1: /* Copyright (C) 1996-1998,2001,2002,2003,2006 Free Software Foundation, Inc.
    2:    This file is part of the GNU C Library.
    3:    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
    4: 
    5:    The GNU C Library is free software; you can redistribute it and/or
    6:    modify it under the terms of the GNU Lesser General Public
    7:    License as published by the Free Software Foundation; either
    8:    version 2.1 of the License, or (at your option) any later version.
    9: 
   10:    The GNU C Library is distributed in the hope that it will be useful,
   11:    but WITHOUT ANY WARRANTY; without even the implied warranty of
   12:    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   13:    Lesser General Public License for more details.
   14: 
   15:    You should have received a copy of the GNU Lesser General Public
   16:    License along with the GNU C Library; if not, write to the Free
   17:    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   18:    02111-1307 USA.  */
   19: 
   20: #include <errno.h>
   21: #include <signal.h>
   22: #include <stddef.h>     /* For NULL.  */
   23: #include <sys/time.h>
   24: #include <sys/select.h>
   25: #include <sysdep-cancel.h>
   26: 
   27: 
   28: /* Check the first NFDS descriptors each in READFDS (if not NULL) for read
   29:    readiness, in WRITEFDS (if not NULL) for write readiness, and in EXCEPTFDS
   30:    (if not NULL) for exceptional conditions.  If TIMEOUT is not NULL, time out
   31:    after waiting the interval specified therein.  Additionally set the sigmask
   32:    SIGMASK for this call.  Returns the number of ready descriptors, or -1 for
   33:    errors.  */
   34: int
   35: __pselect (int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
   36:            const struct timespec *timeout, const sigset_t *sigmask)
   37: {
   38:   struct timeval tval;
   39:   int retval;
   40:   sigset_t savemask;
   41: 
   42:   /* Change nanosecond number to microseconds.  This might mean losing
   43:      precision and therefore the `pselect` should be available.  But
   44:      for now it is hardly found.  */
   45:   if (timeout != NULL)
   46:     TIMESPEC_TO_TIMEVAL (&tval, timeout);
   47: 
   48:   /* The setting and restoring of the signal mask and the select call
   49:      should be an atomic operation.  This can't be done without kernel
   50:      help.  */
   51:   if (sigmask != NULL)
   52:     __sigprocmask (SIG_SETMASK, sigmask, &savemask);
   53: 
   54:   /* Note the pselect() is a cancellation point.  But since we call
   55:      select() which itself is a cancellation point we do not have
   56:      to do anything here.  */
   57:   retval = __select (nfds, readfds, writefds, exceptfds,
   58:                      timeout != NULL ? &tval : NULL);
   59: 
   60:   if (sigmask != NULL)
   61:     __sigprocmask (SIG_SETMASK, &savemask, NULL);
   62: 
   63:   return retval;
   64: }
   65: #ifndef __pselect
   66: weak_alias (__pselect, pselect)
   67: strong_alias (__pselect, __libc_pselect)
   68: /* __select handles cancellation.  */
   69: LIBC_CANCEL_HANDLED ();
   70: #endif