From f5e280f1475eed1e554932aa3b3c9ae88223a974 Mon Sep 17 00:00:00 2001
From: Sebastiaan Koppe <mail@skoppe.eu>
Date: Mon, 18 Jan 2021 14:50:17 +0100
Subject: [PATCH] We really need to do the load_state again after a failed
 casWeak

The original c++ source uses compare_exchange_weak which loads the value
if the compare failes. casWeak doesn't load it on failure.
---
 source/concurrency/stoptoken.d | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/source/concurrency/stoptoken.d b/source/concurrency/stoptoken.d
index 358f053..b1f865e 100644
--- a/source/concurrency/stoptoken.d
+++ b/source/concurrency/stoptoken.d
@@ -209,14 +209,12 @@ public:
 
   bool try_add_callback(StopCallback cb, bool incrementRefCountIfSuccessful) nothrow @safe {
     ulong oldState;
-    goto load_state;
     do {
-      goto check_state;
+      goto load_state;
       do {
         spin_yield();
       load_state:
         oldState = state_.atomicLoad!(MemoryOrder.acq);
-      check_state:
         if (is_stop_requested(oldState)) {
           cb.execute();
           return false;