Kbase 16470: Why the trap "" 13 in the proshut script?
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
10/05/1998 |
|
Why the trap "" 13 in the proshut script?
Why does the proshut script have a trap "" 13?
Before PROGRESS used shared memory, all the IPC (Inter Process
Communication) was done using pipes. One process would spawn all the
child processes. When proshut shut down the database, each of the
pipes to the child _progres processes would get broken. The _mprshut
did not have a signal handler built in, so what would have happened is
a SIGPIPE, or signal 13, would be sent back to the _mprshut from the
_progres, and that would have killed the _mprshut process. It was
trapped to disallow the signal to kill the _mprshut process. This
line is not necessary in versions of PROGRESS that use shared memory
to communicate between processes.
10-Dec-96
Progress Software Technical Support Note # 16470