add a regression test

Signed-off-by: Chen Lihui <lihui.chen@sony.com>

test/unittest/dds/core/condition/WaitSetImplTests.cpp

@@ -13,6 +13,7 @@
 // limitations under the License.
 
 #include <algorithm>
+#include <future>
 
 #include <gtest/gtest.h>
 
@@ -33,7 +34,7 @@ class TestCondition : public Condition
 {
 public:
 
-    bool trigger_value = false;
+    volatile bool trigger_value = false;
 
     bool get_trigger_value() const override
     {
@@ -197,6 +198,47 @@ TEST(WaitSetImplTests, wait)
     }
 }
 
+TEST(WaitSetImplTests, fix_wait_notification_lost)
+{
+    ConditionSeq conditions;
+    WaitSetImpl wait_set;
+
+    // Waiting should return the added connection while the condition triggered
+    {
+        TestCondition triggered_condition;
+
+        // Expecting calls on the notifier of triggered_condition
+        auto notifier = triggered_condition.get_notifier();
+        EXPECT_CALL(*notifier, attach_to(_)).Times(1);
+        EXPECT_CALL(*notifier, will_be_deleted(_)).Times(1);
+        wait_set.attach_condition(triggered_condition);
+
+        std::promise<void> promise;
+        std::future<void> future = promise.get_future();
+        ReturnCode_t ret = ReturnCode_t::RETCODE_ERROR;
+        std::thread add_triggered_condition([&]()
+                {
+                  // not to use `WaitSetImpl::wait` with a timeout value, because the
+                  // `condition_variable::wait_for` could call _Predicate function again
+                  // after timeout in the `WaitSetImpl::wait`.
+                  ret = wait_set.wait(conditions, eprosima::fastrtps::c_TimeInfinite);
+                  promise.set_value();
+                });
+
+        triggered_condition.trigger_value = true;
+        wait_set.wake_up();
+
+        // expect to get notification after wake_up, otherwise output error within 5 seconds
+        future.wait_for(std::chrono::seconds(5));
+        ASSERT_EQ(ReturnCode_t::RETCODE_OK, ret);
+        EXPECT_EQ(1u, conditions.size());
+        EXPECT_NE(conditions.cend(), std::find(conditions.cbegin(), conditions.cend(), &triggered_condition));
+        add_triggered_condition.join();
+
+        wait_set.will_be_deleted(triggered_condition);
+    }
+}
+
 int main(
         int argc,
         char** argv)