You have a race condition. Anything affecting the timing, like printing to STDERR, can cause a problem. It's not a deadlock, though. Solution, change: 
cond_wait $sharedData until $sharedData;

[download]
to 
cond_wait $sharedData until $sharedData || $done;

[download]

In reply to Re: Printing to STDERR causes deadlocks. by Thelonius
in thread Printing to STDERR causes deadlocks. by BrowserUk

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