On 01:04-0700, May 2, 2002, Terry Lambert wrote: > Maxim Konovalov wrote: > > > [ ... patch to wait for children, but do nothing with the result ... ] > > > > > > Why not just set the signal handler for the child process > > > termination to "ignore", so that the child processes do > > > not become zombied in the first place, so it's not ever > > > necessary to do a useless loop whose only purpose is to > > > reap zombies without examining their exit status? > > > > There are two purposes: > > > > a) reap zombies, > > b) exit after all children have done only. > > > > In the current implementation newsyslog(8) forks and execs gzip(1) or > > bzip2(1) and exits immediately. If a log file(s) is big enough the > > compress_log() process(es) will work after newsyslog's death and there > > is no clear way to get know when it(they)'s done. > > Your (a) is statisfied with either approach. > > I don't understand why you think (b) is a requirement.
Let's imagine: # /usr/sbin/newsyslog && ./make_something_with_compressed_log newsyslog exited but there are several compress_log() processes are still running and make_something_with_compressed_log will get a half-compressed logs. > > OpenBSD: > > > > a) SIGCHLD signal handler: waitpid(2) loop, do not examine "status", > > b) the same waitpid(2) loop before exit(2). > > > > I do not think we need a) at all. newsyslog forks/execs all his > > children and enters into the reap loop like SIGCHLD signal handler > > does. > > The point of this is to not reap until you have to; the default > case will be no reaping necessary, so you are adding overhead > unnecessarily by atttempting to reap non-existant children. As you see, OpenBSD has (a) *and* (b). > > NetBSD: > > > > a) waitpid(2) for a child right after fork/exec, > > b) examine "status" and print an exit code. > > > > As you see, NetBSD newsyslog serializes fork/exec and there is only > > one gzip process at the same moment. We can take this way but IMHO it > > will be a POLA violation. [ NetBSD approach arguments ] > There are arguments for both approaches, but if you want to > wait for the operation to complete, the OpenBSD approach is > better than a reap-loop. Again, OpenBSD has a reap loop. [...] -- Maxim Konovalov, MAcomnet, Internet Dept., system engineer phone: +7 (095) 796-9079, mailto:[EMAIL PROTECTED] To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-current" in the body of the message
