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, 2 insertions, 1 deletions

diff --git a/libcxx/test/std/thread/thread.threads/thread.thread.class/thread.thread.member/swap.pass.cpp b/libcxx/test/std/thread/thread.threads/thread.thread.class/thread.thread.member/swap.pass.cpp
index e8dede17b5d..49d4618e86a 100644
--- a/libcxx/test/std/thread/thread.threads/thread.thread.class/thread.thread.member/swap.pass.cpp
+++ b/libcxx/test/std/thread/thread.threads/thread.thread.class/thread.thread.member/swap.pass.cpp
@@ -45,7 +45,8 @@ bool G::op_run = false;
 int main()
 {
     {
-        std::thread t0((G()));
+        G g;
+        std::thread t0(g);
         std::thread::id id0 = t0.get_id();
         std::thread t1;
         std::thread::id id1 = t1.get_id();