From 6bffb44d2bcca4989945e4d76ce8d35cf8cdcebd Mon Sep 17 00:00:00 2001
From: Denis Blank <denis.blank@outlook.com>
Date: Tue, 3 Nov 2020 17:26:20 +0100
Subject: [PATCH] Fix a race condition in cti::transforms::wait() * Thanks to
 p4654545 for reporting this issue and providing a reproducible example *
 Closes #38

---
 include/continuable/detail/transforms/wait.hpp | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/include/continuable/detail/transforms/wait.hpp b/include/continuable/detail/transforms/wait.hpp
index 02ae9be..b24b4b0 100644
--- a/include/continuable/detail/transforms/wait.hpp
+++ b/include/continuable/detail/transforms/wait.hpp
@@ -81,24 +81,26 @@ Result wait_relaxed(continuable_base<Data, Annotation>&& continuable) {
     return std::move(continuable).unpack();
   }
 
-  std::mutex cv_mutex;
   condition_variable_t cv;
-  std::atomic_bool ready{false};
+  std::mutex cv_mutex;
+
+  bool ready{false};
   Result sync_result;
 
   std::move(continuable)
       .next([&](auto&&... args) {
         sync_result = Result::from(std::forward<decltype(args)>(args)...);
 
-        ready.store(true, std::memory_order_release);
+        lock_t lock(cv_mutex);
+        ready = true;
         cv.notify_all();
       })
       .done();
 
-  if (!ready.load(std::memory_order_acquire)) {
-    lock_t lock(cv_mutex);
+  lock_t lock(cv_mutex);
+  if (!ready) {
     cv.wait(lock, [&] {
-      return ready.load(std::memory_order_acquire);
+      return ready;
     });
   }