v1-0001-pg_dump-check-for-_beginthreadex-failure-in-paral.patch

From 9b4696bb7f24b2ef22e204aa3617c9ad81137476 Mon Sep 17 00:00:00 2001
From: Bryan Green <dbryan.green@gmail.com>
Date: Sun, 28 Jun 2026 10:54:54 -0500
Subject: [PATCH v1 1/4] pg_dump: check for _beginthreadex() failure in
 parallel dump

ParallelBackupStart() stored _beginthreadex()'s return value as the
worker's thread handle without checking it.  On failure that value is 0,
which would later reach WaitForMultipleObjects() as a null handle, caught
only by an Assert.  The fork() path already calls pg_fatal() when it
fails; do the same for _beginthreadex(), as pgbench does.
---
 src/bin/pg_dump/parallel.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/bin/pg_dump/parallel.c b/src/bin/pg_dump/parallel.c
index 3e84b881ca..b77d2650df 100644
--- a/src/bin/pg_dump/parallel.c
+++ b/src/bin/pg_dump/parallel.c
@@ -976,6 +976,8 @@ ParallelBackupStart(ArchiveHandle *AH)
 
 		handle = _beginthreadex(NULL, 0, (void *) &init_spawned_worker_win32,
 								wi, 0, &(slot->threadId));
+		if (handle == 0)
+			pg_fatal("could not create worker thread: %m");
 		slot->hThread = handle;
 		slot->workerStatus = WRKR_IDLE;
 #else							/* !WIN32 */
-- 
2.54.0.windows.1