If you look at a list of open processes, either in the Activity Monitor, or in Terminal with the TOP command, why are the assigned PID numbers not all used sequentially.
For example, is this because some processes with certain PID numbers have run and since ceased running, leaving a gap in sequential PID assigned numbers of existing running processes, or are their unlisted processes not visible in the Terminal tops command, or some other reason?
My understanding that after initial start up with PID numbers 0, 1 and a few more are assigned, PID numbers are then allocated from 100. As presented by: AD: What's the maximum pid for Mac OS X? And Wikipedia: Process Identifier.