Repair thread-unsafe modifications of n_alive in F.pass.cpp
In this example, the ctor of G runs in the main thread in the expression G(), and also in the copy ctor of G() in the DECAY_COPY inside std::thread. The main thread destroys the G() instance at the semicolon, and the started thread destroys the G() after it returns. Thus there is a race between the threads on the n_alive variable.
The fix is to join with the background thread before attempting to destroy the G in the main thread.
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@344820 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/std/thread/thread.threads/thread.thread.class/thread.thread.constr/F.pass.cpp b/test/std/thread/thread.threads/thread.thread.class/thread.thread.constr/F.pass.cpp
index d419b8c..be3fc9c 100644
--- a/test/std/thread/thread.threads/thread.thread.class/thread.thread.constr/F.pass.cpp
+++ b/test/std/thread/thread.threads/thread.thread.class/thread.thread.constr/F.pass.cpp
@@ -157,8 +157,11 @@
{
assert(G::n_alive == 0);
assert(!G::op_run);
- std::thread t((G()));
- t.join();
+ {
+ G g;
+ std::thread t(g);
+ t.join();
+ }
assert(G::n_alive == 0);
assert(G::op_run);
}
@@ -185,8 +188,11 @@
{
assert(G::n_alive == 0);
assert(!G::op_run);
- std::thread t(G(), 5, 5.5);
- t.join();
+ {
+ G g;
+ std::thread t(g, 5, 5.5);
+ t.join();
+ }
assert(G::n_alive == 0);
assert(G::op_run);
}
