[node] Need to have a singleton RunLoop instance

platform/node/src/node_mapbox_gl_native.cpp

@@ -6,11 +6,26 @@
 #include <nan.h>
 #pragma GCC diagnostic pop
 
+#include "node_mapbox_gl_native.hpp"
 #include "node_map.hpp"
 #include "node_log.hpp"
 #include "node_request.hpp"
 
+namespace node_mbgl {
+
+mbgl::util::RunLoop& NodeRunLoop() {
+    static mbgl::util::RunLoop nodeRunLoop(uv_default_loop());
+    return nodeRunLoop;
+}
+
+}
+
 NAN_MODULE_INIT(RegisterModule) {
+    // This has the effect of:
+    //   a) Ensuring that the static local variable is initialized before any thread contention.
+    //   b) unreffing an async handle, which otherwise would keep the default loop running.
+    node_mbgl::NodeRunLoop().stop();
+
     node_mbgl::NodeMap::Init(target);
     node_mbgl::NodeRequest::Init(target);