how to use AnyEvent::Handle on the child of AnyEvent::Run (aka portable_socketpair)?

[Fulko Hew]

On Tue, Nov 19, 2013 at 8:16 PM, Andrew Whatson <whatson at gmail.com> wrote:

> Anywhere before "first send to child" should work.  Without this, I
> see the following output sometimes:
>
>   parent rx: child timer
>   parent tx
>   parent rx: child timer
>   child rx: sent to child
>
> The "child timer\n" and "child rx: sent to child\n" messages are being
> received together, due to output buffering in the child process.
> Turning on autoflush forces the process to send each line separately.
>
> I hope this is the problem you're seeing - if not, please explain the
> problem in more detail.
>

I don't think its the same problem.
With or without the autoflush, I see the same results:

parent tx first send
parent rx: child started
parent rx: child timer
parent tx
parent rx: child timer
parent rx: child timer
parent tx

I think its a problem on the receiving end because if I change
the receiver to the code below (without the autoflush),
just to test the 'echo' part (without the child timer async sender)
the child _does_ receive and transmit.

sub child_proc {
    while (1) {
        chomp (my $d = <STDIN>);
        print STDERR "child rx: $d\n";;
        send_msg_to_parent("echoing...$d");
        sleep 1;
    }
}


On 20 November 2013 10:40, Fulko Hew <fulko.hew at gmail.com> wrote:
> On Tue, Nov 19, 2013 at 7:16 PM, Andrew Whatson <whatson at gmail.com> wrote:
>>
>> Hi Fulko,
>>
>> I think you need to turn on autoflush on STDOUT.  After putting $|=1,
>
> Where did you put it, because no mater what I do,
> it doesn't make a difference for me.
>>
>> I get the following output which seems correct:
>>
>> parent tx 'first send'
>> parent rx: child started
>> parent rx: child rx: first send to child
>>
>> parent rx: child timer
>> parent tx
>> parent rx: child rx: sent to child
>>
>> parent rx: child timer
>> parent tx
>> parent rx: child timer
>> parent rx: child rx: sent to child
>>
>> parent rx: child timer
>> parent tx
>> parent rx: child rx: sent to child
>>
>> Regards,
>> Andrew Whatson
>>
>> On 20 November 2013 06:03, Fulko Hew <fulko.hew at gmail.com> wrote:
>> > I'm trying to use AnyEvent:Run, but I need to make my child smarter.
>> > and make it an AnyEvent style process that uses 'event driven I/O'.
>> > But I can't seem to get anywhere, and I'm obviously missing...
>> > something.
>> >
>> > I'm attempting the test example below.
>> >
>> > What I see is the child successfully sending and the parent receiving.
>> > But I'm not getting the parent-to-child pat,  and I don't know if its a
>> > problem in parent or in the child, or I'm just doing it wrong.
>> >
>> > use strict;
>> > use warnings;
>> > use Socket;
>> > use AnyEvent;
>> > use AnyEvent::Run;
>> > use AnyEvent::Handle;
>> >
>> > sub send_msg_to_parent { print "$_[0]\n"; }
>> >
>> > sub child_proc {
>> >     my $child_hdl = new AnyEvent::Handle (
>> >         fh  => \*STDIN,
>> >         on_read => sub {
>> >                        my $hdl = shift;
>> >                        my $d = $hdl->{rbuf};
>> >                        $hdl->{rbuf} = '';
>> >                        send_msg_to_parent("child rx: $d");
>> >                        },
>> >     );
>> >     my $child_timer = AnyEvent->timer (  # send a watchdog msg
>> >         after       => 2,
>> >         interval    => 2,
>> >         cb          => sub {send_msg_to_parent("child timer"),
>> >     );
>> >     send_msg_to_parent("child started");
>> >     my $child_cv = AnyEvent->condvar;
>> >     $child_cv->wait;
>> > }
>> >
>> >
>> > my $child = AnyEvent::Run->new(
>> >     cmd     => sub { child_proc() },
>> >     on_read => sub {
>> >                    my $hdl = shift;
>> >                    my $d = $hdl->{rbuf};
>> >                    $hdl->{rbuf} = '';
>> >                    print "parent rx: $d";
>> >                    },
>> >     on_error    => sub { print "child died\n"; },
>> > );
>> > my $parent_timer = AnyEvent->timer (
>> >     after       => 3,
>> >     interval    => 3,
>> >     cb          => sub { $child->push_write("sent to child\n"); print
>> > "parent tx\n";},
>> > );
>> > $child->push_write("first send to child\n"); print "parent tx 'first
>> > send'\n";
>> > my $cv = AnyEvent->condvar;
>> > $cv->wait;
>> >
>> >
>> > _______________________________________________
>> > anyevent mailing list
>> > anyevent at lists.schmorp.de
>> > http://lists.schmorp.de/mailman/listinfo/anyevent
>
>
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