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.

Author: Bryan Green <dbryan.green@gmail.com>
Discussion: https://www.postgresql.org/message-id/8c712d76-ecf7-4749-a6d8-dddc01f298ec@gmail.com
Backpatch-through: 14

diff --git a/src/bin/pg_dump/parallel.c b/src/bin/pg_dump/parallel.c
index c9f6b86bb05f5d8716cf1953c0ed83aaac45e4b7..4a4296ec85f2d3a42f612b6be14bf634cc0401d2 100644 (file)
--- 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 */