12-19-2016
Quote:
Originally Posted by
SirSalt
Alright, thank you for clarifying that
---------- Post updated 12-18-16 at 09:20 PM ---------- Previous update was 12-17-16 at 10:28 PM ----------
As I meditated on what you said, I thought of something. In your #3 explanation, would the tty be process "A"? Or would the tty in your example be process "B"? I guess I have a slight and subtle confusion about using "fork" and "forked" in the verb context. When you said "You actually forked a child ("B")", was forking the child a result of calling fork() in process "A", or calling fork() in process "B"? I hope you can see what I'm getting at here. :P
In #3, A calls
fork(). At that point you have processes A and B. Then B calls
fork(). At that point you have processes A, B, and C all running the same instructions. Then B calls
exit() leaving you with processes A and C running. Then C calls
execl() (or another function from the
exec family) to replace the instructions C was running with the instructions needed to run the daemon. At that point you then have A running the code it was running and you have C running your daemon.
Note that since C was a child of B and B exited, A cannot use
wait() to determine whether or not C is still running and cannot retrieve the exit status of C using
wait(). (Grandparents do not become the parents of their children's orphaned children when their children die before their grandchildren.)
This User Gave Thanks to Don Cragun For This Post:
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LEARN ABOUT SUSE
net::server::fork
Net::Server::Fork(3) User Contributed Perl Documentation Net::Server::Fork(3)
NAME
Net::Server::Fork - Net::Server personality
SYNOPSIS
use Net::Server::Fork;
@ISA = qw(Net::Server::Fork);
sub process_request {
#...code...
}
__PACKAGE__->run();
DESCRIPTION
Please read the pod on Net::Server first. This module is a personality, or extension, or sub class, of the Net::Server module.
This personality binds to one or more ports and then waits for a client connection. When a connection is received, the server forks a
child. The child handles the request and then closes.
With the exception of parent/child signaling, this module will work (with basic functionality) on Win32 systems.
ARGUMENTS
check_for_dead
Number of seconds to wait before looking for dead children. This only takes place if the maximum number of child processes
(max_servers) has been reached. Default is 60 seconds.
max_servers
The maximum number of children to fork. The server will not accept connections until there are free children. Default is 256 children.
max_dequeue
The maximum number of dequeue processes to start. If a value of zero or undef is given, no dequeue processes will be started. The
number of running dequeue processes will be checked by the check_for_dead variable.
check_for_dequeue
Seconds to wait before forking off a dequeue process. It is intended to use the dequeue process to take care of items such as mail
queues. If a value of undef is given, no dequeue processes will be started.
CONFIGURATION FILE
See Net::Server.
PROCESS FLOW
Process flow follows Net::Server until the post_accept phase. At this point a child is forked. The parent is immediately able to wait for
another request. The child handles the request and then exits.
HOOKS
The Fork server has the following hooks in addition to the hooks provided by the Net::Server base class. See Net::Server
"$self->pre_accept_hook()"
This hook occurs just before the accept is called.
"$self->pre_fork_hook()"
This hook occurs just after accept but before the fork.
"$self->post_accept_hook()"
This hook occurs in the child after the accept and fork.
"$self->run_dequeue()"
This hook only gets called in conjuction with the check_for_dequeue setting.
TO DO
See Net::Server
AUTHOR
Paul Seamons <paul@seamons.com>
Rob Brown <bbb@cpan.org>
SEE ALSO
Please see also Net::Server::INET, Net::Server::PreFork, Net::Server::MultiType, Net::Server::SIG Net::Server::Single
perl v5.12.1 2007-02-03 Net::Server::Fork(3)