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Diffstat (limited to 'm4/lock.m4')
| -rw-r--r-- | m4/lock.m4 | 311 |
1 files changed, 311 insertions, 0 deletions
diff --git a/m4/lock.m4 b/m4/lock.m4 new file mode 100644 index 0000000000..0224f2ff87 --- /dev/null +++ b/m4/lock.m4 @@ -0,0 +1,311 @@ +# lock.m4 serial 6 (gettext-0.16) +dnl Copyright (C) 2005-2006 Free Software Foundation, Inc. +dnl This file is free software; the Free Software Foundation +dnl gives unlimited permission to copy and/or distribute it, +dnl with or without modifications, as long as this notice is preserved. + +dnl From Bruno Haible. + +dnl Tests for a multithreading library to be used. +dnl Defines at most one of the macros USE_POSIX_THREADS, USE_SOLARIS_THREADS, +dnl USE_PTH_THREADS, USE_WIN32_THREADS +dnl Sets the variables LIBTHREAD and LTLIBTHREAD to the linker options for use +dnl in a Makefile (LIBTHREAD for use without libtool, LTLIBTHREAD for use with +dnl libtool). +dnl Sets the variables LIBMULTITHREAD and LTLIBMULTITHREAD similarly, for +dnl programs that really need multithread functionality. The difference +dnl between LIBTHREAD and LIBMULTITHREAD is that on platforms supporting weak +dnl symbols, typically LIBTHREAD="" whereas LIBMULTITHREAD="-lpthread". +dnl Adds to CPPFLAGS the flag -D_REENTRANT or -D_THREAD_SAFE if needed for +dnl multithread-safe programs. + +AC_DEFUN([gl_LOCK_EARLY], +[ + AC_REQUIRE([gl_LOCK_EARLY_BODY]) +]) + +dnl The guts of gl_LOCK_EARLY. Needs to be expanded only once. + +AC_DEFUN([gl_LOCK_EARLY_BODY], +[ + dnl Ordering constraints: This macro modifies CPPFLAGS in a way that + dnl influences the result of the autoconf tests that test for *_unlocked + dnl declarations, on AIX 5 at least. Therefore it must come early. + AC_BEFORE([$0], [gl_FUNC_GLIBC_UNLOCKED_IO])dnl + AC_BEFORE([$0], [gl_ARGP])dnl + + AC_REQUIRE([AC_CANONICAL_HOST]) + AC_REQUIRE([AC_GNU_SOURCE]) dnl needed for pthread_rwlock_t on glibc systems + dnl Check for multithreading. + AC_ARG_ENABLE(threads, +AC_HELP_STRING([--enable-threads={posix|solaris|pth|win32}], [specify multithreading API]) +AC_HELP_STRING([--disable-threads], [build without multithread safety]), + [gl_use_threads=$enableval], + [case "$host_os" in + dnl Disable multithreading by default on OSF/1, because it interferes + dnl with fork()/exec(): When msgexec is linked with -lpthread, its child + dnl process gets an endless segmentation fault inside execvp(). + osf*) gl_use_threads=no ;; + *) gl_use_threads=yes ;; + esac + ]) + if test "$gl_use_threads" = yes || test "$gl_use_threads" = posix; then + # For using <pthread.h>: + case "$host_os" in + osf*) + # On OSF/1, the compiler needs the flag -D_REENTRANT so that it + # groks <pthread.h>. cc also understands the flag -pthread, but + # we don't use it because 1. gcc-2.95 doesn't understand -pthread, + # 2. putting a flag into CPPFLAGS that has an effect on the linker + # causes the AC_TRY_LINK test below to succeed unexpectedly, + # leading to wrong values of LIBTHREAD and LTLIBTHREAD. + CPPFLAGS="$CPPFLAGS -D_REENTRANT" + ;; + esac + # Some systems optimize for single-threaded programs by default, and + # need special flags to disable these optimizations. For example, the + # definition of 'errno' in <errno.h>. + case "$host_os" in + aix* | freebsd*) CPPFLAGS="$CPPFLAGS -D_THREAD_SAFE" ;; + solaris*) CPPFLAGS="$CPPFLAGS -D_REENTRANT" ;; + esac + fi +]) + +dnl The guts of gl_LOCK. Needs to be expanded only once. + +AC_DEFUN([gl_LOCK_BODY], +[ + AC_REQUIRE([gl_LOCK_EARLY_BODY]) + gl_threads_api=none + LIBTHREAD= + LTLIBTHREAD= + LIBMULTITHREAD= + LTLIBMULTITHREAD= + if test "$gl_use_threads" != no; then + dnl Check whether the compiler and linker support weak declarations. + AC_MSG_CHECKING([whether imported symbols can be declared weak]) + gl_have_weak=no + AC_TRY_LINK([extern void xyzzy (); +#pragma weak xyzzy], [xyzzy();], [gl_have_weak=yes]) + AC_MSG_RESULT([$gl_have_weak]) + if test "$gl_use_threads" = yes || test "$gl_use_threads" = posix; then + # On OSF/1, the compiler needs the flag -pthread or -D_REENTRANT so that + # it groks <pthread.h>. It's added above, in gl_LOCK_EARLY_BODY. + AC_CHECK_HEADER(pthread.h, gl_have_pthread_h=yes, gl_have_pthread_h=no) + if test "$gl_have_pthread_h" = yes; then + # Other possible tests: + # -lpthreads (FSU threads, PCthreads) + # -lgthreads + gl_have_pthread= + # Test whether both pthread_mutex_lock and pthread_mutexattr_init exist + # in libc. IRIX 6.5 has the first one in both libc and libpthread, but + # the second one only in libpthread, and lock.c needs it. + AC_TRY_LINK([#include <pthread.h>], + [pthread_mutex_lock((pthread_mutex_t*)0); + pthread_mutexattr_init((pthread_mutexattr_t*)0);], + [gl_have_pthread=yes]) + # Test for libpthread by looking for pthread_kill. (Not pthread_self, + # since it is defined as a macro on OSF/1.) + if test -n "$gl_have_pthread"; then + # The program links fine without libpthread. But it may actually + # need to link with libpthread in order to create multiple threads. + AC_CHECK_LIB(pthread, pthread_kill, + [LIBMULTITHREAD=-lpthread LTLIBMULTITHREAD=-lpthread + # On Solaris and HP-UX, most pthread functions exist also in libc. + # Therefore pthread_in_use() needs to actually try to create a + # thread: pthread_create from libc will fail, whereas + # pthread_create will actually create a thread. + case "$host_os" in + solaris* | hpux*) + AC_DEFINE([PTHREAD_IN_USE_DETECTION_HARD], 1, + [Define if the pthread_in_use() detection is hard.]) + esac + ]) + else + # Some library is needed. Try libpthread and libc_r. + AC_CHECK_LIB(pthread, pthread_kill, + [gl_have_pthread=yes + LIBTHREAD=-lpthread LTLIBTHREAD=-lpthread + LIBMULTITHREAD=-lpthread LTLIBMULTITHREAD=-lpthread]) + if test -z "$gl_have_pthread"; then + # For FreeBSD 4. + AC_CHECK_LIB(c_r, pthread_kill, + [gl_have_pthread=yes + LIBTHREAD=-lc_r LTLIBTHREAD=-lc_r + LIBMULTITHREAD=-lc_r LTLIBMULTITHREAD=-lc_r]) + fi + fi + if test -n "$gl_have_pthread"; then + gl_threads_api=posix + AC_DEFINE([USE_POSIX_THREADS], 1, + [Define if the POSIX multithreading library can be used.]) + if test -n "$LIBMULTITHREAD" || test -n "$LTLIBMULTITHREAD"; then + if test $gl_have_weak = yes; then + AC_DEFINE([USE_POSIX_THREADS_WEAK], 1, + [Define if references to the POSIX multithreading library should be made weak.]) + LIBTHREAD= + LTLIBTHREAD= + fi + fi + # OSF/1 4.0 and MacOS X 10.1 lack the pthread_rwlock_t type and the + # pthread_rwlock_* functions. + AC_CHECK_TYPE([pthread_rwlock_t], + [AC_DEFINE([HAVE_PTHREAD_RWLOCK], 1, + [Define if the POSIX multithreading library has read/write locks.])], + [], + [#include <pthread.h>]) + # glibc defines PTHREAD_MUTEX_RECURSIVE as enum, not as a macro. + AC_TRY_COMPILE([#include <pthread.h>], + [#if __FreeBSD__ == 4 +error "No, in FreeBSD 4.0 recursive mutexes actually don't work." +#else +int x = (int)PTHREAD_MUTEX_RECURSIVE; +return !x; +#endif], + [AC_DEFINE([HAVE_PTHREAD_MUTEX_RECURSIVE], 1, + [Define if the <pthread.h> defines PTHREAD_MUTEX_RECURSIVE.])]) + fi + fi + fi + if test -z "$gl_have_pthread"; then + if test "$gl_use_threads" = yes || test "$gl_use_threads" = solaris; then + gl_have_solaristhread= + gl_save_LIBS="$LIBS" + LIBS="$LIBS -lthread" + AC_TRY_LINK([#include <thread.h> +#include <synch.h>], + [thr_self();], + [gl_have_solaristhread=yes]) + LIBS="$gl_save_LIBS" + if test -n "$gl_have_solaristhread"; then + gl_threads_api=solaris + LIBTHREAD=-lthread + LTLIBTHREAD=-lthread + LIBMULTITHREAD="$LIBTHREAD" + LTLIBMULTITHREAD="$LTLIBTHREAD" + AC_DEFINE([USE_SOLARIS_THREADS], 1, + [Define if the old Solaris multithreading library can be used.]) + if test $gl_have_weak = yes; then + AC_DEFINE([USE_SOLARIS_THREADS_WEAK], 1, + [Define if references to the old Solaris multithreading library should be made weak.]) + LIBTHREAD= + LTLIBTHREAD= + fi + fi + fi + fi + if test "$gl_use_threads" = pth; then + gl_save_CPPFLAGS="$CPPFLAGS" + AC_LIB_LINKFLAGS(pth) + gl_have_pth= + gl_save_LIBS="$LIBS" + LIBS="$LIBS -lpth" + AC_TRY_LINK([#include <pth.h>], [pth_self();], gl_have_pth=yes) + LIBS="$gl_save_LIBS" + if test -n "$gl_have_pth"; then + gl_threads_api=pth + LIBTHREAD="$LIBPTH" + LTLIBTHREAD="$LTLIBPTH" + LIBMULTITHREAD="$LIBTHREAD" + LTLIBMULTITHREAD="$LTLIBTHREAD" + AC_DEFINE([USE_PTH_THREADS], 1, + [Define if the GNU Pth multithreading library can be used.]) + if test -n "$LIBMULTITHREAD" || test -n "$LTLIBMULTITHREAD"; then + if test $gl_have_weak = yes; then + AC_DEFINE([USE_PTH_THREADS_WEAK], 1, + [Define if references to the GNU Pth multithreading library should be made weak.]) + LIBTHREAD= + LTLIBTHREAD= + fi + fi + else + CPPFLAGS="$gl_save_CPPFLAGS" + fi + fi + if test -z "$gl_have_pthread"; then + if test "$gl_use_threads" = yes || test "$gl_use_threads" = win32; then + if { case "$host_os" in + mingw*) true;; + *) false;; + esac + }; then + gl_threads_api=win32 + AC_DEFINE([USE_WIN32_THREADS], 1, + [Define if the Win32 multithreading API can be used.]) + fi + fi + fi + fi + AC_MSG_CHECKING([for multithread API to use]) + AC_MSG_RESULT([$gl_threads_api]) + AC_SUBST(LIBTHREAD) + AC_SUBST(LTLIBTHREAD) + AC_SUBST(LIBMULTITHREAD) + AC_SUBST(LTLIBMULTITHREAD) +]) + +AC_DEFUN([gl_LOCK], +[ + AC_REQUIRE([gl_LOCK_EARLY]) + AC_REQUIRE([gl_LOCK_BODY]) + gl_PREREQ_LOCK +]) + +# Prerequisites of lib/lock.c. +AC_DEFUN([gl_PREREQ_LOCK], [ + AC_REQUIRE([AC_C_INLINE]) +]) + +dnl Survey of platforms: +dnl +dnl Platform Available Compiler Supports test-lock +dnl flavours option weak result +dnl --------------- --------- --------- -------- --------- +dnl Linux 2.4/glibc posix -lpthread Y OK +dnl +dnl GNU Hurd/glibc posix +dnl +dnl FreeBSD 5.3 posix -lc_r Y +dnl posix -lkse ? Y +dnl posix -lpthread ? Y +dnl posix -lthr Y +dnl +dnl FreeBSD 5.2 posix -lc_r Y +dnl posix -lkse Y +dnl posix -lthr Y +dnl +dnl FreeBSD 4.0,4.10 posix -lc_r Y OK +dnl +dnl NetBSD 1.6 -- +dnl +dnl OpenBSD 3.4 posix -lpthread Y OK +dnl +dnl MacOS X 10.[123] posix -lpthread Y OK +dnl +dnl Solaris 7,8,9 posix -lpthread Y Sol 7,8: 0.0; Sol 9: OK +dnl solaris -lthread Y Sol 7,8: 0.0; Sol 9: OK +dnl +dnl HP-UX 11 posix -lpthread N (cc) OK +dnl Y (gcc) +dnl +dnl IRIX 6.5 posix -lpthread Y 0.5 +dnl +dnl AIX 4.3,5.1 posix -lpthread N AIX 4: 0.5; AIX 5: OK +dnl +dnl OSF/1 4.0,5.1 posix -pthread (cc) N OK +dnl -lpthread (gcc) Y +dnl +dnl Cygwin posix -lpthread Y OK +dnl +dnl Any of the above pth -lpth 0.0 +dnl +dnl Mingw win32 N OK +dnl +dnl BeOS 5 -- +dnl +dnl The test-lock result shows what happens if in test-lock.c EXPLICIT_YIELD is +dnl turned off: +dnl OK if all three tests terminate OK, +dnl 0.5 if the first test terminates OK but the second one loops endlessly, +dnl 0.0 if the first test already loops endlessly. |