RealtimeSynchronize block "clock_nanosleep" error on Linux

[bernhard-thiele]

Sporadically there is an error when using Blocks.OperatingSystem.RealtimeSynchronize on Linux. The simulation exits with the message MDDRealtimeSynchronize.h: clock_nanosleep(..) failed.

The reason for this is that

Modelica_DeviceDrivers/Modelica_DeviceDrivers/Resources/Include/MDDRealtimeSynchronize.h

Line 960 in b2fa5d7

ret = clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME, &t_abs, NULL);

fails due to an invalid t_abs (negative t_abs.tv_nsec). The cause is further up in

Modelica_DeviceDrivers/Modelica_DeviceDrivers/Resources/Include/MDDRealtimeSynchronize.h

Line 928 in b2fa5d7

ret = timespec_subtract(&t_elapsed, &t_now, &rtSync->t_last);

where it was overlooked that timespec_subtract(...) may modify its third argument for perfomring a carry.