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Subject: Re: [boost] [asio] Randomly having problems reading from the socket
From: Torben Wiggerich (torben.wiggerich_at_[hidden])
Date: 2011-05-09 04:01:50

Am 05.05.2011 16:30, schrieb Cliff Green:
> The symptoms you describe, based on the code you included in your
> first e-mail, seems to point to a simple and straightforward problem -
> you're running into TCP flow control blockage. This is a traditional
> TCP problem and is not directly related to Asio.
> Anytime you're sending data as fast as possible, and the receiving
> side is just slightly slower at receiving the data, send buffers in
> the OS will fill up. Eventually this will result in the send being
> blocked for a short period of time while the receiving side processes
> the data. If you're using blocking writes, the send will block for a
> period of time. If you're using async writes, the write completion
> handler will take longer before it is called (which is why I greatly
> prefer async operations all around).
> That the problem is transitory and takes a while to manifest is
> another clue - it depends totally on how fast the sending and
> receiving applications are running, and if there's a short period on
> the receiving side where the app can't run as fast (e.g. another app
> takes up some processing time), the blockage will be transitory.
> Cliff

Thanks for your answer and Sorry for my late response...

So I will give the asynchronous connection a try ...

If I understand you correct, just the sender should be blocked for a
time. You say that it is because the buffers are running full. Is there
a method to detect if the buffers are full, so that I should stop
sending new packets? It would be ok if it stops for a few milliseconds,
but not for a such long time like 5 seconds...
But I also don't understand how both sides can stop receiving and
sending data for 5 seconds at the same time...

On the other hand the application where I observed this error didn't
produce so frequently network traffic at all. It produces this packages
only with 25 Hz...

Kind regards

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