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Simo
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 Posted: Fri Feb 20, 2004 6:09 am Post subject: TCP Server / DataArrival |
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I am using D7 PE, Indy 9.00.10.
and am programing TCP stream server application with TIdTCPServer component.
I have a question about it.
How can I detect the data arrival from the client after session connected?
the program can process first data in OnExecute event.
However, next event did not happen.
I'd like to do the data communication and keeping the session.
I need like a DataArrival event of VB.
something mistake?
-
Simo
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Remy Lebeau (TeamB)
Guest
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| Posted: Fri Feb 20, 2004 6:46 am Post subject: Re: TCP Server / DataArrival |
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"Simo" <simo (AT) ict-osaka (DOT) com> wrote
| Quote: | How can I detect the data arrival from the client after session connected?
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You don't "detect" it, you wait for it. Indy is not an asynchronous
library. When you perform a read or write operation, it blocks until it
finishes, or an error occurs. Simply call one of the Read...() methods of
the Connection, and when data eventually arrives, it will be read.
| Quote: | the program can process first data in OnExecute event.
However, next event did not happen.
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Please show your actual code. You are probably not using it properly.
OnExecute is triggered in a loop for the lifetime of the connection. It is
not possible for it to not be triggered, unless you are blocking its thread
somehow.
Gambit
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Simo
Guest
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| Posted: Fri Feb 20, 2004 6:59 am Post subject: Re: TCP Server / DataArrival |
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Thank you for your quick reply.
| Quote: | You don't "detect" it, you wait for it. Indy is not an asynchronous
library. When you perform a read or write operation, it blocks until it
finishes, or an error occurs. Simply call one of the Read...() methods of
the Connection, and when data eventually arrives, it will be read.
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I see.
| Quote: | the program can process first data in OnExecute event.
However, next event did not happen.
Please show your actual code. You are probably not using it properly.
OnExecute is triggered in a loop for the lifetime of the connection. It
is
not possible for it to not be triggered, unless you are blocking its
thread
somehow.
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my description was not enough.
exactly, when the client connected to server, the client was sending a
first data.
well, which component is better to use the asynchronous commnication of
TCP/IP
binary mode?
Regards.
---
Simo.
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Lee_Nover
Guest
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| Posted: Fri Feb 20, 2004 8:02 am Post subject: Re: TCP Server / DataArrival |
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then read the data in the server's OnConnect event
Read will block until data is available for reading
"Simo" <simo (AT) amy (DOT) hi-ho.ne.jp> wrote
| Quote: | Thank you for your quick reply.
You don't "detect" it, you wait for it. Indy is not an asynchronous
library. When you perform a read or write operation, it blocks until it
finishes, or an error occurs. Simply call one of the Read...() methods
of
the Connection, and when data eventually arrives, it will be read.
I see.
the program can process first data in OnExecute event.
However, next event did not happen.
Please show your actual code. You are probably not using it properly.
OnExecute is triggered in a loop for the lifetime of the connection. It
is
not possible for it to not be triggered, unless you are blocking its
thread
somehow.
my description was not enough.
exactly, when the client connected to server, the client was sending a
first data.
well, which component is better to use the asynchronous commnication of
TCP/IP
binary mode?
Regards.
---
Simo.
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Martin James
Guest
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| Posted: Fri Feb 20, 2004 10:47 am Post subject: Re: TCP Server / DataArrival |
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| Quote: | the program can process first data in OnExecute event.
However, next event did not happen.
Please show your actual code. You are probably not using it properly.
OnExecute is triggered in a loop for the lifetime of the connection. It
is
not possible for it to not be triggered, unless you are blocking its
thread
somehow.
my description was not enough.
exactly, when the client connected to server, the client was sending a
first data.
|
Fine - the read call in onExecute will then return with the data received
from the client. Handle it, do whatever it is you do with client data, exit
the onExecute handler - it will be called again so it can read the next
chunk of data from the client.
| Quote: | well, which component is better to use the asynchronous commnication of
TCP/IP
binary mode?
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It's no problem to perform, say, writes, while waiting for a read to return,
you just need to write from another thread. The 'nornal' app events are
fired in the main thread, so, looking at the app as a whole, Indy *is*
asynchronous.
You can, with a little more coding and a 'synchronize' or 'postMessage' or
two, make Indy fire events in the main thread like VB, but for many apps
this is just not neccessary and defeats the simplicity of the Indy
'thread-per-client' design that makes handling multiple clients easy.
If you have to have main-thread events, look at ICS, (Google for it). ICS
is very good if you just have to have an 'asynchronous' component set for
some reason. With such components will come all the awkwardness, latency &
poor responsiveness you get with VB, eg any waits or I/O delays will affect
*all* clients and the GUI, not just the client requesting the wait. Get
reday with your 'hourglass' cursor...
Rgds,
Martin
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Eric Jansen
Guest
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| Posted: Fri Feb 20, 2004 12:13 pm Post subject: Re: TCP Server / DataArrival |
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"Simo" <simo (AT) amy (DOT) hi-ho.ne.jp> schreef in bericht
news:4035b0af$1 (AT) newsgroups (DOT) borland.com...
| Quote: | well, which component is better to use the asynchronous commnication of
TCP/IP
binary mode?
|
I have written a data pump last year (one to many data distributor) in a
single-threaded service, using non-blocking sockets, with the TSocketserver
component. This was the standard Borland component (source included) which
came with D5, before Indy was incorporated in Delphi. I don't know if it is
still there in D7, but I have had very little problems with it. The only
thing I changed in the component (which was easy, because the source was
included) was the connection backlog setting (it was always SOMAXCONN=5).
The service is now in production, feeding about 80 clients now with a
datastream of 2-5 kbyte/s per client. I have stress tested it with 250
clients without any problems.
If the component is no longer there, you might also try the ICS
socketserver. I haven't used it, but I have excellent experiences with the
non-blocking ICS client components (HTTP and FTP).
hth,
Eric Jansen
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Remy Lebeau (TeamB)
Guest
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| Posted: Fri Feb 20, 2004 9:07 pm Post subject: Re: TCP Server / DataArrival |
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"Simo" <simo (AT) amy (DOT) hi-ho.ne.jp> wrote
| Quote: | exactly, when the client connected to server, the client was sending
a first data.
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That is perfectly fine. The OnExeute event will catch that.
| Quote: | well, which component is better to use the asynchronous commnication
of TCP/IP binary mode?
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There is nothing wrong with continuing to use Indy for this. That is why I
asked you to please show your actual code, because you are probably just
mis-using it.
Gambit
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