354 lines
11 KiB
C
354 lines
11 KiB
C
/****************************************************************************
|
|
* sched/pthread/pthread_condtimedwait.c
|
|
*
|
|
* Copyright (C) 2007-2009, 2013-2016 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 <nuttx/compiler.h>
|
|
|
|
#include <stdint.h>
|
|
#include <unistd.h>
|
|
#include <pthread.h>
|
|
#include <signal.h>
|
|
#include <time.h>
|
|
#include <errno.h>
|
|
#include <assert.h>
|
|
#include <debug.h>
|
|
|
|
#include <nuttx/irq.h>
|
|
#include <nuttx/wdog.h>
|
|
#include <nuttx/cancelpt.h>
|
|
|
|
#include "sched/sched.h"
|
|
#include "pthread/pthread.h"
|
|
#include "clock/clock.h"
|
|
#include "signal/signal.h"
|
|
|
|
/****************************************************************************
|
|
* Private Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: pthread_condtimedout
|
|
*
|
|
* Description:
|
|
* This function is called if the timeout elapses before
|
|
* the condition is signaled.
|
|
*
|
|
* Parameters:
|
|
* argc - the number of arguments (should be 2)
|
|
* pid - the task ID of the task to wakeup
|
|
* signo - The signal to use to wake up the task
|
|
*
|
|
* Return Value:
|
|
* None
|
|
*
|
|
* Assumptions:
|
|
*
|
|
****************************************************************************/
|
|
|
|
static void pthread_condtimedout(int argc, uint32_t pid, uint32_t signo)
|
|
{
|
|
#ifdef HAVE_GROUP_MEMBERS
|
|
|
|
FAR struct tcb_s *tcb;
|
|
siginfo_t info;
|
|
|
|
/* The logic below if equivalent to sigqueue(), but uses sig_tcbdispatch()
|
|
* instead of sig_dispatch(). This avoids the group signal deliver logic
|
|
* and assures, instead, that the signal is delivered specifically to this
|
|
* thread that is known to be waiting on the signal.
|
|
*/
|
|
|
|
/* Get the waiting TCB. sched_gettcb() might return NULL if the task has
|
|
* exited for some reason.
|
|
*/
|
|
|
|
tcb = sched_gettcb((pid_t)pid);
|
|
if (tcb)
|
|
{
|
|
/* Create the siginfo structure */
|
|
|
|
info.si_signo = signo;
|
|
info.si_code = SI_QUEUE;
|
|
info.si_errno = ETIMEDOUT;
|
|
info.si_value.sival_ptr = NULL;
|
|
#ifdef CONFIG_SCHED_HAVE_PARENT
|
|
info.si_pid = (pid_t)pid;
|
|
info.si_status = OK;
|
|
#endif
|
|
|
|
/* Process the receipt of the signal. The scheduler is not locked as
|
|
* is normally the case when this function is called because we are in
|
|
* a watchdog timer interrupt handler.
|
|
*/
|
|
|
|
(void)sig_tcbdispatch(tcb, &info);
|
|
}
|
|
|
|
#else /* HAVE_GROUP_MEMBERS */
|
|
|
|
/* Things are a little easier if there are not group members. We can just
|
|
* use sigqueue().
|
|
*/
|
|
|
|
#ifdef CONFIG_CAN_PASS_STRUCTS
|
|
union sigval value;
|
|
|
|
/* Send the specified signal to the specified task. */
|
|
|
|
value.sival_ptr = NULL;
|
|
(void)sigqueue((int)pid, (int)signo, value);
|
|
#else
|
|
(void)sigqueue((int)pid, (int)signo, NULL);
|
|
#endif
|
|
|
|
#endif /* HAVE_GROUP_MEMBERS */
|
|
}
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: pthread_cond_timedwait
|
|
*
|
|
* Description:
|
|
* A thread can perform a timed wait on a condition variable.
|
|
*
|
|
* Parameters:
|
|
* cond - the condition variable to wait on
|
|
* mutex - the mutex that protects the condition variable
|
|
* abstime - wait until this absolute time
|
|
*
|
|
* Return Value:
|
|
* OK (0) on success; A non-zero errno value is returned on failure.
|
|
*
|
|
* Assumptions:
|
|
* Timing is of resolution 1 msec, with +/-1 millisecond accuracy.
|
|
*
|
|
****************************************************************************/
|
|
|
|
int pthread_cond_timedwait(FAR pthread_cond_t *cond, FAR pthread_mutex_t *mutex,
|
|
FAR const struct timespec *abstime)
|
|
{
|
|
FAR struct tcb_s *rtcb = this_task();
|
|
irqstate_t flags;
|
|
uint16_t oldstate;
|
|
ssystime_t ticks;
|
|
int mypid = (int)getpid();
|
|
int ret = OK;
|
|
int status;
|
|
|
|
sinfo("cond=0x%p mutex=0x%p abstime=0x%p\n", cond, mutex, abstime);
|
|
|
|
DEBUGASSERT(rtcb->waitdog == NULL);
|
|
|
|
/* pthread_cond_timedwait() is a cancellation point */
|
|
|
|
(void)enter_cancellation_point();
|
|
|
|
/* Make sure that non-NULL references were provided. */
|
|
|
|
if (!cond || !mutex)
|
|
{
|
|
ret = EINVAL;
|
|
}
|
|
|
|
/* Make sure that the caller holds the mutex */
|
|
|
|
else if (mutex->pid != mypid)
|
|
{
|
|
ret = EPERM;
|
|
}
|
|
|
|
/* If no wait time is provided, this function degenerates to
|
|
* the same behavior as pthread_cond_wait().
|
|
*/
|
|
|
|
else if (!abstime)
|
|
{
|
|
ret = pthread_cond_wait(cond, mutex);
|
|
}
|
|
|
|
else
|
|
{
|
|
/* Create a watchdog */
|
|
|
|
rtcb->waitdog = wd_create();
|
|
if (!rtcb->waitdog)
|
|
{
|
|
ret = EINVAL;
|
|
}
|
|
else
|
|
{
|
|
sinfo("Give up mutex...\n");
|
|
|
|
/* We must disable pre-emption and interrupts here so that
|
|
* the time stays valid until the wait begins. This adds
|
|
* complexity because we assure that interrupts and
|
|
* pre-emption are re-enabled correctly.
|
|
*/
|
|
|
|
sched_lock();
|
|
flags = enter_critical_section();
|
|
|
|
/* Convert the timespec to clock ticks. We must disable pre-emption
|
|
* here so that this time stays valid until the wait begins.
|
|
*/
|
|
|
|
ret = clock_abstime2ticks(CLOCK_REALTIME, abstime, &ticks);
|
|
if (ret)
|
|
{
|
|
/* Restore interrupts (pre-emption will be enabled when
|
|
* we fall through the if/then/else)
|
|
*/
|
|
|
|
leave_critical_section(flags);
|
|
}
|
|
else
|
|
{
|
|
/* Check the absolute time to wait. If it is now or in the past, then
|
|
* just return with the timedout condition.
|
|
*/
|
|
|
|
if (ticks <= 0)
|
|
{
|
|
/* Restore interrupts and indicate that we have already timed out.
|
|
* (pre-emption will be enabled when we fall through the
|
|
* if/then/else
|
|
*/
|
|
|
|
leave_critical_section(flags);
|
|
ret = ETIMEDOUT;
|
|
}
|
|
else
|
|
{
|
|
/* Give up the mutex */
|
|
|
|
mutex->pid = -1;
|
|
ret = pthread_mutex_give(mutex);
|
|
if (ret != 0)
|
|
{
|
|
/* Restore interrupts (pre-emption will be enabled when
|
|
* we fall through the if/then/else)
|
|
*/
|
|
|
|
leave_critical_section(flags);
|
|
}
|
|
else
|
|
{
|
|
/* Start the watchdog */
|
|
|
|
wd_start(rtcb->waitdog, ticks, (wdentry_t)pthread_condtimedout,
|
|
2, (uint32_t)mypid, (uint32_t)SIGCONDTIMEDOUT);
|
|
|
|
/* Take the condition semaphore. Do not restore interrupts
|
|
* until we return from the wait. This is necessary to
|
|
* make sure that the watchdog timer and the condition wait
|
|
* are started atomically.
|
|
*/
|
|
|
|
status = sem_wait((FAR sem_t *)&cond->sem);
|
|
|
|
/* Did we get the condition semaphore. */
|
|
|
|
if (status != OK)
|
|
{
|
|
/* NO.. Handle the special case where the semaphore wait was
|
|
* awakened by the receipt of a signal -- presumably the
|
|
* signal posted by pthread_condtimedout().
|
|
*/
|
|
|
|
if (get_errno() == EINTR)
|
|
{
|
|
serr("ERROR: Timedout!\n");
|
|
ret = ETIMEDOUT;
|
|
}
|
|
else
|
|
{
|
|
ret = EINVAL;
|
|
}
|
|
}
|
|
|
|
/* The interrupts stay disabled until after we sample the errno.
|
|
* This is because when debug is enabled and the console is used
|
|
* for debug output, then the errno can be altered by interrupt
|
|
* handling! (bad)
|
|
*/
|
|
|
|
leave_critical_section(flags);
|
|
}
|
|
|
|
/* Reacquire the mutex (retaining the ret). */
|
|
|
|
sinfo("Re-locking...\n");
|
|
|
|
oldstate = pthread_disable_cancel();
|
|
status = pthread_mutex_take(mutex, false);
|
|
pthread_enable_cancel(oldstate);
|
|
|
|
if (status == OK)
|
|
{
|
|
mutex->pid = mypid;
|
|
}
|
|
else if (ret == 0)
|
|
{
|
|
ret = status;
|
|
}
|
|
}
|
|
|
|
/* Re-enable pre-emption (It is expected that interrupts
|
|
* have already been re-enabled in the above logic)
|
|
*/
|
|
|
|
sched_unlock();
|
|
}
|
|
|
|
/* We no longer need the watchdog */
|
|
|
|
wd_delete(rtcb->waitdog);
|
|
rtcb->waitdog = NULL;
|
|
}
|
|
}
|
|
|
|
leave_cancellation_point();
|
|
sinfo("Returning %d\n", ret);
|
|
return ret;
|
|
}
|
|
|