Hello again, Daniel,

I was asked to emphasize the fact that we use several threads, and each
thread has its own multi-handle. So we are doing multi-threaded transfers,
while each thread operates on its own multi-handle. Does such usage require
providing these SSL callbacks?

Thanks,
Alex.

-----Original Message-----
From: Alex Lyakas
Sent: Thursday, April 14, 2016 2:40 PM
To: Daniel Stenberg
Cc: libcurl hacking ; Yaron Presente
Subject: Re: libcurl segfaults in curl_multi_perform

Hello Daniel,

We have found out that we did not provide the "locking_function" and the
"threadid_func" to openSSL (and we are using https), as showin in
https://curl.haxx.se/libcurl/c/threaded-ssl.html.
Could this explain these crashes that we see from time to time? We are using
curl_multi_perform/curl_multi_wait and each multi-handle is accessed by a
single thread only.

Thanks,
Alex.

-----Original Message-----
From: Daniel Stenberg
Sent: Thursday, March 24, 2016 1:50 PM
To: Alex Lyakas
Cc: libcurl hacking
Subject: Re: libcurl segfaults in curl_multi_perform

On Thu, 24 Mar 2016, Alex Lyakas wrote:

> We upgraded the libcurl to 7.45.0. After several weeks, the same or very
> similar problem happened 3 times within 24 hours, unfortunately.

Did you upgrade OpenSSL? It looks more like a problem in OpenSSL so I
suspect
just upgrading libcurl won't help for this.

Further, if the problem remains I think you should consider building custom
versions of libcurl and openssl with debug systems present so that future
crashes get more details provided. I'd also urge you to try to come up with
a
way to reproduce the problem since just randomly occuring crashes are
notoriously hard to work with.

-- 
  / daniel.haxx.se
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