I've been testing a critical application against signals it might receive:
SIGTEMRM aka kill -15 can be ignored, so in this case I can take any time cleaning up everything before a graceful shutdown;
SIGKILL aka kill -9 cannot be caught by the application, so in this case I cannot do much;
SIGABORT aka kill -6 can be caught by the application, but I cannot be ignored. In this case, how many time do I have approximately to perform cleanup and a graceful shutdown? Is that a few milliseconds or less?