mavsdk tests: use tester sleep_for function #24266
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the previously used std::this_thread::sleep_for is with respect to host system time which is different from autopilot time if: - speed factor != 1 - something runs slower than realtime regardless of speed factor - debugging or otherwise interrupting PX4 control code tester.sleep_for (which already existed) correctly sleeps w.r.t. px4/simulation time.
| @@ -62,8 +62,7 @@ TEST_CASE("Control Allocation - Remove one motor", "[controlallocation]") | |||
| tester.check_tracks_mission(5.f); | |||
| tester.store_home(); | |||
| tester.enable_actuator_output_status(); | |||
| std::this_thread::sleep_for(std::chrono::seconds( | |||
| 1)); // This is necessary for the takeoff altitude to be applied properly | |||
| tester.sleep_for(std::chrono::seconds(1)); // Necessary for the takeoff altitude to be applied properly | |||
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Thanks for this find. I am still not sure if this is a proper solution. The reason is i am not sure why this sleep is needed at all. I agree that the std::this_thread::sleep_for is dumb and can screw up timings on a faster than real time scenario. But from the comment, if they want to make sure that the altitude takeoff is applied, it should sent a command to set the altitude and then get feedback that it is applied and then continue not sleep for an arbitrary amount (also then scaling with the speed factor might not work as then the comm is not done yet and you continue before PX4 receives the command).
But checking the tester.set_takeoff_altitude(flight_altitude); function it actually does check if the parameter is properly set. So can we test if the sleep is needed at all? Because the comment then oes not make sense to me.
Solved Problem
Some mavsdk tests currently have hardcoded sleep statements using
std::this_thread::sleep_for. This leads to test behaviour depending heavily on the speed with which the simulation runs -- if we run at a large speed factor, a (real-time) sleep of only a few seconds may already trigger all kinds of timeouts in PX4.Solution
We instead use the function
AutopilotTester::sleep_forwhich sleeps w.r.t. PX4 simulation time, not host system time. This should lead to more reliable test behaviour across different speed factors.Alternatives
Open to all suggestions & reasons why this might not be such a great idea.
Context
Should we set up some CI warning that reminds anyone putting real-time sleeps in tests of this footgun?