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Re: libCurl 7.16.3: Are there any problems known for timeouts set with CURLOPT_TIMEOUT ?

From: Stefan Krause <>
Date: Wed, 09 Apr 2008 20:47:03 +0200

>>> I have observed one case, where I set 2 minutes timeout and it
>>> expired after exactly 9 minutes.
>> Wow! Very strange behavior.
>>> Does anybody have a clue what might be the reson for such a
>>> behaviour or under what conditions that may happen. ?
>>> Is the 9 minutes timeout a special timeout internally defined by
>>> libCurl?
>> No, there's no special 9 minutes timeout and it is expected to use
>> the set timeout and nothing else.
> Some further tests regarding the issue were made and here are the
> findings so far.
> The effect with the 9 minutes timeout instead of the configured 2
> minutes timeout appearead reproducible in case
> a) HTTPS (and therefore SSL) is used and
> b) In case the physical layer of the network connection is removed by
> hand (e.g. remove the antenna in our case; a wireless connection is
> used) _during_ the SSL handshake phase.
> The libCurl debug function prints out the following information: "SSL
> connection timeout" after 9 minutes.
> I have not dived into the problem further until know. So, here are my
> conclusions / questions:
> 1) Is the configured easy handle timeout of 2 minutes also relevant
> for the OpenSSL library, or does OpenSSL has its own timeouts for the
> handshake phase, which are not under control of libCurl?
> 2) I looked for the "SSL connection timeout" string and found it in
> the file ssluse.c. Do you have a clue what is going wrong at the
> respective places ? I'll try to debug the issue on QNX or Win32. Can
> you give me your thoughts of what might goes wrong here and were to
> look best in order to track the problem down ?
> Used OS is QNX 6.3.2 and libcurl 7.16.3 is used. OpenSSL is 0.9.8e (I
> am not quite sure about the minor number at the moment)

I forgot to add something:
I found a similar problem description here:

Unfortunately the thread does not contain solution for the problem,
maybe it still exists. Up to now I didn't try it with the latest libcurl
7.18.1. The changelog does not mention any bugfix for that particular
problem (not under the term "ssl connection timeout" or similar). Maybe
it still exists.
Received on 2008-04-09