Make TestTimerFixture.test_timer_not_ready not fail sporadically

[durko]

Bug report

Required Info:

• Operating System:
  • Ubuntu 16.04, 18.04
• Installation type:
  • source
• Version or commit hash:
  • 7f6b914
• DDS implementation:
  • any
• Client library (if applicable):
  • rcl

Steps to reproduce issue

• Run test suite
• Test TestTimerFixture.test_timer_not_ready fails occasionaly

Expected behavior

Tests always pass

Actual behavior

Tests randomly fail

Additional information

This is related to #188, however we are proposing a solution to one sporadic failure here.

The problem we are seeing with this test is, that the 5ms timer

rcl/rcl/test/rcl/test_timer.cpp

Line 190 in 7f6b914

&timer, &clock, this->context_ptr, RCL_MS_TO_NS(5), nullptr, rcl_get_default_allocator());

becomes ready during 1ms wait on the waitset. On our CI machine the 5ms timer sometimes run out before

rcl/rcl/test/rcl/test_timer.cpp

Line 206 in 7f6b914

ret = rcl_wait(&wait_set, RCL_MS_TO_NS(1));

is reached. Basically our runtime under moderate load is a few ms for the couple of lines in between.

Is there a specific reason for the rather tight value of 5ms on the timer, or would it be possible to significantly relax the timer constraint to lets say 1s?

[jacobperron]

I don't see a reason why the timer value should be so low. Considering the nature of the test, bumping the timer value to 1 second sounds reasonable to me. I'd like to get a second opinion, but feel free to open a PR with the proposed change.

[clalancette]

It looks like these values were increased a while ago, and we haven't seen this flaky test in a while on the buildfarm. Closing this out, but feel free to reopen if this is still an issue.