zephyr/kernel/timer.c

/*
 * Copyright (c) 1997-2016 Wind River Systems, Inc.
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <kernel.h>
#include <debug/object_tracing_common.h>
#include <init.h>
#include <wait_q.h>
#include <syscall_handler.h>
#include <stdbool.h>
#include <spinlock.h>

static struct k_spinlock lock;

#ifdef CONFIG_OBJECT_TRACING

struct k_timer *_trace_list_k_timer;

/*
 * Complete initialization of statically defined timers.
 */
static int init_timer_module(struct device *dev)
{
	ARG_UNUSED(dev);

	Z_STRUCT_SECTION_FOREACH(k_timer, timer) {
		SYS_TRACING_OBJ_INIT(k_timer, timer);
	}
	return 0;
}

SYS_INIT(init_timer_module, PRE_KERNEL_1, CONFIG_KERNEL_INIT_PRIORITY_OBJECTS);

#endif /* CONFIG_OBJECT_TRACING */

/**
 * @brief Handle expiration of a kernel timer object.
 *
 * @param t  Timeout used by the timer.
 *
 * @return N/A
 */
void z_timer_expiration_handler(struct _timeout *t)
{
	struct k_timer *timer = CONTAINER_OF(t, struct k_timer, timeout);
	struct k_thread *thread;

	/*
	 * if the timer is periodic, start it again; don't add _TICK_ALIGN
	 * since we're already aligned to a tick boundary
	 */
	if (timer->period > 0) {
		z_add_timeout(&timer->timeout, z_timer_expiration_handler,
			     timer->period);
	}

	/* update timer's status */
	timer->status += 1U;

	/* invoke timer expiry function */
	if (timer->expiry_fn != NULL) {
		timer->expiry_fn(timer);
	}

	thread = z_waitq_head(&timer->wait_q);

	if (thread == NULL) {
		return;
	}

	/*
	 * Interrupts _DO NOT_ have to be locked in this specific
	 * instance of thread unpending because a) this is the only
	 * place a thread can be taken off this pend queue, and b) the
	 * only place a thread can be put on the pend queue is at
	 * thread level, which of course cannot interrupt the current
	 * context.
	 */
	z_unpend_thread_no_timeout(thread);

	z_ready_thread(thread);

	z_set_thread_return_value(thread, 0);
}


void k_timer_init(struct k_timer *timer,
			 k_timer_expiry_t expiry_fn,
			 k_timer_stop_t stop_fn)
{
	timer->expiry_fn = expiry_fn;
	timer->stop_fn = stop_fn;
	timer->status = 0U;

	z_waitq_init(&timer->wait_q);
	z_init_timeout(&timer->timeout, z_timer_expiration_handler);
	SYS_TRACING_OBJ_INIT(k_timer, timer);

	timer->user_data = NULL;

	z_object_init(timer);
}


void z_impl_k_timer_start(struct k_timer *timer, s32_t duration, s32_t period)
{
	__ASSERT(duration >= 0 && period >= 0 &&
		 (duration != 0 || period != 0), "invalid parameters\n");

	volatile s32_t period_in_ticks, duration_in_ticks;

	period_in_ticks = z_ms_to_ticks(period);
	duration_in_ticks = z_ms_to_ticks(duration);

	(void)z_abort_timeout(&timer->timeout);
	timer->period = period_in_ticks;
	timer->status = 0U;
	z_add_timeout(&timer->timeout, z_timer_expiration_handler,
		     duration_in_ticks);
}

#ifdef CONFIG_USERSPACE
Z_SYSCALL_HANDLER(k_timer_start, timer, duration_p, period_p)
{
	s32_t duration, period;

	duration = (s32_t)duration_p;
	period = (s32_t)period_p;

	Z_OOPS(Z_SYSCALL_VERIFY(duration >= 0 && period >= 0 &&
				(duration != 0 || period != 0)));
	Z_OOPS(Z_SYSCALL_OBJ(timer, K_OBJ_TIMER));
	z_impl_k_timer_start((struct k_timer *)timer, duration, period);
	return 0;
}
#endif

void z_impl_k_timer_stop(struct k_timer *timer)
{
	int inactive = z_abort_timeout(&timer->timeout) != 0;

	if (inactive) {
		return;
	}

	if (timer->stop_fn != NULL) {
		timer->stop_fn(timer);
	}

	struct k_thread *pending_thread = z_unpend1_no_timeout(&timer->wait_q);

	if (pending_thread != NULL) {
		z_ready_thread(pending_thread);
		z_reschedule_unlocked();
	}
}

#ifdef CONFIG_USERSPACE
Z_SYSCALL_HANDLER1_SIMPLE_VOID(k_timer_stop, K_OBJ_TIMER, struct k_timer *);
#endif

u32_t z_impl_k_timer_status_get(struct k_timer *timer)
{
	k_spinlock_key_t key = k_spin_lock(&lock);
	u32_t result = timer->status;

	timer->status = 0U;
	k_spin_unlock(&lock, key);

	return result;
}

#ifdef CONFIG_USERSPACE
Z_SYSCALL_HANDLER1_SIMPLE(k_timer_status_get, K_OBJ_TIMER, struct k_timer *);
#endif

u32_t z_impl_k_timer_status_sync(struct k_timer *timer)
{
	__ASSERT(!z_is_in_isr(), "");

	k_spinlock_key_t key = k_spin_lock(&lock);
	u32_t result = timer->status;

	if (result == 0U) {
		if (!z_is_inactive_timeout(&timer->timeout)) {
			/* wait for timer to expire or stop */
			(void)z_pend_curr(&lock, key, &timer->wait_q, K_FOREVER);

			/* get updated timer status */
			key = k_spin_lock(&lock);
			result = timer->status;
		} else {
			/* timer is already stopped */
		}
	} else {
		/* timer has already expired at least once */
	}

	timer->status = 0U;
	k_spin_unlock(&lock, key);

	return result;
}

#ifdef CONFIG_USERSPACE
Z_SYSCALL_HANDLER1_SIMPLE(k_timer_status_sync, K_OBJ_TIMER, struct k_timer *);
#endif

#ifdef CONFIG_USERSPACE
Z_SYSCALL_HANDLER1_SIMPLE(k_timer_remaining_get, K_OBJ_TIMER, struct k_timer *);
Z_SYSCALL_HANDLER1_SIMPLE(k_timer_user_data_get, K_OBJ_TIMER, struct k_timer *);

Z_SYSCALL_HANDLER(k_timer_user_data_set, timer, user_data)
{
	Z_OOPS(Z_SYSCALL_OBJ(timer, K_OBJ_TIMER));
	z_impl_k_timer_user_data_set((struct k_timer *)timer, (void *)user_data);
	return 0;
}
#endif