1 files changed, 23 insertions, 0 deletions
diff --git a/ext/raindrops/raindrops_atomic.h b/ext/raindrops/raindrops_atomic.h
new file mode 100644
index 0000000..fd5f23b
--- /dev/null
+++ b/ext/raindrops/raindrops_atomic.h
@@ -0,0 +1,23 @@
+/*
+ * use wrappers around libatomic-ops for folks that don't have GCC
+ * or a new enough version of GCC
+ */
+#ifndef HAVE_GCC_ATOMIC_BUILTINS
+#include <atomic_ops.h>
+
+static inline unsigned long
+__sync_add_and_fetch(unsigned long *dst, unsigned long incr)
+{
+        AO_t tmp = AO_fetch_and_add((AO_t *)dst, (AO_t)incr);
+
+        return (unsigned long)tmp + incr;
+}
+
+static inline unsigned long
+__sync_sub_and_fetch(unsigned long *dst, unsigned long incr)
+{
+        AO_t tmp = AO_fetch_and_add((AO_t *)dst, (AO_t)(-(long)incr));
+
+        return (unsigned long)tmp - incr;
+}
+#endif /* HAVE_GCC_ATOMIC_BUILTINS */