async_hooks integration -- address comments

Author: kjin

packages/grpc-native-core/deps/grpc

@@ -31,16 +31,23 @@ var useAsyncHooks = semver.satisfies(process.version, '>=8');
  */
 
 if (useAsyncHooks) {
-  var asyncHooks = require('async_hooks');
-  module.exports = function createAsyncResourceWrapper(name) {
-    var resource = new asyncHooks.AsyncResource(name);
+  const asyncHooks = require('async_hooks');
+  class GrpcAsyncResource extends asyncHooks.AsyncResource {
+    constructor(name, handle) {
+      super(name);
+      this.handle = handle;
+    }
+  }
+  module.exports = function createAsyncResourceWrapper(name, handle) {
+    let resource = new GrpcAsyncResource(name, handle);
     return {
-      wrap: function(fn) {
+      wrap: (fn) => {
         return function() {
           if (resource) {
             resource.emitBefore();
+            let result;
             try {
-              var result = fn.apply(this, arguments);
+              result = fn.apply(this, arguments);
             } finally {
               resource.emitAfter();
             }
@@ -50,18 +57,20 @@ if (useAsyncHooks) {
           }
         }
       },
-      destroy: function() {
-        if (resource) {
-          resource.emitDestroy();
-          resource = null;
-        }
+      destroy: () => {
+        setImmediate(() => {
+            if (resource) {
+            resource.emitDestroy();
+            resource = null;
+          }
+        });
       }
     };
   }
 } else {
-  var noImpl = {
-    wrap: function(fn) { return fn; },
-    destroy: function() {}
+  const noImpl = {
+    wrap: fn => fn,
+    destroy: () => {}
   };
   module.exports = function createAsyncResourceWrapper() { return noImpl; }
 }

packages/grpc-native-core/src/async-hooks-integration.js

@@ -576,27 +576,31 @@ ServerDuplexStream.prototype.waitForCancel = waitForCancel;
  * @param {grpc.Metadata} metadata Metadata from the client
  */
 function handleUnary(call, handler, metadata) {
-  var asyncResource = createAsyncResourceWrapper('GrpcServerRequest');
   var emitter = new ServerUnaryCall(call, metadata);
+  var asyncResource = createAsyncResourceWrapper('grpc.ServerRequest', emitter);
   emitter.on('error', function(error) {
     handleError(call, error);
+    asyncResource.destroy();
   });
   emitter.waitForCancel();
   var batch = {};
   batch[grpc.opType.RECV_MESSAGE] = true;
   call.startBatch(batch, asyncResource.wrap(function(err, result) {
     if (err) {
       handleError(call, err);
+      asyncResource.destroy();
       return;
     }
     try {
       emitter.request = handler.deserialize(result.read);
     } catch (e) {
       e.code = constants.status.INTERNAL;
       handleError(call, e);
+      asyncResource.destroy();
       return;
     }
     if (emitter.cancelled) {
+      asyncResource.destroy();
       return;
     }
     handler.func(emitter, function sendUnaryData(err, value, trailer, flags) {
@@ -633,8 +637,8 @@ function handleUnary(call, handler, metadata) {
  * @param {grpc.Metadata} metadata Metadata from the client
  */
 function handleServerStreaming(call, handler, metadata) {
-  var asyncResource = createAsyncResourceWrapper('GrpcServerRequest');
   var stream = new ServerWritableStream(call, metadata, handler.serialize);
+  var asyncResource = createAsyncResourceWrapper('grpc.ServerRequest', stream);
   stream.on('error', asyncResource.destroy);
   stream.on('finish', asyncResource.destroy);
   stream.waitForCancel();
@@ -677,10 +681,11 @@ function handleServerStreaming(call, handler, metadata) {
  * @param {grpc.Metadata} metadata Metadata from the client
  */
 function handleClientStreaming(call, handler, metadata) {
-  var asyncResource = createAsyncResourceWrapper('GrpcServerRequest');
   var stream = new ServerReadableStream(call, metadata, handler.deserialize);
+  var asyncResource = createAsyncResourceWrapper('grpc.ServerRequest', stream);
   stream.on('error', function(error) {
     handleError(call, error);
+    asyncResource.destroy();
   });
   stream.waitForCancel();
   asyncResource.wrap(function() {
@@ -719,9 +724,9 @@ function handleClientStreaming(call, handler, metadata) {
  * @param {Metadata} metadata Metadata from the client
  */
 function handleBidiStreaming(call, handler, metadata) {
-  var asyncResource = createAsyncResourceWrapper('GrpcServerRequest');
   var stream = new ServerDuplexStream(call, metadata, handler.serialize,
                                       handler.deserialize);
+  var asyncResource = createAsyncResourceWrapper('grpc.ServerRequest', stream);
   stream.on('error', asyncResource.destroy);
   stream.on('finish', asyncResource.destroy);
   stream.waitForCancel();
@@ -766,7 +771,7 @@ Server.prototype.start = function() {
   }
   var self = this;
   this.started = true;
-  this.asyncResourceWrap = createAsyncResourceWrapper('GrpcServer');
+  this.asyncResourceWrap = createAsyncResourceWrapper('grpc.Server', this);
   this._server.start();
   /**
    * Handles the SERVER_RPC_NEW event. If there is a handler associated with