kc3-lang/gnulib/lib/pselect.c

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• Hash : 88811b7d
  Author :
  Date : 2023-05-14T23:27:51
  

  timespec: fill in other members
  
  This problem was found when compiling GNU Emacs with
  --enable-gcc-warnings on a platform where tv_sec is 64 bits and
  tv_nsec is 32 bits, and struct timespec has padding.  GCC
  -Wuse-of-uninitialized-value complained when a struct timespec
  initialized only via assigning to tv_sec and tv_nsec was copied
  via assignment (this was in lib/timespec.h’s make_timespec).
  Although behavior is well-defined on this platform, the warning is
  annoying and the behavior might not be well-defined on theoretical
  platforms where struct timespec has other members.  To work around
  this, initialize all the struct’s members.
  * lib/getsockopt.c (rpl_getsockopt):
  * lib/gettime.c (gettime):
  * lib/gettimeofday.c (gettimeofday):
  * lib/glthread/thread.c (gl_thread_self):
  * lib/nanosleep.c (nanosleep):
  * lib/parse-datetime.y (digits_to_date_time, set_hhmmss)
  (signed_seconds, unsigned_seconds, yylex, parse_datetime_body):
  * lib/poll.c (poll):
  * lib/pselect.c (pselect):
  * lib/pthread-cond.c (endlessly, pthread_cond_timedwait):
  * lib/pthread-rwlock.c (pthread_rwlock_timedrdlock)
  (pthread_rwlock_timedwrlock):
  * lib/pthread_mutex_timedlock.c (pthread_mutex_timedlock):
  * lib/select.c (rpl_select):
  * lib/settime.c (settime):
  * lib/stat-time.h (get_stat_atime, get_stat_ctime)
  (get_stat_mtime, get_stat_birthtime):
  * lib/thrd.c (rpl_thrd_current):
  * lib/timespec.h (make_timespec):
  * lib/timespec_getres.c (timespec_getres):
  * lib/utimecmp.c (utimecmpat):
  * lib/utimens.c (fdutimens):
  When filling in a struct timespec or similar time-related structure
  that might be copied elsewhere, also assign to any storage other
  than tv_sec and tv_nsec, to avoid undefined behavior on (likely
  theoretical) platforms where struct timespec has other members,
  and also to avoid warnings from GCC and/or valgrind.
  

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• lib/pselect.c

• /* pselect - synchronous I/O multiplexing
  
     Copyright 2011-2023 Free Software Foundation, Inc.
  
     This file is part of gnulib.
  
     This file is free software: you can redistribute it and/or modify
     it under the terms of the GNU Lesser General Public License as
     published by the Free Software Foundation; either version 2.1 of the
     License, or (at your option) any later version.
  
     This file is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU Lesser General Public License for more details.
  
     You should have received a copy of the GNU Lesser General Public License
     along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  
  /* written by Paul Eggert */
  
  #include <config.h>
  
  #include <sys/select.h>
  
  #include <errno.h>
  #include <signal.h>
  
  /* Examine the size-NFDS file descriptor sets in RFDS, WFDS, and XFDS
     to see whether some of their descriptors are ready for reading,
     ready for writing, or have exceptions pending.  Wait for at most
     TIMEOUT seconds, and use signal mask SIGMASK while waiting.  A null
     pointer parameter stands for no descriptors, an infinite timeout,
     or an unaffected signal mask.  */
  
  #if !HAVE_PSELECT
  
  int
  pselect (int nfds, fd_set *restrict rfds,
           fd_set *restrict wfds, fd_set *restrict xfds,
           struct timespec const *restrict timeout,
           sigset_t const *restrict sigmask)
  {
    int select_result;
    sigset_t origmask;
    struct timeval tv, *tvp;
  
    if (nfds < 0 || nfds > FD_SETSIZE)
      {
        errno = EINVAL;
        return -1;
      }
  
    if (timeout)
      {
        if (! (0 <= timeout->tv_nsec && timeout->tv_nsec < 1000000000))
          {
            errno = EINVAL;
            return -1;
          }
  
        tv = (struct timeval) {
          .tv_sec = timeout->tv_sec,
          .tv_usec = (timeout->tv_nsec + 999) / 1000
        };
        tvp = &tv;
      }
    else
      tvp = NULL;
  
    /* Signal mask munging should be atomic, but this is the best we can
       do in this emulation.  */
    if (sigmask)
      pthread_sigmask (SIG_SETMASK, sigmask, &origmask);
  
    select_result = select (nfds, rfds, wfds, xfds, tvp);
  
    if (sigmask)
      {
        int select_errno = errno;
        pthread_sigmask (SIG_SETMASK, &origmask, NULL);
        errno = select_errno;
      }
  
    return select_result;
  }
  
  #else /* HAVE_PSELECT */
  # include <unistd.h>
  # undef pselect
  
  int
  rpl_pselect (int nfds, fd_set *restrict rfds,
               fd_set *restrict wfds, fd_set *restrict xfds,
               struct timespec const *restrict timeout,
               sigset_t const *restrict sigmask)
  {
    int i;
  
    /* FreeBSD 8.2 has a bug: it does not always detect invalid fds.  */
    if (nfds < 0 || nfds > FD_SETSIZE)
      {
        errno = EINVAL;
        return -1;
      }
    for (i = 0; i < nfds; i++)
      {
        if (((rfds && FD_ISSET (i, rfds))
             || (wfds && FD_ISSET (i, wfds))
             || (xfds && FD_ISSET (i, xfds)))
            && dup2 (i, i) != i)
          return -1;
      }
  
    return pselect (nfds, rfds, wfds, xfds, timeout, sigmask);
  }
  
  #endif
  

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