summaryrefslogtreecommitdiff
path: root/m4/threadlib.m4
diff options
context:
space:
mode:
Diffstat (limited to 'm4/threadlib.m4')
-rw-r--r--m4/threadlib.m4389
1 files changed, 389 insertions, 0 deletions
diff --git a/m4/threadlib.m4 b/m4/threadlib.m4
new file mode 100644
index 000000000..dc9a3d8e8
--- /dev/null
+++ b/m4/threadlib.m4
@@ -0,0 +1,389 @@
+# threadlib.m4 serial 11 (gettext-0.18.2)
+dnl Copyright (C) 2005-2014 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.
+
+dnl From Bruno Haible.
+
+dnl gl_THREADLIB
+dnl ------------
+dnl Tests for a multithreading library to be used.
+dnl If the configure.ac contains a definition of the gl_THREADLIB_DEFAULT_NO
+dnl (it must be placed before the invocation of gl_THREADLIB_EARLY!), then the
+dnl default is 'no', otherwise it is system dependent. In both cases, the user
+dnl can change the choice through the options --enable-threads=choice or
+dnl --disable-threads.
+dnl Defines at most one of the macros USE_POSIX_THREADS, USE_SOLARIS_THREADS,
+dnl USE_PTH_THREADS, USE_WINDOWS_THREADS
+dnl Sets the variables LIBTHREAD and LTLIBTHREAD to the linker options for use
+dnl in a Makefile (LIBTHREAD for use without libtool, LTLIBTHREAD for use with
+dnl libtool).
+dnl Sets the variables LIBMULTITHREAD and LTLIBMULTITHREAD similarly, for
+dnl programs that really need multithread functionality. The difference
+dnl between LIBTHREAD and LIBMULTITHREAD is that on platforms supporting weak
+dnl symbols, typically LIBTHREAD is empty whereas LIBMULTITHREAD is not.
+dnl Adds to CPPFLAGS the flag -D_REENTRANT or -D_THREAD_SAFE if needed for
+dnl multithread-safe programs.
+
+AC_DEFUN([gl_THREADLIB_EARLY],
+[
+ AC_REQUIRE([gl_THREADLIB_EARLY_BODY])
+])
+
+dnl The guts of gl_THREADLIB_EARLY. Needs to be expanded only once.
+
+AC_DEFUN([gl_THREADLIB_EARLY_BODY],
+[
+ dnl Ordering constraints: This macro modifies CPPFLAGS in a way that
+ dnl influences the result of the autoconf tests that test for *_unlocked
+ dnl declarations, on AIX 5 at least. Therefore it must come early.
+ AC_BEFORE([$0], [gl_FUNC_GLIBC_UNLOCKED_IO])dnl
+ AC_BEFORE([$0], [gl_ARGP])dnl
+
+ AC_REQUIRE([AC_CANONICAL_HOST])
+ dnl _GNU_SOURCE is needed for pthread_rwlock_t on glibc systems.
+ dnl AC_USE_SYSTEM_EXTENSIONS was introduced in autoconf 2.60 and obsoletes
+ dnl AC_GNU_SOURCE.
+ m4_ifdef([AC_USE_SYSTEM_EXTENSIONS],
+ [AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])],
+ [AC_REQUIRE([AC_GNU_SOURCE])])
+ dnl Check for multithreading.
+ m4_ifdef([gl_THREADLIB_DEFAULT_NO],
+ [m4_divert_text([DEFAULTS], [gl_use_threads_default=no])],
+ [m4_divert_text([DEFAULTS], [gl_use_threads_default=])])
+ AC_ARG_ENABLE([threads],
+AC_HELP_STRING([--enable-threads={posix|solaris|pth|windows}], [specify multithreading API])m4_ifdef([gl_THREADLIB_DEFAULT_NO], [], [
+AC_HELP_STRING([--disable-threads], [build without multithread safety])]),
+ [gl_use_threads=$enableval],
+ [if test -n "$gl_use_threads_default"; then
+ gl_use_threads="$gl_use_threads_default"
+ else
+changequote(,)dnl
+ case "$host_os" in
+ dnl Disable multithreading by default on OSF/1, because it interferes
+ dnl with fork()/exec(): When msgexec is linked with -lpthread, its
+ dnl child process gets an endless segmentation fault inside execvp().
+ dnl Disable multithreading by default on Cygwin 1.5.x, because it has
+ dnl bugs that lead to endless loops or crashes. See
+ dnl <http://cygwin.com/ml/cygwin/2009-08/msg00283.html>.
+ osf*) gl_use_threads=no ;;
+ cygwin*)
+ case `uname -r` in
+ 1.[0-5].*) gl_use_threads=no ;;
+ *) gl_use_threads=yes ;;
+ esac
+ ;;
+ *) gl_use_threads=yes ;;
+ esac
+changequote([,])dnl
+ fi
+ ])
+ if test "$gl_use_threads" = yes || test "$gl_use_threads" = posix; then
+ # For using <pthread.h>:
+ case "$host_os" in
+ osf*)
+ # On OSF/1, the compiler needs the flag -D_REENTRANT so that it
+ # groks <pthread.h>. cc also understands the flag -pthread, but
+ # we don't use it because 1. gcc-2.95 doesn't understand -pthread,
+ # 2. putting a flag into CPPFLAGS that has an effect on the linker
+ # causes the AC_LINK_IFELSE test below to succeed unexpectedly,
+ # leading to wrong values of LIBTHREAD and LTLIBTHREAD.
+ CPPFLAGS="$CPPFLAGS -D_REENTRANT"
+ ;;
+ esac
+ # Some systems optimize for single-threaded programs by default, and
+ # need special flags to disable these optimizations. For example, the
+ # definition of 'errno' in <errno.h>.
+ case "$host_os" in
+ aix* | freebsd*) CPPFLAGS="$CPPFLAGS -D_THREAD_SAFE" ;;
+ solaris*) CPPFLAGS="$CPPFLAGS -D_REENTRANT" ;;
+ esac
+ fi
+])
+
+dnl The guts of gl_THREADLIB. Needs to be expanded only once.
+
+AC_DEFUN([gl_THREADLIB_BODY],
+[
+ AC_REQUIRE([gl_THREADLIB_EARLY_BODY])
+ gl_threads_api=none
+ LIBTHREAD=
+ LTLIBTHREAD=
+ LIBMULTITHREAD=
+ LTLIBMULTITHREAD=
+ if test "$gl_use_threads" != no; then
+ dnl Check whether the compiler and linker support weak declarations.
+ AC_CACHE_CHECK([whether imported symbols can be declared weak],
+ [gl_cv_have_weak],
+ [gl_cv_have_weak=no
+ dnl First, test whether the compiler accepts it syntactically.
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[extern void xyzzy ();
+#pragma weak xyzzy]],
+ [[xyzzy();]])],
+ [gl_cv_have_weak=maybe])
+ if test $gl_cv_have_weak = maybe; then
+ dnl Second, test whether it actually works. On Cygwin 1.7.2, with
+ dnl gcc 4.3, symbols declared weak always evaluate to the address 0.
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE([[
+#include <stdio.h>
+#pragma weak fputs
+int main ()
+{
+ return (fputs == NULL);
+}]])],
+ [gl_cv_have_weak=yes],
+ [gl_cv_have_weak=no],
+ [dnl When cross-compiling, assume that only ELF platforms support
+ dnl weak symbols.
+ AC_EGREP_CPP([Extensible Linking Format],
+ [#ifdef __ELF__
+ Extensible Linking Format
+ #endif
+ ],
+ [gl_cv_have_weak="guessing yes"],
+ [gl_cv_have_weak="guessing no"])
+ ])
+ fi
+ ])
+ if test "$gl_use_threads" = yes || test "$gl_use_threads" = posix; then
+ # On OSF/1, the compiler needs the flag -pthread or -D_REENTRANT so that
+ # it groks <pthread.h>. It's added above, in gl_THREADLIB_EARLY_BODY.
+ AC_CHECK_HEADER([pthread.h],
+ [gl_have_pthread_h=yes], [gl_have_pthread_h=no])
+ if test "$gl_have_pthread_h" = yes; then
+ # Other possible tests:
+ # -lpthreads (FSU threads, PCthreads)
+ # -lgthreads
+ gl_have_pthread=
+ # Test whether both pthread_mutex_lock and pthread_mutexattr_init exist
+ # in libc. IRIX 6.5 has the first one in both libc and libpthread, but
+ # the second one only in libpthread, and lock.c needs it.
+ #
+ # If -pthread works, prefer it to -lpthread, since Ubuntu 14.04
+ # needs -pthread for some reason. See:
+ # http://lists.gnu.org/archive/html/bug-gnulib/2014-09/msg00023.html
+ save_LIBS=$LIBS
+ for gl_pthread in '' '-pthread'; do
+ LIBS="$LIBS $gl_pthread"
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <pthread.h>
+ pthread_mutex_t m;
+ pthread_mutexattr_t ma;
+ ]],
+ [[pthread_mutex_lock (&m);
+ pthread_mutexattr_init (&ma);]])],
+ [gl_have_pthread=yes
+ LIBTHREAD=$gl_pthread LTLIBTHREAD=$gl_pthread
+ LIBMULTITHREAD=$gl_pthread LTLIBMULTITHREAD=$gl_pthread])
+ LIBS=$save_LIBS
+ test -n "$gl_have_pthread" && break
+ done
+
+ # Test for libpthread by looking for pthread_kill. (Not pthread_self,
+ # since it is defined as a macro on OSF/1.)
+ if test -n "$gl_have_pthread" && test -z "$LIBTHREAD"; then
+ # The program links fine without libpthread. But it may actually
+ # need to link with libpthread in order to create multiple threads.
+ AC_CHECK_LIB([pthread], [pthread_kill],
+ [LIBMULTITHREAD=-lpthread LTLIBMULTITHREAD=-lpthread
+ # On Solaris and HP-UX, most pthread functions exist also in libc.
+ # Therefore pthread_in_use() needs to actually try to create a
+ # thread: pthread_create from libc will fail, whereas
+ # pthread_create will actually create a thread.
+ case "$host_os" in
+ solaris* | hpux*)
+ AC_DEFINE([PTHREAD_IN_USE_DETECTION_HARD], [1],
+ [Define if the pthread_in_use() detection is hard.])
+ esac
+ ])
+ elif test -z "$gl_have_pthread"; then
+ # Some library is needed. Try libpthread and libc_r.
+ AC_CHECK_LIB([pthread], [pthread_kill],
+ [gl_have_pthread=yes
+ LIBTHREAD=-lpthread LTLIBTHREAD=-lpthread
+ LIBMULTITHREAD=-lpthread LTLIBMULTITHREAD=-lpthread])
+ if test -z "$gl_have_pthread"; then
+ # For FreeBSD 4.
+ AC_CHECK_LIB([c_r], [pthread_kill],
+ [gl_have_pthread=yes
+ LIBTHREAD=-lc_r LTLIBTHREAD=-lc_r
+ LIBMULTITHREAD=-lc_r LTLIBMULTITHREAD=-lc_r])
+ fi
+ fi
+ if test -n "$gl_have_pthread"; then
+ gl_threads_api=posix
+ AC_DEFINE([USE_POSIX_THREADS], [1],
+ [Define if the POSIX multithreading library can be used.])
+ if test -n "$LIBMULTITHREAD" || test -n "$LTLIBMULTITHREAD"; then
+ if case "$gl_cv_have_weak" in *yes) true;; *) false;; esac; then
+ AC_DEFINE([USE_POSIX_THREADS_WEAK], [1],
+ [Define if references to the POSIX multithreading library should be made weak.])
+ LIBTHREAD=
+ LTLIBTHREAD=
+ fi
+ fi
+ fi
+ fi
+ fi
+ if test -z "$gl_have_pthread"; then
+ if test "$gl_use_threads" = yes || test "$gl_use_threads" = solaris; then
+ gl_have_solaristhread=
+ gl_save_LIBS="$LIBS"
+ LIBS="$LIBS -lthread"
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[
+#include <thread.h>
+#include <synch.h>
+ ]],
+ [[thr_self();]])],
+ [gl_have_solaristhread=yes])
+ LIBS="$gl_save_LIBS"
+ if test -n "$gl_have_solaristhread"; then
+ gl_threads_api=solaris
+ LIBTHREAD=-lthread
+ LTLIBTHREAD=-lthread
+ LIBMULTITHREAD="$LIBTHREAD"
+ LTLIBMULTITHREAD="$LTLIBTHREAD"
+ AC_DEFINE([USE_SOLARIS_THREADS], [1],
+ [Define if the old Solaris multithreading library can be used.])
+ if case "$gl_cv_have_weak" in *yes) true;; *) false;; esac; then
+ AC_DEFINE([USE_SOLARIS_THREADS_WEAK], [1],
+ [Define if references to the old Solaris multithreading library should be made weak.])
+ LIBTHREAD=
+ LTLIBTHREAD=
+ fi
+ fi
+ fi
+ fi
+ if test "$gl_use_threads" = pth; then
+ gl_save_CPPFLAGS="$CPPFLAGS"
+ AC_LIB_LINKFLAGS([pth])
+ gl_have_pth=
+ gl_save_LIBS="$LIBS"
+ LIBS="$LIBS $LIBPTH"
+ AC_LINK_IFELSE(
+ [AC_LANG_PROGRAM([[#include <pth.h>]], [[pth_self();]])],
+ [gl_have_pth=yes])
+ LIBS="$gl_save_LIBS"
+ if test -n "$gl_have_pth"; then
+ gl_threads_api=pth
+ LIBTHREAD="$LIBPTH"
+ LTLIBTHREAD="$LTLIBPTH"
+ LIBMULTITHREAD="$LIBTHREAD"
+ LTLIBMULTITHREAD="$LTLIBTHREAD"
+ AC_DEFINE([USE_PTH_THREADS], [1],
+ [Define if the GNU Pth multithreading library can be used.])
+ if test -n "$LIBMULTITHREAD" || test -n "$LTLIBMULTITHREAD"; then
+ if case "$gl_cv_have_weak" in *yes) true;; *) false;; esac; then
+ AC_DEFINE([USE_PTH_THREADS_WEAK], [1],
+ [Define if references to the GNU Pth multithreading library should be made weak.])
+ LIBTHREAD=
+ LTLIBTHREAD=
+ fi
+ fi
+ else
+ CPPFLAGS="$gl_save_CPPFLAGS"
+ fi
+ fi
+ if test -z "$gl_have_pthread"; then
+ case "$gl_use_threads" in
+ yes | windows | win32) # The 'win32' is for backward compatibility.
+ if { case "$host_os" in
+ mingw*) true;;
+ *) false;;
+ esac
+ }; then
+ gl_threads_api=windows
+ AC_DEFINE([USE_WINDOWS_THREADS], [1],
+ [Define if the native Windows multithreading API can be used.])
+ fi
+ ;;
+ esac
+ fi
+ fi
+ AC_MSG_CHECKING([for multithread API to use])
+ AC_MSG_RESULT([$gl_threads_api])
+ AC_SUBST([LIBTHREAD])
+ AC_SUBST([LTLIBTHREAD])
+ AC_SUBST([LIBMULTITHREAD])
+ AC_SUBST([LTLIBMULTITHREAD])
+])
+
+AC_DEFUN([gl_THREADLIB],
+[
+ AC_REQUIRE([gl_THREADLIB_EARLY])
+ AC_REQUIRE([gl_THREADLIB_BODY])
+])
+
+
+dnl gl_DISABLE_THREADS
+dnl ------------------
+dnl Sets the gl_THREADLIB default so that threads are not used by default.
+dnl The user can still override it at installation time, by using the
+dnl configure option '--enable-threads'.
+
+AC_DEFUN([gl_DISABLE_THREADS], [
+ m4_divert_text([INIT_PREPARE], [gl_use_threads_default=no])
+])
+
+
+dnl Survey of platforms:
+dnl
+dnl Platform Available Compiler Supports test-lock
+dnl flavours option weak result
+dnl --------------- --------- --------- -------- ---------
+dnl Linux 2.4/glibc posix -lpthread Y OK
+dnl
+dnl GNU Hurd/glibc posix
+dnl
+dnl Ubuntu 14.04 posix -pthread Y OK
+dnl
+dnl FreeBSD 5.3 posix -lc_r Y
+dnl posix -lkse ? Y
+dnl posix -lpthread ? Y
+dnl posix -lthr Y
+dnl
+dnl FreeBSD 5.2 posix -lc_r Y
+dnl posix -lkse Y
+dnl posix -lthr Y
+dnl
+dnl FreeBSD 4.0,4.10 posix -lc_r Y OK
+dnl
+dnl NetBSD 1.6 --
+dnl
+dnl OpenBSD 3.4 posix -lpthread Y OK
+dnl
+dnl Mac OS X 10.[123] posix -lpthread Y OK
+dnl
+dnl Solaris 7,8,9 posix -lpthread Y Sol 7,8: 0.0; Sol 9: OK
+dnl solaris -lthread Y Sol 7,8: 0.0; Sol 9: OK
+dnl
+dnl HP-UX 11 posix -lpthread N (cc) OK
+dnl Y (gcc)
+dnl
+dnl IRIX 6.5 posix -lpthread Y 0.5
+dnl
+dnl AIX 4.3,5.1 posix -lpthread N AIX 4: 0.5; AIX 5: OK
+dnl
+dnl OSF/1 4.0,5.1 posix -pthread (cc) N OK
+dnl -lpthread (gcc) Y
+dnl
+dnl Cygwin posix -lpthread Y OK
+dnl
+dnl Any of the above pth -lpth 0.0
+dnl
+dnl Mingw windows N OK
+dnl
+dnl BeOS 5 --
+dnl
+dnl The test-lock result shows what happens if in test-lock.c EXPLICIT_YIELD is
+dnl turned off:
+dnl OK if all three tests terminate OK,
+dnl 0.5 if the first test terminates OK but the second one loops endlessly,
+dnl 0.0 if the first test already loops endlessly.