process: add getActiveResources()

This is supposed to be a public alternative of the private APIs,
`process._getActiveResources()` and `process._getActiveHandles()`. When
called, it returns an array of objects containing the `type`, `asyncId`
and the `triggerAsyncId` of the currently active `requests`, `handles`
and `timers`.

Signed-off-by: Darshan Sen <[email protected]>

lib/internal/bootstrap/node.js

@@ -39,19 +39,24 @@
 setupPrepareStackTrace();
 
 const {
+  ArrayPrototypeConcat,
+  ArrayPrototypeForEach,
+  ArrayPrototypePush,
   FunctionPrototypeCall,
   JSONParse,
   ObjectDefineProperty,
   ObjectDefineProperties,
   ObjectGetPrototypeOf,
   ObjectPreventExtensions,
   ObjectSetPrototypeOf,
+  ObjectValues,
   ReflectGet,
   ReflectSet,
   SymbolToStringTag,
   globalThis,
 } = primordials;
 const config = internalBinding('config');
+const internalTimers = require('internal/timers');
 const { deprecate, lazyDOMExceptionClass } = require('internal/util');
 
 setupProcessObject();
@@ -150,6 +155,37 @@ const rawMethods = internalBinding('process_methods');
   process._getActiveRequests = rawMethods._getActiveRequests;
   process._getActiveHandles = rawMethods._getActiveHandles;
 
+  process.getActiveResources = function() {
+    const resources = ArrayPrototypeConcat(rawMethods._getActiveRequests2(),
+                                           rawMethods._getActiveHandles2());
+
+    ArrayPrototypeForEach(ObjectValues(internalTimers.timerListMap), (list) => {
+      let timeout = list._idlePrev === list ? null : list._idlePrev;
+      while (timeout !== null) {
+        ArrayPrototypePush(resources, {
+          type: 'Timeout',
+          asyncId: timeout[internalTimers.async_id_symbol],
+          triggerAsyncId: timeout[internalTimers.trigger_async_id_symbol],
+        });
+        timeout = timeout._idlePrev === list ? null : list._idlePrev;
+      }
+    });
+
+    const queue = internalTimers.outstandingQueue.head !== null ?
+      internalTimers.outstandingQueue : internalTimers.immediateQueue;
+    let immediate = queue.head;
+    while (immediate !== null) {
+      ArrayPrototypePush(resources, {
+        type: 'Immediate',
+        asyncId: immediate[internalTimers.async_id_symbol],
+        triggerAsyncId: immediate[internalTimers.trigger_async_id_symbol],
+      });
+      immediate = immediate._idleNext;
+    }
+
+    return resources;
+  };
+
   // TODO(joyeecheung): remove these
   process.reallyExit = rawMethods.reallyExit;
   process._kill = rawMethods._kill;
@@ -357,9 +393,11 @@ process.emitWarning = emitWarning;
   // TODO(joyeecheung): either remove it or make it public
   process._tickCallback = runNextTicks;
 
-  const { getTimerCallbacks } = require('internal/timers');
   const { setupTimers } = internalBinding('timers');
-  const { processImmediate, processTimers } = getTimerCallbacks(runNextTicks);
+  const {
+    processImmediate,
+    processTimers,
+  } = internalTimers.getTimerCallbacks(runNextTicks);
   // Sets two per-Environment callbacks that will be run from libuv:
   // - processImmediate will be run in the callback of the per-Environment
   //   check handle.

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;
 
@@ -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,

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"
@@ -257,13 +258,44 @@ static void GetActiveRequests(const FunctionCallbackInfo<Value>& args) {
     AsyncWrap* w = req_wrap->GetAsyncWrap();
     if (w->persistent().IsEmpty())
       continue;
+
     request_v.emplace_back(w->GetOwner());
   }
 
   args.GetReturnValue().Set(
       Array::New(env->isolate(), request_v.data(), request_v.size()));
 }
 
+static void GetActiveRequests2(const FunctionCallbackInfo<Value>& args) {
+  Environment* env = Environment::GetCurrent(args);
+
+  std::vector<Local<Value>> requests;
+  for (ReqWrapBase* req_wrap : *env->req_wrap_queue()) {
+    AsyncWrap* w = req_wrap->GetAsyncWrap();
+    if (w->persistent().IsEmpty())
+      continue;
+
+    Local<Object> request = Object::New(env->isolate());
+    if (request->Set(env->context(),
+                     OneByteString(env->isolate(), "type"),
+                     OneByteString(env->isolate(), w->MemoryInfoName().c_str()))
+                         .IsNothing() ||
+        request->Set(env->context(),
+                     OneByteString(env->isolate(), "asyncId"),
+                     Number::New(env->isolate(), w->get_async_id()))
+                         .IsNothing() ||
+        request->Set(env->context(),
+                     OneByteString(env->isolate(), "triggerAsyncId"),
+                     Number::New(env->isolate(), w->get_trigger_async_id()))
+                         .IsNothing()) return;
+
+    requests.emplace_back(request);
+  }
+
+  args.GetReturnValue().Set(
+      Array::New(env->isolate(), requests.data(), requests.size()));
+}
+
 // Non-static, friend of HandleWrap. Could have been a HandleWrap method but
 // implemented here for consistency with GetActiveRequests().
 void GetActiveHandles(const FunctionCallbackInfo<Value>& args) {
@@ -279,6 +311,35 @@ void GetActiveHandles(const FunctionCallbackInfo<Value>& args) {
       Array::New(env->isolate(), handle_v.data(), handle_v.size()));
 }
 
+void GetActiveHandles2(const FunctionCallbackInfo<Value>& args) {
+  Environment* env = Environment::GetCurrent(args);
+
+  std::vector<Local<Value>> handles;
+  for (HandleWrap* w : *env->handle_wrap_queue()) {
+    if (w->persistent().IsEmpty() || !HandleWrap::HasRef(w))
+      continue;
+
+    Local<Object> handle = Object::New(env->isolate());
+    if (handle->Set(env->context(),
+                    OneByteString(env->isolate(), "type"),
+                    OneByteString(env->isolate(), w->MemoryInfoName().c_str()))
+                        .IsNothing() ||
+        handle->Set(env->context(),
+                    OneByteString(env->isolate(), "asyncId"),
+                    Number::New(env->isolate(), w->get_async_id()))
+                        .IsNothing() ||
+        handle->Set(env->context(),
+                    OneByteString(env->isolate(), "triggerAsyncId"),
+                    Number::New(env->isolate(), w->get_trigger_async_id()))
+                        .IsNothing()) return;
+
+    handles.emplace_back(handle);
+  }
+
+  args.GetReturnValue().Set(
+      Array::New(env->isolate(), handles.data(), handles.size()));
+}
+
 static void ResourceUsage(const FunctionCallbackInfo<Value>& args) {
   Environment* env = Environment::GetCurrent(args);
 
@@ -559,7 +620,9 @@ static void InitializeProcessMethods(Local<Object> target,
   env->SetMethod(target, "resourceUsage", ResourceUsage);
 
   env->SetMethod(target, "_getActiveRequests", GetActiveRequests);
+  env->SetMethod(target, "_getActiveRequests2", GetActiveRequests2);
   env->SetMethod(target, "_getActiveHandles", GetActiveHandles);
+  env->SetMethod(target, "_getActiveHandles2", GetActiveHandles2);
   env->SetMethod(target, "_kill", Kill);
 
   env->SetMethodNoSideEffect(target, "cwd", Cwd);
@@ -586,7 +649,9 @@ void RegisterProcessMethodsExternalReferences(
   registry->Register(ResourceUsage);
 
   registry->Register(GetActiveRequests);
+  registry->Register(GetActiveRequests2);
   registry->Register(GetActiveHandles);
+  registry->Register(GetActiveHandles2);
   registry->Register(Kill);
 
   registry->Register(Cwd);