+
+dnl ===========================================================================
+
+#
+# Thread-safety primitives
+#
+
+AC_CACHE_CHECK([for Intel atomic primitives], fc_cv_have_intel_atomic_primitives, [
+ fc_cv_have_intel_atomic_primitives=false
+ AC_TRY_LINK([
+ void memory_barrier (void) { __sync_synchronize (); }
+ int atomic_add (int *i) { return __sync_fetch_and_add (i, 1); }
+ int mutex_trylock (int *m) { return __sync_lock_test_and_set (m, 1); }
+ void mutex_unlock (int *m) { __sync_lock_release (m); }
+ ], [], fc_cv_have_intel_atomic_primitives=true
+ )
+])
+if $fc_cv_have_intel_atomic_primitives; then
+ AC_DEFINE(HAVE_INTEL_ATOMIC_PRIMITIVES, 1, [Have Intel __sync_* atomic primitives])
+fi
+
+AC_CACHE_CHECK([for Solaris atomic operations], fc_cv_have_solaris_atomic_ops, [
+ fc_cv_have_solaris_atomic_ops=false
+ AC_TRY_LINK([
+ #include <atomic.h>
+ /* This requires Solaris Studio 12.2 or newer: */
+ #include <mbarrier.h>
+ void memory_barrier (void) { __machine_rw_barrier (); }
+ int atomic_add (volatile unsigned *i) { return atomic_add_int_nv (i, 1); }
+ void *atomic_ptr_cmpxchg (volatile void **target, void *cmp, void *newval) { return atomic_cas_ptr (target, cmp, newval); }
+ ], [], fc_cv_have_solaris_atomic_ops=true
+ )
+])
+if $fc_cv_have_solaris_atomic_ops; then
+ AC_DEFINE(HAVE_SOLARIS_ATOMIC_OPS, 1, [Have Solaris __machine_*_barrier and atomic_* operations])
+fi
+
+if test "$os_win32" = no && ! $have_pthread; then
+ AC_CHECK_HEADERS(sched.h)
+ AC_SEARCH_LIBS(sched_yield,rt,AC_DEFINE(HAVE_SCHED_YIELD, 1, [Have sched_yield]))
+fi
+
+have_pthread=false
+if test "$os_win32" = no; then
+ AX_PTHREAD([have_pthread=true])
+fi
+if $have_pthread; then
+ LIBS="$PTHREAD_LIBS $LIBS"
+ CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
+ CC="$PTHREAD_CC"
+ AC_DEFINE(HAVE_PTHREAD, 1, [Have POSIX threads])
+fi
+AM_CONDITIONAL(HAVE_PTHREAD, $have_pthread)
+
+
+dnl ===========================================================================
+