Workaround TSAN CI bug

fix #2499

CHANGELOG.md

@@ -1,3 +1,7 @@
+* Workaround TSAN CI bug.
+
+--------------------------------------------------------------------------------
+
 Version 332: 
 
 * Fix beast::zlib warnings

test/extras/include/boost/beast/test/yield_to.hpp

@@ -121,6 +121,11 @@ inline
 void
 enable_yield_to::
 spawn(F0&& f, FN&&... fn)
+{
+    // dispatch of spawn is a workaround for
+    // https://github.com/boostorg/beast/issues/2499
+    asio::dispatch(ioc_, 
+        [&]
         {
             asio::spawn(ioc_,
                 [&](yield_context yield)
@@ -131,6 +136,7 @@ spawn(F0&& f, FN&&... fn)
                         cv_.notify_all();
                 }
                 , boost::coroutines::attributes(2 * 1024 * 1024));
+        });
     spawn(fn...);
 }