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dc6c21da TT |
1 | # threadlib.m4 serial 32 |
2 | dnl Copyright (C) 2005-2022 Free Software Foundation, Inc. | |
5abebf3c CB |
3 | dnl This file is free software; the Free Software Foundation |
4 | dnl gives unlimited permission to copy and/or distribute it, | |
5 | dnl with or without modifications, as long as this notice is preserved. | |
6 | ||
7 | dnl From Bruno Haible. | |
8 | ||
c0c3707f CB |
9 | AC_PREREQ([2.60]) |
10 | ||
5df4cba6 SM |
11 | dnl The general structure of the multithreading modules in gnulib is that we |
12 | dnl have three set of modules: | |
13 | dnl | |
14 | dnl * POSIX API: | |
15 | dnl pthread, which combines | |
16 | dnl pthread-h | |
17 | dnl pthread-thread | |
18 | dnl pthread-once | |
19 | dnl pthread-mutex | |
20 | dnl pthread-rwlock | |
21 | dnl pthread-cond | |
22 | dnl pthread-tss | |
23 | dnl pthread-spin | |
24 | dnl sched_yield | |
25 | dnl | |
26 | dnl * ISO C API: | |
27 | dnl threads, which combines | |
28 | dnl threads-h | |
29 | dnl thrd | |
30 | dnl mtx | |
31 | dnl cnd | |
32 | dnl tss | |
33 | dnl | |
34 | dnl * Gnulib API, with an implementation that can be chosen at configure | |
35 | dnl time through the option --enable-threads=... | |
36 | dnl thread | |
37 | dnl lock | |
38 | dnl cond | |
39 | dnl tls | |
40 | dnl yield | |
41 | dnl | |
42 | dnl They are independent, except for the fact that | |
43 | dnl - the implementation of the ISO C API may use the POSIX (or some other | |
44 | dnl platform dependent) API, | |
45 | dnl - the implementation of the Gnulib API may use the POSIX or ISO C or | |
46 | dnl some other platform dependent API, depending on the --enable-threads | |
47 | dnl option. | |
48 | dnl | |
49 | dnl This file contains macros for all of these APIs! | |
c0c3707f | 50 | |
5df4cba6 SM |
51 | dnl ============================================================================ |
52 | dnl Macros for all thread APIs | |
c0c3707f CB |
53 | |
54 | AC_DEFUN([gl_ANYTHREADLIB_EARLY], | |
55 | [ | |
56 | AC_REQUIRE([AC_CANONICAL_HOST]) | |
57 | if test -z "$gl_anythreadlib_early_done"; then | |
58 | case "$host_os" in | |
59 | osf*) | |
60 | # On OSF/1, the compiler needs the flag -D_REENTRANT so that it | |
61 | # groks <pthread.h>. cc also understands the flag -pthread, but | |
62 | # we don't use it because 1. gcc-2.95 doesn't understand -pthread, | |
63 | # 2. putting a flag into CPPFLAGS that has an effect on the linker | |
64 | # causes the AC_LINK_IFELSE test below to succeed unexpectedly, | |
65 | # leading to wrong values of LIBTHREAD and LTLIBTHREAD. | |
66 | CPPFLAGS="$CPPFLAGS -D_REENTRANT" | |
67 | ;; | |
68 | esac | |
69 | # Some systems optimize for single-threaded programs by default, and | |
70 | # need special flags to disable these optimizations. For example, the | |
71 | # definition of 'errno' in <errno.h>. | |
72 | case "$host_os" in | |
73 | aix* | freebsd*) CPPFLAGS="$CPPFLAGS -D_THREAD_SAFE" ;; | |
74 | solaris*) CPPFLAGS="$CPPFLAGS -D_REENTRANT" ;; | |
75 | esac | |
76 | gl_anythreadlib_early_done=done | |
77 | fi | |
78 | ]) | |
5abebf3c | 79 | |
c0c3707f CB |
80 | dnl Checks whether the compiler and linker support weak declarations of symbols. |
81 | ||
82 | AC_DEFUN([gl_WEAK_SYMBOLS], | |
83 | [ | |
5df4cba6 | 84 | AC_REQUIRE([AC_CANONICAL_HOST]) |
c0c3707f CB |
85 | AC_CACHE_CHECK([whether imported symbols can be declared weak], |
86 | [gl_cv_have_weak], | |
dc6c21da TT |
87 | [case "$host_os" in |
88 | cygwin*) | |
89 | dnl On Cygwin 3.2.0 with gcc 10.2, the test below would succeed, but | |
90 | dnl programs that use pthread_in_use() with weak symbol references | |
91 | dnl crash miserably at runtime. | |
92 | gl_cv_have_weak="guessing no" | |
93 | ;; | |
94 | *) | |
95 | gl_cv_have_weak=no | |
96 | dnl First, test whether the compiler accepts it syntactically. | |
97 | AC_LINK_IFELSE( | |
98 | [AC_LANG_PROGRAM( | |
99 | [[extern void xyzzy (); | |
c0c3707f | 100 | #pragma weak xyzzy]], |
dc6c21da TT |
101 | [[xyzzy();]])], |
102 | [gl_cv_have_weak=maybe]) | |
103 | if test $gl_cv_have_weak = maybe; then | |
104 | dnl Second, test whether it actually works. On Cygwin 1.7.2, with | |
105 | dnl gcc 4.3, symbols declared weak always evaluate to the address 0. | |
106 | AC_RUN_IFELSE( | |
107 | [AC_LANG_SOURCE([[ | |
c0c3707f CB |
108 | #include <stdio.h> |
109 | #pragma weak fputs | |
110 | int main () | |
111 | { | |
112 | return (fputs == NULL); | |
113 | }]])], | |
dc6c21da TT |
114 | [gl_cv_have_weak=yes], |
115 | [gl_cv_have_weak=no], | |
116 | [dnl When cross-compiling, assume that only ELF platforms support | |
117 | dnl weak symbols. | |
118 | AC_EGREP_CPP([Extensible Linking Format], | |
119 | [#ifdef __ELF__ | |
120 | Extensible Linking Format | |
121 | #endif | |
122 | ], | |
123 | [gl_cv_have_weak="guessing yes"], | |
124 | [gl_cv_have_weak="guessing no"]) | |
125 | ]) | |
126 | fi | |
127 | ;; | |
128 | esac | |
c0c3707f CB |
129 | dnl But when linking statically, weak symbols don't work. |
130 | case " $LDFLAGS " in | |
131 | *" -static "*) gl_cv_have_weak=no ;; | |
132 | esac | |
5df4cba6 SM |
133 | dnl Test for a bug in FreeBSD 11: A link error occurs when using a weak |
134 | dnl symbol and linking against a shared library that has a dependency on | |
135 | dnl the shared library that defines the symbol. | |
136 | case "$gl_cv_have_weak" in | |
137 | *yes) | |
138 | case "$host_os" in | |
dc6c21da | 139 | freebsd* | dragonfly* | midnightbsd*) |
5df4cba6 SM |
140 | : > conftest1.c |
141 | $CC $CPPFLAGS $CFLAGS $LDFLAGS -fPIC -shared -o libempty.so conftest1.c -lpthread >&AS_MESSAGE_LOG_FD 2>&1 | |
142 | cat <<EOF > conftest2.c | |
143 | #include <pthread.h> | |
144 | #pragma weak pthread_mutexattr_gettype | |
145 | int main () | |
146 | { | |
147 | return (pthread_mutexattr_gettype != NULL); | |
148 | } | |
149 | EOF | |
150 | $CC $CPPFLAGS $CFLAGS $LDFLAGS -o conftest conftest2.c libempty.so >&AS_MESSAGE_LOG_FD 2>&1 \ | |
151 | || gl_cv_have_weak=no | |
152 | rm -f conftest1.c libempty.so conftest2.c conftest | |
153 | ;; | |
154 | esac | |
155 | ;; | |
156 | esac | |
c0c3707f CB |
157 | ]) |
158 | case "$gl_cv_have_weak" in | |
159 | *yes) | |
160 | AC_DEFINE([HAVE_WEAK_SYMBOLS], [1], | |
161 | [Define to 1 if the compiler and linker support weak declarations of symbols.]) | |
162 | ;; | |
163 | esac | |
164 | ]) | |
165 | ||
5df4cba6 SM |
166 | dnl ============================================================================ |
167 | dnl Macros for the POSIX API | |
168 | ||
169 | dnl gl_PTHREADLIB | |
170 | dnl ------------- | |
171 | dnl Tests for the libraries needs for using the POSIX threads API. | |
172 | dnl Sets the variable LIBPTHREAD to the linker options for use in a Makefile. | |
173 | dnl Sets the variable LIBPMULTITHREAD, for programs that really need | |
174 | dnl multithread functionality. The difference between LIBPTHREAD and | |
175 | dnl LIBPMULTITHREAD is that on platforms supporting weak symbols, typically | |
176 | dnl LIBPTHREAD is empty whereas LIBPMULTITHREAD is not. | |
177 | dnl Sets the variable LIB_SCHED_YIELD to the linker options needed to use the | |
178 | dnl sched_yield() function. | |
179 | dnl Adds to CPPFLAGS the flag -D_REENTRANT or -D_THREAD_SAFE if needed for | |
180 | dnl multithread-safe programs. | |
181 | dnl Defines the C macro HAVE_PTHREAD_API if (at least parts of) the POSIX | |
182 | dnl threads API is available. | |
183 | ||
c0c3707f CB |
184 | dnl The guts of gl_PTHREADLIB. Needs to be expanded only once. |
185 | ||
186 | AC_DEFUN([gl_PTHREADLIB_BODY], | |
187 | [ | |
188 | AC_REQUIRE([gl_ANYTHREADLIB_EARLY]) | |
5df4cba6 | 189 | if test -z "$gl_pthreadlib_body_done"; then |
c0c3707f CB |
190 | gl_pthread_api=no |
191 | LIBPTHREAD= | |
192 | LIBPMULTITHREAD= | |
193 | # On OSF/1, the compiler needs the flag -pthread or -D_REENTRANT so that | |
194 | # it groks <pthread.h>. It's added above, in gl_ANYTHREADLIB_EARLY. | |
195 | AC_CHECK_HEADER([pthread.h], | |
196 | [gl_have_pthread_h=yes], [gl_have_pthread_h=no]) | |
197 | if test "$gl_have_pthread_h" = yes; then | |
198 | # Other possible tests: | |
199 | # -lpthreads (FSU threads, PCthreads) | |
200 | # -lgthreads | |
201 | # Test whether both pthread_mutex_lock and pthread_mutexattr_init exist | |
202 | # in libc. IRIX 6.5 has the first one in both libc and libpthread, but | |
203 | # the second one only in libpthread, and lock.c needs it. | |
204 | # | |
205 | # If -pthread works, prefer it to -lpthread, since Ubuntu 14.04 | |
206 | # needs -pthread for some reason. See: | |
207 | # https://lists.gnu.org/r/bug-gnulib/2014-09/msg00023.html | |
208 | save_LIBS=$LIBS | |
209 | for gl_pthread in '' '-pthread'; do | |
210 | LIBS="$LIBS $gl_pthread" | |
211 | AC_LINK_IFELSE( | |
212 | [AC_LANG_PROGRAM( | |
213 | [[#include <pthread.h> | |
214 | pthread_mutex_t m; | |
215 | pthread_mutexattr_t ma; | |
216 | ]], | |
217 | [[pthread_mutex_lock (&m); | |
218 | pthread_mutexattr_init (&ma);]])], | |
219 | [gl_pthread_api=yes | |
220 | LIBPTHREAD=$gl_pthread | |
221 | LIBPMULTITHREAD=$gl_pthread]) | |
222 | LIBS=$save_LIBS | |
223 | test $gl_pthread_api = yes && break | |
224 | done | |
dc6c21da TT |
225 | echo "$as_me:__oline__: gl_pthread_api=$gl_pthread_api" >&AS_MESSAGE_LOG_FD |
226 | echo "$as_me:__oline__: LIBPTHREAD=$LIBPTHREAD" >&AS_MESSAGE_LOG_FD | |
227 | ||
228 | gl_pthread_in_glibc=no | |
229 | # On Linux with glibc >= 2.34, libc contains the fully functional | |
230 | # pthread functions. | |
231 | case "$host_os" in | |
232 | linux*) | |
233 | AC_EGREP_CPP([Lucky user], | |
234 | [#include <features.h> | |
235 | #ifdef __GNU_LIBRARY__ | |
236 | #if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 34) || (__GLIBC__ > 2) | |
237 | Lucky user | |
238 | #endif | |
239 | #endif | |
240 | ], | |
241 | [gl_pthread_in_glibc=yes], | |
242 | []) | |
243 | ;; | |
244 | esac | |
245 | echo "$as_me:__oline__: gl_pthread_in_glibc=$gl_pthread_in_glibc" >&AS_MESSAGE_LOG_FD | |
c0c3707f CB |
246 | |
247 | # Test for libpthread by looking for pthread_kill. (Not pthread_self, | |
248 | # since it is defined as a macro on OSF/1.) | |
249 | if test $gl_pthread_api = yes && test -z "$LIBPTHREAD"; then | |
250 | # The program links fine without libpthread. But it may actually | |
251 | # need to link with libpthread in order to create multiple threads. | |
252 | AC_CHECK_LIB([pthread], [pthread_kill], | |
dc6c21da TT |
253 | [if test $gl_pthread_in_glibc = yes; then |
254 | LIBPMULTITHREAD= | |
255 | else | |
256 | LIBPMULTITHREAD=-lpthread | |
257 | # On Solaris and HP-UX, most pthread functions exist also in libc. | |
258 | # Therefore pthread_in_use() needs to actually try to create a | |
259 | # thread: pthread_create from libc will fail, whereas | |
260 | # pthread_create will actually create a thread. | |
261 | # On Solaris 10 or newer, this test is no longer needed, because | |
262 | # libc contains the fully functional pthread functions. | |
263 | case "$host_os" in | |
264 | solaris | solaris2.[1-9] | solaris2.[1-9].* | hpux*) | |
265 | AC_DEFINE([PTHREAD_IN_USE_DETECTION_HARD], [1], | |
266 | [Define if the pthread_in_use() detection is hard.]) | |
267 | esac | |
268 | fi | |
c0c3707f CB |
269 | ]) |
270 | elif test $gl_pthread_api != yes; then | |
271 | # Some library is needed. Try libpthread and libc_r. | |
272 | AC_CHECK_LIB([pthread], [pthread_kill], | |
273 | [gl_pthread_api=yes | |
274 | LIBPTHREAD=-lpthread | |
275 | LIBPMULTITHREAD=-lpthread]) | |
276 | if test $gl_pthread_api != yes; then | |
277 | # For FreeBSD 4. | |
278 | AC_CHECK_LIB([c_r], [pthread_kill], | |
279 | [gl_pthread_api=yes | |
280 | LIBPTHREAD=-lc_r | |
281 | LIBPMULTITHREAD=-lc_r]) | |
282 | fi | |
283 | fi | |
dc6c21da | 284 | echo "$as_me:__oline__: LIBPMULTITHREAD=$LIBPMULTITHREAD" >&AS_MESSAGE_LOG_FD |
c0c3707f CB |
285 | fi |
286 | AC_MSG_CHECKING([whether POSIX threads API is available]) | |
287 | AC_MSG_RESULT([$gl_pthread_api]) | |
288 | AC_SUBST([LIBPTHREAD]) | |
289 | AC_SUBST([LIBPMULTITHREAD]) | |
290 | if test $gl_pthread_api = yes; then | |
291 | AC_DEFINE([HAVE_PTHREAD_API], [1], | |
292 | [Define if you have the <pthread.h> header and the POSIX threads API.]) | |
293 | fi | |
5df4cba6 SM |
294 | |
295 | dnl On some systems, sched_yield is in librt, rather than in libpthread. | |
296 | AC_LINK_IFELSE( | |
297 | [AC_LANG_PROGRAM( | |
298 | [[#include <sched.h>]], | |
299 | [[sched_yield ();]])], | |
300 | [LIB_SCHED_YIELD= | |
301 | ], | |
302 | [dnl Solaris 7...10 has sched_yield in librt, not in libpthread or libc. | |
303 | AC_CHECK_LIB([rt], [sched_yield], [LIB_SCHED_YIELD=-lrt], | |
304 | [dnl Solaris 2.5.1, 2.6 has sched_yield in libposix4, not librt. | |
305 | AC_CHECK_LIB([posix4], [sched_yield], [LIB_SCHED_YIELD=-lposix4])]) | |
306 | ]) | |
307 | AC_SUBST([LIB_SCHED_YIELD]) | |
308 | ||
309 | gl_pthreadlib_body_done=done | |
310 | fi | |
311 | ]) | |
312 | ||
313 | AC_DEFUN([gl_PTHREADLIB], | |
314 | [ | |
315 | AC_REQUIRE([gl_ANYTHREADLIB_EARLY]) | |
316 | gl_PTHREADLIB_BODY | |
317 | ]) | |
318 | ||
319 | dnl ============================================================================ | |
320 | dnl Macros for the ISO C API | |
321 | ||
322 | dnl gl_STDTHREADLIB | |
323 | dnl --------------- | |
324 | dnl Tests for the libraries needs for using the ISO C threads API. | |
325 | dnl Sets the variable LIBSTDTHREAD to the linker options for use in a Makefile. | |
326 | dnl Adds to CPPFLAGS the flag -D_REENTRANT or -D_THREAD_SAFE if needed for | |
327 | dnl multithread-safe programs. | |
328 | dnl Defines the C macro HAVE_THREADS_H if (at least parts of) the ISO C threads | |
329 | dnl API is available. | |
330 | ||
331 | dnl The guts of gl_STDTHREADLIB. Needs to be expanded only once. | |
332 | ||
333 | AC_DEFUN([gl_STDTHREADLIB_BODY], | |
334 | [ | |
335 | AC_REQUIRE([gl_ANYTHREADLIB_EARLY]) | |
336 | AC_REQUIRE([AC_CANONICAL_HOST]) | |
337 | if test -z "$gl_stdthreadlib_body_done"; then | |
338 | AC_CHECK_HEADERS_ONCE([threads.h]) | |
339 | ||
340 | case "$host_os" in | |
341 | mingw*) | |
342 | LIBSTDTHREAD= | |
343 | ;; | |
344 | *) | |
345 | gl_PTHREADLIB_BODY | |
346 | if test $ac_cv_header_threads_h = yes; then | |
347 | dnl glibc >= 2.29 has thrd_create in libpthread. | |
348 | dnl FreeBSD >= 10 has thrd_create in libstdthreads; this library depends | |
349 | dnl on libpthread (for the symbol 'pthread_mutexattr_gettype'). | |
dc6c21da TT |
350 | dnl glibc >= 2.34, AIX >= 7.1, and Solaris >= 11.4 have thrd_create in |
351 | dnl libc. | |
5df4cba6 SM |
352 | AC_CHECK_FUNCS([thrd_create]) |
353 | if test $ac_cv_func_thrd_create = yes; then | |
354 | LIBSTDTHREAD= | |
355 | else | |
356 | AC_CHECK_LIB([stdthreads], [thrd_create], [ | |
357 | LIBSTDTHREAD='-lstdthreads -lpthread' | |
358 | ], [ | |
359 | dnl Guess that thrd_create is in libpthread. | |
360 | LIBSTDTHREAD="$LIBPMULTITHREAD" | |
361 | ]) | |
362 | fi | |
363 | else | |
364 | dnl Libraries needed by thrd.c, mtx.c, cnd.c, tss.c. | |
365 | LIBSTDTHREAD="$LIBPMULTITHREAD $LIB_SCHED_YIELD" | |
366 | fi | |
367 | ;; | |
368 | esac | |
369 | AC_SUBST([LIBSTDTHREAD]) | |
370 | ||
371 | AC_MSG_CHECKING([whether ISO C threads API is available]) | |
372 | AC_MSG_RESULT([$ac_cv_header_threads_h]) | |
373 | gl_stdthreadlib_body_done=done | |
374 | fi | |
375 | ]) | |
376 | ||
377 | AC_DEFUN([gl_STDTHREADLIB], | |
378 | [ | |
379 | AC_REQUIRE([gl_ANYTHREADLIB_EARLY]) | |
380 | gl_STDTHREADLIB_BODY | |
381 | ]) | |
382 | ||
383 | dnl ============================================================================ | |
384 | dnl Macros for the Gnulib API | |
385 | ||
386 | dnl gl_THREADLIB | |
387 | dnl ------------ | |
388 | dnl Tests for a multithreading library to be used. | |
389 | dnl If the configure.ac contains a definition of the gl_THREADLIB_DEFAULT_NO | |
390 | dnl (it must be placed before the invocation of gl_THREADLIB_EARLY!), then the | |
391 | dnl default is 'no', otherwise it is system dependent. In both cases, the user | |
392 | dnl can change the choice through the options --enable-threads=choice or | |
393 | dnl --disable-threads. | |
394 | dnl Defines at most one of the macros USE_ISOC_THREADS, USE_POSIX_THREADS, | |
395 | dnl USE_ISOC_AND_POSIX_THREADS, USE_WINDOWS_THREADS. | |
396 | dnl The choice --enable-threads=isoc+posix is available only on platforms that | |
397 | dnl have both the ISO C and the POSIX threads APIs. It has the effect of using | |
398 | dnl the ISO C API for most things and the POSIX API only for creating and | |
399 | dnl controlling threads (because there is no equivalent to pthread_atfork in | |
400 | dnl the ISO C API). | |
401 | dnl Sets the variables LIBTHREAD and LTLIBTHREAD to the linker options for use | |
402 | dnl in a Makefile (LIBTHREAD for use without libtool, LTLIBTHREAD for use with | |
403 | dnl libtool). | |
404 | dnl Sets the variables LIBMULTITHREAD and LTLIBMULTITHREAD similarly, for | |
405 | dnl programs that really need multithread functionality. The difference | |
406 | dnl between LIBTHREAD and LIBMULTITHREAD is that on platforms supporting weak | |
407 | dnl symbols, typically LIBTHREAD is empty whereas LIBMULTITHREAD is not. | |
408 | dnl Adds to CPPFLAGS the flag -D_REENTRANT or -D_THREAD_SAFE if needed for | |
409 | dnl multithread-safe programs. | |
410 | dnl Since support for GNU pth was removed, $LTLIBTHREAD and $LIBTHREAD have the | |
411 | dnl same value, and similarly $LTLIBMULTITHREAD and $LIBMULTITHREAD have the | |
412 | dnl same value. Only system libraries are needed. | |
413 | ||
414 | AC_DEFUN([gl_THREADLIB_EARLY], | |
415 | [ | |
416 | AC_REQUIRE([gl_THREADLIB_EARLY_BODY]) | |
417 | ]) | |
418 | ||
419 | dnl The guts of gl_THREADLIB_EARLY. Needs to be expanded only once. | |
420 | ||
421 | AC_DEFUN([gl_THREADLIB_EARLY_BODY], | |
422 | [ | |
423 | dnl Ordering constraints: This macro modifies CPPFLAGS in a way that | |
424 | dnl influences the result of the autoconf tests that test for *_unlocked | |
425 | dnl declarations, on AIX 5 at least. Therefore it must come early. | |
426 | AC_BEFORE([$0], [gl_FUNC_GLIBC_UNLOCKED_IO])dnl | |
427 | AC_BEFORE([$0], [gl_ARGP])dnl | |
428 | ||
429 | AC_REQUIRE([AC_CANONICAL_HOST]) | |
430 | dnl _GNU_SOURCE is needed for pthread_rwlock_t on glibc systems. | |
431 | AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS]) | |
432 | dnl Check for multithreading. | |
433 | m4_ifdef([gl_THREADLIB_DEFAULT_NO], | |
434 | [m4_divert_text([DEFAULTS], [gl_use_threads_default=no])], | |
435 | [m4_divert_text([DEFAULTS], [gl_use_threads_default=])]) | |
436 | m4_divert_text([DEFAULTS], [gl_use_winpthreads_default=]) | |
437 | AC_ARG_ENABLE([threads], | |
9c9d63b1 PM |
438 | AS_HELP_STRING([--enable-threads={isoc|posix|isoc+posix|windows}], [specify multithreading API])m4_ifdef([gl_THREADLIB_DEFAULT_NO], [], [ |
439 | AS_HELP_STRING([--disable-threads], [build without multithread safety])]), | |
5df4cba6 SM |
440 | [gl_use_threads=$enableval], |
441 | [if test -n "$gl_use_threads_default"; then | |
442 | gl_use_threads="$gl_use_threads_default" | |
443 | else | |
444 | changequote(,)dnl | |
445 | case "$host_os" in | |
446 | dnl Disable multithreading by default on OSF/1, because it interferes | |
447 | dnl with fork()/exec(): When msgexec is linked with -lpthread, its | |
448 | dnl child process gets an endless segmentation fault inside execvp(). | |
449 | osf*) gl_use_threads=no ;; | |
450 | dnl Disable multithreading by default on Cygwin 1.5.x, because it has | |
451 | dnl bugs that lead to endless loops or crashes. See | |
452 | dnl <https://cygwin.com/ml/cygwin/2009-08/msg00283.html>. | |
453 | cygwin*) | |
454 | case `uname -r` in | |
455 | 1.[0-5].*) gl_use_threads=no ;; | |
456 | *) gl_use_threads=yes ;; | |
457 | esac | |
458 | ;; | |
459 | dnl Obey gl_AVOID_WINPTHREAD on mingw. | |
460 | mingw*) | |
461 | case "$gl_use_winpthreads_default" in | |
462 | yes) gl_use_threads=posix ;; | |
463 | no) gl_use_threads=windows ;; | |
464 | *) gl_use_threads=yes ;; | |
465 | esac | |
466 | ;; | |
467 | *) gl_use_threads=yes ;; | |
468 | esac | |
469 | changequote([,])dnl | |
470 | fi | |
471 | ]) | |
472 | if test "$gl_use_threads" = yes \ | |
473 | || test "$gl_use_threads" = isoc \ | |
474 | || test "$gl_use_threads" = posix \ | |
475 | || test "$gl_use_threads" = isoc+posix; then | |
476 | # For using <threads.h> or <pthread.h>: | |
477 | gl_ANYTHREADLIB_EARLY | |
5abebf3c CB |
478 | fi |
479 | ]) | |
480 | ||
481 | dnl The guts of gl_THREADLIB. Needs to be expanded only once. | |
482 | ||
483 | AC_DEFUN([gl_THREADLIB_BODY], | |
484 | [ | |
485 | AC_REQUIRE([gl_THREADLIB_EARLY_BODY]) | |
486 | gl_threads_api=none | |
487 | LIBTHREAD= | |
488 | LTLIBTHREAD= | |
489 | LIBMULTITHREAD= | |
490 | LTLIBMULTITHREAD= | |
491 | if test "$gl_use_threads" != no; then | |
492 | dnl Check whether the compiler and linker support weak declarations. | |
c0c3707f CB |
493 | gl_WEAK_SYMBOLS |
494 | if case "$gl_cv_have_weak" in *yes) true;; *) false;; esac; then | |
495 | dnl If we use weak symbols to implement pthread_in_use / pth_in_use / | |
496 | dnl thread_in_use, we also need to test whether the ISO C 11 thrd_create | |
497 | dnl facility is in use. | |
498 | AC_CHECK_HEADERS_ONCE([threads.h]) | |
499 | : | |
500 | fi | |
501 | if test "$gl_use_threads" = isoc || test "$gl_use_threads" = isoc+posix; then | |
502 | AC_CHECK_HEADERS_ONCE([threads.h]) | |
5df4cba6 | 503 | gl_have_isoc_threads="$ac_cv_header_threads_h" |
c0c3707f CB |
504 | fi |
505 | if test "$gl_use_threads" = yes \ | |
506 | || test "$gl_use_threads" = posix \ | |
507 | || test "$gl_use_threads" = isoc+posix; then | |
508 | gl_PTHREADLIB_BODY | |
509 | LIBTHREAD=$LIBPTHREAD LTLIBTHREAD=$LIBPTHREAD | |
510 | LIBMULTITHREAD=$LIBPMULTITHREAD LTLIBMULTITHREAD=$LIBPMULTITHREAD | |
511 | if test $gl_pthread_api = yes; then | |
512 | if test "$gl_use_threads" = isoc+posix && test "$gl_have_isoc_threads" = yes; then | |
513 | gl_threads_api='isoc+posix' | |
514 | AC_DEFINE([USE_ISOC_AND_POSIX_THREADS], [1], | |
515 | [Define if the combination of the ISO C and POSIX multithreading APIs can be used.]) | |
516 | LIBTHREAD= LTLIBTHREAD= | |
517 | else | |
5abebf3c CB |
518 | gl_threads_api=posix |
519 | AC_DEFINE([USE_POSIX_THREADS], [1], | |
520 | [Define if the POSIX multithreading library can be used.]) | |
dc6c21da TT |
521 | if test -z "$LIBMULTITHREAD" && test -z "$LTLIBMULTITHREAD"; then |
522 | AC_DEFINE([USE_POSIX_THREADS_FROM_LIBC], [1], | |
523 | [Define if references to the POSIX multithreading library are satisfied by libc.]) | |
524 | else | |
5abebf3c CB |
525 | if case "$gl_cv_have_weak" in *yes) true;; *) false;; esac; then |
526 | AC_DEFINE([USE_POSIX_THREADS_WEAK], [1], | |
527 | [Define if references to the POSIX multithreading library should be made weak.]) | |
c0c3707f | 528 | LIBTHREAD= LTLIBTHREAD= |
9c9d63b1 PM |
529 | else |
530 | case "$host_os" in | |
dc6c21da | 531 | freebsd* | dragonfly* | midnightbsd*) |
9c9d63b1 PM |
532 | if test "x$LIBTHREAD" != "x$LIBMULTITHREAD"; then |
533 | dnl If weak symbols can't tell whether pthread_create(), pthread_key_create() | |
534 | dnl etc. will succeed, we need a runtime test. | |
535 | AC_DEFINE([PTHREAD_IN_USE_DETECTION_HARD], [1], | |
536 | [Define if the pthread_in_use() detection is hard.]) | |
537 | fi | |
538 | ;; | |
539 | esac | |
5abebf3c CB |
540 | fi |
541 | fi | |
542 | fi | |
543 | fi | |
544 | fi | |
c0c3707f CB |
545 | if test $gl_threads_api = none; then |
546 | if test "$gl_use_threads" = isoc && test "$gl_have_isoc_threads" = yes; then | |
5df4cba6 SM |
547 | gl_STDTHREADLIB_BODY |
548 | LIBTHREAD=$LIBSTDTHREAD LTLIBTHREAD=$LIBSTDTHREAD | |
549 | LIBMULTITHREAD=$LIBSTDTHREAD LTLIBMULTITHREAD=$LIBSTDTHREAD | |
c0c3707f CB |
550 | gl_threads_api=isoc |
551 | AC_DEFINE([USE_ISOC_THREADS], [1], | |
552 | [Define if the ISO C multithreading library can be used.]) | |
5abebf3c CB |
553 | fi |
554 | fi | |
c0c3707f | 555 | if test $gl_threads_api = none; then |
5abebf3c CB |
556 | case "$gl_use_threads" in |
557 | yes | windows | win32) # The 'win32' is for backward compatibility. | |
558 | if { case "$host_os" in | |
559 | mingw*) true;; | |
560 | *) false;; | |
561 | esac | |
562 | }; then | |
563 | gl_threads_api=windows | |
564 | AC_DEFINE([USE_WINDOWS_THREADS], [1], | |
565 | [Define if the native Windows multithreading API can be used.]) | |
566 | fi | |
567 | ;; | |
568 | esac | |
569 | fi | |
570 | fi | |
571 | AC_MSG_CHECKING([for multithread API to use]) | |
572 | AC_MSG_RESULT([$gl_threads_api]) | |
573 | AC_SUBST([LIBTHREAD]) | |
574 | AC_SUBST([LTLIBTHREAD]) | |
575 | AC_SUBST([LIBMULTITHREAD]) | |
576 | AC_SUBST([LTLIBMULTITHREAD]) | |
577 | ]) | |
578 | ||
579 | AC_DEFUN([gl_THREADLIB], | |
580 | [ | |
581 | AC_REQUIRE([gl_THREADLIB_EARLY]) | |
582 | AC_REQUIRE([gl_THREADLIB_BODY]) | |
583 | ]) | |
584 | ||
585 | ||
586 | dnl gl_DISABLE_THREADS | |
587 | dnl ------------------ | |
588 | dnl Sets the gl_THREADLIB default so that threads are not used by default. | |
589 | dnl The user can still override it at installation time, by using the | |
590 | dnl configure option '--enable-threads'. | |
591 | ||
592 | AC_DEFUN([gl_DISABLE_THREADS], [ | |
593 | m4_divert_text([INIT_PREPARE], [gl_use_threads_default=no]) | |
594 | ]) | |
595 | ||
596 | ||
c0c3707f CB |
597 | dnl gl_AVOID_WINPTHREAD |
598 | dnl ------------------- | |
599 | dnl Sets the gl_THREADLIB default so that on mingw, a dependency to the | |
600 | dnl libwinpthread DLL (mingw-w64 winpthreads library) is avoided. | |
601 | dnl The user can still override it at installation time, by using the | |
602 | dnl configure option '--enable-threads'. | |
603 | ||
604 | AC_DEFUN([gl_AVOID_WINPTHREAD], [ | |
605 | m4_divert_text([INIT_PREPARE], [gl_use_winpthreads_default=no]) | |
606 | ]) | |
607 | ||
608 | ||
5df4cba6 SM |
609 | dnl ============================================================================ |
610 | ||
611 | ||
5abebf3c CB |
612 | dnl Survey of platforms: |
613 | dnl | |
614 | dnl Platform Available Compiler Supports test-lock | |
615 | dnl flavours option weak result | |
616 | dnl --------------- --------- --------- -------- --------- | |
617 | dnl Linux 2.4/glibc posix -lpthread Y OK | |
618 | dnl | |
dc6c21da TT |
619 | dnl Linux/glibc 2.34 posix Y OK |
620 | dnl | |
621 | dnl GNU Hurd/glibc posix -lpthread Y OK | |
5abebf3c CB |
622 | dnl |
623 | dnl Ubuntu 14.04 posix -pthread Y OK | |
624 | dnl | |
625 | dnl FreeBSD 5.3 posix -lc_r Y | |
626 | dnl posix -lkse ? Y | |
627 | dnl posix -lpthread ? Y | |
628 | dnl posix -lthr Y | |
629 | dnl | |
630 | dnl FreeBSD 5.2 posix -lc_r Y | |
631 | dnl posix -lkse Y | |
632 | dnl posix -lthr Y | |
633 | dnl | |
634 | dnl FreeBSD 4.0,4.10 posix -lc_r Y OK | |
635 | dnl | |
636 | dnl NetBSD 1.6 -- | |
637 | dnl | |
638 | dnl OpenBSD 3.4 posix -lpthread Y OK | |
639 | dnl | |
640 | dnl Mac OS X 10.[123] posix -lpthread Y OK | |
641 | dnl | |
642 | dnl Solaris 7,8,9 posix -lpthread Y Sol 7,8: 0.0; Sol 9: OK | |
5abebf3c CB |
643 | dnl |
644 | dnl HP-UX 11 posix -lpthread N (cc) OK | |
645 | dnl Y (gcc) | |
646 | dnl | |
647 | dnl IRIX 6.5 posix -lpthread Y 0.5 | |
648 | dnl | |
649 | dnl AIX 4.3,5.1 posix -lpthread N AIX 4: 0.5; AIX 5: OK | |
650 | dnl | |
651 | dnl OSF/1 4.0,5.1 posix -pthread (cc) N OK | |
652 | dnl -lpthread (gcc) Y | |
653 | dnl | |
654 | dnl Cygwin posix -lpthread Y OK | |
655 | dnl | |
5abebf3c CB |
656 | dnl Mingw windows N OK |
657 | dnl | |
658 | dnl BeOS 5 -- | |
659 | dnl | |
660 | dnl The test-lock result shows what happens if in test-lock.c EXPLICIT_YIELD is | |
661 | dnl turned off: | |
662 | dnl OK if all three tests terminate OK, | |
663 | dnl 0.5 if the first test terminates OK but the second one loops endlessly, | |
664 | dnl 0.0 if the first test already loops endlessly. |