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Revision 1.2 - (show annotations)
Wed Jan 22 07:51:49 2003 UTC (17 years, 8 months ago) by nmav
Branch: MAIN
CVS Tags: hydra_0_1_6_without_hic, hydra_0_1_7, hydra_0_1_6, hydra_0_1_4, hydra_0_1_8, HEAD
Changes since 1.1: +226 -0 lines
merged changes from 0.1.x branch.

1 dnl @synopsis ACX_PTHREAD([ACTION-IF-FOUND[, ACTION-IF-NOT-FOUND]])
2 dnl
3 dnl This macro figures out how to build C programs using POSIX
4 dnl threads. It sets the PTHREAD_LIBS output variable to the threads
5 dnl library and linker flags, and the PTHREAD_CFLAGS output variable
6 dnl to any special C compiler flags that are needed. (The user can also
7 dnl force certain compiler flags/libs to be tested by setting these
8 dnl environment variables.)
9 dnl
10 dnl Also sets PTHREAD_CC to any special C compiler that is needed for
11 dnl multi-threaded programs (defaults to the value of CC otherwise).
12 dnl (This is necessary on AIX to use the special cc_r compiler alias.)
13 dnl
14 dnl If you are only building threads programs, you may wish to
15 dnl use these variables in your default LIBS, CFLAGS, and CC:
16 dnl
17 dnl LIBS="$PTHREAD_LIBS $LIBS"
18 dnl CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
19 dnl CC="$PTHREAD_CC"
20 dnl
21 dnl In addition, if the PTHREAD_CREATE_JOINABLE thread-attribute
22 dnl constant has a nonstandard name, defines PTHREAD_CREATE_JOINABLE
23 dnl to that name (e.g. PTHREAD_CREATE_UNDETACHED on AIX).
24 dnl
25 dnl ACTION-IF-FOUND is a list of shell commands to run if a threads
26 dnl library is found, and ACTION-IF-NOT-FOUND is a list of commands
27 dnl to run it if it is not found. If ACTION-IF-FOUND is not specified,
28 dnl the default action will define HAVE_PTHREAD.
29 dnl
30 dnl Please let the authors know if this macro fails on any platform,
31 dnl or if you have any other suggestions or comments. This macro was
32 dnl based on work by SGJ on autoconf scripts for FFTW (www.fftw.org)
33 dnl (with help from M. Frigo), as well as ac_pthread and hb_pthread
34 dnl macros posted by AFC to the autoconf macro repository. We are also
35 dnl grateful for the helpful feedback of numerous users.
36 dnl
37 dnl @version $Id: acx_pthread.m4,v 1.1.2.1 2003/01/04 12:07:04 nmav Exp $
38 dnl @author Steven G. Johnson <stevenj@alum.mit.edu> and Alejandro Forero Cuervo <bachue@bachue.com>
39
40 AC_DEFUN([ACX_PTHREAD], [
41 AC_REQUIRE([AC_CANONICAL_HOST])
42 AC_LANG_SAVE
43 AC_LANG_C
44 acx_pthread_ok=no
45
46 # We used to check for pthread.h first, but this fails if pthread.h
47 # requires special compiler flags (e.g. on True64 or Sequent).
48 # It gets checked for in the link test anyway.
49
50 # First of all, check if the user has set any of the PTHREAD_LIBS,
51 # etcetera environment variables, and if threads linking works using
52 # them:
53 if test x"$PTHREAD_LIBS$PTHREAD_CFLAGS" != x; then
54 save_CFLAGS="$CFLAGS"
55 CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
56 save_LIBS="$LIBS"
57 LIBS="$PTHREAD_LIBS $LIBS"
58 AC_MSG_CHECKING([for pthread_join in LIBS=$PTHREAD_LIBS with CFLAGS=$PTHREAD_CFLAGS])
59 AC_TRY_LINK_FUNC(pthread_join, acx_pthread_ok=yes)
60 AC_MSG_RESULT($acx_pthread_ok)
61 if test x"$acx_pthread_ok" = xno; then
62 PTHREAD_LIBS=""
63 PTHREAD_CFLAGS=""
64 fi
65 LIBS="$save_LIBS"
66 CFLAGS="$save_CFLAGS"
67 fi
68
69 # We must check for the threads library under a number of different
70 # names; the ordering is very important because some systems
71 # (e.g. DEC) have both -lpthread and -lpthreads, where one of the
72 # libraries is broken (non-POSIX).
73
74 # Create a list of thread flags to try. Items starting with a "-" are
75 # C compiler flags, and other items are library names, except for "none"
76 # which indicates that we try without any flags at all.
77
78 acx_pthread_flags="pthreads none -Kthread -kthread lthread -pthread -pthreads -mthreads pthread --thread-safe -mt"
79
80 # The ordering *is* (sometimes) important. Some notes on the
81 # individual items follow:
82
83 # pthreads: AIX (must check this before -lpthread)
84 # none: in case threads are in libc; should be tried before -Kthread and
85 # other compiler flags to prevent continual compiler warnings
86 # -Kthread: Sequent (threads in libc, but -Kthread needed for pthread.h)
87 # -kthread: FreeBSD kernel threads (preferred to -pthread since SMP-able)
88 # lthread: LinuxThreads port on FreeBSD (also preferred to -pthread)
89 # -pthread: Linux/gcc (kernel threads), BSD/gcc (userland threads)
90 # -pthreads: Solaris/gcc
91 # -mthreads: Mingw32/gcc, Lynx/gcc
92 # -mt: Sun Workshop C (may only link SunOS threads [-lthread], but it
93 # doesn't hurt to check since this sometimes defines pthreads too;
94 # also defines -D_REENTRANT)
95 # pthread: Linux, etcetera
96 # --thread-safe: KAI C++
97
98 case "${host_cpu}-${host_os}" in
99 *solaris*)
100
101 # On Solaris (at least, for some versions), libc contains stubbed
102 # (non-functional) versions of the pthreads routines, so link-based
103 # tests will erroneously succeed. (We need to link with -pthread or
104 # -lpthread.) (The stubs are missing pthread_cleanup_push, or rather
105 # a function called by this macro, so we could check for that, but
106 # who knows whether they'll stub that too in a future libc.) So,
107 # we'll just look for -pthreads and -lpthread first:
108
109 acx_pthread_flags="-pthread -pthreads pthread -mt $acx_pthread_flags"
110 ;;
111 esac
112
113 if test x"$acx_pthread_ok" = xno; then
114 for flag in $acx_pthread_flags; do
115
116 case $flag in
117 none)
118 AC_MSG_CHECKING([whether pthreads work without any flags])
119 ;;
120
121 -*)
122 AC_MSG_CHECKING([whether pthreads work with $flag])
123 PTHREAD_CFLAGS="$flag"
124 ;;
125
126 *)
127 AC_MSG_CHECKING([for the pthreads library -l$flag])
128 PTHREAD_LIBS="-l$flag"
129 ;;
130 esac
131
132 save_LIBS="$LIBS"
133 save_CFLAGS="$CFLAGS"
134 LIBS="$PTHREAD_LIBS $LIBS"
135 CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
136
137 # Check for various functions. We must include pthread.h,
138 # since some functions may be macros. (On the Sequent, we
139 # need a special flag -Kthread to make this header compile.)
140 # We check for pthread_join because it is in -lpthread on IRIX
141 # while pthread_create is in libc. We check for pthread_attr_init
142 # due to DEC craziness with -lpthreads. We check for
143 # pthread_cleanup_push because it is one of the few pthread
144 # functions on Solaris that doesn't have a non-functional libc stub.
145 # We try pthread_create on general principles.
146 AC_TRY_LINK([#include <pthread.h>],
147 [pthread_t th; pthread_join(th, 0);
148 pthread_attr_init(0); pthread_cleanup_push(0, 0);
149 pthread_create(0,0,0,0); pthread_cleanup_pop(0); ],
150 [acx_pthread_ok=yes])
151
152 LIBS="$save_LIBS"
153 CFLAGS="$save_CFLAGS"
154
155 AC_MSG_RESULT($acx_pthread_ok)
156 if test "x$acx_pthread_ok" = xyes; then
157 break;
158 fi
159
160 PTHREAD_LIBS=""
161 PTHREAD_CFLAGS=""
162 done
163 fi
164
165 # Various other checks:
166 if test "x$acx_pthread_ok" = xyes; then
167 save_LIBS="$LIBS"
168 LIBS="$PTHREAD_LIBS $LIBS"
169 save_CFLAGS="$CFLAGS"
170 CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
171
172 # Detect AIX lossage: threads are created detached by default
173 # and the JOINABLE attribute has a nonstandard name (UNDETACHED).
174 AC_MSG_CHECKING([for joinable pthread attribute])
175 AC_TRY_LINK([#include <pthread.h>],
176 [int attr=PTHREAD_CREATE_JOINABLE;],
177 ok=PTHREAD_CREATE_JOINABLE, ok=unknown)
178 if test x"$ok" = xunknown; then
179 AC_TRY_LINK([#include <pthread.h>],
180 [int attr=PTHREAD_CREATE_UNDETACHED;],
181 ok=PTHREAD_CREATE_UNDETACHED, ok=unknown)
182 fi
183 if test x"$ok" != xPTHREAD_CREATE_JOINABLE; then
184 AC_DEFINE(PTHREAD_CREATE_JOINABLE, $ok,
185 [Define to the necessary symbol if this constant
186 uses a non-standard name on your system.])
187 fi
188 AC_MSG_RESULT(${ok})
189 if test x"$ok" = xunknown; then
190 AC_MSG_WARN([we do not know how to create joinable pthreads])
191 fi
192
193 AC_MSG_CHECKING([if more special flags are required for pthreads])
194 flag=no
195 case "${host_cpu}-${host_os}" in
196 *-aix* | *-freebsd*) flag="-D_THREAD_SAFE";;
197 *solaris* | *-osf* | *-hpux*) flag="-D_REENTRANT";;
198 esac
199 AC_MSG_RESULT(${flag})
200 if test "x$flag" != xno; then
201 PTHREAD_CFLAGS="$flag $PTHREAD_CFLAGS"
202 fi
203
204 LIBS="$save_LIBS"
205 CFLAGS="$save_CFLAGS"
206
207 # More AIX lossage: must compile with cc_r
208 AC_CHECK_PROG(PTHREAD_CC, cc_r, cc_r, ${CC})
209 else
210 PTHREAD_CC="$CC"
211 fi
212
213 AC_SUBST(PTHREAD_LIBS)
214 AC_SUBST(PTHREAD_CFLAGS)
215 AC_SUBST(PTHREAD_CC)
216
217 # Finally, execute ACTION-IF-FOUND/ACTION-IF-NOT-FOUND:
218 if test x"$acx_pthread_ok" = xyes; then
219 ifelse([$1],,AC_DEFINE(HAVE_PTHREAD,1,[Define if you have POSIX threads libraries and header files.]),[$1])
220 :
221 else
222 acx_pthread_ok=no
223 $2
224 fi
225 AC_LANG_RESTORE
226 ])dnl ACX_PTHREAD

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