Add us_listen_socket_close and graceful shutdown example

examples/GracefulShutdown.js

@@ -0,0 +1,39 @@
+/* Minimal example that shuts down gracefully */
+
+const uWS = require('../dist/uws.js');
+const port = 9001;
+
+/* We store the listen socket here, so that we can shut it down later */
+let listenSocket;
+
+const app = uWS./*SSL*/App({
+  key_file_name: 'misc/key.pem',
+  cert_file_name: 'misc/cert.pem',
+  passphrase: '1234'
+}).get('/shutdown', (res, req) => {
+  if (listenSocket) {
+    res.end('Okay, shutting down now!');
+    /* This function is provided directly by µSockets */
+    uWS.us_listen_socket_close(listenSocket);
+    listenSocket = null;
+  } else {
+    /* We just refuse if alrady shutting down */
+    res.close();
+  }
+}).listen(port, (token) => {
+  /* Save the listen socket for later shut down */
+  listenSocket = token;
+  /* Did we even manage to listen? */
+  if (token) {
+    console.log('Listening to port ' + port);
+
+    /* Stop listening soon */
+    setTimeout(() => {
+      console.log('Shutting down now');
+      uWS.us_listen_socket_close(listenSocket);
+      listenSocket = null;
+    }, 1000);
+  } else {
+    console.log('Failed to listen to port ' + port);
+  }
+});

src/AppWrapper.h

@@ -160,7 +160,7 @@ void uWS_App_listen(const FunctionCallbackInfo<Value> &args) {
     int port = args[0]->Uint32Value(args.GetIsolate()->GetCurrentContext()).ToChecked();
 
     app->listen(port, [&args](auto *token) {
-        Local<Value> argv[] = {Boolean::New(isolate, token)};
+        Local<Value> argv[] = {External::New(isolate, token)};
         Local<Function>::Cast(args[1])->Call(isolate->GetCurrentContext()->Global(), 1, argv);
     });
 

src/addon.cpp

@@ -53,16 +53,21 @@ void emptyNextTickQueue(Isolate *isolate) {
     }
 }
 
+/* todo: Put this function and all inits of it in its own header */
+void uWS_us_listen_socket_close(const FunctionCallbackInfo<Value> &args) {
+    us_listen_socket_close((struct us_listen_socket *) External::Cast(*args[0])->Value());
+}
+
 void Main(Local<Object> exports) {
     /* I guess we store this statically */
     isolate = exports->GetIsolate();
 
-    /* Register our own nextTick handler */
+    /* Register our own nextTick handlers */
     uWS::Loop::defaultLoop()->setPostHandler([](uWS::Loop *) {
         emptyNextTickQueue(isolate);
     });
 
-    /* Also empty in pre, it doesn't matter */
+    /* We also do need it on pre */
     uWS::Loop::defaultLoop()->setPreHandler([](uWS::Loop *) {
         emptyNextTickQueue(isolate);
     });
@@ -75,7 +80,8 @@ void Main(Local<Object> exports) {
     exports->Set(String::NewFromUtf8(isolate, "SSLApp"), FunctionTemplate::New(isolate, uWS_App<uWS::SSLApp>)->GetFunction());
     exports->Set(String::NewFromUtf8(isolate, "nextTick"), FunctionTemplate::New(isolate, nextTick)->GetFunction());
 
-    // these inits should probably happen elsewhere (in their respective struct's constructor)?
+    /* Expose some µSockets functions directly under uWS namespace */
+    exports->Set(String::NewFromUtf8(isolate, "us_listen_socket_close"), FunctionTemplate::New(isolate, uWS_us_listen_socket_close)->GetFunction());
 
     /* The template for websockets */
     WebSocketWrapper::initWsTemplate<0>();