This code stayed unchanged for many years, but for some reason rtl_adsb started hanging upon exit:

*b66116a5164b69281eacc42ae950; ^CSignal caught, exiting! <------ hangs here forever

Examining it with gdb reveals that the demod thread waits peacefully on the condition variable, which we're trying to destroy. Either the signals killed all threads before, or condition variables were possible to destroy while other threads still waited on them.

The easiest fix appears to be just cancel the demod thread and wait for it to exit before proceeding for the door. --- src/rtl_adsb.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/src/rtl_adsb.c b/src/rtl_adsb.c index 07fdd2a..9087de4 100644 --- a/src/rtl_adsb.c +++ b/src/rtl_adsb.c @@ -492,6 +492,8 @@ int main(int argc, char **argv) else { fprintf(stderr, "\nLibrary error %d, exiting...\n", r);} rtlsdr_cancel_async(dev); + pthread_cancel(demod_thread); + pthread_join(demod_thread, NULL); pthread_cond_destroy(&ready); pthread_mutex_destroy(&ready_m);