| 1 | # threadlib.m4 serial 10 (gettext-0.18.2) |
| 2 | dnl Copyright (C) 2005-2014 Free Software Foundation, Inc. |
| 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 | |
| 9 | dnl gl_THREADLIB |
| 10 | dnl ------------ |
| 11 | dnl Tests for a multithreading library to be used. |
| 12 | dnl If the configure.ac contains a definition of the gl_THREADLIB_DEFAULT_NO |
| 13 | dnl (it must be placed before the invocation of gl_THREADLIB_EARLY!), then the |
| 14 | dnl default is 'no', otherwise it is system dependent. In both cases, the user |
| 15 | dnl can change the choice through the options --enable-threads=choice or |
| 16 | dnl --disable-threads. |
| 17 | dnl Defines at most one of the macros USE_POSIX_THREADS, USE_SOLARIS_THREADS, |
| 18 | dnl USE_PTH_THREADS, USE_WINDOWS_THREADS |
| 19 | dnl Sets the variables LIBTHREAD and LTLIBTHREAD to the linker options for use |
| 20 | dnl in a Makefile (LIBTHREAD for use without libtool, LTLIBTHREAD for use with |
| 21 | dnl libtool). |
| 22 | dnl Sets the variables LIBMULTITHREAD and LTLIBMULTITHREAD similarly, for |
| 23 | dnl programs that really need multithread functionality. The difference |
| 24 | dnl between LIBTHREAD and LIBMULTITHREAD is that on platforms supporting weak |
| 25 | dnl symbols, typically LIBTHREAD="" whereas LIBMULTITHREAD="-lpthread". |
| 26 | dnl Adds to CPPFLAGS the flag -D_REENTRANT or -D_THREAD_SAFE if needed for |
| 27 | dnl multithread-safe programs. |
| 28 | |
| 29 | AC_DEFUN([gl_THREADLIB_EARLY], |
| 30 | [ |
| 31 | AC_REQUIRE([gl_THREADLIB_EARLY_BODY]) |
| 32 | ]) |
| 33 | |
| 34 | dnl The guts of gl_THREADLIB_EARLY. Needs to be expanded only once. |
| 35 | |
| 36 | AC_DEFUN([gl_THREADLIB_EARLY_BODY], |
| 37 | [ |
| 38 | dnl Ordering constraints: This macro modifies CPPFLAGS in a way that |
| 39 | dnl influences the result of the autoconf tests that test for *_unlocked |
| 40 | dnl declarations, on AIX 5 at least. Therefore it must come early. |
| 41 | AC_BEFORE([$0], [gl_FUNC_GLIBC_UNLOCKED_IO])dnl |
| 42 | AC_BEFORE([$0], [gl_ARGP])dnl |
| 43 | |
| 44 | AC_REQUIRE([AC_CANONICAL_HOST]) |
| 45 | dnl _GNU_SOURCE is needed for pthread_rwlock_t on glibc systems. |
| 46 | dnl AC_USE_SYSTEM_EXTENSIONS was introduced in autoconf 2.60 and obsoletes |
| 47 | dnl AC_GNU_SOURCE. |
| 48 | m4_ifdef([AC_USE_SYSTEM_EXTENSIONS], |
| 49 | [AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])], |
| 50 | [AC_REQUIRE([AC_GNU_SOURCE])]) |
| 51 | dnl Check for multithreading. |
| 52 | m4_ifdef([gl_THREADLIB_DEFAULT_NO], |
| 53 | [m4_divert_text([DEFAULTS], [gl_use_threads_default=no])], |
| 54 | [m4_divert_text([DEFAULTS], [gl_use_threads_default=])]) |
| 55 | AC_ARG_ENABLE([threads], |
| 56 | AC_HELP_STRING([--enable-threads={posix|solaris|pth|windows}], [specify multithreading API])m4_ifdef([gl_THREADLIB_DEFAULT_NO], [], [ |
| 57 | AC_HELP_STRING([--disable-threads], [build without multithread safety])]), |
| 58 | [gl_use_threads=$enableval], |
| 59 | [if test -n "$gl_use_threads_default"; then |
| 60 | gl_use_threads="$gl_use_threads_default" |
| 61 | else |
| 62 | changequote(,)dnl |
| 63 | case "$host_os" in |
| 64 | dnl Disable multithreading by default on OSF/1, because it interferes |
| 65 | dnl with fork()/exec(): When msgexec is linked with -lpthread, its |
| 66 | dnl child process gets an endless segmentation fault inside execvp(). |
| 67 | dnl Disable multithreading by default on Cygwin 1.5.x, because it has |
| 68 | dnl bugs that lead to endless loops or crashes. See |
| 69 | dnl <http://cygwin.com/ml/cygwin/2009-08/msg00283.html>. |
| 70 | osf*) gl_use_threads=no ;; |
| 71 | cygwin*) |
| 72 | case `uname -r` in |
| 73 | 1.[0-5].*) gl_use_threads=no ;; |
| 74 | *) gl_use_threads=yes ;; |
| 75 | esac |
| 76 | ;; |
| 77 | *) gl_use_threads=yes ;; |
| 78 | esac |
| 79 | changequote([,])dnl |
| 80 | fi |
| 81 | ]) |
| 82 | if test "$gl_use_threads" = yes || test "$gl_use_threads" = posix; then |
| 83 | # For using <pthread.h>: |
| 84 | case "$host_os" in |
| 85 | osf*) |
| 86 | # On OSF/1, the compiler needs the flag -D_REENTRANT so that it |
| 87 | # groks <pthread.h>. cc also understands the flag -pthread, but |
| 88 | # we don't use it because 1. gcc-2.95 doesn't understand -pthread, |
| 89 | # 2. putting a flag into CPPFLAGS that has an effect on the linker |
| 90 | # causes the AC_LINK_IFELSE test below to succeed unexpectedly, |
| 91 | # leading to wrong values of LIBTHREAD and LTLIBTHREAD. |
| 92 | CPPFLAGS="$CPPFLAGS -D_REENTRANT" |
| 93 | ;; |
| 94 | esac |
| 95 | # Some systems optimize for single-threaded programs by default, and |
| 96 | # need special flags to disable these optimizations. For example, the |
| 97 | # definition of 'errno' in <errno.h>. |
| 98 | case "$host_os" in |
| 99 | aix* | freebsd*) CPPFLAGS="$CPPFLAGS -D_THREAD_SAFE" ;; |
| 100 | solaris*) CPPFLAGS="$CPPFLAGS -D_REENTRANT" ;; |
| 101 | esac |
| 102 | fi |
| 103 | ]) |
| 104 | |
| 105 | dnl The guts of gl_THREADLIB. Needs to be expanded only once. |
| 106 | |
| 107 | AC_DEFUN([gl_THREADLIB_BODY], |
| 108 | [ |
| 109 | AC_REQUIRE([gl_THREADLIB_EARLY_BODY]) |
| 110 | gl_threads_api=none |
| 111 | LIBTHREAD= |
| 112 | LTLIBTHREAD= |
| 113 | LIBMULTITHREAD= |
| 114 | LTLIBMULTITHREAD= |
| 115 | if test "$gl_use_threads" != no; then |
| 116 | dnl Check whether the compiler and linker support weak declarations. |
| 117 | AC_CACHE_CHECK([whether imported symbols can be declared weak], |
| 118 | [gl_cv_have_weak], |
| 119 | [gl_cv_have_weak=no |
| 120 | dnl First, test whether the compiler accepts it syntactically. |
| 121 | AC_LINK_IFELSE( |
| 122 | [AC_LANG_PROGRAM( |
| 123 | [[extern void xyzzy (); |
| 124 | #pragma weak xyzzy]], |
| 125 | [[xyzzy();]])], |
| 126 | [gl_cv_have_weak=maybe]) |
| 127 | if test $gl_cv_have_weak = maybe; then |
| 128 | dnl Second, test whether it actually works. On Cygwin 1.7.2, with |
| 129 | dnl gcc 4.3, symbols declared weak always evaluate to the address 0. |
| 130 | AC_RUN_IFELSE( |
| 131 | [AC_LANG_SOURCE([[ |
| 132 | #include <stdio.h> |
| 133 | #pragma weak fputs |
| 134 | int main () |
| 135 | { |
| 136 | return (fputs == NULL); |
| 137 | }]])], |
| 138 | [gl_cv_have_weak=yes], |
| 139 | [gl_cv_have_weak=no], |
| 140 | [dnl When cross-compiling, assume that only ELF platforms support |
| 141 | dnl weak symbols. |
| 142 | AC_EGREP_CPP([Extensible Linking Format], |
| 143 | [#ifdef __ELF__ |
| 144 | Extensible Linking Format |
| 145 | #endif |
| 146 | ], |
| 147 | [gl_cv_have_weak="guessing yes"], |
| 148 | [gl_cv_have_weak="guessing no"]) |
| 149 | ]) |
| 150 | fi |
| 151 | ]) |
| 152 | if test "$gl_use_threads" = yes || test "$gl_use_threads" = posix; then |
| 153 | # On OSF/1, the compiler needs the flag -pthread or -D_REENTRANT so that |
| 154 | # it groks <pthread.h>. It's added above, in gl_THREADLIB_EARLY_BODY. |
| 155 | AC_CHECK_HEADER([pthread.h], |
| 156 | [gl_have_pthread_h=yes], [gl_have_pthread_h=no]) |
| 157 | if test "$gl_have_pthread_h" = yes; then |
| 158 | # Other possible tests: |
| 159 | # -lpthreads (FSU threads, PCthreads) |
| 160 | # -lgthreads |
| 161 | gl_have_pthread= |
| 162 | # Test whether both pthread_mutex_lock and pthread_mutexattr_init exist |
| 163 | # in libc. IRIX 6.5 has the first one in both libc and libpthread, but |
| 164 | # the second one only in libpthread, and lock.c needs it. |
| 165 | AC_LINK_IFELSE( |
| 166 | [AC_LANG_PROGRAM( |
| 167 | [[#include <pthread.h>]], |
| 168 | [[pthread_mutex_lock((pthread_mutex_t*)0); |
| 169 | pthread_mutexattr_init((pthread_mutexattr_t*)0);]])], |
| 170 | [gl_have_pthread=yes]) |
| 171 | # Test for libpthread by looking for pthread_kill. (Not pthread_self, |
| 172 | # since it is defined as a macro on OSF/1.) |
| 173 | if test -n "$gl_have_pthread"; then |
| 174 | # The program links fine without libpthread. But it may actually |
| 175 | # need to link with libpthread in order to create multiple threads. |
| 176 | AC_CHECK_LIB([pthread], [pthread_kill], |
| 177 | [LIBMULTITHREAD=-lpthread LTLIBMULTITHREAD=-lpthread |
| 178 | # On Solaris and HP-UX, most pthread functions exist also in libc. |
| 179 | # Therefore pthread_in_use() needs to actually try to create a |
| 180 | # thread: pthread_create from libc will fail, whereas |
| 181 | # pthread_create will actually create a thread. |
| 182 | case "$host_os" in |
| 183 | solaris* | hpux*) |
| 184 | AC_DEFINE([PTHREAD_IN_USE_DETECTION_HARD], [1], |
| 185 | [Define if the pthread_in_use() detection is hard.]) |
| 186 | esac |
| 187 | ]) |
| 188 | else |
| 189 | # Some library is needed. Try libpthread and libc_r. |
| 190 | AC_CHECK_LIB([pthread], [pthread_kill], |
| 191 | [gl_have_pthread=yes |
| 192 | LIBTHREAD=-lpthread LTLIBTHREAD=-lpthread |
| 193 | LIBMULTITHREAD=-lpthread LTLIBMULTITHREAD=-lpthread]) |
| 194 | if test -z "$gl_have_pthread"; then |
| 195 | # For FreeBSD 4. |
| 196 | AC_CHECK_LIB([c_r], [pthread_kill], |
| 197 | [gl_have_pthread=yes |
| 198 | LIBTHREAD=-lc_r LTLIBTHREAD=-lc_r |
| 199 | LIBMULTITHREAD=-lc_r LTLIBMULTITHREAD=-lc_r]) |
| 200 | fi |
| 201 | fi |
| 202 | if test -n "$gl_have_pthread"; then |
| 203 | gl_threads_api=posix |
| 204 | AC_DEFINE([USE_POSIX_THREADS], [1], |
| 205 | [Define if the POSIX multithreading library can be used.]) |
| 206 | if test -n "$LIBMULTITHREAD" || test -n "$LTLIBMULTITHREAD"; then |
| 207 | if case "$gl_cv_have_weak" in *yes) true;; *) false;; esac; then |
| 208 | AC_DEFINE([USE_POSIX_THREADS_WEAK], [1], |
| 209 | [Define if references to the POSIX multithreading library should be made weak.]) |
| 210 | LIBTHREAD= |
| 211 | LTLIBTHREAD= |
| 212 | fi |
| 213 | fi |
| 214 | fi |
| 215 | fi |
| 216 | fi |
| 217 | if test -z "$gl_have_pthread"; then |
| 218 | if test "$gl_use_threads" = yes || test "$gl_use_threads" = solaris; then |
| 219 | gl_have_solaristhread= |
| 220 | gl_save_LIBS="$LIBS" |
| 221 | LIBS="$LIBS -lthread" |
| 222 | AC_LINK_IFELSE( |
| 223 | [AC_LANG_PROGRAM( |
| 224 | [[ |
| 225 | #include <thread.h> |
| 226 | #include <synch.h> |
| 227 | ]], |
| 228 | [[thr_self();]])], |
| 229 | [gl_have_solaristhread=yes]) |
| 230 | LIBS="$gl_save_LIBS" |
| 231 | if test -n "$gl_have_solaristhread"; then |
| 232 | gl_threads_api=solaris |
| 233 | LIBTHREAD=-lthread |
| 234 | LTLIBTHREAD=-lthread |
| 235 | LIBMULTITHREAD="$LIBTHREAD" |
| 236 | LTLIBMULTITHREAD="$LTLIBTHREAD" |
| 237 | AC_DEFINE([USE_SOLARIS_THREADS], [1], |
| 238 | [Define if the old Solaris multithreading library can be used.]) |
| 239 | if case "$gl_cv_have_weak" in *yes) true;; *) false;; esac; then |
| 240 | AC_DEFINE([USE_SOLARIS_THREADS_WEAK], [1], |
| 241 | [Define if references to the old Solaris multithreading library should be made weak.]) |
| 242 | LIBTHREAD= |
| 243 | LTLIBTHREAD= |
| 244 | fi |
| 245 | fi |
| 246 | fi |
| 247 | fi |
| 248 | if test "$gl_use_threads" = pth; then |
| 249 | gl_save_CPPFLAGS="$CPPFLAGS" |
| 250 | AC_LIB_LINKFLAGS([pth]) |
| 251 | gl_have_pth= |
| 252 | gl_save_LIBS="$LIBS" |
| 253 | LIBS="$LIBS $LIBPTH" |
| 254 | AC_LINK_IFELSE( |
| 255 | [AC_LANG_PROGRAM([[#include <pth.h>]], [[pth_self();]])], |
| 256 | [gl_have_pth=yes]) |
| 257 | LIBS="$gl_save_LIBS" |
| 258 | if test -n "$gl_have_pth"; then |
| 259 | gl_threads_api=pth |
| 260 | LIBTHREAD="$LIBPTH" |
| 261 | LTLIBTHREAD="$LTLIBPTH" |
| 262 | LIBMULTITHREAD="$LIBTHREAD" |
| 263 | LTLIBMULTITHREAD="$LTLIBTHREAD" |
| 264 | AC_DEFINE([USE_PTH_THREADS], [1], |
| 265 | [Define if the GNU Pth multithreading library can be used.]) |
| 266 | if test -n "$LIBMULTITHREAD" || test -n "$LTLIBMULTITHREAD"; then |
| 267 | if case "$gl_cv_have_weak" in *yes) true;; *) false;; esac; then |
| 268 | AC_DEFINE([USE_PTH_THREADS_WEAK], [1], |
| 269 | [Define if references to the GNU Pth multithreading library should be made weak.]) |
| 270 | LIBTHREAD= |
| 271 | LTLIBTHREAD= |
| 272 | fi |
| 273 | fi |
| 274 | else |
| 275 | CPPFLAGS="$gl_save_CPPFLAGS" |
| 276 | fi |
| 277 | fi |
| 278 | if test -z "$gl_have_pthread"; then |
| 279 | case "$gl_use_threads" in |
| 280 | yes | windows | win32) # The 'win32' is for backward compatibility. |
| 281 | if { case "$host_os" in |
| 282 | mingw*) true;; |
| 283 | *) false;; |
| 284 | esac |
| 285 | }; then |
| 286 | gl_threads_api=windows |
| 287 | AC_DEFINE([USE_WINDOWS_THREADS], [1], |
| 288 | [Define if the native Windows multithreading API can be used.]) |
| 289 | fi |
| 290 | ;; |
| 291 | esac |
| 292 | fi |
| 293 | fi |
| 294 | AC_MSG_CHECKING([for multithread API to use]) |
| 295 | AC_MSG_RESULT([$gl_threads_api]) |
| 296 | AC_SUBST([LIBTHREAD]) |
| 297 | AC_SUBST([LTLIBTHREAD]) |
| 298 | AC_SUBST([LIBMULTITHREAD]) |
| 299 | AC_SUBST([LTLIBMULTITHREAD]) |
| 300 | ]) |
| 301 | |
| 302 | AC_DEFUN([gl_THREADLIB], |
| 303 | [ |
| 304 | AC_REQUIRE([gl_THREADLIB_EARLY]) |
| 305 | AC_REQUIRE([gl_THREADLIB_BODY]) |
| 306 | ]) |
| 307 | |
| 308 | |
| 309 | dnl gl_DISABLE_THREADS |
| 310 | dnl ------------------ |
| 311 | dnl Sets the gl_THREADLIB default so that threads are not used by default. |
| 312 | dnl The user can still override it at installation time, by using the |
| 313 | dnl configure option '--enable-threads'. |
| 314 | |
| 315 | AC_DEFUN([gl_DISABLE_THREADS], [ |
| 316 | m4_divert_text([INIT_PREPARE], [gl_use_threads_default=no]) |
| 317 | ]) |
| 318 | |
| 319 | |
| 320 | dnl Survey of platforms: |
| 321 | dnl |
| 322 | dnl Platform Available Compiler Supports test-lock |
| 323 | dnl flavours option weak result |
| 324 | dnl --------------- --------- --------- -------- --------- |
| 325 | dnl Linux 2.4/glibc posix -lpthread Y OK |
| 326 | dnl |
| 327 | dnl GNU Hurd/glibc posix |
| 328 | dnl |
| 329 | dnl FreeBSD 5.3 posix -lc_r Y |
| 330 | dnl posix -lkse ? Y |
| 331 | dnl posix -lpthread ? Y |
| 332 | dnl posix -lthr Y |
| 333 | dnl |
| 334 | dnl FreeBSD 5.2 posix -lc_r Y |
| 335 | dnl posix -lkse Y |
| 336 | dnl posix -lthr Y |
| 337 | dnl |
| 338 | dnl FreeBSD 4.0,4.10 posix -lc_r Y OK |
| 339 | dnl |
| 340 | dnl NetBSD 1.6 -- |
| 341 | dnl |
| 342 | dnl OpenBSD 3.4 posix -lpthread Y OK |
| 343 | dnl |
| 344 | dnl Mac OS X 10.[123] posix -lpthread Y OK |
| 345 | dnl |
| 346 | dnl Solaris 7,8,9 posix -lpthread Y Sol 7,8: 0.0; Sol 9: OK |
| 347 | dnl solaris -lthread Y Sol 7,8: 0.0; Sol 9: OK |
| 348 | dnl |
| 349 | dnl HP-UX 11 posix -lpthread N (cc) OK |
| 350 | dnl Y (gcc) |
| 351 | dnl |
| 352 | dnl IRIX 6.5 posix -lpthread Y 0.5 |
| 353 | dnl |
| 354 | dnl AIX 4.3,5.1 posix -lpthread N AIX 4: 0.5; AIX 5: OK |
| 355 | dnl |
| 356 | dnl OSF/1 4.0,5.1 posix -pthread (cc) N OK |
| 357 | dnl -lpthread (gcc) Y |
| 358 | dnl |
| 359 | dnl Cygwin posix -lpthread Y OK |
| 360 | dnl |
| 361 | dnl Any of the above pth -lpth 0.0 |
| 362 | dnl |
| 363 | dnl Mingw windows N OK |
| 364 | dnl |
| 365 | dnl BeOS 5 -- |
| 366 | dnl |
| 367 | dnl The test-lock result shows what happens if in test-lock.c EXPLICIT_YIELD is |
| 368 | dnl turned off: |
| 369 | dnl OK if all three tests terminate OK, |
| 370 | dnl 0.5 if the first test terminates OK but the second one loops endlessly, |
| 371 | dnl 0.0 if the first test already loops endlessly. |