[MESOS-5886] FUTURE_DISPATCH may react on irrelevant dispatch.

• Type: Bug
• Status: Accepted
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.1.2, 1.2.1, 1.3.0, 1.4.0, 1.5.1, 1.6.1, 1.7.0
• Labels: foundations mesosphere tech-debt tech-debt-test
• Story Points: 5
• Assignee: Unassigned
• Reporter: Alex R
• Created: 22/Jul/16 10:12
• Updated: 06/Feb/19 17:28

Description

FUTURE_DISPATCH uses DispatchMatcher to figure out whether a processed DispatchEvent is the same the user is waiting for. However, comparing std::type_info of function pointers is not enough: different class methods with same signatures will be matched. Here is the test that proves this:

class DispatchProcess : public Process<DispatchProcess>
{
public:
  MOCK_METHOD0(func0, void());
  MOCK_METHOD1(func1, bool(bool));
  MOCK_METHOD1(func1_same_but_different, bool(bool));
  MOCK_METHOD1(func2, Future<bool>(bool));
  MOCK_METHOD1(func3, int(int));
  MOCK_METHOD2(func4, Future<bool>(bool, int));
};

TEST(ProcessTest, DispatchMatch)
{
  DispatchProcess process;

  PID<DispatchProcess> pid = spawn(&process);

  Future<Nothing> future = FUTURE_DISPATCH(
      pid,
      &DispatchProcess::func1_same_but_different);

  EXPECT_CALL(process, func1(_))
    .WillOnce(ReturnArg<0>());

  dispatch(pid, &DispatchProcess::func1, true);

  AWAIT_READY(future);

  terminate(pid);
  wait(pid);
}

The test passes:

[ RUN      ] ProcessTest.DispatchMatch
[       OK ] ProcessTest.DispatchMatch (1 ms)

This change was introduced in https://reviews.apache.org/r/28052/.

Issue Links

• is related to: MESOS-8662 Consider introducing a clang-tidy check to catch ambiguous use of FUTURE_DISPATH
• relates to: MESOS-5887 Enhance DispatchEvent to include demangled method name.
• links to: On fixing FUTURE_DISPATCH.