/*
* Copyright (c) 2001-2004 Jakub Jermar
* Copyright (c) 2022 Jiří Zárevúcky
* 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.
*/
/** @addtogroup kernel_time
* @{
*/
/**
* @file
* @brief Timeout management functions.
*/
#include <time/timeout.h>
#include <typedefs.h>
#include <config.h>
#include <panic.h>
#include <synch/spinlock.h>
#include <halt.h>
#include <cpu.h>
#include <arch/asm.h>
#include <arch.h>
/** Initialize timeouts
*
* Initialize kernel timeouts.
*
*/
void timeout_init(void)
{
irq_spinlock_initialize(&CPU->timeoutlock, "cpu.timeoutlock");
list_initialize(&CPU->timeout_active_list);
}
/** Initialize timeout
*
* Initialize all members including the lock.
*
* @param timeout Timeout to be initialized.
*
*/
void timeout_initialize(timeout_t *timeout)
{
link_initialize(&timeout->link);
timeout->cpu = NULL;
}
/* Only call when interrupts are disabled. */
deadline_t timeout_deadline_in_usec(uint32_t usec)
{
if (usec == 0)
return 0;
return CPU_LOCAL->current_clock_tick + us2ticks(usec);
}
static void timeout_register_deadline_locked(timeout_t *timeout, deadline_t deadline,
timeout_handler_t handler, void *arg)
{
assert(!link_in_use(&timeout->link));
*timeout = (timeout_t) {
.cpu = CPU,
.deadline = deadline,
.handler = handler,
.arg = arg,
.finished = ATOMIC_VAR_INIT(false),
};
/* Insert timeout into the active timeouts list according to timeout->deadline. */
link_t *last = list_last(&CPU->timeout_active_list);
if (last == NULL || timeout->deadline >= list_get_instance(last, timeout_t, link)->deadline) {
list_append(&timeout->link, &CPU->timeout_active_list);
} else {
for (link_t *cur = list_first(&CPU->timeout_active_list); cur != NULL;
cur = list_next(cur, &CPU->timeout_active_list)) {
if (timeout->deadline < list_get_instance(cur, timeout_t, link)->deadline) {
list_insert_before(&timeout->link, cur);
break;
}
}
}
}
/** Register timeout
*
* Insert timeout handler f (with argument arg)
* to timeout list and make it execute in
* time microseconds (or slightly more).
*
* @param timeout Timeout structure.
* @param time Number of usec in the future to execute the handler.
* @param handler Timeout handler function.
* @param arg Timeout handler argument.
*
*/
void timeout_register(timeout_t *timeout, uint64_t time,
timeout_handler_t handler, void *arg)
{
irq_spinlock_lock(&CPU->timeoutlock, true);
timeout_register_deadline_locked(timeout, timeout_deadline_in_usec(time), handler, arg);
irq_spinlock_unlock(&CPU->timeoutlock, true);
}
void timeout_register_deadline(timeout_t *timeout, deadline_t deadline,
timeout_handler_t handler, void *arg)
{
irq_spinlock_lock(&CPU->timeoutlock, true);
timeout_register_deadline_locked(timeout, deadline, handler, arg);
irq_spinlock_unlock(&CPU->timeoutlock, true);
}
/** Unregister timeout
*
* Remove timeout from timeout list.
*
* @param timeout Timeout to unregister.
*
* @return True on success, false on failure.
*
*/
bool timeout_unregister(timeout_t *timeout)
{
if (atomic_load_explicit(&timeout->finished, memory_order_acquire))
/* The timeout fired and finished already, no need to check the list. */
return false;
assert(timeout->cpu);
irq_spinlock_lock(&timeout->cpu->timeoutlock, true);
bool success = link_in_use(&timeout->link);
if (success) {
list_remove(&timeout->link);
}
irq_spinlock_unlock(&timeout->cpu->timeoutlock, true);
if (!success) {
/* Timeout was fired, we need to wait for the callback to finish. */
while (!atomic_load_explicit(&timeout->finished, memory_order_acquire))
cpu_spin_hint();
}
return success;
}
/** @}
*/