[33042] in Perl-Users-Digest
Perl-Users Digest, Issue: 4318 Volume: 11
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Fri Nov 28 09:09:17 2014
Date: Fri, 28 Nov 2014 06:09:03 -0800 (PST)
From: Perl-Users Digest <Perl-Users-Request@ruby.OCE.ORST.EDU>
To: Perl-Users@ruby.OCE.ORST.EDU (Perl-Users Digest)
Perl-Users Digest Fri, 28 Nov 2014 Volume: 11 Number: 4318
Today's topics:
Re: [Q] How does a sub know it is called during compila <bauhaus@futureapps.invalid>
Re: answers sackyhack@yahoo.com.au
Re: answers <rweikusat@mobileactivedefense.com>
half-blocking sockets <luca_remove@alice.it>
Re: half-blocking sockets <gravitalsun@hotmail.foo>
Re: half-blocking sockets <whynot@pozharski.name>
Re: half-blocking sockets <gamo@telecable.es>
Sockets. Threads, Demons...confused. <luca_remove@alice.it>
Re: Sockets. Threads, Demons...confused. <news@todbe.com>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Wed, 26 Nov 2014 16:06:14 +0100
From: "G.B." <bauhaus@futureapps.invalid>
Subject: Re: [Q] How does a sub know it is called during compilation?
Message-Id: <m54q8n$vla$1@dont-email.me>
On 25.11.14 15:22, Peter Makholm wrote:
> "G.B." <bauhaus@futureapps.invalid> writes:
>
>> As first approximation, I am trying the following sub:
>>
>> sub is_BEGIN_in_caller
>> {
>
> Since Perl 5.14.0 there is a ${^GLOBAL_PHASE}
Thanks to all for the suggestions. Unfortunately, I'm stuck
with Perl 5.10.0. But I'll tweak a test installation for
trying solutions in all cases I can think of, injecting errors
and finding the elephant in Africa mathematically.
------------------------------
Date: Wed, 26 Nov 2014 04:17:48 -0800 (PST)
From: sackyhack@yahoo.com.au
Subject: Re: answers
Message-Id: <3069b326-4b37-41c9-ae2b-a5ca6f99f6d6@googlegroups.com>
deez posts are like really old yo. lolz
------------------------------
Date: Wed, 26 Nov 2014 14:53:10 +0000
From: Rainer Weikusat <rweikusat@mobileactivedefense.com>
Subject: Re: answers
Message-Id: <87a93e6mjt.fsf@doppelsaurus.mobileactivedefense.com>
sackyhack@yahoo.com.au writes:
> deez posts are like really old yo. lolz
It's more that you're stuck in the past.
------------------------------
Date: Wed, 26 Nov 2014 16:01:35 -0500
From: Luca <luca_remove@alice.it>
Subject: half-blocking sockets
Message-Id: <Qcrdw.718130$Ub6.714083@fx20.iad>
Is there a way for me to look at the $clientdata object and understand
if a non-blocking socket has produced some value or not?
$socket = new IO::Socket::INET (
LocalHost => '127.0.0.1',
LocalPort => '1055',
Proto => 'tcp',
Listen => 1,
Reuse => 1,
# Blocking => 1
) or die "Oops: $@ \n";
print "Waiting for the Client.\n";
$clientsocket = $socket->accept();
while (1) {
while ($clientdata = <$clientsocket>;) {
#print Dumper($clientdata);
if ($clientdata) {...}
Thanks
------------------------------
Date: Thu, 27 Nov 2014 00:58:52 +0200
From: George Mpouras <gravitalsun@hotmail.foo>
Subject: Re: half-blocking sockets
Message-Id: <m55lvl$2qa4$1@news.ntua.gr>
On 26/11/2014 23:01, Luca wrote:
>
> Is there a way for me to look at the $clientdata object and understand
> if a non-blocking socket has produced some value or not?
>
> $socket = new IO::Socket::INET (
> LocalHost => '127.0.0.1',
> LocalPort => '1055',
> Proto => 'tcp',
> Listen => 1,
> Reuse => 1,
> # Blocking => 1
> ) or die "Oops: $@ \n";
>
> print "Waiting for the Client.\n";
>
> $clientsocket = $socket->accept();
>
> while (1) {
>
> while ($clientdata = <$clientsocket>;) {
>
> #print Dumper($clientdata);
> if ($clientdata) {...}
>
> Thanks
if you read the $clientdata then you have a value from the socket!
your while loop is blocking.
by the way have a look at the module Net-Server
------------------------------
Date: Thu, 27 Nov 2014 09:28:04 +0200
From: Eric Pozharski <whynot@pozharski.name>
Subject: Re: half-blocking sockets
Message-Id: <slrnm7dkk4.bri.whynot@orphan.zombinet>
with <Qcrdw.718130$Ub6.714083@fx20.iad> Luca wrote:
> Is there a way for me to look at the $clientdata object and understand
> if a non-blocking socket has produced some value or not?
Yes. Its name is select(2). Perl has IO::Select readily available.
p.s. Also:
perldoc perlipc
You might appreciate it.
*CUT*
--
Torvalds' goal for Linux is very simple: World Domination
Stallman's goal for GNU is even simpler: Freedom
------------------------------
Date: Thu, 27 Nov 2014 22:58:11 +0100
From: gamo <gamo@telecable.es>
Subject: Re: half-blocking sockets
Message-Id: <m586pf$h6d$1@speranza.aioe.org>
El 26/11/14 a las 22:01, Luca escribió:
>
> Is there a way for me to look at the $clientdata object and understand
> if a non-blocking socket has produced some value or not?
>
Multitasking servers are covered in Chapter 16 of the Camel book.
Sorry, I have at hand only the second edition.
HTH
--
http://www.telecable.es/personales/gamo/
------------------------------
Date: Wed, 26 Nov 2014 10:10:22 -0500
From: Luca <luca_remove@alice.it>
Subject: Sockets. Threads, Demons...confused.
Message-Id: <y3mdw.9245$Mq4.4212@fx25.iad>
Hi, I used to program Perl many years ago (and the fact that it was Perl
4 isn't helping particularly :).
I am writing the spec for a Unix Demon process and a corresponding CLI
utility to interact with it. The tool will be implemented in C/C++, but
I wanted to impress the engineering team with a fully working proof of
concept in Perl. Things are not so simple as I was assuming, though. A
few hours of hacking later, I am sort of stuck with issues that could
probably greatly benefit from feedback from those who have specific
experience in the field.
The Client will send in-band directives and the data through a TCP
socket to the server. The server will respond with processed data (and
in-band directives) though the same socket. The two programs often get
stuck waiting for one another to send content down the pipe.
Questions:
- My server.pl is using this code to await data and directives:
while (1) {
$clientsocket = $socket->accept();
while ($clientdata = <$clientsocket>) {
:
Is there a way to tell the system to do something else if no data is coming?
- Would it make sense to spawn sub-processes to handle each connecting
client? What's the best way to achieve it? Proc::Daemon? should I look
into threads?
Will I need to pass a reference to the socket to each sub-process/thread?
- Since the in-band directives effectively implement a protocol, I'll
probably need to manage the state of both client and server at all
times, to avoid that the two process get stuck waiting on one another.
Is there a Perl module that helps with that?
I know this is a lot of stuff. Thanks in advance to those who can share
their advice/experience...
------------------------------
Date: Wed, 26 Nov 2014 22:14:45 -0800
From: "$Bill" <news@todbe.com>
Subject: Re: Sockets. Threads, Demons...confused.
Message-Id: <m56fgj$ott$1@dont-email.me>
On 11/26/2014 07:10, Luca wrote:
>
> Hi, I used to program Perl many years ago (and the fact that it was Perl 4 isn't helping particularly :).
>
> I am writing the spec for a Unix Demon process and a corresponding CLI utility to interact with it. The tool will be implemented in C/C++, but I wanted to impress the engineering team with a fully working proof of concept in Perl. Things are not so simple as I was assuming, though. A few hours of hacking later, I am sort of stuck with issues that could probably greatly benefit from feedback from those who have specific experience in the field.
> The Client will send in-band directives and the data through a TCP socket to the server. The server will respond with processed data (and in-band directives) though the same socket. The two programs often get stuck waiting for one another to send content down the pipe.
>
> Questions:
>
> - My server.pl is using this code to await data and directives:
>
> while (1) {
> $clientsocket = $socket->accept();
> while ($clientdata = <$clientsocket>) {
> :
>
> Is there a way to tell the system to do something else if no data is coming?
>
> - Would it make sense to spawn sub-processes to handle each connecting client? What's the best way to achieve it? Proc::Daemon? should I look into threads?
> Will I need to pass a reference to the socket to each sub-process/thread?
open/listen/accept/IO::select/IO::can_read are all your friends. Since you appear to be on
UNIX, I would think it would be a good idea to fork/exec off a process to handle the
transaction unless it just requires a simple response.
Check perlipc man page for additional insight or code for a simple server that someone
has already written for UNIX.
------------------------------
Date: 6 Apr 2001 21:33:47 GMT (Last modified)
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Subject: Digest Administrivia (Last modified: 6 Apr 01)
Message-Id: <null>
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End of Perl-Users Digest V11 Issue 4318
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