aboutsummaryrefslogtreecommitdiff
path: root/gl/m4/lock.m4
diff options
context:
space:
mode:
Diffstat (limited to 'gl/m4/lock.m4')
-rw-r--r--gl/m4/lock.m4311
1 files changed, 311 insertions, 0 deletions
diff --git a/gl/m4/lock.m4 b/gl/m4/lock.m4
new file mode 100644
index 00000000..0224f2ff
--- /dev/null
+++ b/gl/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.
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-22 11:15:52 +0000