From d3d31105e99f5265880d0f010436ed5c6baab034 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Mon, 6 Aug 2018 12:45:27 +0200
Subject: clarify partially initialized Mutex issues

---
 src/libstd/thread/mod.rs | 3 +++
 1 file changed, 3 insertions(+)

(limited to 'src/libstd/thread')

diff --git a/src/libstd/thread/mod.rs b/src/libstd/thread/mod.rs
index bbe80df7e8b..98b4ca36c26 100644
--- a/src/libstd/thread/mod.rs
+++ b/src/libstd/thread/mod.rs
@@ -940,6 +940,9 @@ pub struct ThreadId(u64);
 impl ThreadId {
     // Generate a new unique thread ID.
     fn new() -> ThreadId {
+        // `GUARD` is never initialized fully, so this mutex is reentrant!
+        // Do not use it in a way that might be reentrant, that could lead to
+        // aliasing `&mut`.
         static GUARD: mutex::Mutex = mutex::Mutex::new();
         static mut COUNTER: u64 = 0;
 
-- 
cgit 1.4.1-3-g733a5