posix/src/sigsuspend.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  * @file
0005  *
0006  * @ingroup POSIXAPI
0007  *
0008  * @brief Replacing signal mask with *sigmask and suspending calling process
0009  */
0010
0011 /*
0012  *  3.3.7 Wait for a Signal, P1003.1b-1993, p. 75
0013  *
0014  *  COPYRIGHT (c) 1989-2004.
0015  *  On-Line Applications Research Corporation (OAR).
0016  *
0017  * Redistribution and use in source and binary forms, with or without
0018  * modification, are permitted provided that the following conditions
0019  * are met:
0020  * 1. Redistributions of source code must retain the above copyright
0021  *    notice, this list of conditions and the following disclaimer.
0022  * 2. Redistributions in binary form must reproduce the above copyright
0023  *    notice, this list of conditions and the following disclaimer in the
0024  *    documentation and/or other materials provided with the distribution.
0025  *
0026  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0027  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0028  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0029  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0030  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0031  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0032  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0033  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0034  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0035  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0036  * POSSIBILITY OF SUCH DAMAGE.
0037  */
0038
0039 #ifdef HAVE_CONFIG_H
0040 #include "config.h"
0041 #endif
0042
0043 #include <stddef.h>
0044 #include <assert.h>
0045 #include <signal.h>
0046 #include <errno.h>
0047
0048 #include <rtems/seterr.h>
0049
0050 int sigsuspend(
0051   const sigset_t  *sigmask
0052 )
0053 {
0054   sigset_t            saved_signals_blocked;
0055   sigset_t            current_unblocked_signals;
0056 #if defined(RTEMS_DEBUG)
0057     int                 status;
0058 #endif
0059
0060   /*
0061    *  We use SIG_BLOCK and not SIG_SETMASK because there may be
0062    *  signals which might be pending, which might get caught here.
0063    *  We want the signals to be caught inside sigtimedwait.
0064    *
0065    *  We ignore the return status codes because sigsuspend() is
0066    *  defined to either terminate or return -1 with errno set to
0067    *  EINTR.
0068    */
0069 #if defined(RTEMS_DEBUG)
0070     status =
0071 #else
0072   (void)
0073 #endif
0074       sigprocmask( SIG_BLOCK, sigmask, &saved_signals_blocked );
0075
0076   current_unblocked_signals = ~(*sigmask);
0077
0078   #if defined(RTEMS_DEBUG)
0079     status =
0080 #else
0081   (void)
0082 #endif
0083       sigtimedwait( &current_unblocked_signals, NULL, NULL );
0084
0085   (void) sigprocmask( SIG_SETMASK, &saved_signals_blocked, NULL );
0086
0087   /*
0088    * sigtimedwait() returns the signal number while sigsuspend()
0089    * is supposed to return -1 and EINTR when a signal is caught.
0090    */
0091   #if defined(RTEMS_DEBUG)
0092     assert( status != -1 );
0093   #endif
0094
0095   rtems_set_errno_and_return_minus_one( EINTR );
0096 }