Re: Listening without forking

I've heard before that the Event module is the way to go... I've not played with it, but I have tried out IO::Select, and it seemed worthy.

IO::Select runs as an event loop blocking on the select() command until any specified handly (typically any read handle) handles become 'active' by having data available. you can perform non-blocking reads with this quite well, so the only time the server is blocking is when nothing is happening, or when it is actively getting data from a buffer, which is a fast operation.

needless to say this causes other intereseting problems in coding, like dealing with data when it is more likely than not incomplete from the non-blocking read... but things like timeouts should be much less of a problem.

Comment on Re: Listening without forking

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Re: Re: Listening without forking by zengargoyle (Deacon) on Feb 24, 2002 at 02:11 UTC
In the Event Tutorial (maybe POD doc) there was mention of the blocking problem, recommendation was IPC::LDT or similar. Use messages that include the total length at the beginning of the message. `read SOCK, $len_raw, 4; $len = unpack 'N', $len_raw; read SOCK, $msg, $len; and $len = length $msg; $len_raw = pack 'N', $len; write SOCK, $len_raw, 4; write SOCK, $msg, $len; or write SOCK, "$len_raw$msg", $len+4;` [download] Something like that should handle the simple cases.	[reply] [d/l]

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Re: Re: Listening without forking
by zengargoyle (Deacon) on Feb 24, 2002 at 02:11 UTC

In the Event Tutorial (maybe POD doc) there was mention of the blocking problem, recommendation was IPC::LDT or similar. Use messages that include the total length at the beginning of the message.

read SOCK, $len_raw, 4;
$len = unpack 'N', $len_raw;
read SOCK, $msg, $len;

and

$len = length $msg;
$len_raw = pack 'N', $len;
write SOCK, $len_raw, 4;
write SOCK, $msg, $len;

or

write SOCK, "$len_raw$msg", $len+4;
[download]

Something like that should handle the simple cases.

[reply]
[d/l]