stdin/stdout: Streamline documentation of {pre,post}_select().

[paraslash.git] / sched.c

diff --git a/sched.c b/sched.c
index 1db9169b38b511918cc711fc28dcb667e1242e5f..4ca040f44f337a126ab24b4ec36fb297fa273687 100644 (file)
--- a/sched.c
+++ b/sched.c
@@ -1,8 +1,4 @@
-/*
- * Copyright (C) 2006 Andre Noll <maan@tuebingen.mpg.de>
- *
- * Licensed under the GPL v2. For licencing details see COPYING.
- */
+/* Copyright (C) 2006 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
 
 /** \file sched.c Paraslash's scheduling functions. */
 
@@ -66,7 +62,10 @@ static void sched_preselect(struct sched *s)
 
 static void unlink_and_free_task(struct task *t)
 {
-       PARA_INFO_LOG("freeing task %s\n", t->name);
+       PARA_INFO_LOG("freeing task %s (%s)\n", t->name, t->status < 0?
+               para_strerror(-t->status) :
+               (t->status == TS_DEAD? "[dead]" : "[running]"));
+
        list_del(&t->node);
        free(t->name);
        free(t);
@@ -138,12 +137,12 @@ int schedule(struct sched *s)
 again:
        FD_ZERO(&s->rfds);
        FD_ZERO(&s->wfds);
-       s->select_timeout = s->default_timeout;
+       s->timeout = s->default_timeout;
        s->max_fileno = -1;
        clock_get_realtime(&now_struct);
        sched_preselect(s);
        ret = s->select_function(s->max_fileno + 1, &s->rfds, &s->wfds,
-               &s->select_timeout);
+               s->timeout);
        if (ret < 0)
                return ret;
        if (ret == 0) {
@@ -169,7 +168,7 @@ again:
  * \param tptr Identifies the task to reap.
  *
  * This function is similar to wait(2) in that it returns information about a
- * terminated task and allows to release the resources associated with the
+ * terminated task which allows releasing the resources associated with the
  * task. Until this function is called, the terminated task remains in a zombie
  * state.
  *
@@ -245,7 +244,7 @@ struct task *task_register(struct task_info *info, struct sched *s)
        assert(info->post_select);
 
        if (!s->task_list.next)
-               INIT_LIST_HEAD(&s->task_list);
+               init_list_head(&s->task_list);
 
        t->info = *info;
        t->name = para_strdup(info->name);
@@ -371,7 +370,7 @@ void task_notify_all(struct sched *s, int err)
  */
 void sched_min_delay(struct sched *s)
 {
-       s->select_timeout.tv_sec = s->select_timeout.tv_usec = 0;
+       s->timeout = 0;
 }
 
 /**
@@ -384,12 +383,13 @@ void sched_min_delay(struct sched *s)
  * function does nothing. Otherwise the timeout for the next select() call is
  * set to the given value.
  *
- * \sa sched_request_timeout_ms().
+ * \sa \ref 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;
+       long unsigned ms = tv2ms(to);
+       if (s->timeout > ms)
+               s->timeout = ms;
 }
 
 /**
@@ -417,7 +417,7 @@ void sched_request_timeout_ms(long unsigned ms, struct sched *s)
  * \return If \a barrier is in the past, this function does nothing and returns
  * zero. Otherwise it returns one.
  *
- * \sa sched_request_barrier_or_min_delay().
+ * \sa \ref sched_request_barrier_or_min_delay().
  */
 int sched_request_barrier(struct timeval *barrier, struct sched *s)
 {
@@ -438,7 +438,7 @@ int sched_request_barrier(struct timeval *barrier, struct sched *s)
  * \return If \a barrier is in the past, this function requests a minimal
  * timeout and returns zero. Otherwise it returns one.
  *
- * \sa sched_min_delay(), sched_request_barrier().
+ * \sa \ref sched_min_delay(), \ref sched_request_barrier().
  */
 int sched_request_barrier_or_min_delay(struct timeval *barrier, struct sched *s)
 {
@@ -451,3 +451,45 @@ int sched_request_barrier_or_min_delay(struct timeval *barrier, struct sched *s)
        sched_request_timeout(&diff, s);
        return 1;
 }
+
+static void sched_fd_set(int fd, fd_set *fds, int *max_fileno)
+{
+       assert(fd >= 0 && fd < FD_SETSIZE);
+#if 0
+       {
+               int flags = fcntl(fd, F_GETFL);
+               if (!(flags & O_NONBLOCK)) {
+                       PARA_EMERG_LOG("fd %d is a blocking file descriptor\n", fd);
+                       exit(EXIT_FAILURE);
+               }
+       }
+#endif
+       FD_SET(fd, fds);
+       *max_fileno = PARA_MAX(*max_fileno, fd);
+}
+
+/**
+ * Instruct the scheduler to monitor an fd for readiness for reading.
+ *
+ * \param fd The file descriptor.
+ * \param s The scheduler.
+ *
+ * \sa \ref sched_monitor_writefd().
+ */
+void sched_monitor_readfd(int fd, struct sched *s)
+{
+       sched_fd_set(fd, &s->rfds, &s->max_fileno);
+}
+
+/**
+ * Instruct the scheduler to monitor an fd for readiness for writing.
+ *
+ * \param fd The file descriptor.
+ * \param s The scheduler.
+ *
+ * \sa \ref sched_monitor_readfd().
+ */
+void sched_monitor_writefd(int fd, struct sched *s)
+{
+       sched_fd_set(fd, &s->wfds, &s->max_fileno);
+}