lib: child process queue pending messages

It fixes the problem for the child process not receiving messages.

Fixes: #41134

lib/internal/child_process.js

@@ -13,6 +13,7 @@ const {
   StringPrototypeSlice,
   Symbol,
   Uint8Array,
+  SafeSet,
 } = primordials;
 
 const {
@@ -81,6 +82,7 @@ let HTTPParser;
 const MAX_HANDLE_RETRANSMISSIONS = 3;
 const kChannelHandle = Symbol('kChannelHandle');
 const kIsUsedAsStdio = Symbol('kIsUsedAsStdio');
+const kPendingMessages = Symbol('pendingMessages');
 
 // This object contain function to convert TCP objects to native handle objects
 // and back again.
@@ -526,6 +528,7 @@ class Control extends EventEmitter {
   constructor(channel) {
     super();
     this.#channel = channel;
+    this[kPendingMessages] = new SafeSet();
   }
 
   // The methods keeping track of the counter are being used to track the
@@ -699,6 +702,19 @@ function setupChannel(target, channel, serializationMode) {
     });
   });
 
+  target.on('newListener', function () {
+    if(!target.channel) return;
+
+    const messages = target.channel[kPendingMessages];
+    if (!messages.size) return;
+
+    for (const messageParams of messages) {
+      process.nextTick(() => ReflectApply(target.emit, target, messageParams));
+    }
+
+    messages.clear();
+  });
+
   target.send = function(message, handle, options, callback) {
     if (typeof handle === 'function') {
       callback = handle;
@@ -912,7 +928,15 @@ function setupChannel(target, channel, serializationMode) {
   };
 
   function emit(event, message, handle) {
-    target.emit(event, message, handle);
+    const args = [event, message, handle];
+    const isInternalMessage = "internalMessage" === event;
+    const hasListenersInstalled = target.listenerCount('message');
+    if (hasListenersInstalled || isInternalMessage) { 
+      target.emit(event, message, handle);
+      return;
+    }
+
+    target.channel[kPendingMessages].add(args);
   }
 
   function handleMessage(message, handle, internal) {