[Lldb-commits] [lldb] [lldb] Fix race condition in Process::WaitForProcessToStop() (PR #144919)

[Pavel Labath via lldb-commits]

================
@@ -150,3 +150,84 @@ TEST(ListenerTest, StartStopListeningForEventSpec) {
   ASSERT_EQ(event_sp->GetBroadcaster(), &broadcaster1);
   ASSERT_FALSE(listener_sp->GetEvent(event_sp, std::chrono::seconds(0)));
 }
+
+TEST(ListenerTest, MoveEventsOnHijackAndRestore) {
+  Broadcaster broadcaster(nullptr, "test-broadcaster");
+  const uint32_t event_mask = 1;
+  EventSP event_sp;
+
+  // Create the original listener and start listening.
+  ListenerSP original_listener = Listener::MakeListener("original-listener");
+  ASSERT_EQ(event_mask, original_listener->StartListeningForEvents(&broadcaster,
+                                                                   event_mask));
+  broadcaster.SetPrimaryListener(original_listener);
+
+  // Queue two events to original listener, but do not consume them yet.
+  broadcaster.BroadcastEvent(event_mask, nullptr);
+  broadcaster.BroadcastEvent(event_mask, nullptr);
+
+  // Hijack.
+  ListenerSP hijack_listener = Listener::MakeListener("hijack-listener");
+  broadcaster.HijackBroadcaster(hijack_listener, event_mask);
+
+  // The events should have been moved to the hijack listener.
+  EXPECT_FALSE(original_listener->GetEvent(event_sp, std::chrono::seconds(0)));
+  EXPECT_TRUE(hijack_listener->GetEvent(event_sp, std::chrono::seconds(0)));
+  EXPECT_TRUE(hijack_listener->GetEvent(event_sp, std::chrono::seconds(0)));
+
+  // Queue two events while hijacked, but do not consume them yet.
+  broadcaster.BroadcastEvent(event_mask, nullptr);
+  broadcaster.BroadcastEvent(event_mask, nullptr);
+
+  // Restore the original listener.
+  broadcaster.RestoreBroadcaster();
+
+  // The events queued while hijacked should have been moved back to the
+  // original listener.
+  EXPECT_FALSE(hijack_listener->GetEvent(event_sp, std::chrono::seconds(0)));
+  EXPECT_TRUE(original_listener->GetEvent(event_sp, std::chrono::seconds(0)));
+  EXPECT_TRUE(original_listener->GetEvent(event_sp, std::chrono::seconds(0)));
+}
+
+TEST(ListenerTest, MoveEventsBetweenHijackers) {
+  Broadcaster broadcaster(nullptr, "test-broadcaster");
+  const uint32_t event_mask = 1;
+  EventSP event_sp;
+
+  // Create the original listener and start listening.
+  ListenerSP original_listener = Listener::MakeListener("original-listener");
+  ASSERT_EQ(event_mask, original_listener->StartListeningForEvents(&broadcaster,
+                                                                   event_mask));
+  broadcaster.SetPrimaryListener(original_listener);
+
+  // First hijack.
+  ListenerSP hijack_listener1 = Listener::MakeListener("hijack-listener1");
+  broadcaster.HijackBroadcaster(hijack_listener1, event_mask);
+
+  // Queue two events while hijacked, but do not consume
+  // them yet.
+  broadcaster.BroadcastEvent(event_mask, nullptr);
+  broadcaster.BroadcastEvent(event_mask, nullptr);
+
+  // Second hijack.
+  ListenerSP hijack_listener2 = Listener::MakeListener("hijack-listener2");
+  broadcaster.HijackBroadcaster(hijack_listener2, event_mask);
+
+  // The second hijacker should have the events now.
+  EXPECT_FALSE(hijack_listener1->GetEvent(event_sp, std::chrono::seconds(0)));
+  EXPECT_TRUE(hijack_listener2->GetEvent(event_sp, std::chrono::seconds(0)));
+  EXPECT_TRUE(hijack_listener2->GetEvent(event_sp, std::chrono::seconds(0)));
+
+  // Queue two events while hijacked with second hijacker, but do not consume
+  // them yet.
+  broadcaster.BroadcastEvent(event_mask, nullptr);
+  broadcaster.BroadcastEvent(event_mask, nullptr);
+
+  // Restore the previous hijacker.
+  broadcaster.RestoreBroadcaster();
+
+  // The first hijacker should now have the events.
+  EXPECT_FALSE(hijack_listener2->GetEvent(event_sp, std::chrono::seconds(0)));
+  EXPECT_TRUE(hijack_listener1->GetEvent(event_sp, std::chrono::seconds(0)));
+  EXPECT_TRUE(hijack_listener1->GetEvent(event_sp, std::chrono::seconds(0)));
+}
----------------
labath wrote:

add a newline here

https://github.com/llvm/llvm-project/pull/144919