QTimer clock source in Genode

Steven Harp steven.harp at adventiumlabs.com
Mon Apr 1 16:20:08 CEST 2019

I tripped across a situation where one of my Qt5 applications
that used a periodic QTimer stops receiving timeout signals
after 1 hour 10 minutes of normal operation. 

(This is in Genode 18.08, x86_32 and x86_64, nova and seL4.)  

The same application keeps on ticking (for many hours at least)
when compiled and run under Linux.

A Qt Forum participant speculates "a 2^32 wraparound? Because 
4294967296 (2^32)  microseconds is 4295 seconds." This is just
about the observed time.

The Qt5 documentation suggests that some Qt timers on some platforms
can have this problem--it depends on the underlying clock source.

Can anyone comment on the relevant clock source for QTimer in the
Genode port?

For reference, a native Genode Timer connection does not
exhibit this problem, so using it in this application was a
viable workaround.

// Steve

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