util: add getActiveResources

This change picks up the changes from the
referenced PR and moves the implementation of
`getActiveResources` to `util` to return a summary
of the resources.

Refs: #21453

Author: RaisinTen

lib/internal/timers.js

@@ -139,6 +139,11 @@ const kRefed = Symbol('refed');
 // Create a single linked list instance only once at startup
 const immediateQueue = new ImmediateList();
 
+// If an uncaught exception was thrown during execution of immediateQueue,
+// this queue will store all remaining Immediates that need to run upon
+// resolution of all error handling (if process is still alive).
+const outstandingQueue = new ImmediateList();
+
 let nextExpiry = Infinity;
 let refCount = 0;
 
@@ -279,11 +284,11 @@ ImmediateList.prototype.append = function(item) {
 // Removes an item from the linked list, adjusting the pointers of adjacent
 // items and the linked list's head or tail pointers as necessary
 ImmediateList.prototype.remove = function(item) {
-  if (item._idleNext) {
+  if (item._idleNext !== null) {
     item._idleNext._idlePrev = item._idlePrev;
   }
 
-  if (item._idlePrev) {
+  if (item._idlePrev !== null) {
     item._idlePrev._idleNext = item._idleNext;
   }
 
@@ -413,11 +418,6 @@ function setPosition(node, pos) {
 }
 
 function getTimerCallbacks(runNextTicks) {
-  // If an uncaught exception was thrown during execution of immediateQueue,
-  // this queue will store all remaining Immediates that need to run upon
-  // resolution of all error handling (if process is still alive).
-  const outstandingQueue = new ImmediateList();
-
   function processImmediate() {
     const queue = outstandingQueue.head !== null ?
       outstandingQueue : immediateQueue;
@@ -649,6 +649,7 @@ module.exports = {
   setUnrefTimeout,
   getTimerDuration,
   immediateQueue,
+  outstandingQueue,
   getTimerCallbacks,
   immediateInfoFields: {
     kCount,

lib/internal/util.js

@@ -3,6 +3,7 @@
 const {
   ArrayFrom,
   ArrayIsArray,
+  ArrayPrototypeForEach,
   ArrayPrototypePush,
   ArrayPrototypeSlice,
   ArrayPrototypeSort,
@@ -14,6 +15,7 @@ const {
   ObjectGetOwnPropertyDescriptors,
   ObjectGetPrototypeOf,
   ObjectSetPrototypeOf,
+  ObjectValues,
   Promise,
   ReflectApply,
   ReflectConstruct,
@@ -45,6 +47,10 @@ const {
   sleep: _sleep
 } = internalBinding('util');
 const { isNativeError } = internalBinding('types');
+const {
+  _getActiveHandles,
+  _getActiveRequests,
+} = internalBinding('process_methods');
 
 const noCrypto = !process.versions.openssl;
 
@@ -441,6 +447,39 @@ function createDeferredPromise() {
   return { promise, resolve, reject };
 }
 
+let internalTimers;
+
+function getActiveResources() {
+  if (internalTimers == null) {
+    internalTimers = require('internal/timers');
+  }
+  const handles = _getActiveHandles();
+  const reqs = _getActiveRequests();
+
+  const timers = {};
+  ArrayPrototypeForEach(ObjectValues(internalTimers.timerListMap), (list) => {
+    let timer = list._idlePrev === list ? null : list._idlePrev;
+
+    while (timer !== null) {
+      timers[timer[internalTimers.async_id_symbol]] = timer;
+
+      timer = timer._idlePrev === list ? null : list._idlePrev;
+    }
+  });
+
+  const immediates = {};
+  const queue = internalTimers.outstandingQueue.head !== null ?
+    internalTimers.outstandingQueue : internalTimers.immediateQueue;
+  let immediate = queue.head;
+  while (immediate !== null) {
+    immediates[immediate[internalTimers.async_id_symbol]] = immediate;
+
+    immediate = immediate._idleNext;
+  }
+
+  return { ...handles, ...reqs, ...timers, ...immediates };
+}
+
 module.exports = {
   assertCrypto,
   cachedResult,
@@ -451,6 +490,7 @@ module.exports = {
   deprecate,
   emitExperimentalWarning,
   filterDuplicateStrings,
+  getActiveResources,
   getConstructorOf,
   getSystemErrorMap,
   getSystemErrorName,

lib/util.js

@@ -67,6 +67,7 @@ const types = require('internal/util/types');
 
 const {
   deprecate,
+  getActiveResources,
   getSystemErrorMap,
   getSystemErrorName: internalErrorName,
   promisify
@@ -257,6 +258,7 @@ module.exports = {
   deprecate,
   format,
   formatWithOptions,
+  getActiveResources,
   getSystemErrorMap,
   getSystemErrorName,
   inherits,

src/node_process_methods.cc

@@ -1,3 +1,4 @@
+#include "async_wrap-inl.h"
 #include "base_object-inl.h"
 #include "debug_utils-inl.h"
 #include "env-inl.h"
@@ -35,7 +36,6 @@ typedef int mode_t;
 namespace node {
 
 using v8::ApiObject;
-using v8::Array;
 using v8::ArrayBuffer;
 using v8::BackingStore;
 using v8::CFunction;
@@ -253,31 +253,43 @@ static void Uptime(const FunctionCallbackInfo<Value>& args) {
 static void GetActiveRequests(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  std::vector<Local<Value>> request_v;
+  Local<Context> ctx = env->context();
+  Local<Object> return_obj = Object::New(args.GetIsolate());
+
   for (ReqWrapBase* req_wrap : *env->req_wrap_queue()) {
     AsyncWrap* w = req_wrap->GetAsyncWrap();
     if (w->persistent().IsEmpty())
       continue;
-    request_v.emplace_back(w->GetOwner());
+    double async_id = w->get_async_id();
+    Local<Object> req_obj = w->object();
+
+    USE(return_obj->Set(ctx,
+                        Number::New(args.GetIsolate(), async_id),
+                        req_obj));
   }
 
-  args.GetReturnValue().Set(
-      Array::New(env->isolate(), request_v.data(), request_v.size()));
+  args.GetReturnValue().Set(return_obj);
 }
 
 // Non-static, friend of HandleWrap. Could have been a HandleWrap method but
 // implemented here for consistency with GetActiveRequests().
 void GetActiveHandles(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
-  std::vector<Local<Value>> handle_v;
+  Local<Context> ctx = env->context();
+  Local<Object> return_obj = Object::New(args.GetIsolate());
+
   for (auto w : *env->handle_wrap_queue()) {
-    if (!HandleWrap::HasRef(w))
+    if (w->persistent().IsEmpty() || !HandleWrap::HasRef(w))
       continue;
-    handle_v.emplace_back(w->GetOwner());
+    double async_id = w->get_async_id();
+    Local<Object> handle_object = w->object();
+    USE(return_obj->Set(ctx, Number::New(args.GetIsolate(),
+                                         async_id),
+                                         handle_object));
   }
-  args.GetReturnValue().Set(
-      Array::New(env->isolate(), handle_v.data(), handle_v.size()));
+
+  args.GetReturnValue().Set(return_obj);
 }
 
 static void ResourceUsage(const FunctionCallbackInfo<Value>& args) {

test/parallel/test-handle-wrap-isrefed.js

@@ -4,6 +4,7 @@
 const common = require('../common');
 const strictEqual = require('assert').strictEqual;
 const { internalBinding } = require('internal/test/binding');
+const { getActiveResources } = require('util');
 
 // child_process
 {
@@ -107,4 +108,25 @@ const { kStateSymbol } = require('internal/dgram');
 }
 
 
+// timers
+{
+  const { Timeout } = require('internal/timers');
+  strictEqual(Object.values(getActiveResources()).filter(
+    (handle) => (handle instanceof Timeout)).length, 0);
+  const timer = setTimeout(() => {}, 500);
+  const handles = Object.values(getActiveResources()).filter(
+    (handle) => (handle instanceof Timeout));
+  strictEqual(handles.length, 1);
+  const handle = handles[0];
+  strictEqual(Object.getPrototypeOf(handle).hasOwnProperty('hasRef'),
+              true, 'timer: hasRef() missing');
+  strictEqual(handle.hasRef(), true);
+  timer.unref();
+  strictEqual(handle.hasRef(),
+              false, 'timer: unref() ineffective');
+  timer.ref();
+  strictEqual(handle.hasRef(),
+              true, 'timer: ref() ineffective');
+}
+
 // See also test/pseudo-tty/test-handle-wrap-isrefed-tty.js

test/parallel/test-process-getactiverequests.js renamed to test/parallel/test-util-getactiveresources-requests.js

@@ -3,8 +3,9 @@
 const common = require('../common');
 const assert = require('assert');
 const fs = require('fs');
+const { getActiveResources } = require('util');
 
 for (let i = 0; i < 12; i++)
   fs.open(__filename, 'r', common.mustCall());
 
-assert.strictEqual(process._getActiveRequests().length, 12);
+assert.strictEqual(Object.values(getActiveResources()).length, 12);

test/parallel/test-process-getactivehandles.js renamed to test/parallel/test-util-getactiveresources.js

@@ -3,6 +3,8 @@
 require('../common');
 const assert = require('assert');
 const net = require('net');
+const { getActiveResources } = require('util');
+
 const NUM = 8;
 const connections = [];
 const clients = [];
@@ -30,18 +32,18 @@ function clientConnected(client) {
 
 
 function checkAll() {
-  const handles = process._getActiveHandles();
+  const handles = Object.values(getActiveResources());
 
   clients.forEach(function(item) {
-    assert.ok(handles.includes(item));
+    assert.ok(handles.includes(item._handle));
     item.destroy();
   });
 
   connections.forEach(function(item) {
-    assert.ok(handles.includes(item));
+    assert.ok(handles.includes(item._handle));
     item.end();
   });
 
-  assert.ok(handles.includes(server));
+  assert.ok(handles.includes(server._handle));
   server.close();
 }

test/pseudo-tty/ref_keeps_node_running.js

@@ -6,6 +6,7 @@ require('../common');
 const { internalBinding } = require('internal/test/binding');
 const { TTY, isTTY } = internalBinding('tty_wrap');
 const strictEqual = require('assert').strictEqual;
+const { getActiveResources } = require('util');
 
 strictEqual(isTTY(0), true, 'fd 0 is not a TTY');
 
@@ -14,7 +15,8 @@ handle.readStart();
 handle.onread = () => {};
 
 function isHandleActive(handle) {
-  return process._getActiveHandles().some((active) => active === handle);
+  return Object.values(getActiveResources())
+    .some((active) => active === handle);
 }
 
 strictEqual(isHandleActive(handle), true, 'TTY handle not initially active');