From 255627efc53e7970e1b1e757e8cafc1cff7578b2 Mon Sep 17 00:00:00 2001
From: Marten Richter <marten.richter@tu-berlin.de>
Date: Sun, 21 Jun 2026 14:04:09 +0200
Subject: [PATCH] quic: fix wake up blob

The quic implementation calls setWakeUp with
the assumption, that it is only executed once
per event loop cycle.
This assumption is wrong.
Only setImmediate will guarantee, that the
execution is delayed to later in the event loop
and happening once in the event loop.

Fixes: https://github.com/nodejs/node/issues/64035
Signed-off-by: Marten Richter <marten.richter@freenet.de>
---
 lib/internal/blob.js | 22 ++++++++++++++++++----
 1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/lib/internal/blob.js b/lib/internal/blob.js
index 20f7078d1d0915..8ad349d9407ff8 100644
--- a/lib/internal/blob.js
+++ b/lib/internal/blob.js
@@ -455,9 +455,15 @@ function createBlobReaderStream(reader) {
       this.pendingPulls = [];
       // Register a wakeup callback that the C++ side can invoke
       // when new data is available after a STATUS_BLOCK.
+      let immediate;
       reader.setWakeup(() => {
-        if (this.pendingPulls.length > 0) {
-          this.readNext(c);
+        if (this.pendingPulls.length > 0 &&
+          typeof immediate === 'undefined') {
+          // Postpone the execution to the next steps of the event loop
+          immediate = setImmediate(() => {
+            immediate = undefined;
+            this.readNext(c);
+          });
         }
       });
     },
@@ -544,7 +550,16 @@ const kMaxBatchChunks = 16;
 async function* createBlobReaderIterable(reader, options = kEmptyObject) {
   const { getReadError } = options;
   let wakeup = PromiseWithResolvers();
-  reader.setWakeup(wakeup.resolve);
+  let immediate;
+  reader.setWakeup(() => {
+    if (typeof immediate === 'undefined') {
+      // Postpone the execution to the next steps of the event loop
+      immediate = setImmediate(() => {
+        immediate = undefined;
+        wakeup.resolve?.();
+      });
+    }
+  });
 
   try {
     while (true) {
@@ -591,7 +606,6 @@ async function* createBlobReaderIterable(reader, options = kEmptyObject) {
       if (blocked) {
         const fin = await wakeup.promise;
         wakeup = PromiseWithResolvers();
-        reader.setWakeup(wakeup.resolve);
         // If the wakeup was triggered by FIN (EndReadable), the DataQueue
         // is capped. Continue the loop to pull again -- the next pull will
         // return EOS. Without this, a race between the data notification