1 ##### http://autoconf-archive.cryp.to/acx_pthread.html
5 # ACX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
9 # This macro figures out how to build C programs using POSIX threads.
10 # It sets the PTHREAD_LIBS output variable to the threads library and
11 # linker flags, and the PTHREAD_CFLAGS output variable to any special
12 # C compiler flags that are needed. (The user can also force certain
13 # compiler flags/libs to be tested by setting these environment
16 # Also sets PTHREAD_CC to any special C compiler that is needed for
17 # multi-threaded programs (defaults to the value of CC otherwise).
18 # (This is necessary on AIX to use the special cc_r compiler alias.)
20 # NOTE: You are assumed to not only compile your program with these
21 # flags, but also link it with them as well. e.g. you should link
22 # with $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS
25 # If you are only building threads programs, you may wish to use
26 # these variables in your default LIBS, CFLAGS, and CC:
28 # LIBS="$PTHREAD_LIBS $LIBS"
29 # CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
32 # In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute
33 # constant has a nonstandard name, defines PTHREAD_CREATE_JOINABLE to
34 # that name (e.g. PTHREAD_CREATE_UNDETACHED on AIX).
36 # ACTION-IF-FOUND is a list of shell commands to run if a threads
37 # library is found, and ACTION-IF-NOT-FOUND is a list of commands to
38 # run it if it is not found. If ACTION-IF-FOUND is not specified, the
39 # default action will define HAVE_PTHREAD.
41 # Please let the authors know if this macro fails on any platform, or
42 # if you have any other suggestions or comments. This macro was based
43 # on work by SGJ on autoconf scripts for FFTW (http://www.fftw.org/)
44 # (with help from M. Frigo), as well as ac_pthread and hb_pthread
45 # macros posted by Alejandro Forero Cuervo to the autoconf macro
46 # repository. We are also grateful for the helpful feedback of
51 # Copyright (c) 2007, 2008 Sebastian Freundt <hroptatyr@sxemacs.org>
52 # Copyright (c) 2006 Steven G. Johnson <stevenj@alum.mit.edu>
54 # This program is free software: you can redistribute it and/or
55 # modify it under the terms of the GNU General Public License as
56 # published by the Free Software Foundation, either version 3 of the
57 # License, or (at your option) any later version.
59 # This program is distributed in the hope that it will be useful,
60 # but WITHOUT ANY WARRANTY; without even the implied warranty of
61 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
62 # General Public License for more details.
64 # You should have received a copy of the GNU General Public License
65 # along with this program. If not, see <http://www.gnu.org/licenses/>.
67 # As a special exception, the respective Autoconf Macro's copyright
68 # owner gives unlimited permission to copy, distribute and modify the
69 # configure scripts that are the output of Autoconf when processing
70 # the Macro. You need not follow the terms of the GNU General Public
71 # License when using or distributing such scripts, even though
72 # portions of the text of the Macro appear in them. The GNU General
73 # Public License (GPL) does govern all other use of the material that
74 # constitutes the Autoconf Macro.
76 # This special exception to the GPL applies to versions of the
77 # Autoconf Macro released by the Autoconf Macro Archive. When you
78 # make and distribute a modified version of the Autoconf Macro, you
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80 # modified version as well.
82 AC_DEFUN([ACX_PTHREAD], [
83 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=$PTHREAD_CFLAGS])
100 AC_CHECK_FUNC([pthread_join], [acx_pthread_ok=yes])
101 AC_MSG_RESULT($acx_pthread_ok)
102 if test x"$acx_pthread_ok" = xno; then
107 CFLAGS="$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 acx_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 acx_pthread_flags="-pthreads pthread -mt -pthread $acx_pthread_flags"
157 if test x"$acx_pthread_ok" = xno; then
158 for flag in $acx_pthread_flags; do
162 AC_MSG_CHECKING([whether pthreads work without any flags])
166 AC_MSG_CHECKING([whether pthreads work with $flag])
167 PTHREAD_CFLAGS="$flag"
171 AC_CHECK_PROG(acx_pthread_config, pthread-config, yes, no)
172 if test x"$acx_pthread_config" = xno; then continue; fi
173 PTHREAD_CFLAGS="`pthread-config --cflags`"
174 PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"
178 AC_MSG_CHECKING([for the pthreads library -l$flag])
179 PTHREAD_LIBS="-l$flag"
184 save_CFLAGS="$CFLAGS"
185 LIBS="$PTHREAD_LIBS $LIBS"
186 CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
188 # Check for various functions. We must include pthread.h,
189 # since some functions may be macros. (On the Sequent, we
190 # need a special flag -Kthread to make this header compile.)
191 # We check for pthread_join because it is in -lpthread on IRIX
192 # while pthread_create is in libc. We check for pthread_attr_init
193 # due to DEC craziness with -lpthreads. We check for
194 # pthread_cleanup_push because it is one of the few pthread
195 # functions on Solaris that doesn't have a non-functional libc stub.
196 # We try pthread_create on general principles.
197 AC_LINK_IFELSE([AC_LANG_SOURCE([[
204 pthread_attr_init(0);
205 pthread_cleanup_push(0, 0);
206 pthread_create(0,0,0,0);
207 pthread_cleanup_pop(0);
210 ]])], [acx_pthread_ok=yes])
213 CFLAGS="$save_CFLAGS"
215 AC_MSG_RESULT($acx_pthread_ok)
216 if test "x$acx_pthread_ok" = xyes; then
225 # Various other checks:
226 if test "x$acx_pthread_ok" = xyes; then
228 LIBS="$PTHREAD_LIBS $LIBS"
229 save_CFLAGS="$CFLAGS"
230 CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
232 # Detect AIX lossage: JOINABLE attribute is called UNDETACHED.
233 AC_MSG_CHECKING([for joinable pthread attribute])
235 for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do
236 AC_LINK_IFELSE([AC_LANG_SOURCE([[
244 ]])], [attr_name=$attr; break])
246 AC_MSG_RESULT($attr_name)
247 if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then
248 AC_DEFINE_UNQUOTED(PTHREAD_CREATE_JOINABLE, $attr_name,
249 [Define to necessary symbol if this constant
250 uses a non-standard name on your system.])
253 AC_MSG_CHECKING([if more special flags are required for pthreads])
255 case "${host_cpu}-${host_os}" in
256 *-aix* | *-freebsd* | *-darwin*) flag="-D_THREAD_SAFE";;
257 *solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";;
259 AC_MSG_RESULT(${flag})
260 if test "x$flag" != xno; then
261 PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
265 CFLAGS="$save_CFLAGS"
267 # More AIX lossage: must compile with xlc_r or cc_r
268 if test x"$GCC" != xyes; then
269 AC_CHECK_PROGS(PTHREAD_CC, xlc_r cc_r, ${CC})
277 AC_SUBST(PTHREAD_LIBS)
278 AC_SUBST(PTHREAD_CFLAGS)
281 # Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
282 if test x"$acx_pthread_ok" = xyes; then
283 ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1])