# pthread_sigmask.m4 serial 18
dnl Copyright (C) 2011-2020 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.
AC_DEFUN([gl_FUNC_PTHREAD_SIGMASK],
[
AC_REQUIRE([gl_SIGNAL_H_DEFAULTS])
AC_CHECK_FUNCS_ONCE([pthread_sigmask])
dnl On MinGW pthread_sigmask is just a macro which always returns 0.
dnl It does not exist as a real function, which is required by POSIX.
AC_CACHE_CHECK([whether pthread_sigmask is a macro],
[gl_cv_func_pthread_sigmask_macro],
[AC_EGREP_CPP([headers_define_pthread_sigmask], [
#include <pthread.h>
#include <signal.h>
#ifdef pthread_sigmask
headers_define_pthread_sigmask
#endif],
[gl_cv_func_pthread_sigmask_macro=yes],
[gl_cv_func_pthread_sigmask_macro=no])
])
LIB_PTHREAD_SIGMASK=
if test $gl_cv_func_pthread_sigmask_macro = yes; then
dnl pthread_sigmask is a dummy macro.
HAVE_PTHREAD_SIGMASK=0
dnl Make sure to '#undef pthread_sigmask' before defining it.
REPLACE_PTHREAD_SIGMASK=1
else
dnl Test whether the gnulib module 'threadlib' is in use.
dnl Some packages like Emacs use --avoid=threadlib.
dnl Write the symbol in such a way that it does not cause 'aclocal' to pick
dnl the threadlib.m4 file that is installed in $PREFIX/share/aclocal/.
m4_ifdef([gl_][THREADLIB], [
AC_REQUIRE([gl_][THREADLIB])
if test "$gl_threads_api" = posix; then
if test $ac_cv_func_pthread_sigmask = yes; then
dnl pthread_sigmask is available without -lpthread.
:
else
if test -n "$LIBMULTITHREAD"; then
AC_CACHE_CHECK([for pthread_sigmask in $LIBMULTITHREAD],
[gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD],
[gl_save_LIBS="$LIBS"
LIBS="$LIBS $LIBMULTITHREAD"
AC_LINK_IFELSE(
[AC_LANG_PROGRAM(
[[#include <pthread.h>
#include <signal.h>
]],
[[return pthread_sigmask (0, (sigset_t *) 0, (sigset_t *) 0);]])
],
[gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD=yes],
[gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD=no])
LIBS="$gl_save_LIBS"
])
if test $gl_cv_func_pthread_sigmask_in_LIBMULTITHREAD = yes; then
dnl pthread_sigmask is available with -pthread or -lpthread.
LIB_PTHREAD_SIGMASK="$LIBMULTITHREAD"
else
dnl pthread_sigmask is not available at all.
HAVE_PTHREAD_SIGMASK=0
fi
else
dnl pthread_sigmask is not available at all.
HAVE_PTHREAD_SIGMASK=0
fi
fi
else
dnl pthread_sigmask may exist but does not interoperate with the chosen
dnl multithreading facility.
if test $ac_cv_func_pthread_sigmask = yes; then
REPLACE_PTHREAD_SIGMASK=1
else
HAVE_PTHREAD_SIGMASK=0
fi
fi
], [
dnl The module 'threadlib' is not in use, due to --avoid=threadlib being
dnl specified.
dnl The package either has prepared CPPFLAGS and LIBS for use of
dnl POSIX:2008 threads, or wants to build single-threaded programs.
if test $ac_cv_func_pthread_sigmask = yes; then
dnl pthread_sigmask exists and does not require extra libraries.
dnl Assume that it is declared.
:
else
dnl pthread_sigmask either does not exist or needs extra libraries.
HAVE_PTHREAD_SIGMASK=0
dnl Define the symbol rpl_pthread_sigmask, not pthread_sigmask,
dnl so as to not accidentally override the system's pthread_sigmask
dnl symbol from libpthread. This is necessary on IRIX 6.5.
REPLACE_PTHREAD_SIGMASK=1
fi
])
fi
AC_SUBST([LIB_PTHREAD_SIGMASK])
dnl We don't need a variable LTLIB_PTHREAD_SIGMASK, because when
dnl "$gl_threads_api" = posix, $LTLIBMULTITHREAD and $LIBMULTITHREAD are the
dnl same.
dnl Now test for some bugs in the system function.
if test $HAVE_PTHREAD_SIGMASK = 1; then
AC_REQUIRE([AC_PROG_CC])
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
dnl On FreeBSD 6.4, HP-UX 11.31, Solaris 9, in programs that are not linked
dnl with -lpthread, the pthread_sigmask() function always returns 0 and has
dnl no effect.
if test -z "$LIB_PTHREAD_SIGMASK"; then
case " $LIBS " in
*' -pthread '*) ;;
*' -lpthread '*) ;;
*)
AC_CACHE_CHECK([whether pthread_sigmask works without -lpthread],
[gl_cv_func_pthread_sigmask_in_libc_works],
[
AC_RUN_IFELSE(
[AC_LANG_SOURCE([[
#include <pthread.h>
#include <signal.h>
#include <stddef.h>
int main ()
{
sigset_t set;
sigemptyset (&set);
return pthread_sigmask (1729, &set, NULL) != 0;
}]])],
[gl_cv_func_pthread_sigmask_in_libc_works=no],
[gl_cv_func_pthread_sigmask_in_libc_works=yes],
[
changequote(,)dnl
case "$host_os" in
freebsd* | hpux* | solaris | solaris2.[2-9]*)
gl_cv_func_pthread_sigmask_in_libc_works="guessing no";;
*)
gl_cv_func_pthread_sigmask_in_libc_works="guessing yes";;
esac
changequote([,])dnl
])
])
case "$gl_cv_func_pthread_sigmask_in_libc_works" in
*no)
REPLACE_PTHREAD_SIGMASK=1
AC_DEFINE([PTHREAD_SIGMASK_INEFFECTIVE], [1],
[Define to 1 if pthread_sigmask may return 0 and have no effect.])
;;
esac;;
esac
fi
dnl On Cygwin 1.7.5, the pthread_sigmask() has a wrong return value
dnl convention: Upon failure, it returns -1 and sets errno.
AC_CACHE_CHECK([whether pthread_sigmask returns error numbers],
[gl_cv_func_pthread_sigmask_return_works],
[
gl_save_LIBS="$LIBS"
LIBS="$LIBS $LIB_PTHREAD_SIGMASK"
AC_RUN_IFELSE(
[AC_LANG_SOURCE([[
#include <pthread.h>
#include <signal.h>
#include <stddef.h>
int main ()
{
sigset_t set;
sigemptyset (&set);
if (pthread_sigmask (1729, &set, NULL) == -1)
return 1;
return 0;
}]])],
[gl_cv_func_pthread_sigmask_return_works=yes],
[gl_cv_func_pthread_sigmask_return_works=no],
[case "$host_os" in
cygwin*)
gl_cv_func_pthread_sigmask_return_works="guessing no";;
*)
gl_cv_func_pthread_sigmask_return_works="guessing yes";;
esac
])
LIBS="$gl_save_LIBS"
])
case "$gl_cv_func_pthread_sigmask_return_works" in
*no)
REPLACE_PTHREAD_SIGMASK=1
AC_DEFINE([PTHREAD_SIGMASK_FAILS_WITH_ERRNO], [1],
[Define to 1 if pthread_sigmask(), when it fails, returns -1 and sets errno.])
;;
esac
dnl On IRIX 6.5, in a single-threaded program, pending signals are not
dnl immediately delivered when they are unblocked through pthread_sigmask,
dnl only a little while later.
AC_CACHE_CHECK([whether pthread_sigmask unblocks signals correctly],
[gl_cv_func_pthread_sigmask_unblock_works],
[
case "$host_os" in
irix*)
gl_cv_func_pthread_sigmask_unblock_works="guessing no";;
*)
gl_cv_func_pthread_sigmask_unblock_works="guessing yes";;
esac
m4_ifdef([gl_][THREADLIB],
[dnl Link against $LIBMULTITHREAD, not only $LIB_PTHREAD_SIGMASK.
dnl Otherwise we get a false positive on those platforms where
dnl $gl_cv_func_pthread_sigmask_in_libc_works is "no".
gl_save_LIBS=$LIBS
LIBS="$LIBS $LIBMULTITHREAD"])
AC_RUN_IFELSE(
[AC_LANG_SOURCE([[
#include <pthread.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
static volatile int sigint_occurred;
static void
sigint_handler (int sig)
{
sigint_occurred++;
}
int main ()
{
sigset_t set;
int pid = getpid ();
char command[80];
signal (SIGINT, sigint_handler);
sigemptyset (&set);
sigaddset (&set, SIGINT);
if (!(pthread_sigmask (SIG_BLOCK, &set, NULL) == 0))
return 1;
sprintf (command, "sh -c 'sleep 1; kill -%d %d' &", SIGINT, pid);
if (!(system (command) == 0))
return 2;
sleep (2);
if (!(sigint_occurred == 0))
return 3;
if (!(pthread_sigmask (SIG_UNBLOCK, &set, NULL) == 0))
return 4;
if (!(sigint_occurred == 1)) /* This fails on IRIX. */
return 5;
return 0;
}]])],
[:],
[gl_cv_func_pthread_sigmask_unblock_works=no],
[:])
m4_ifdef([gl_][THREADLIB], [LIBS=$gl_save_LIBS])
])
case "$gl_cv_func_pthread_sigmask_unblock_works" in
*no)
REPLACE_PTHREAD_SIGMASK=1
AC_DEFINE([PTHREAD_SIGMASK_UNBLOCK_BUG], [1],
[Define to 1 if pthread_sigmask() unblocks signals incorrectly.])
;;
esac
fi
])
# Prerequisite of lib/pthread_sigmask.c.
AC_DEFUN([gl_PREREQ_PTHREAD_SIGMASK],
[
if test $HAVE_PTHREAD_SIGMASK = 1; then
AC_DEFINE([HAVE_PTHREAD_SIGMASK], [1],
[Define to 1 if the pthread_sigmask function can be used (despite bugs).])
fi
])