From 2750d3ac6a4f6015a7a9720b8fbcb3610aa691e1 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Fri, 9 Jul 2021 20:50:08 +0200
Subject: avoid reentrant lock acquire when ThreadIds run out

---
 library/std/src/thread/mod.rs | 1 +
 1 file changed, 1 insertion(+)

(limited to 'library/std/src/thread')

diff --git a/library/std/src/thread/mod.rs b/library/std/src/thread/mod.rs
index da2d1160493..5630904da77 100644
--- a/library/std/src/thread/mod.rs
+++ b/library/std/src/thread/mod.rs
@@ -1004,6 +1004,7 @@ impl ThreadId {
             // If we somehow use up all our bits, panic so that we're not
             // covering up subtle bugs of IDs being reused.
             if COUNTER == u64::MAX {
+                drop(_guard); // in case the panic handler ends up calling `ThreadId::new()`, avoid reentrant lock acquire.
                 panic!("failed to generate unique thread ID: bitspace exhausted");
             }
 
-- 
cgit 1.4.1-3-g733a5