node: improve GetActiveHandles performance

Improve performance of process._getActiveHandles by sending handles in
batches to JS to be set on the passed Array. Add test to check proper
active handles are returned.

Alter implementation of GetActiveRequests to match GetActiveHandles'
implementation.

PR-URL: nodejs#3780
Reviewed-By: Fedor Indutny <fedor@indutny.com>

Author: trevnorris

src/node.cc

@@ -1608,27 +1608,21 @@ static void GetActiveRequests(const FunctionCallbackInfo<Value>& args) {
   Local<Array> ary = Array::New(args.GetIsolate());
   Local<Context> ctx = env->context();
   Local<Function> fn = env->push_values_to_array_function();
-  static const size_t argc = 8;
-  Local<Value> argv[argc];
-  size_t i = 0;
+  Local<Value> argv[NODE_PUSH_VAL_TO_ARRAY_MAX];
+  size_t idx = 0;
 
   for (auto w : *env->req_wrap_queue()) {
-    if (w->persistent().IsEmpty() == false) {
-      argv[i++ % argc] = w->object();
-      if ((i % argc) == 0) {
-        HandleScope scope(env->isolate());
-        fn->Call(ctx, ary, argc, argv).ToLocalChecked();
-        for (auto&& arg : argv) {
-          arg = Local<Value>();
-        }
-      }
+    if (w->persistent().IsEmpty())
+      continue;
+    argv[idx] = w->object();
+    if (++idx >= ARRAY_SIZE(argv)) {
+      fn->Call(ctx, ary, idx, argv).ToLocalChecked();
+      idx = 0;
     }
   }
 
-  const size_t remainder = i % argc;
-  if (remainder > 0) {
-    HandleScope scope(env->isolate());
-    fn->Call(ctx, ary, remainder, argv).ToLocalChecked();
+  if (idx > 0) {
+    fn->Call(ctx, ary, idx, argv).ToLocalChecked();
   }
 
   args.GetReturnValue().Set(ary);
@@ -1641,7 +1635,10 @@ void GetActiveHandles(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
   Local<Array> ary = Array::New(env->isolate());
-  int i = 0;
+  Local<Context> ctx = env->context();
+  Local<Function> fn = env->push_values_to_array_function();
+  Local<Value> argv[NODE_PUSH_VAL_TO_ARRAY_MAX];
+  size_t idx = 0;
 
   Local<String> owner_sym = env->owner_string();
 
@@ -1652,7 +1649,14 @@ void GetActiveHandles(const FunctionCallbackInfo<Value>& args) {
     Local<Value> owner = object->Get(owner_sym);
     if (owner->IsUndefined())
       owner = object;
-    ary->Set(i++, owner);
+    argv[idx] = owner;
+    if (++idx >= ARRAY_SIZE(argv)) {
+      fn->Call(ctx, ary, idx, argv).ToLocalChecked();
+      idx = 0;
+    }
+  }
+  if (idx > 0) {
+    fn->Call(ctx, ary, idx, argv).ToLocalChecked();
   }
 
   args.GetReturnValue().Set(ary);

test/parallel/test-process-getactivehandles.js

@@ -0,0 +1,44 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const net = require('net');
+const NUM = 8;
+const connections = [];
+const clients = [];
+var clients_counter = 0;
+
+const server = net.createServer(function listener(c) {
+  connections.push(c);
+}).listen(common.PORT, function makeConnections() {
+  for (var i = 0; i < NUM; i++) {
+    net.connect(common.PORT, function connected() {
+      clientConnected(this);
+    });
+  }
+});
+
+
+function clientConnected(client) {
+  clients.push(client);
+  if (++clients_counter >= NUM)
+    checkAll();
+}
+
+
+function checkAll() {
+  const handles = process._getActiveHandles();
+
+  clients.forEach(function(item) {
+    assert.ok(handles.indexOf(item) > -1);
+    item.destroy();
+  });
+
+  connections.forEach(function(item) {
+    assert.ok(handles.indexOf(item) > -1);
+    item.end();
+  });
+
+  assert.ok(handles.indexOf(server) > -1);
+  server.close();
+}