WebSVN – HelenOS-historic – Diff – /kernel/trunk/generic/src/time/timeout.c

 /*
  * Copyright (C) 2001-2004 Jakub Jermar
  * All rights reserved.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
+ *
  * - Redistributions of source code must retain the above copyright
  *   notice, this list of conditions and the following disclaimer.
  * - Redistributions in binary form must reproduce the above copyright
  *   notice, this list of conditions and the following disclaimer in the
  *   documentation and/or other materials provided with the distribution.
  * - The name of the author may not be used to endorse or promote products
  *   derived from this software without specific prior written permission.
+ *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 #include <time/timeout.h>
 #include <typedefs.h>
 #include <arch/types.h>
 #include <config.h>
 #include <panic.h>
 #include <synch/spinlock.h>
 #include <func.h>
 #include <cpu.h>
 #include <print.h>
 #include <arch/asm.h>
 #include <arch.h>
+/** Initialize timeouts
+ *
+ * Initialize kernel timeouts.
+ *
+ */
 void timeout_init(void)
+{
     spinlock_initialize(&CPU->timeoutlock);
     list_initialize(&CPU->timeout_active_head);
+}
+/** Initialize empty timeout list
+ *
+ * Initialize the timeout list to be empty.
+ *
+ * @param t Timeout list to be initialized.
+ *
+ */
 void timeout_reinitialize(timeout_t *t)
+{
     t->cpu = NULL;
     t->ticks = 0;
     t->handler = NULL;
     t->arg = NULL;
     link_initialize(&t->link);
+}
+/** Initialize timeout list
+ *
+ * Initialize the timeout list and its spinlock.
+ *
+ * @param t Timeout list to be initialized.
+ *
+ */
 void timeout_initialize(timeout_t *t)
+{
     spinlock_initialize(&t->lock);
     timeout_reinitialize(t);
+}
+/** Register timeout callback
-/*
+ *
+ * Insert the timeout handler f (with argument arg)
+ * to the timeout list and make it execute in
+ * time microseconds (or slightly more).
+ *
+ * @param t    Timeout list.
- * This function registers f for execution in about time microseconds.
+ * @patam time Number of usec in the future to execute
+ *             the handler.
+ * @param f    Timeout handler function.
+ * @param arg  Timeout handler argument.
+ *
  */
 void timeout_register(timeout_t *t, __u64 time, timeout_handler f, void *arg)
+{
     timeout_t *hlp;
     link_t *l, *m;
     pri_t pri;
     __u64 sum;
     pri = cpu_priority_high();
     spinlock_lock(&CPU->timeoutlock);
     spinlock_lock(&t->lock);
     if (t->cpu)
         panic("t->cpu != 0");
     t->cpu = CPU;
     t->ticks = us2ticks(time);
     t->handler = f;
     t->arg = arg;
     /*
      * Insert t into the active timeouts list according to t->ticks.
      */
     sum = 0;
     l = CPU->timeout_active_head.next;
     while (l != &CPU->timeout_active_head) {
         hlp = list_get_instance(l, timeout_t, link);
         spinlock_lock(&hlp->lock);
         if (t->ticks < sum + hlp->ticks) {
             spinlock_unlock(&hlp->lock);
             break;
+        }
         sum += hlp->ticks;
         spinlock_unlock(&hlp->lock);
         l = l->next;
+    }
     m = l->prev;
     list_prepend(&t->link, m); /* avoid using l->prev */
     /*
      * Adjust t->ticks according to ticks accumulated in h's predecessors.
      */
     t->ticks -= sum;
     /*
      * Decrease ticks of t's immediate succesor by t->ticks.
      */
     if (l != &CPU->timeout_active_head) {
         spinlock_lock(&hlp->lock);
         hlp->ticks -= t->ticks;
         spinlock_unlock(&hlp->lock);
+    }
     spinlock_unlock(&t->lock);
     spinlock_unlock(&CPU->timeoutlock);
     cpu_priority_restore(pri);
+}
+/** Unregister timeout callback
+ *
+ * Remove timeout from timeout list.
+ *
+ * @param t Timeout to unregister.
+ *
+ */
 int timeout_unregister(timeout_t *t)
+{
     timeout_t *hlp;
     link_t *l;
     pri_t pri;
 grab_locks:
     pri = cpu_priority_high();
     spinlock_lock(&t->lock);
     if (!t->cpu) {
         spinlock_unlock(&t->lock);
         cpu_priority_restore(pri);
         return 0;
+    }
     if (!spinlock_trylock(&t->cpu->timeoutlock)) {
         spinlock_unlock(&t->lock);
         cpu_priority_restore(pri);
         goto grab_locks;
+    }
     /*
      * Now we know for sure that t hasn't been activated yet
      * and is lurking in t->cpu->timeout_active_head queue.
      */
     l = t->link.next;
     if (l != &t->cpu->timeout_active_head) {
         hlp = list_get_instance(l, timeout_t, link);
         spinlock_lock(&hlp->lock);
         hlp->ticks += t->ticks;
         spinlock_unlock(&hlp->lock);
+    }
     list_remove(&t->link);
     spinlock_unlock(&t->cpu->timeoutlock);
     timeout_reinitialize(t);
     spinlock_unlock(&t->lock);
     cpu_priority_restore(pri);
     return 1;
+}

Subversion Repositories HelenOS-historic

(root)/kernel/trunk/generic/src/time/timeout.c @ 1780 – Rev 103 → 107