/*
* 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.
*/
/**
* @file timeout.c
* @brief Timeout management functions.
*/
#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 <arch/asm.h>
#include <arch.h>
/** Initialize timeouts
*
* Initialize kernel timeouts.
*
*/
void timeout_init(void)
{
spinlock_initialize(&CPU->timeoutlock, "timeout_lock");
list_initialize(&CPU->timeout_active_head);
}
/** Reinitialize timeout
*
* Initialize all members except the lock.
*
* @param t Timeout 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
*
* Initialize all members including the lock.
*
* @param t Timeout to be initialized.
*
*/
void timeout_initialize(timeout_t *t)
{
spinlock_initialize(&t->lock, "timeout_t_lock");
timeout_reinitialize(t);
}
/** Register timeout
*
* Insert timeout handler f (with argument arg)
* to timeout list and make it execute in
* time microseconds (or slightly more).
*
* @param t Timeout structure.
* @param 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_t f
, void *arg
) {
timeout_t *hlp = NULL;
link_t *l, *m;
ipl_t ipl;
__u64 sum;
ipl = interrupts_disable();
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);
interrupts_restore(ipl);
}
/** Unregister timeout
*
* Remove timeout from timeout list.
*
* @param t Timeout to unregister.
*
* @return true on success, false on failure.
*/
bool timeout_unregister(timeout_t *t)
{
timeout_t *hlp;
link_t *l;
ipl_t ipl;
grab_locks:
ipl = interrupts_disable();
spinlock_lock(&t->lock);
if (!t->cpu) {
spinlock_unlock(&t->lock);
interrupts_restore(ipl);
return false;
}
if (!spinlock_trylock(&t->cpu->timeoutlock)) {
spinlock_unlock(&t->lock);
interrupts_restore(ipl);
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);
interrupts_restore(ipl);
return true;
}