Usually it is easiest and it is also easy to go manually to set up a folder/file(log structure to read/write/check between processes. Even checking if a process is a live in memory does not say much. You do not know if it is waiting for something or in a loop or hanging.
2012/1/2 Ian Clark <earthspo...@gmail.com> > Please forgive these questions I post to the list to which I know the > answer. Or rather: *an* answer. I learn a lot from others' responses. > Even if it's "my way is best after all" -- that's a valuable thing to > know. > > I have two separate J processes running (assume Linux / Darwin, though > I'm keen on cross-platform solutions). They communicate by each > writing a text file which is read by the other > (keep-it-simple-stupid). Is there a neat, robust way of one process > asking the other: "are you there?" or "are you still alive?" > > I'm au-fait with how the yellow-J works, all the solutions involving > timer-driven duty-cycles, timeouts, and reading files written by the > sister process, Or the files' timestamps, or permissions. But these > all seem so clunky. I guess what I want is something that was so easy > in the 1970s but is so awkward on today's machines: just reserve a > pair of bits in absolute memory -- or a pair of pixels on the screen > -- or some inessential system flags -- and play pat-a-cake with them. > > Once upon a time there was such a thing as "common memory". > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
