INTEGRATION_WeakPluginPtr test fails

[osrf-migration]

Original report (archived issue) by Juan Oxoby (Bitbucket: Juan Oxoby).

---

Prerequisites

• [X ] Put an X between the brackets on this line if you have done all of the following:

  • Checked the Q&A board for common solutions: http://answers.gazebosim.org
  • Checked that your issue isn't already filed.
  • Checked that there is not already an Ignition package that provides the described functionality: https://ignitionrobotics.org/libs

Description

INTEGRATION_WeakPluginPtr is failing on my machine.

Steps to Reproduce

1. Run INTEGRATION_WeakPluginPtr

Expected behavior:

PASSED

Actual behavior:

[==========] Running 2 tests from 1 test case.
[----------] Global test environment set-up.
[----------] 2 tests from WeakPluginPtr
[ RUN      ] WeakPluginPtr.Lifecycle
/home/juan/ignition_workspace/src/ign-plugin/test/integration/WeakPluginPtr.cc:59: Failure
Expected equality of these values:
  nullptr
    Which is: NULL
  dlHandle
    Which is: 0x55fdb805a330
[  FAILED  ] WeakPluginPtr.Lifecycle (0 ms)
[ RUN      ] WeakPluginPtr.CopyMove
[       OK ] WeakPluginPtr.CopyMove (0 ms)
[----------] 2 tests from WeakPluginPtr (0 ms total)

[----------] Global test environment tear-down
[==========] 2 tests from 1 test case ran. (0 ms total)
[  PASSED  ] 1 test.
[  FAILED  ] 1 test, listed below:
[  FAILED  ] WeakPluginPtr.Lifecycle

Reproduces how often:

Always

Versions

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 18.04.3 LTS
Release:    18.04
Codename:   bionic

$ gcc --version
gcc (Ubuntu 8.3.0-6ubuntu1~18.04.1) 8.3.0
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Additional Information

The error points to the macro CHECK_FOR_LIBRARY defined on integration/utils.hh

There’s a comment there saying:

/////////////////////////////////////////////////
// Note (MXG): According to some online discussions, there is no guarantee
// that a correct number of calls to dlclose(void*) will actually unload the
// shared library. In fact, there is no guarantee that a dynamically loaded
// library from dlopen will ever be unloaded until the program is terminated.
// This may cause dlopen(~, RTLD_NOLOAD) to return a non-null handle even if
// we are managing the handles correctly. If the test for
// EXPECT_EQ(nullptr, dlHandle) is found to fail occasionally, we should
// consider removing it because it may be unreliable. At the very least, if
// it fails very infrequently, then we can safely consider the failures to be
// false negatives and may want to consider relaxing this test.

Avoiding the check EXPECT_EQ(nullptr, dlHandle) in the macro CHECK_FOR_LIBRARY makes the test pass.

[osrf-migration]

Original comment by Juan Oxoby (Bitbucket: Juan Oxoby).

---

• Edited issue description