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Diffstat (limited to 'm4/pthread_sigmask.m4')
| -rw-r--r-- | m4/pthread_sigmask.m4 | 274 |
1 files changed, 274 insertions, 0 deletions
diff --git a/m4/pthread_sigmask.m4 b/m4/pthread_sigmask.m4 new file mode 100644 index 0000000..0aa8c53 --- /dev/null +++ b/m4/pthread_sigmask.m4 @@ -0,0 +1,274 @@ +# pthread_sigmask.m4 serial 21 +dnl Copyright (C) 2011-2022 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 $HAVE_PTHREAD_SIGMASK = 1; then + AC_REQUIRE([AC_PROG_CC]) + AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles + + dnl On FreeBSD 13.0, MidnightBSD 1.1, HP-UX 11.31, Solaris 9, in programs + dnl that are not linked with -lpthread, the pthread_sigmask() function + dnl always returns 0 and has no effect. + if test -z "$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* | midnightbsd* | 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 $LIBMULTITHREAD"]) + AC_RUN_IFELSE( + [AC_LANG_SOURCE([[ +#include <pthread.h> +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +]GL_MDA_DEFINES[ +static volatile int sigint_occurred; +static void +sigint_handler (int sig) +{ + sigint_occurred++; +} +int main () +{ + sigset_t set; + int pid = getpid (); + char command[80]; + signal (SIGINT, sigint_handler); + sigemptyset (&set); + sigaddset (&set, SIGINT); + if (!(pthread_sigmask (SIG_BLOCK, &set, NULL) == 0)) + return 1; + sprintf (command, "sh -c 'sleep 1; kill -%d %d' &", SIGINT, pid); + if (!(system (command) == 0)) + return 2; + sleep (2); + if (!(sigint_occurred == 0)) + return 3; + if (!(pthread_sigmask (SIG_UNBLOCK, &set, NULL) == 0)) + return 4; + if (!(sigint_occurred == 1)) /* This fails on IRIX. */ + return 5; + return 0; +}]])], + [:], + [gl_cv_func_pthread_sigmask_unblock_works=no], + [:]) + m4_ifdef([gl_][THREADLIB], [LIBS=$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 +]) |