TCPClient Losing Data

[DrZoop]

Long story short: I am misusing the TCPClient class. I am sending
400-500 byte messages, and data is being lost.

How can the TCPClient class be misused to lose data?

Background notes:
-I know the TCP protocol doesn't lose data. Don't tell me that. I am
educated.
-I am buffering all data being received before checking for messages
and reading them, so don't tell me this either. I have quite a spiffy
message system tried and proven. It's just these large chunks of data
screwing me over.
-I am using BeginRead/EndRead to receive my data.
-I am using a huge receive and send buffers, this simply can't be the
problem unless I'm misusing them.
-Changing the receive buffer does affect how long before it breaks.
However, how many bytes it takes before it breaks is inconsistent,
even with the same bytes being sent each time.
-Through tedious byte by byte comparison, it appears that "older"
bytes are being overwritten with newer, more recently received bytes.
By comparing the sent and received bytes, there is a gap of missing
bytes in the center. It's as if the buffer is too small, though, 3
megabytes for 500 bytes should be plenty of space... plus, the EndRead
function should be called anyway!
-I have read that the ReceiveTimeOut property should be set to
something else than zero to ensure no loss of data. Why is this? What
if it ran out of time and no bytes were received? Wouldn't this return
a length of zero bytes and appear to be a disconnection?
-Where it breaks is inconsistent. I can do the same login procedure
time and time again, and it will break at different places.

-Kinda unrelated: What is the State argument for in the BeginRead
function!? MSDN says you should "at the minimum pass the NetworkStream
class." One example passes the TCPClient class. Another example passes
seemingly random things (the form, a button on a toolstrip). The
example I based mine off of passed nothing/null.

Worst case scenario: can someone show me an example (I learn best by
examples honestly) that features a little program that can send and
receive using the TCPClient class many complete 400-500 byte messages?

Thanks; I'm sorry for the ugliness of this post. I lost my full,
detailed, nicely written post.

[=?Utf-8?B?QU1lcmNlcg==?=]

Long story short: I am misusing the TCPClient class. I am sending

400-500 byte messages, and data is being lost.

-I am using BeginRead/EndRead to receive my data.

Some time ago, I gave up on BeginWhatever/EndWhatever owing to, well, I
don't know exactly what, but I had troubles that would not go away. Pressed
for time, I implemented what I needed with synchronous methods and I launched
a thread to achieve asynchronous operations. In some cases, I launched one
thread per use, and in other cases, I used one persistent thread with a queue
for batching. I never looked back, and I am a happy camper.

My suggestion is to try a test that isolates the problem to Begin/End.
Would it be much work to comment out these calls and replace them with their
synchronous counterparts? Not too much work I hope. Then run a stress test
to see if you lose data. Hopefully, you will continue to lose data, and
further fault isolation should be a snap because of the simpler single thread
setting. But my guess is that your data loss problems will go away. Now you
will have good news (you have a working model and a partly isolated fault in
the original design) and bad news (you don't have the answer to your original
question). What happens next is up to you.

I suspect you may find my response unsatisfying - sorry about that. We all
get set in our ways using techniques we like and trust and avoiding others.
I neither like nor trust the begin/end .net approach to asynchronous
operations. Too complicated, too quirky, too much going on under the
covers, and that is why I responded. Good luck on what sounds like a
challenging problem.

[Jon Skeet [C# MVP]]

On Jun 28, 6:29 pm, DrZoop <DrZ...@gmail.c omwrote:

<snip>

I will copy and paste my post on another forum (I have to post in
three places minimum or else it will take ages (or forever) for me to
get help on my problem). It contains the code, super commented, along
with some further details.

<snip>

It's got lots of comments, but:
1) It contains code we should apparently ignore. It's worth getting
rid of such code.
2) It's not complete - we can't run it and see the problem.

The best way to get help - one which almost always works, in my
experience, is to post a short but *complete* program which
demonstrates the problem. This should:

1) Compile as written (preferably with no need to create a Visual
Studio project etc)
2) Only contain the necessary code (console apps tend to be simpler
than GUI apps)
3) Show what goes wrong

At that point it's much easier to reproduce the issue and help you.

See http://pobox.com/~skeet/csharp/complete.html for more information.

Jon