Re: RFC: add a mechanism to call epicsExit when signals are received

[Jure Varlec via Tech-talk <tech-talk at aps.anl.gov>]

On 4/3/25 11:34, Michael Davidsaver via Tech-talk wrote:
> wrt. your attached epicsSignalExit.cpp, the method epicsSignalExit::getInstance()
> is not async safe since (depending on c++ version) it will run the class
> epicsSignalExit constructor. 

I don't think that's the case. The signal handler is run only if it is first registered using epicsExitOnSignal(), presumably from iocsh. getInstance() is first used there, which constructs the static object. The next invocation of getInstance() (from the signal handler) will not run the contructor.

If this feels icky to you, there might be another approach. Have a global bool specifying whether this feature is enabled or not. The iocsh command then only sets this flag. Thread creation and handler registration is done at IOC init, if the flag is set.

Érico, I don't have the time right now to look deeper into this, but I would love to see something like this because it would make managing IOCs via Systemd more straightforward, not to mention making compulsive use of C-c to terminate IOCs nicer. Thanks for pushing this forward!

Best,
Jure