1
dnl @synopsis ACX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
3
dnl @summary figure out how to build C programs using POSIX threads
5
dnl This macro figures out how to build C programs using POSIX threads.
6
dnl It sets the PTHREAD_LIBS output variable to the threads library and
7
dnl linker flags, and the PTHREAD_CFLAGS output variable to any special
8
dnl C compiler flags that are needed. (The user can also force certain
9
dnl compiler flags/libs to be tested by setting these environment
12
dnl Also sets PTHREAD_CC to any special C compiler that is needed for
13
dnl multi-threaded programs (defaults to the value of CC otherwise).
14
dnl (This is necessary on AIX to use the special cc_r compiler alias.)
16
dnl NOTE: You are assumed to not only compile your program with these
17
dnl flags, but also link it with them as well. e.g. you should link
18
dnl with $PTHREAD_CC $CFLAGS $PTHREAD_CFLAGS $LDFLAGS ... $PTHREAD_LIBS
21
dnl If you are only building threads programs, you may wish to use
22
dnl these variables in your default LIBS, CFLAGS, and CC:
24
dnl LIBS="$PTHREAD_LIBS $LIBS"
25
dnl CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
28
dnl In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute
29
dnl constant has a nonstandard name, defines PTHREAD_CREATE_JOINABLE to
30
dnl that name (e.g. PTHREAD_CREATE_UNDETACHED on AIX).
32
dnl ACTION-IF-FOUND is a list of shell commands to run if a threads
33
dnl library is found, and ACTION-IF-NOT-FOUND is a list of commands to
34
dnl run it if it is not found. If ACTION-IF-FOUND is not specified, the
35
dnl default action will define HAVE_PTHREAD.
37
dnl Please let the authors know if this macro fails on any platform, or
38
dnl if you have any other suggestions or comments. This macro was based
39
dnl on work by SGJ on autoconf scripts for FFTW (www.fftw.org) (with
40
dnl help from M. Frigo), as well as ac_pthread and hb_pthread macros
41
dnl posted by Alejandro Forero Cuervo to the autoconf macro repository.
42
dnl We are also grateful for the helpful feedback of numerous users.
44
dnl @category InstalledPackages
45
dnl @author Steven G. Johnson <stevenj@alum.mit.edu>
46
dnl @version 2005-06-15
47
dnl @license GPLWithACException
49
AC_DEFUN([ACX_PTHREAD], [
50
AC_REQUIRE([AC_CANONICAL_HOST])
55
# We used to check for pthread.h first, but this fails if pthread.h
56
# requires special compiler flags (e.g. on True64 or Sequent).
57
# It gets checked for in the link test anyway.
59
# First of all, check if the user has set any of the PTHREAD_LIBS,
60
# etcetera environment variables, and if threads linking works using
62
if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then
64
CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
66
LIBS="$PTHREAD_LIBS $LIBS"
67
AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS])
68
AC_TRY_LINK_FUNC(pthread_join, acx_pthread_ok=yes)
69
AC_MSG_RESULT($acx_pthread_ok)
70
if test x"$acx_pthread_ok" = xno; then
78
# We must check for the threads library under a number of different
79
# names; the ordering is very important because some systems
80
# (e.g. DEC) have both -lpthread and -lpthreads, where one of the
81
# libraries is broken (non-POSIX).
83
# Create a list of thread flags to try. Items starting with a "-" are
84
# C compiler flags, and other items are library names, except for "none"
85
# which indicates that we try without any flags at all, and "pthread-config"
86
# which is a program returning the flags for the Pth emulation library.
88
acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt pthread-config"
90
# The ordering *is* (sometimes) important. Some notes on the
91
# individual items follow:
93
# pthreads: AIX (must check this before -lpthread)
94
# none: in case threads are in libc; should be tried before -Kthread and
95
# other compiler flags to prevent continual compiler warnings
96
# -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h)
97
# -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able)
98
# lthread: LinuxThreads port on FreeBSD (also preferred to -pthread)
99
# -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads)
100
# -pthreads: Solaris/gcc
101
# -mthreads: Mingw32/gcc, Lynx/gcc
102
# -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it
103
# doesn't hurt to check since this sometimes defines pthreads too;
104
# also defines -D_REENTRANT)
105
# ... -mt is also the pthreads flag for HP/aCC
106
# pthread: Linux, etcetera
107
# --thread-safe: KAI C++
108
# pthread-config: use pthread-config program (for GNU Pth library)
110
case "${host_cpu}-${host_os}" in
113
# On Solaris (at least, for some versions), libc contains stubbed
114
# (non-functional) versions of the pthreads routines, so link-based
115
# tests will erroneously succeed. (We need to link with -pthreads/-mt/
116
# -lpthread.) (The stubs are missing pthread_cleanup_push, or rather
117
# a function called by this macro, so we could check for that, but
118
# who knows whether they'll stub that too in a future libc.) So,
119
# we'll just look for -pthreads and -lpthread first:
121
acx_pthread_flags="-pthreads pthread -mt -pthread $acx_pthread_flags"
125
if test x"$acx_pthread_ok" = xno; then
126
for flag in $acx_pthread_flags; do
130
AC_MSG_CHECKING([whether pthreads work without any flags])
134
AC_MSG_CHECKING([whether pthreads work with $flag])
135
PTHREAD_CFLAGS="$flag"
139
AC_CHECK_PROG(acx_pthread_config, pthread-config, yes, no)
140
if test x"$acx_pthread_config" = xno; then continue; fi
141
PTHREAD_CFLAGS="`pthread-config --cflags`"
142
PTHREAD_LIBS="`pthread-config --ldflags` `pthread-config --libs`"
146
AC_MSG_CHECKING([for the pthreads library -l$flag])
147
PTHREAD_LIBS="-l$flag"
152
save_CFLAGS="$CFLAGS"
153
LIBS="$PTHREAD_LIBS $LIBS"
154
CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
156
# Check for various functions. We must include pthread.h,
157
# since some functions may be macros. (On the Sequent, we
158
# need a special flag -Kthread to make this header compile.)
159
# We check for pthread_join because it is in -lpthread on IRIX
160
# while pthread_create is in libc. We check for pthread_attr_init
161
# due to DEC craziness with -lpthreads. We check for
162
# pthread_cleanup_push because it is one of the few pthread
163
# functions on Solaris that doesn't have a non-functional libc stub.
164
# We try pthread_create on general principles.
165
AC_TRY_LINK([#include <pthread.h>],
166
[pthread_t th; pthread_join(th, 0);
167
pthread_attr_init(0); pthread_cleanup_push(0, 0);
168
pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
169
[acx_pthread_ok=yes])
172
CFLAGS="$save_CFLAGS"
174
AC_MSG_RESULT($acx_pthread_ok)
175
if test "x$acx_pthread_ok" = xyes; then
184
# Various other checks:
185
if test "x$acx_pthread_ok" = xyes; then
187
LIBS="$PTHREAD_LIBS $LIBS"
188
save_CFLAGS="$CFLAGS"
189
CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
191
# Detect AIX lossage: JOINABLE attribute is called UNDETACHED.
192
AC_MSG_CHECKING([for joinable pthread attribute])
194
for attr in PTHREAD_CREATE_JOINABLE PTHREAD_CREATE_UNDETACHED; do
195
AC_TRY_LINK([#include <pthread.h>], [int attr=$attr; return attr;],
196
[attr_name=$attr; break])
198
AC_MSG_RESULT($attr_name)
199
if test "$attr_name" != PTHREAD_CREATE_JOINABLE; then
200
AC_DEFINE_UNQUOTED(PTHREAD_CREATE_JOINABLE, $attr_name,
201
[Define to necessary symbol if this constant
202
uses a non-standard name on your system.])
205
AC_MSG_CHECKING([if more special flags are required for pthreads])
207
case "${host_cpu}-${host_os}" in
208
*-aix* | *-freebsd* | *-darwin*) flag="-D_THREAD_SAFE";;
209
*solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";;
211
AC_MSG_RESULT(${flag})
212
if test "x$flag" != xno; then
213
PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
217
CFLAGS="$save_CFLAGS"
219
# More AIX lossage: must compile with cc_r
220
AC_CHECK_PROG(PTHREAD_CC, cc_r, cc_r, ${CC})
225
AC_SUBST(PTHREAD_LIBS)
226
AC_SUBST(PTHREAD_CFLAGS)
229
# Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
230
if test x"$acx_pthread_ok" = xyes; then
231
ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1])