timers: use ref counts to count timers

The additional objects that were getting added and deleted from the activeTimersMap object were slowing down the rest of the timers code, so this change falls back to using the ref counts to count the active timers inside process.getActiveResourcesInfo(). Fixes: nodejs#41219 Signed-off-by: Darshan Sen <[email protected]> PR-URL: nodejs#41231 Reviewed-By: Anatoli Papirovski <[email protected]> Reviewed-By: Antoine du Hamel <[email protected]>
Linkgoron · Jan 31, 2022 · 5b2bef9 · 5b2bef9
1 parent 1572876
commit 5b2bef9
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Showing 3 changed files with 14 additions and 22 deletions.
diff --git a/lib/internal/bootstrap/node.js b/lib/internal/bootstrap/node.js
@@ -39,17 +39,16 @@
 setupPrepareStackTrace();
 
 const {
+  Array,
   ArrayPrototypeConcat,
-  ArrayPrototypeFilter,
-  ArrayPrototypeMap,
+  ArrayPrototypeFill,
   FunctionPrototypeCall,
   JSONParse,
   ObjectDefineProperty,
   ObjectDefineProperties,
   ObjectGetPrototypeOf,
   ObjectPreventExtensions,
   ObjectSetPrototypeOf,
-  ObjectValues,
   ReflectGet,
   ReflectSet,
   SymbolToStringTag,
@@ -156,13 +155,12 @@ const rawMethods = internalBinding('process_methods');
   process._getActiveHandles = rawMethods._getActiveHandles;
 
   process.getActiveResourcesInfo = function() {
+    const timerCounts = internalTimers.getTimerCounts();
     return ArrayPrototypeConcat(
       rawMethods._getActiveRequestsInfo(),
       rawMethods._getActiveHandlesInfo(),
-      ArrayPrototypeMap(
-        ArrayPrototypeFilter(ObjectValues(internalTimers.activeTimersMap),
-                             ({ resource }) => resource.hasRef()),
-        ({ type }) => type));
+      ArrayPrototypeFill(new Array(timerCounts.timeoutCount), 'Timeout'),
+      ArrayPrototypeFill(new Array(timerCounts.immediateCount), 'Immediate'));
   };
 
   // TODO(joyeecheung): remove these

diff --git a/lib/internal/timers.js b/lib/internal/timers.js
@@ -139,12 +139,6 @@ const kRefed = Symbol('refed');
 // Create a single linked list instance only once at startup
 const immediateQueue = new ImmediateList();
 
-// Object map containing timers
-//
-// - key = asyncId
-// - value = { type, resource }
-const activeTimersMap = ObjectCreate(null);
-
 let nextExpiry = Infinity;
 let refCount = 0;
 
@@ -166,7 +160,6 @@ function initAsyncResource(resource, type) {
     resource[trigger_async_id_symbol] = getDefaultTriggerAsyncId();
   if (initHooksExist())
     emitInit(asyncId, type, triggerAsyncId, resource);
-  activeTimersMap[asyncId] = { type, resource };
 }
 
 // Timer constructor function.
@@ -478,7 +471,6 @@ function getTimerCallbacks(runNextTicks) {
 
         if (destroyHooksExist())
           emitDestroy(asyncId);
-        delete activeTimersMap[asyncId];
 
         outstandingQueue.head = immediate = immediate._idleNext;
       }
@@ -551,7 +543,6 @@ function getTimerCallbacks(runNextTicks) {
 
           if (destroyHooksExist())
             emitDestroy(asyncId);
-          delete activeTimersMap[asyncId];
         }
         continue;
       }
@@ -580,7 +571,6 @@ function getTimerCallbacks(runNextTicks) {
 
           if (destroyHooksExist())
             emitDestroy(asyncId);
-          delete activeTimersMap[asyncId];
         }
       }
 
@@ -648,6 +638,13 @@ class Immediate {
   }
 }
 
+function getTimerCounts() {
+  return {
+    timeoutCount: refCount,
+    immediateCount: immediateInfo[kRefCount],
+  };
+}
+
 module.exports = {
   TIMEOUT_MAX,
   kTimeout: Symbol('timeout'), // For hiding Timeouts on other internals.
@@ -670,9 +667,9 @@ module.exports = {
   active,
   unrefActive,
   insert,
-  activeTimersMap,
   timerListMap,
   timerListQueue,
   decRefCount,
-  incRefCount
+  incRefCount,
+  getTimerCounts,
 };
diff --git a/lib/timers.js b/lib/timers.js
@@ -45,7 +45,6 @@ const {
   kRefed,
   kHasPrimitive,
   getTimerDuration,
-  activeTimersMap,
   timerListMap,
   timerListQueue,
   immediateQueue,
@@ -88,7 +87,6 @@ function unenroll(item) {
   // Fewer checks may be possible, but these cover everything.
   if (destroyHooksExist() && item[async_id_symbol] !== undefined)
     emitDestroy(item[async_id_symbol]);
-  delete activeTimersMap[item[async_id_symbol]];
 
   L.remove(item);
 
@@ -331,7 +329,6 @@ function clearImmediate(immediate) {
   if (destroyHooksExist() && immediate[async_id_symbol] !== undefined) {
     emitDestroy(immediate[async_id_symbol]);
   }
-  delete activeTimersMap[immediate[async_id_symbol]];
 
   immediate._onImmediate = null;