/**
* @file
*
* @brief Wait for Queued Signals
* @ingroup POSIXAPI
*/
/*
* COPYRIGHT (c) 1989-2008.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <signal.h>
#include <rtems/posix/pthreadimpl.h>
#include <rtems/posix/psignalimpl.h>
#include <rtems/posix/posixapi.h>
#include <rtems/score/threadqimpl.h>
#include <rtems/score/todimpl.h>
#include <rtems/score/watchdogimpl.h>
#include <rtems/score/isr.h>
static int _POSIX_signals_Get_lowest(
sigset_t set
)
{
int signo;
for ( signo = SIGRTMIN ; signo <= SIGRTMAX ; signo++ ) {
if ( set & signo_to_mask( signo ) ) {
goto found_it;
}
}
/*
* We assume SIGHUP == 1 and is the first non-real-time signal.
*/
#if (SIGHUP != 1)
#error "Assumption that SIGHUP==1 violated!!"
#endif
for ( signo = SIGHUP ; signo <= __SIGLASTNOTRT ; signo++ ) {
if ( set & signo_to_mask( signo ) ) {
goto found_it;
}
}
/*
* This is structured this way to eliminate the need to have
* a return 0. This routine will NOT be called unless a signal
* is pending in the set passed in.
*/
found_it:
return signo;
}
/**
* 3.3.8 Synchronously Accept a Signal, P1003.1b-1993, p. 76
*/
int sigtimedwait(
const sigset_t *__restrict set,
siginfo_t *__restrict info,
const struct timespec *__restrict timeout
)
{
Thread_Control *executing;
POSIX_API_Control *api;
siginfo_t signal_information;
siginfo_t *the_info;
int signo;
Thread_queue_Context queue_context;
int error;
/*
* Error check parameters before disabling interrupts.
*/
if ( !set )
rtems_set_errno_and_return_minus_one( EINVAL );
_Thread_queue_Context_initialize( &queue_context );
/* NOTE: This is very specifically a RELATIVE not ABSOLUTE time
* in the Open Group specification.
*/
if ( timeout != NULL ) {
_Thread_queue_Context_set_enqueue_timeout_monotonic_timespec(
&queue_context,
timeout,
false
);
} else {
_Thread_queue_Context_set_enqueue_do_nothing_extra( &queue_context );
}
/*
* Initialize local variables.
*/
the_info = ( info ) ? info : &signal_information;
executing = _Thread_Get_executing();
api = executing->API_Extensions[ THREAD_API_POSIX ];
/*
* What if they are already pending?
*/
/* API signals pending? */
_POSIX_signals_Acquire( &queue_context );
if ( *set & api->signals_pending ) {
/* XXX real info later */
the_info->si_signo = _POSIX_signals_Get_lowest( api->signals_pending );
_POSIX_signals_Clear_signals(
api,
the_info->si_signo,
the_info,
false,
false,
false
);
_POSIX_signals_Release( &queue_context );
the_info->si_code = SI_USER;
the_info->si_value.sival_int = 0;
return the_info->si_signo;
}
/* Process pending signals? */
if ( *set & _POSIX_signals_Pending ) {
signo = _POSIX_signals_Get_lowest( _POSIX_signals_Pending );
_POSIX_signals_Clear_signals( api, signo, the_info, true, false, false );
_POSIX_signals_Release( &queue_context );
the_info->si_signo = signo;
the_info->si_code = SI_USER;
the_info->si_value.sival_int = 0;
return signo;
}
the_info->si_signo = -1;
executing->Wait.option = *set;
executing->Wait.return_argument = the_info;
_Thread_queue_Context_set_thread_state(
&queue_context,
STATES_WAITING_FOR_SIGNAL | STATES_INTERRUPTIBLE_BY_SIGNAL
);
_Thread_queue_Enqueue(
&_POSIX_signals_Wait_queue.Queue,
POSIX_SIGNALS_TQ_OPERATIONS,
executing,
&queue_context
);
/*
* When the thread is set free by a signal, it is need to eliminate
* the signal.
*/
_POSIX_signals_Clear_signals(
api,
the_info->si_signo,
the_info,
false,
false,
true
);
/* Set errno only if return code is not EINTR or
* if EINTR was caused by a signal being caught, which
* was not in our set.
*/
error = _POSIX_Get_error_after_wait( executing );
if (
error != EINTR
|| ( *set & signo_to_mask( the_info->si_signo ) ) == 0
) {
if ( error == ETIMEDOUT ) {
error = EAGAIN;
}
rtems_set_errno_and_return_minus_one( error );
}
return the_info->si_signo;
}