+ list_for_each_entry_safe(t, tmp, &s->pre_select_list, pre_select_node) {
+ char *tmp_msg;
+ tmp_msg = make_message("%s%p\tpre\t%s\n", msg? msg : "", t, t->status);
+ free(msg);
+ msg = tmp_msg;
+ }
+ list_for_each_entry_safe(t, tmp, &s->post_select_list, post_select_node) {
+ char *tmp_msg;
+// if (t->pre_select)
+// continue;
+ tmp_msg = make_message("%s%p\tpost\t%s\n", msg? msg : "", t, t->status);
+ free(msg);
+ msg = tmp_msg;
+ }
+ //PARA_DEBUG_LOG("task list:\n%s", msg);
+ return msg;
+}
+
+/**
+ * Set the notification value of a task.
+ *
+ * \param t The task to notify.
+ * \param err A positive error code.
+ *
+ * Tasks which honor notifications are supposed to call \ref
+ * task_get_notification() in their post_select function and act on the
+ * returned notification value.
+ *
+ * If the scheduler detects during its pre_select loop that at least one task
+ * has been notified, the loop terminates, and the post_select methods of all
+ * taks are immediately called again.
+ *
+ * The notification for a task is reset after the call to its post_select
+ * method.
+ *
+ * \sa \ref task_get_notification().
+ */
+void task_notify(struct task *t, int err)
+{
+ assert(err > 0);
+ if (t->notification == -err) /* ignore subsequent notifications */
+ return;
+ PARA_INFO_LOG("notifying task %s: %s\n", t->status, para_strerror(err));
+ t->notification = -err;
+}
+
+/**
+ * Return the notification value of a task.
+ *
+ * \param t The task to get the notification value from.
+ *
+ * \return The notification value. If this is negative, the task has been
+ * notified by another task. Tasks are supposed to check for notifications by
+ * calling this function from their post_select method.
+ *
+ * \sa \ref task_notify().
+ */
+int task_get_notification(struct task *t)
+{
+ return t->notification;
+}
+
+/**
+ * Set the select timeout to the minimal possible value.
+ *
+ * \param s Pointer to the scheduler struct.
+ *
+ * This causes the next select() call to return immediately.
+ */
+void sched_min_delay(struct sched *s)
+{
+ s->select_timeout.tv_sec = s->select_timeout.tv_usec = 0;
+}
+
+/**
+ * Impose an upper bound for the timeout of the next select() call.
+ *
+ * \param to Maximal allowed timeout.
+ * \param s Pointer to the scheduler struct.
+ *
+ * If the current scheduler timeout is already smaller than \a to, this
+ * function does nothing. Otherwise the timeout for the next select() call is
+ * set to the given value.
+ *
+ * \sa sched_request_timeout_ms().
+ */
+void sched_request_timeout(struct timeval *to, struct sched *s)
+{
+ if (tv_diff(&s->select_timeout, to, NULL) > 0)
+ s->select_timeout = *to;
+}