exec doesn't killed linked processes properly about erlexec

[saleyn]

I tried the following test, which seems to work correctly.
If you find a bug - patches are welcome.

$ sleep 2000
$ ps aux | grep sleep                                                                                                                                
serge    13085  0.0  0.0   5800   724 pts/3    S+   17:14   0:00 sleep 2000
6> exec:manage(13085, [link]).
{ok,<0.45.0>,13085}
7> 1 = 2.
** exception error: no match of right hand side value 2
# At this point the shell running "sleep 2000" gets terminated

[gatesn]

Correct me if this is insane and incorrect, but I'm trying to use run_link in a supervisor child spec, e.g.

{child_id, {exec, run_link, [Cmd, [exec args...]]}, permanent, 5000, worker, [exec]}

When the supervisor is shutdown, firstly I'd expect the linked process to be killed nicely (i.e. according to kill_group, kill command etc) and then I'd want it to exit with reason shutdown. So the supervisor doesn't complain about a shutdown error. Perhaps it's worth catching the normal/shutdown case separately from the parent exiting badly?

[saleyn]

This is not going to work for several reasons, but primarily because a supervisor expects a return from the child process being {ok, Pid}, and exec returns {ok, Pid, OsPid}. Aside from that a spawned child needs to adhere to OTP principles (e.g. processing system messages, which is handled under the hood by gen_* behaviors).