incubator-nuttx/sched/timer/timer_setitimer.c

132 lines
4.8 KiB
C

/****************************************************************************
* sched/timer/timer_setitimer.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <errno.h>
#include <time.h>
#include <sys/time.h>
#include "sched/sched.h"
#ifndef CONFIG_DISABLE_POSIX_TIMERS
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: setitimer
*
* Description:
* The setitimer() function sets the time until the next expiration of
* the timer specified by which from the it_value member of the value
* argument and arm the timer if the it_value member of value is non-zero.
* If the specified timer was already armed when setitimer() is
* called, this call will reset the time until next expiration to the
* value specified. If the it_value member of value is zero, the timer
* will be disarmed. The effect of disarming or resetting a timer with
* pending expiration notifications is unspecified.
*
* The reload value of the timer will be set to the value specified by the
* it_interval member of value. When a timer is armed with a non-zero
* it_interval, a periodic (or repetitive) timer is specified.
*
* Time values that are between two consecutive non-negative integer
* multiples of the resolution of the specified timer will be rounded up
* to the larger multiple of the resolution. Quantization error will not
* cause the timer to expire earlier than the rounded time value.
*
* If the argument ovalue is not NULL, the setitimer() function will
* store, in the location referenced by ovalue, a value representing the
* previous amount of time before the timer would have expired, or zero if
* the timer was disarmed, together with the previous timer reload value.
* Timers will not expire before their scheduled time.
*
* Input Parameters:
* which - The predefined timer id
* value - Specifies the timer value to set
* ovalue - A location in which to return the time remaining from the
* previous timer setting.
*
* Returned Value:
* If the setitimer() succeeds, a value of 0 (OK) will be returned.
* If an error occurs, the value -1 (ERROR) will be returned, and errno set
* to indicate the error.
*
* EINVAL - The which argument does not correspond to an predefined ID.
* EINVAL - A value structure specified a microsecond value less than zero
* or greater than or equal to 1000 million, and the it_value member of
* that structure did not specify zero seconds and nanoseconds.
*
* Assumptions:
*
****************************************************************************/
int setitimer(int which, FAR const struct itimerval *value,
FAR struct itimerval *ovalue)
{
FAR struct tcb_s *rtcb = this_task();
struct itimerspec spec;
struct itimerspec ospec;
irqstate_t flags;
int ret = OK;
if (which != ITIMER_REAL || !value)
{
set_errno(EINVAL);
return ERROR;
}
if (!rtcb->group->itimer)
{
flags = enter_critical_section();
if (!rtcb->group->itimer)
{
ret = timer_create(CLOCK_REALTIME, NULL, &rtcb->group->itimer);
}
leave_critical_section(flags);
if (ret != OK)
{
return ret;
}
}
TIMEVAL_TO_TIMESPEC(&value->it_value, &spec.it_value);
TIMEVAL_TO_TIMESPEC(&value->it_interval, &spec.it_interval);
ret = timer_settime(rtcb->group->itimer, 0, &spec, ovalue ? &ospec : NULL);
if (ret == OK && ovalue)
{
TIMESPEC_TO_TIMEVAL(&ovalue->it_value, &ospec.it_value);
TIMESPEC_TO_TIMEVAL(&ovalue->it_interval, &ospec.it_interval);
}
return ret;
}
#endif /* CONFIG_DISABLE_POSIX_TIMERS */