sys/select.c

   1 /*
   2  * Copyright (c) 2005, 2007 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 #if defined(__LP64__) && (defined(VARIANT_CANCELABLE) || defined(VARIANT_PRE1050))
  24 #undef __DARWIN_NON_CANCELABLE
  25 #define __DARWIN_NON_CANCELABLE 0
  26 #endif /* __LP64__ && (VARIANT_CANCELABLE || VARIANT_PRE1050) */
  27 #include <sys/select.h>
  28 #include <errno.h>
  29
  30 #if defined(VARIANT_CANCELABLE) || defined(VARIANT_PRE1050)
  31 extern int __select(int, fd_set * __restrict, fd_set * __restrict,
  32         fd_set * __restrict, struct timeval * __restrict);
  33 #else /* !VARIANT_CANCELABLE && !VARIANT_PRE1050 */
  34 int __select_nocancel(int, fd_set * __restrict, fd_set * __restrict,
  35         fd_set * __restrict, struct timeval * __restrict);
  36 #endif /* VARIANT_CANCELABLE || VARIANT_PRE1050 */
  37
  38 /*
  39  * select stub, return error if nfds > FD_SETSIZE
  40  * add pthread cancelability
  41  * mandated for conformance.
  42  *
  43  * This is only for (non DARWINEXTSN) UNIX03 (both cancelable and
  44  * non-cancelable) and for legacy
  45  */
  46 int
  47 select(int nfds, fd_set * __restrict readfds, fd_set * __restrict writefds,
  48         fd_set * __restrict exceptfds, struct timeval * __restrict
  49 #if defined(VARIANT_LEGACY) || defined(VARIANT_PRE1050)
  50         intimeout
  51 #else /* !VARIANT_LEGACY && !VARIANT_PRE1050 */
  52         timeout
  53 #endif /* VARIANT_LEGACY || VARIANT_PRE1050 */
  54         )
  55 {
  56
  57 #if defined(VARIANT_LEGACY) || defined(VARIANT_PRE1050)
  58         struct timeval tb, *timeout;
  59
  60         /*
  61          * Legacy select behavior is minimum 10 msec when tv_usec is non-zero
  62          */
  63         if (intimeout && intimeout->tv_sec == 0 && intimeout->tv_usec > 0 && intimeout->tv_usec < 10000) {
  64                 tb.tv_sec = 0;
  65                 tb.tv_usec = 10000;
  66                 timeout = &tb;
  67         } else
  68                 timeout = intimeout;
  69 #else /* !VARIANT_LEGACY && !VARIANT_PRE1050 */
  70         if (nfds > FD_SETSIZE) {
  71                 errno = EINVAL;
  72                 return -1;
  73         }
  74 #endif /* VARIANT_LEGACY || VARIANT_PRE1050 */
  75 #if defined(VARIANT_CANCELABLE) || defined(VARIANT_PRE1050)
  76         return __select(nfds, readfds, writefds, exceptfds, timeout);
  77 #else /* !VARIANT_CANCELABLE && !VARIANT_PRE1050 */
  78         return __select_nocancel(nfds, readfds, writefds, exceptfds, timeout);
  79 #endif /* VARIANT_CANCELABLE || VARIANT_PRE1050 */
  80 }