Re: CVS commit: src/usr.bin/tic

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Fri, 5 May 2017 11:49:28 +0100
    From:        Roy Marples <roy%marples.name@localhost>
    Message-ID:  <d4678b06-236a-286d-eaf8-19d40971a54f%marples.name@localhost>

  | In this case, exit() isn't called, the main function returns.

Same thing, return from main is defined as implicitly calling exit.

  | In the RTEMS case, everything runs in one process and a thread is
  | launched for each command, sharing memory thus exit() can never be called.

It doesn't need to "exit" in that sense, but when that thread completes,
whatever resources it allocated needs to be reclaimed (whether they be
file descriptors, or memory, or whatever else).   How that is done is the
implementations business, but it needs to be done.

If not, you'd have bigger problems with tic if you intended to run it
on such a system - I see its grow_tbuf(), save_term(), write_database()
(and main(), though those calls are less of a problem) fuunctions all call
err() on error.  err() is defined not to return.  No memory gets
freed, nothing gets closed, other that whatever side-effect of the
program completing (calling exit) is.

I wouldn't start worrying about programs that don't bother to clean
up when they reach the end until you handle all the programs that simply
abort when something goes wrong, and clean up nothing at all.

  | So my question stands, is this something we should support via a compile
  | time guard or just not bother?

Leave the __VALGRIND__ guard in, and clean up in that case only, not that
a program like tic should really be too concerned about memory loss,
because exit (or whatever happens to it when it falls off main) really
needs to clean up for it, but just in case someone wants to debug
its memory use (perhaps it might be of use when debugging the hash table
library functions memory uses - to make sure that when the program does 
hdestroy*() that everything is freed ... as while tic really doesn't
care, some other long running daemon program might.)

Or if debugging memory use in tic isn't important, simply delete the
whole code block (turn the #ifdef __VALGRIND__ into #if 0, and then
delete the entire block later.)

kre