- 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