+      GNUNET_NETWORK_fdset_zero (sh->rs);
+      GNUNET_NETWORK_fdset_zero (sh->ws);
+      // FIXME: do we have to remove FdInfos from fds if they are not ready?
+      tc.fds_len = pos->fds_len;
+      tc.fds = pos->fds;
+      for (unsigned int i = 0; i != pos->fds_len; ++i)
       {
-        GNUNET_NETWORK_fdset_set_native (sh->ws,
-                                         fdi->sock);
+        struct GNUNET_SCHEDULER_FdInfo *fdi = &pos->fds[i];
+        if (0 != (GNUNET_SCHEDULER_ET_IN & fdi->et))
+        {
+          GNUNET_NETWORK_fdset_set_native (sh->rs,
+                                           fdi->sock);
+        }
+        if (0 != (GNUNET_SCHEDULER_ET_OUT & fdi->et))
+        {
+          GNUNET_NETWORK_fdset_set_native (sh->ws,
+                                           fdi->sock);
+        }
       }
-    }
-    tc.read_ready = sh->rs;
-    tc.write_ready = sh->ws;
-    LOG (GNUNET_ERROR_TYPE_DEBUG,
-         "Running task %p\n",
-         pos);
-    GNUNET_assert (NULL != pos->callback);
-    pos->callback (pos->callback_cls);
-    if (NULL != pos->fds)
-    {
-      int del_result = scheduler_driver->del (scheduler_driver->cls, pos);
-      if (GNUNET_OK != del_result)
+      tc.read_ready = sh->rs;
+      tc.write_ready = sh->ws;
+      LOG (GNUNET_ERROR_TYPE_DEBUG,
+           "Running task %p\n",
+           pos);
+      GNUNET_assert (NULL != pos->callback);
+      pos->callback (pos->callback_cls);
+      if (NULL != pos->fds)
       {
-        LOG (GNUNET_ERROR_TYPE_ERROR,
-           "driver could not delete task %p\n", pos);
-        GNUNET_assert (0);
+        int del_result = scheduler_driver->del (scheduler_driver->cls, pos);
+        if (GNUNET_OK != del_result)
+        {
+          LOG (GNUNET_ERROR_TYPE_ERROR,
+             "driver could not delete task %p\n", pos);
+          GNUNET_assert (0);
+        }
       }
+      active_task = NULL;
+      dump_backtrace (pos);
+      destroy_task (pos);
     }
-    active_task = NULL;
-    dump_backtrace (pos);
-    destroy_task (pos);
   }
   shutdown_if_no_lifeness ();
   if (0 == ready_count)