Timer other than \t & .z.ts in KDB

Question

Is there a way i can use the system timer (unix) in KDB?

I understand .z.ts & \t can be used to setup a timer function and timer frequency respectively . However there is always a risk of overwriting the .z.ts unintentionally. I can create a generic function which internally have a list of functions that needs to called and their timer frequency but i want to explore if there is any other way to get this done.

Answer 1

You can block unintentional overwrites/inserts/amends/additions of global variables, such as .z.ts, by

• reval - http://code.kx.com/wiki/Reference/reval
• read-only mode - http://code.kx.com/wiki/Reference/Cmdlineb. Further, more useful examples here - http://code.kx.com/wiki/Contrib/UsingDotz#Slamming_the_Doors
• or, albeit more complex, you can force the execution of queries to slave threads. Clients will then always be blocked in updating globals. You can do this manually with your own code, or even look at multithreaded input mode - http://code.kx.com/wiki/Cookbook/MultithreadedInputMode. This mode isn't specifically designed for your use case, but it's an option if you were to need it and its other features.

Answer 2

You can use timerfd and friends. I wrote a "tickless" timer library a few years back which can use the timerfd implementation but can also (ab-)use .z.ts to wake up "just in time"

https://github.com/darrenarmstrong85/kdb-ts