Fix race conditions in test class used throughout the std::thread tests.

The test class 'G' reads and writes to the same static variables in its
constructor, destructor and call operator. When threads are
constructed using `std::thread t((G()))` there is a race condition between the
destruction of the temporary and the execution of `G::operator()()`.

The fix is to simply create the input before creating the thread.

llvm-svn: 233946

1 files changed, 5 insertions, 3 deletions

diff --git a/libcxx/test/std/thread/thread.threads/thread.thread.class/thread.thread.constr/move.pass.cpp b/libcxx/test/std/thread/thread.threads/thread.thread.class/thread.thread.constr/move.pass.cpp
index 36e0fbd7b59..e88304ec8da 100644
--- a/libcxx/test/std/thread/thread.threads/thread.thread.class/thread.thread.constr/move.pass.cpp
+++ b/libcxx/test/std/thread/thread.threads/thread.thread.class/thread.thread.constr/move.pass.cpp
@@ -55,16 +55,18 @@ int main()
 {
 #ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
     {
-        assert(G::n_alive == 0);
+        G g;
+        assert(G::n_alive == 1);
         assert(!G::op_run);
-        std::thread t0(G(), 5, 5.5);
+        std::thread t0(g, 5, 5.5);
         std::thread::id id = t0.get_id();
         std::thread t1 = std::move(t0);
         assert(t1.get_id() == id);
         assert(t0.get_id() == std::thread::id());
         t1.join();
-        assert(G::n_alive == 0);
+        assert(G::n_alive == 1);
         assert(G::op_run);
     }
+    assert(G::n_alive == 0);
 #endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
 }