incubator-nuttx/sched/timer/timer_getoverrun.c

84 lines
3.5 KiB
C

/****************************************************************************
* sched/timer/timer_getoverrun.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 <time.h>
#include <errno.h>
#include "timer/timer.h"
#ifndef CONFIG_DISABLE_POSIX_TIMERS
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: timer_getoverrun
*
* Description:
* Only a single signal will be queued to the process for a given timer at
* any point in time. When a timer for which a signal is still pending
* expires, no signal will be queued, and a timer overrun will occur. When
* a timer expiration signal is delivered to or accepted by a process, if
* the implementation supports the Realtime Signals Extension, the
* timer_getoverrun() function will return the timer expiration overrun
* count for the specified timer. The overrun count returned contains the
* number of extra timer expirations that occurred between the time the
* signal was generated (queued) and when it was delivered or accepted, up
* to but not including an implementation-defined maximum of
* DELAYTIMER_MAX. If the number of such extra expirations is greater than
* or equal to DELAYTIMER_MAX, then the overrun count will be set to
* DELAYTIMER_MAX. The value returned by timer_getoverrun() will apply to
* the most recent expiration signal delivery or acceptance for the timer.
* If no expiration signal has been delivered for the timer, or if the
* Realtime Signals Extension is not supported, the return value of
* timer_getoverrun() is unspecified.
*
* Input Parameters:
* timerid - The pre-thread timer, previously created by the call to
* timer_create(), whose overrun count will be returned..
*
* Returned Value:
* If the timer_getoverrun() function succeeds, it will return the timer
* expiration overrun count as explained above. timer_getoverrun() will
* fail if:
*
* EINVAL - The timerid argument does not correspond to an ID returned by
* timer_create() but not yet deleted by timer_delete().
*
* Assumptions:
*
****************************************************************************/
int timer_getoverrun(timer_t timerid)
{
UNUSED(timerid);
set_errno(EINVAL);
return ERROR;
}
#endif /* CONFIG_DISABLE_POSIX_TIMERS */