GitLab

For some reason, GUI operations which run for extended periods of time
may cause the engine to crash with a SIGHUP error on Linux. Apparently
this is caused by the watchdog bailing out and taking the engine with
it. This affects the new print operation as well as the existing message
operation in the file menu, possibly also search index generation for
the help browser, and maybe some other operations that still need to be
identified.

The new gui-busy method lets the GUI set an internal flag in the engine
which makes the engine keep the watchdog happy while the GUI does its
thing, using the same mechanism that is already in place to ping the
watchdog when running GUI-less. To these ends, the GUI needs to invoke
"pd gui-busy 1" when starting the time-consuming operation, and "pd
gui-busy 0" when the operation is done.

Get rid of some really annoying legacy Tcl commands in the core. As long as we don't have any LED indicators in the console window, show an error for audio dropouts instead. Also get rid of some debugging messages in the pddp.

 *fixed typo in the m_sched.c that caused problems with pthread, merged some of the upstream code cleanup

 *fixed regression caused by the Haswell/Skylake CPU pthread improvement as reported by Antonio Roberts

*updated locking mechanism to prevent multiple locks or unlocks in a row, which in turn causes crashes on newer Intel processors.

added additional check to make sure clock_unset is not trying to unset something that just happened (may require further testing, based on one gdb segfault log)