1 # threadlib.m4 serial 10 (gettext-0.18.2) 2 dnl Copyright (C) 2005-2012 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. 372
