Re: Memory leaks are observed for libgnutls in multi-thread mode

[Nikos Mavrogiannopoulos]

tangtong wrote:
> Hi,Nikos and Simon
> 
> To verify the issue, I have configured my server to run as signle thread 
> mode. Under high TPS, the memory leak still happen in gnutls_handshake, which 
> means the root-cause is not caused by multi-thread. 
> 
> By more logs and analysis, I have the following findings:
> Under high TPS, my server can't serve every session timely, which leads to 
> the closure of the sockets by the clients for timeout reason. The write 
> operation on the server side of the corresponding socket leads to broken pipe 
> error. gnutls_handshake() reports GNUTLS_E_PUSH_ERROR, -53. As a result, the 
> hand-shake stage of tls session is not finished successfully. 
> 
> After repeated testing, It is evident when aborted tls session caused by 
> error -53 are observed, the memory leak happen. 
> 
> I have double check my codes, for these aborted session, I have called the 
> gnutls_bye()/gnutls_deinit() function.
> 
> My assumption now is for those session which has unfinished hand-shake stage, 
> the resourses are not released properly in gnutls_handshake() for some reason.

Could you for this (memory leak) scenario to send us debugging output of
gnutls? To do that just add a logging function such as:

static void
tls_log_func (int level, const char *str)
{
  fprintf (stderr, "|<%d>| %s", level, str);
}

and call those after initialization of gnutls.
  gnutls_global_set_log_function (tls_log_func);
  gnutls_global_set_log_level (2);


regards,
Nikos