1 # ===========================================================================
2 # http://www.gnu.org/software/autoconf-archive/ax_pthread.html
3 # ===========================================================================
7 # AX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
11 # This macro figures out how to build C programs using POSIX threads. It
12 # sets the PTHREAD_LIBS output variable to the threads library and linker
13 # flags, and the PTHREAD_CFLAGS output variable to any special C compiler
14 # flags that are needed. (The user can also force certain compiler
15 # flags/libs to be tested by setting these environment variables.)
17 # Also sets PTHREAD_CC to any special C compiler that is needed for
18 # multi-threaded programs (defaults to the value of CC otherwise). (This
19 # is necessary on AIX to use the special cc_r compiler alias.)
21 # NOTE: You are assumed to not only compile your program with these flags,
22 # but also link it with them as well. e.g. you should link with
23 # $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS $LIBS
25 # If you are only building threads programs, you may wish to use these
26 # variables in your default LIBS, CFLAGS, and CC:
28 # LIBS="$PTHREAD_LIBS $LIBS"
29 # CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
32 # In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute constant
33 # has a nonstandard name, defines PTHREAD_CREATE_JOINABLE to that name
34 # (e.g. PTHREAD_CREATE_UNDETACHED on AIX).
36 # ACTION-IF-FOUND is a list of shell commands to run if a threads library
37 # is found, and ACTION-IF-NOT-FOUND is a list of commands to run it if it
38 # is not found. If ACTION-IF-FOUND is not specified, the default action
39 # will define HAVE_PTHREAD.
41 # Please let the authors know if this macro fails on any platform, or if
42 # you have any other suggestions or comments. This macro was based on work
43 # by SGJ on autoconf scripts for FFTW (http://www.fftw.org/) (with help
44 # from M. Frigo), as well as ac_pthread and hb_pthread macros posted by
45 # Alejandro Forero Cuervo to the autoconf macro repository. We are also
46 # grateful for the helpful feedback of numerous users.
50 # Copyright (c) 2008 Steven G. Johnson <stevenj@alum.mit.edu>
52 # This program is free software: you can redistribute it and/or modify it
53 # under the terms of the GNU General Public License as published by the
54 # Free Software Foundation, either version 3 of the License, or (at your
55 # option) any later version.
57 # This program is distributed in the hope that it will be useful, but
58 # WITHOUT ANY WARRANTY; without even the implied warranty of
59 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
60 # Public License for more details.
62 # You should have received a copy of the GNU General Public License along
63 # with this program. If not, see <http://www.gnu.org/licenses/>.
65 # As a special exception, the respective Autoconf Macro's copyright owner
66 # gives unlimited permission to copy, distribute and modify the configure
67 # scripts that are the output of Autoconf when processing the Macro. You
68 # need not follow the terms of the GNU General Public License when using
69 # or distributing such scripts, even though portions of the text of the
70 # Macro appear in them. The GNU General Public License (GPL) does govern
71 # all other use of the material that constitutes the Autoconf Macro.
73 # This special exception to the GPL applies to versions of the Autoconf
74 # Macro released by the Autoconf Archive. When you make and distribute a
75 # modified version of the Autoconf Macro, you may extend this special
76 # exception to the GPL to apply to your modified version as well.
80 AU_ALIAS([ACX_PTHREAD], [AX_PTHREAD])
81 AC_DEFUN([AX_PTHREAD], [
82 AC_REQUIRE([AC_CANONICAL_HOST])
87 # We used to check for pthread.h first, but this fails if pthread.h
88 # requires special compiler flags (e.g. on True64 or Sequent).
89 # It gets checked for in the link test anyway.
91 # First of all, check if the user has set any of the PTHREAD_LIBS,
92 # etcetera environment variables, and if threads linking works using
94 if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then
96 CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
98 LIBS="$PTHREAD_LIBS $LIBS"
99 AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS])
100 AC_TRY_LINK_FUNC(pthread_join, ax_pthread_ok=yes)
101 AC_MSG_RESULT($ax_pthread_ok)
102 if test x"$ax_pthread_ok" = xno; then
107 CFLAGS="$save_CFLAGS"
110 # We must check for the threads library under a number of different
111 # names; the ordering is very important because some systems
112 # (e.g. DEC) have both -lpthread and -lpthreads, where one of the
113 # libraries is broken (non-POSIX).
115 # Create a list of thread flags to try. Items starting with a "-" are
116 # C compiler flags, and other items are library names, except for "none"
117 # which indicates that we try without any flags at all, and "pthread-config"
118 # which is a program returning the flags for the Pth emulation library.
120 ax_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"
122 # The ordering *is* (sometimes) important. Some notes on the
123 # individual items follow:
125 # pthreads: AIX (must check this before -lpthread)
126 # none: in case threads are in libc; should be tried before -Kthread and
127 # other compiler flags to prevent continual compiler warnings
128 # -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h)
129 # -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able)
130 # lthread: LinuxThreads port on FreeBSD (also preferred to -pthread)
131 # -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads)
132 # -pthreads: Solaris/gcc
133 # -mthreads: Mingw32/gcc, Lynx/gcc
134 # -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it
135 # doesn't hurt to check since this sometimes defines pthreads too;
136 # also defines -D_REENTRANT)
137 # ... -mt is also the pthreads flag for HP/aCC
138 # pthread: Linux, etcetera
139 # --thread-safe: KAI C++
140 # pthread-config: use pthread-config program (for GNU Pth library)
142 case "${host_cpu}-${host_os}" in
145 # On Solaris (at least, for some versions), libc contains stubbed
146 # (non-functional) versions of the pthreads routines, so link-based
147 # tests will erroneously succeed. (We need to link with -pthreads/-mt/
148 # -lpthread.) (The stubs are missing pthread_cleanup_push, or rather
149 # a function called by this macro, so we could check for that, but
150 # who knows whether they'll stub that too in a future libc.) So,
151 # we'll just look for -pthreads and -lpthread first:
153 ax_pthread_flags="-pthreads pthread -mt -pthread $ax_pthread_flags"
157 ax_pthread_flags="-pthread $ax_pthread_flags"
161 if test x"$ax_pthread_ok" = xno; then
162 for flag in $ax_pthread_flags; do
166 AC_MSG_CHECKING([whether pthreads work without any flags])
170 AC_MSG_CHECKING([whether pthreads work with $flag])
171 PTHREAD_CFLAGS="$flag"
175 AC_CHECK_PROG(ax_pthread_config, pthread-config, yes, no)
176 if test x"$ax_pthread_config" = xno; then continue; fi
177 PTHREAD_CFLAGS="`pthread-config --cflags`"
178 PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"
182 AC_MSG_CHECKING([for the pthreads library -l$flag])
183 PTHREAD_LIBS="-l$flag"
188 save_CFLAGS="$CFLAGS"
189 LIBS="$PTHREAD_LIBS $LIBS"
190 CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
192 # Check for various functions. We must include pthread.h,
193 # since some functions may be macros. (On the Sequent, we
194 # need a special flag -Kthread to make this header compile.)
195 # We check for pthread_join because it is in -lpthread on IRIX
196 # while pthread_create is in libc. We check for pthread_attr_init
197 # due to DEC craziness with -lpthreads. We check for
198 # pthread_cleanup_push because it is one of the few pthread
199 # functions on Solaris that doesn't have a non-functional libc stub.
200 # We try pthread_create on general principles.
201 AC_TRY_LINK([#include <pthread.h>
202 static void routine(void* a) {a=0;}
203 static void* start_routine(void* a) {return a;}],
204 [pthread_t th; pthread_attr_t attr;
205 pthread_create(&th,0,start_routine,0);
207 pthread_attr_init(&attr);
208 pthread_cleanup_push(routine, 0);
209 pthread_cleanup_pop(0); ],
213 CFLAGS="$save_CFLAGS"
215 AC_MSG_RESULT($ax_pthread_ok)
216 if test "x$ax_pthread_ok" = xyes; then
225 # Various other checks:
226 if test "x$ax_pthread_ok" = xyes; then
228 LIBS="$PTHREAD_LIBS $LIBS"
229 save_CFLAGS="$CFLAGS"
230 CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
232 # Detect AIX lossage: JOINABLE attribute is called UNDETACHED.
233 AC_MSG_CHECKING([for joinable pthread attribute])
235 for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do
236 AC_TRY_LINK([#include <pthread.h>], [int attr=$attr; return attr;],
237 [attr_name=$attr; break])
239 AC_MSG_RESULT($attr_name)
240 if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then
241 AC_DEFINE_UNQUOTED(PTHREAD_CREATE_JOINABLE, $attr_name,
242 [Define to necessary symbol if this constant
243 uses a non-standard name on your system.])
246 AC_MSG_CHECKING([if more special flags are required for pthreads])
248 case "${host_cpu}-${host_os}" in
249 *-aix* | *-freebsd* | *-darwin*) flag="-D_THREAD_SAFE";;
250 *solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";;
252 AC_MSG_RESULT(${flag})
253 if test "x$flag" != xno; then
254 PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
258 CFLAGS="$save_CFLAGS"
260 # More AIX lossage: must compile with xlc_r or cc_r
261 if test x"$GCC" != xyes; then
262 AC_CHECK_PROGS(PTHREAD_CC, xlc_r cc_r, ${CC})
270 AC_SUBST(PTHREAD_LIBS)
271 AC_SUBST(PTHREAD_CFLAGS)
274 # Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
275 if test x"$ax_pthread_ok" = xyes; then
276 ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1])