Separate macro file for atomic operations

To unclutter configure.ac and to make it easier re-usable, move the check
for atomic operations into a separate m4 macro file and call the macro
RS_ATOMIC_OPERATIONS (RS for RSyslog)

1 files changed, 53 insertions, 0 deletions

diff --git a/m4/atomic_operations.m4 b/m4/atomic_operations.m4
new file mode 100644
index 00000000..ad0ee606
--- /dev/null
+++ b/m4/atomic_operations.m4
@@ -0,0 +1,53 @@
+# rsyslog
+#
+# atomic_operations.m4 - autoconf macro to check if compiler supports atomic
+# operations
+#
+# rgerhards, 2008-09-18, added based on
+# http://svn.apache.org/repos/asf/apr/apr/trunk/configure.in
+#
+#
+AC_DEFUN([RS_ATOMIC_OPERATIONS],
+[AC_CACHE_CHECK([whether the compiler provides atomic builtins], [ap_cv_atomic_builtins],
+[AC_TRY_RUN([
+int main()
+{
+    unsigned long val = 1010, tmp, *mem = &val;
+
+    if (__sync_fetch_and_add(&val, 1010) != 1010 || val != 2020)
+        return 1;
+
+    tmp = val;
+
+    if (__sync_fetch_and_sub(mem, 1010) != tmp || val != 1010)
+        return 1;
+
+    if (__sync_sub_and_fetch(&val, 1010) != 0 || val != 0)
+        return 1;
+
+    tmp = 3030;
+
+    if (__sync_val_compare_and_swap(mem, 0, tmp) != 0 || val != tmp)
+        return 1;
+
+    if (__sync_lock_test_and_set(&val, 4040) != 3030)
+        return 1;
+
+    mem = &tmp;
+
+    if (__sync_val_compare_and_swap(&mem, &tmp, &val) != &tmp)
+        return 1;
+
+    __sync_synchronize();
+
+    if (mem != &val)
+        return 1;
+
+    return 0;
+}], [ap_cv_atomic_builtins=yes], [ap_cv_atomic_builtins=no], [ap_cv_atomic_builtins=no])])
+
+if test "$ap_cv_atomic_builtins" = "yes"; then
+    AC_DEFINE(HAVE_ATOMIC_BUILTINS, 1, [Define if compiler provides atomic builtins])
+fi
+
+])