m4/pthread_sigmask.m4

   1 # pthread_sigmask.m4 serial 13
   2 dnl Copyright (C) 2011-2013 Free Software Foundation, Inc.
   3 dnl This file is free software; the Free Software Foundation
   4 dnl gives unlimited permission to copy and/or distribute it,
   5 dnl with or without modifications, as long as this notice is preserved.
   6
   7 AC_DEFUN([gl_FUNC_PTHREAD_SIGMASK],
   8 [
   9   AC_REQUIRE([gl_SIGNAL_H_DEFAULTS])
  10
  11   AC_CHECK_FUNCS_ONCE([pthread_sigmask])
  12   LIB_PTHREAD_SIGMASK=
  13
  14   dnl Test whether the gnulib module 'threadlib' is in use.
  15   dnl Some packages like Emacs use --avoid=threadlib.
  16   dnl Write the symbol in such a way that it does not cause 'aclocal' to pick
  17   dnl the threadlib.m4 file that is installed in $PREFIX/share/aclocal/.
  18   m4_ifdef([gl_][THREADLIB], [
  19     AC_REQUIRE([gl_][THREADLIB])
  20
  21     if test "$gl_threads_api" = posix; then
  22       if test $ac_cv_func_pthread_sigmask = yes; then
  23         dnl pthread_sigmask is available without -lpthread.
  24         :
  25       else
  26         if test -n "$LIBMULTITHREAD"; then
  27           AC_CACHE_CHECK([for pthread_sigmask in $LIBMULTITHREAD],
  28             [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD],
  29             [gl_save_LIBS="$LIBS"
  30              LIBS="$LIBS $LIBMULTITHREAD"
  31              AC_LINK_IFELSE(
  32                [AC_LANG_PROGRAM(
  33                   [[#include <pthread.h>
  34                     #include <signal.h>
  35                   ]],
  36                   [[return pthread_sigmask (0, (sigset_t *) 0, (sigset_t *) 0);]])
  37                ],
  38                [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD=yes],
  39                [gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD=no])
  40              LIBS="$gl_save_LIBS"
  41             ])
  42           if test $gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD = yes; then
  43             dnl pthread_sigmask is available with -lpthread.
  44             LIB_PTHREAD_SIGMASK="$LIBMULTITHREAD"
  45           else
  46             dnl pthread_sigmask is not available at all.
  47             HAVE_PTHREAD_SIGMASK=0
  48           fi
  49         else
  50           dnl pthread_sigmask is not available at all.
  51           HAVE_PTHREAD_SIGMASK=0
  52         fi
  53       fi
  54     else
  55       dnl pthread_sigmask may exist but does not interoperate with the chosen
  56       dnl multithreading facility.
  57       dnl If "$gl_threads_api" = pth, we could use the function pth_sigmask,
  58       dnl but it is equivalent to sigprocmask, so we choose to emulate
  59       dnl pthread_sigmask with sigprocmask also in this case. This yields fewer
  60       dnl link dependencies.
  61       if test $ac_cv_func_pthread_sigmask = yes; then
  62         REPLACE_PTHREAD_SIGMASK=1
  63       else
  64         HAVE_PTHREAD_SIGMASK=0
  65       fi
  66     fi
  67   ], [
  68     dnl The module 'threadlib' is not in use, due to --avoid=threadlib being
  69     dnl specified.
  70     dnl The package either has prepared CPPFLAGS and LIBS for use of POSIX:2008
  71     dnl threads, or wants to build single-threaded programs.
  72     if test $ac_cv_func_pthread_sigmask = yes; then
  73       dnl pthread_sigmask exists and does not require extra libraries.
  74       dnl Assume that it is declared.
  75       :
  76     else
  77       dnl pthread_sigmask either does not exist or needs extra libraries.
  78       HAVE_PTHREAD_SIGMASK=0
  79       dnl Define the symbol rpl_pthread_sigmask, not pthread_sigmask,
  80       dnl so as to not accidentally override the system's pthread_sigmask
  81       dnl symbol from libpthread. This is necessary on IRIX 6.5.
  82       REPLACE_PTHREAD_SIGMASK=1
  83     fi
  84   ])
  85
  86   AC_SUBST([LIB_PTHREAD_SIGMASK])
  87   dnl We don't need a variable LTLIB_PTHREAD_SIGMASK, because when
  88   dnl "$gl_threads_api" = posix, $LTLIBMULTITHREAD and $LIBMULTITHREAD are the
  89   dnl same: either both empty or both "-lpthread".
  90
  91   dnl Now test for some bugs in the system function.
  92   if test $HAVE_PTHREAD_SIGMASK = 1; then
  93     AC_REQUIRE([AC_PROG_CC])
  94     AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
  95
  96     dnl On FreeBSD 6.4, HP-UX 11.31, Solaris 9, in programs that are not linked
  97     dnl with -lpthread, the pthread_sigmask() function always returns 0 and has
  98     dnl no effect.
  99     if test -z "$LIB_PTHREAD_SIGMASK"; then
 100       AC_CACHE_CHECK([whether pthread_sigmask works without -lpthread],
 101         [gl_cv_func_pthread_sigmask_in_libc_works],
 102         [
 103           AC_RUN_IFELSE(
 104             [AC_LANG_SOURCE([[
 105 #include <pthread.h>
 106 #include <signal.h>
 107 #include <stddef.h>
 108 int main ()
 109 {
 110   sigset_t set;
 111   sigemptyset (&set);
 112   return pthread_sigmask (1729, &set, NULL) != 0;
 113 }]])],
 114             [gl_cv_func_pthread_sigmask_in_libc_works=no],
 115             [gl_cv_func_pthread_sigmask_in_libc_works=yes],
 116             [
 117 changequote(,)dnl
 118              case "$host_os" in
 119                freebsd* | hpux* | solaris | solaris2.[2-9]*)
 120                  gl_cv_func_pthread_sigmask_in_libc_works="guessing no";;
 121                *)
 122                  gl_cv_func_pthread_sigmask_in_libc_works="guessing yes";;
 123              esac
 124 changequote([,])dnl
 125             ])
 126         ])
 127       case "$gl_cv_func_pthread_sigmask_in_libc_works" in
 128         *no)
 129           REPLACE_PTHREAD_SIGMASK=1
 130           AC_DEFINE([PTHREAD_SIGMASK_INEFFECTIVE], [1],
 131             [Define to 1 if pthread_sigmask() may returns 0 and have no effect.])
 132           ;;
 133       esac
 134     fi
 135
 136     dnl On Cygwin 1.7.5, the pthread_sigmask() has a wrong return value
 137     dnl convention: Upon failure, it returns -1 and sets errno.
 138     AC_CACHE_CHECK([whether pthread_sigmask returns error numbers],
 139       [gl_cv_func_pthread_sigmask_return_works],
 140       [
 141         gl_save_LIBS="$LIBS"
 142         LIBS="$LIBS $LIB_PTHREAD_SIGMASK"
 143         AC_RUN_IFELSE(
 144           [AC_LANG_SOURCE([[
 145 #include <pthread.h>
 146 #include <signal.h>
 147 #include <stddef.h>
 148 int main ()
 149 {
 150   sigset_t set;
 151   sigemptyset (&set);
 152   if (pthread_sigmask (1729, &set, NULL) == -1)
 153     return 1;
 154   return 0;
 155 }]])],
 156           [gl_cv_func_pthread_sigmask_return_works=yes],
 157           [gl_cv_func_pthread_sigmask_return_works=no],
 158           [case "$host_os" in
 159              cygwin*)
 160                gl_cv_func_pthread_sigmask_return_works="guessing no";;
 161              *)
 162                gl_cv_func_pthread_sigmask_return_works="guessing yes";;
 163            esac
 164           ])
 165         LIBS="$gl_save_LIBS"
 166       ])
 167     case "$gl_cv_func_pthread_sigmask_return_works" in
 168       *no)
 169         REPLACE_PTHREAD_SIGMASK=1
 170         AC_DEFINE([PTHREAD_SIGMASK_FAILS_WITH_ERRNO], [1],
 171           [Define to 1 if pthread_sigmask(), when it fails, returns -1 and sets errno.])
 172         ;;
 173     esac
 174
 175     dnl On IRIX 6.5, in a single-threaded program, pending signals are not
 176     dnl immediately delivered when they are unblocked through pthread_sigmask,
 177     dnl only a little while later.
 178     AC_CACHE_CHECK([whether pthread_sigmask unblocks signals correctly],
 179       [gl_cv_func_pthread_sigmask_unblock_works],
 180       [
 181         case "$host_os" in
 182           irix*)
 183             gl_cv_func_pthread_sigmask_unblock_works="guessing no";;
 184           *)
 185             gl_cv_func_pthread_sigmask_unblock_works="guessing yes";;
 186         esac
 187         dnl Here we link against $LIBMULTITHREAD, not only $LIB_PTHREAD_SIGMASK,
 188         dnl otherwise we get a false positive on those platforms where
 189         dnl $gl_cv_func_pthread_sigmask_in_libc_works is "no".
 190         gl_save_LIBS="$LIBS"
 191         LIBS="$LIBS $LIBMULTITHREAD"
 192         AC_RUN_IFELSE(
 193           [AC_LANG_SOURCE([[
 194 #include <pthread.h>
 195 #include <signal.h>
 196 #include <stdio.h>
 197 #include <stdlib.h>
 198 #include <unistd.h>
 199 static volatile int sigint_occurred;
 200 static void
 201 sigint_handler (int sig)
 202 {
 203   sigint_occurred++;
 204 }
 205 int main ()
 206 {
 207   sigset_t set;
 208   int pid = getpid ();
 209   char command[80];
 210   signal (SIGINT, sigint_handler);
 211   sigemptyset (&set);
 212   sigaddset (&set, SIGINT);
 213   if (!(pthread_sigmask (SIG_BLOCK, &set, NULL) == 0))
 214     return 1;
 215   sprintf (command, "sh -c 'sleep 1; kill -%d %d' &", SIGINT, pid);
 216   if (!(system (command) == 0))
 217     return 2;
 218   sleep (2);
 219   if (!(sigint_occurred == 0))
 220     return 3;
 221   if (!(pthread_sigmask (SIG_UNBLOCK, &set, NULL) == 0))
 222     return 4;
 223   if (!(sigint_occurred == 1)) /* This fails on IRIX.  */
 224     return 5;
 225   return 0;
 226 }]])],
 227           [:],
 228           [gl_cv_func_pthread_sigmask_unblock_works=no],
 229           [:])
 230         LIBS="$gl_save_LIBS"
 231       ])
 232     case "$gl_cv_func_pthread_sigmask_unblock_works" in
 233       *no)
 234         REPLACE_PTHREAD_SIGMASK=1
 235         AC_DEFINE([PTHREAD_SIGMASK_UNBLOCK_BUG], [1],
 236           [Define to 1 if pthread_sigmask() unblocks signals incorrectly.])
 237         ;;
 238     esac
 239   fi
 240 ])
 241
 242 # Prerequisite of lib/pthread_sigmask.c.
 243 AC_DEFUN([gl_PREREQ_PTHREAD_SIGMASK],
 244 [
 245   if test $HAVE_PTHREAD_SIGMASK = 1; then
 246     AC_DEFINE([HAVE_PTHREAD_SIGMASK], [1],
 247       [Define to 1 if the pthread_sigmask function can be used (despite bugs).])
 248   fi
 249 ])