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px4-firmware/nuttx/sched/timer_settime.c

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/********************************************************************************
* sched/timer_settime.c
*
* Copyright (C) 2007-2010 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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
* COPYRIGHT OWNER OR CONTRIBUTORS 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.
*
********************************************************************************/
/********************************************************************************
* Included Files
********************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <time.h>
#include <string.h>
#include <errno.h>
#include "os_internal.h"
#include "clock_internal.h"
#include "sig_internal.h"
#include "timer_internal.h"
#ifndef CONFIG_DISABLE_POSIX_TIMERS
/********************************************************************************
* Definitions
********************************************************************************/
/********************************************************************************
* Private Data
********************************************************************************/
/********************************************************************************
* Public Data
********************************************************************************/
/********************************************************************************
* Private Function Prototypes
********************************************************************************/
static void inline timer_sigqueue(FAR struct posix_timer_s *timer);
static void inline timer_restart(FAR struct posix_timer_s *timer, uint32_t itimer);
static void timer_timeout(int argc, uint32_t itimer);
/********************************************************************************
* Private Functions
********************************************************************************/
/********************************************************************************
* Name: timer_sigqueue
*
* Description:
* This function basically reimplements sigqueue() so that the si_code can
* be correctly set to SI_TIMER
*
* Parameters:
* timer - A reference to the POSIX timer that just timed out
*
* Return Value:
* None
*
* Assumptions:
* This function executes in the context of the watchod timer interrupt.
*
********************************************************************************/
static void inline timer_sigqueue(FAR struct posix_timer_s *timer)
{
FAR _TCB *tcb;
/* Get the TCB of the receiving task */
tcb = sched_gettcb(timer->pt_owner);
if (tcb)
{
siginfo_t info;
/* Create the siginfo structure */
info.si_signo = timer->pt_signo;
info.si_code = SI_TIMER;
#ifdef CONFIG_CAN_PASS_STRUCTS
info.si_value = timer->pt_value;
#else
info.si_value.sival_ptr = timer->pt_value.sival_ptr;
#endif
#ifdef CONFIG_SCHED_HAVE_PARENT
info.si_pid = 0; /* Not applicable */
info.si_status = OK;
#endif
/* Send the signal */
(void)sig_received(tcb, &info);
}
}
/********************************************************************************
* Name: timer_restart
*
* Description:
* If a periodic timer has been selected, then restart the watchdog.
*
* Parameters:
* timer - A reference to the POSIX timer that just timed out
*
* Return Value:
* None
*
* Assumptions:
* This function executes in the context of the watchod timer interrupt.
*
********************************************************************************/
static void inline timer_restart(FAR struct posix_timer_s *timer, uint32_t itimer)
{
/* If this is a repetitive timer, then restart the watchdog */
if (timer->pt_delay)
{
timer->pt_last = timer->pt_delay;
(void)wd_start(timer->pt_wdog, timer->pt_delay, (wdentry_t)timer_timeout,
1, itimer);
}
}
/********************************************************************************
* Name: timer_timeout
*
* Description:
* This function is called if the timeout elapses before the condition is
* signaled.
*
* Parameters:
* argc - the number of arguments (should be 1)
* itimer - A reference to the POSIX timer that just timed out
* signo - The signal to use to wake up the task
*
* Return Value:
* None
*
* Assumptions:
* This function executes in the context of the watchod timer interrupt.
*
********************************************************************************/
static void timer_timeout(int argc, uint32_t itimer)
{
#ifndef CONFIG_CAN_PASS_STRUCTS
/* On many small machines, pointers are encoded and cannot be simply cast from
* uint32_t to _TCB*. The following union works around this (see wdogparm_t).
*/
union
{
FAR struct posix_timer_s *timer;
uint32_t itimer;
} u;
u.itimer = itimer;
/* Send the specified signal to the specified task. Increment the reference
* count on the timer first so that will not be deleted until after the
* signal handler returns.
*/
u.timer->pt_crefs++;
timer_sigqueue(u.timer);
/* Release the reference. timer_release will return nonzero if the timer
* was not deleted.
*/
if (timer_release(u.timer))
{
/* If this is a repetitive timer, the restart the watchdog */
timer_restart(u.timer, itimer);
}
#else
/* (casting to uintptr_t first eliminates complaints on some architectures
* where the sizeof uint32_t is different from the size of a pointer).
*/
FAR struct posix_timer_s *timer = (FAR struct posix_timer_s *)((uintptr_t)itimer);
/* Send the specified signal to the specified task. Increment the reference
* count on the timer first so that will not be deleted until after the
* signal handler returns.
*/
timer->pt_crefs++;
timer_sigqueue(timer);
/* Release the reference. timer_release will return nonzero if the timer
* was not deleted.
*/
if (timer_release(timer))
{
/* If this is a repetitive timer, the restart the watchdog */
timer_restart(timer, itimer);
}
#endif
}
/********************************************************************************
* Public Functions
********************************************************************************/
/********************************************************************************
* Name: timer_settime
*
* Description:
* The timer_settime() function sets the time until the next expiration of the
* timer specified by timerid 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 timer_settime() 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.
*
* If the flag TIMER_ABSTIME is not set in the argument flags, timer_settime()
* will behave as if the time until next expiration is set to be equal to the
* interval specified by the it_value member of value. That is, the timer will
* expire in it_value nanoseconds from when the call is made. If the flag
* TIMER_ABSTIME is set in the argument flags, timer_settime() will behave as
* if the time until next expiration is set to be equal to the difference between
* the absolute time specified by the it_value member of value and the current
* value of the clock associated with timerid. That is, the timer will expire
* when the clock reaches the value specified by the it_value member of value.
* If the specified time has already passed, the function will succeed and the
* expiration notification will be made.
*
* 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 timer_settime() 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.
*
* Parameters:
* timerid - The pre-thread timer, previously created by the call to
* timer_create(), to be be set.
* flags - Specifie characteristics of the timer (see above)
* value - Specifies the timer value to set
* ovalue - A location in which to return the time remaining from the previous
* timer setting. (ignored)
*
* Return Value:
* If the timer_settime() 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 timerid argument does not correspond to an ID returned by
* timer_create() but not yet deleted by timer_delete().
* EINVAL - A value structure specified a nanosecond 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 timer_settime(timer_t timerid, int flags, FAR const struct itimerspec *value,
FAR struct itimerspec *ovalue)
{
FAR struct posix_timer_s *timer = (FAR struct posix_timer_s *)timerid;
irqstate_t state;
int delay;
int ret = OK;
/* Some sanity checks */
if (!timer || !value)
{
errno = EINVAL;
return ERROR;
}
/* Disarm the timer (in case the timer was already armed when timer_settime()
* is called).
*/
(void)wd_cancel(timer->pt_wdog);
/* If the it_value member of value is zero, the timer will not be re-armed */
if (value->it_value.tv_sec <= 0 && value->it_value.tv_nsec <= 0)
{
return OK;
}
/* Setup up any repititive timer */
if (value->it_interval.tv_sec > 0 || value->it_interval.tv_nsec > 0)
{
(void)clock_time2ticks(&value->it_interval, &timer->pt_delay);
}
else
{
timer->pt_delay = 0;
}
/* We need to disable timer interrupts through the following section so
* that the system timer is stable.
*/
state = irqsave();
/* Check if abstime is selected */
if ((flags & TIMER_ABSTIME) != 0)
{
#ifdef CONFIG_DISABLE_CLOCK
/* Absolute timing depends upon having access to clock functionality */
errno = ENOSYS;
return ERROR;
#else
/* Calculate a delay corresponding to the absolute time in 'value'.
* NOTE: We have internal knowledge the clock_abstime2ticks only
* returns an error if clockid != CLOCK_REALTIME.
*/
(void)clock_abstime2ticks(CLOCK_REALTIME, &value->it_value, &delay);
#endif
}
else
{
/* Calculate a delay assuming that 'value' holds the relative time
* to wait. We have internal knowledge that clock_time2ticks always
* returns success.
*/
(void)clock_time2ticks(&value->it_value, &delay);
}
/* If the time is in the past or now, then set up the next interval
* instead (assuming a repititive timer).
*/
if (delay <= 0)
{
delay = timer->pt_delay;
}
/* Then start the watchdog */
if (delay > 0)
{
timer->pt_last = delay;
ret = wd_start(timer->pt_wdog, delay, (wdentry_t)timer_timeout,
1, (uint32_t)((uintptr_t)timer));
}
irqrestore(state);
return ret;
}
#endif /* CONFIG_DISABLE_POSIX_TIMERS */
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