gen/FreeBSD/pselect.c

   1 /*
   2  * Copyright 2000 Massachusetts Institute of Technology
   3  *
   4  * Permission to use, copy, modify, and distribute this software and
   5  * its documentation for any purpose and without fee is hereby
   6  * granted, provided that both the above copyright notice and this
   7  * permission notice appear in all copies, that both the above
   8  * copyright notice and this permission notice appear in all
   9  * supporting documentation, and that the name of M.I.T. not be used
  10  * in advertising or publicity pertaining to distribution of the
  11  * software without specific, written prior permission.  M.I.T. makes
  12  * no representations about the suitability of this software for any
  13  * purpose.  It is provided "as is" without express or implied
  14  * warranty.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
  17  * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
  18  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
  20  * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
  23  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  25  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  26  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #if (defined(VARIANT_CANCELABLE) || defined(VARIANT_PRE1050)) && __DARWIN_NON_CANCELABLE != 0
  31 #error cancellable call vs. __DARWIN_NON_CANCELABLE mismatch
  32 #endif
  33
  34 #ifdef VARIANT_DARWINEXTSN
  35 #define _DARWIN_UNLIMITED_SELECT
  36 #endif /* VARIANT_DARWINEXTSN */
  37
  38 #include <sys/cdefs.h>
  39 __FBSDID("$FreeBSD: src/lib/libc/gen/pselect.c,v 1.6 2002/10/12 16:13:37 mike Exp $");
  40
  41 #include "namespace.h"
  42 #include <sys/types.h>
  43 #include <sys/select.h>
  44 #include <sys/time.h>
  45 #include <unistd.h>
  46
  47 #include <errno.h>
  48 #include <signal.h>
  49 #include "un-namespace.h"
  50
  51 __weak_reference(__pselect, pselect);
  52
  53 // Returns -1 and sets errno in contrast to pthread_sigmask which returns errno
  54 extern int __pthread_sigmask(int, const sigset_t *, sigset_t *);
  55
  56 /*
  57  * Emulate the POSIX 1003.1g-2000 `pselect' interface.  This is the
  58  * same as the traditional BSD `select' function, except that it uses
  59  * a timespec rather than a timeval, doesn't modify the timeout argument,
  60  * and allows the user to specify a signal mask to apply during the select.
  61  */
  62 int
  63 __pselect(int count, fd_set * __restrict rfds, fd_set * __restrict wfds,
  64         fd_set * __restrict efds, const struct timespec * __restrict timo,
  65         const sigset_t * __restrict mask)
  66 {
  67         sigset_t omask;
  68         struct timeval tvtimo, *tvp;
  69         int rv, sverrno;
  70
  71         if (timo) {
  72                 TIMESPEC_TO_TIMEVAL(&tvtimo, timo);
  73                 tvp = &tvtimo;
  74         } else
  75                 tvp = 0;
  76
  77         if (mask != 0) {
  78                 rv = __pthread_sigmask(SIG_SETMASK, mask, &omask);
  79                 if (rv != 0)
  80                         return rv;
  81         }
  82
  83         rv = _select(count, rfds, wfds, efds, tvp);
  84         if (mask != 0) {
  85                 sverrno = errno;
  86                 __pthread_sigmask(SIG_SETMASK, &omask, (sigset_t *)0);
  87                 errno = sverrno;
  88         }
  89
  90         return rv;
  91 }