Re: Crash noticed multiple times using libssh 0.3.4

[Vic Lee <llyzs@xxxxxxx>]

Hi,

Personally, I would consider libssh is "thread-aware" or "partially
thread-safe", but not completely thread-safe. When we say something is
thread-safe it's supposed to be able to access the same object in
different threads at the same time and the object locks resources
automatically.

But I much more prefer libssh to work as it currently is, because it's a
library and better to avoid having more dependency.

One thread-safe example should be glib - it provides its own locking but
has to link to pthread or gth, which is not what I want. It shouldn't be
a big deal for the application to use its own lock.

Vic

On Sat, 2010-01-16 at 09:43 +0100, Guido Moonen wrote:
> Hi All,
> 
> I have a similar problem on 0.4.0 windows build, but only in the 
> ssh_connect function, solved it by using a mutex around the ssh_connect 
> call. haven't seen any other threading issues.
> 
> With kind regards,
>   Guido
> 
> Uday Tennety wrote:
> > Hello,
> > In our development environment, we noticed that some error in libssh 
> > library resulted in crashing our application server. We saw this issue 
> > a few times. Our scenario is:
> > We are using libssh 0.3.4 and noticed the crash when our libssh client 
> > was trying to connect to multiple ssh servers running on various 
> > network elements. Before we dive deep into the code, I wanted to find 
> > out if there is a known threading issue in 0.3.4 with a libssh client 
> > trying to connect to multiple ssh servers?  Also, it would really help 
> > if someone can point me in the right direction looking at the error. I 
> > really appreciate your time and help.
> >
> > Thanks,
> > Uday.
> >
> >
> >
> > Sample Error:
> > -------------
> >
> > [func]              leaving function ssh_disconnect line 690 in 
> > /home/public/temp/libssh-0.3.4/libssh/client.c
> > [func]             entering function ssh_cleanup line 91 in 
> > /home/public/temp/libssh-0.3.4/libssh/session.c
> > [func]              entering function channel_free line 724 in 
> > /home/public/temp/libssh-0.3.4/libssh/channels.c
> > [func]              leaving function channel_free line 755 in 
> > /home/public/temp/libssh-0.3.4/libssh/channels.c
> > Current time:Fri Jan 15 16:10:29 PST 2010
> > Remote host is 10.2.32.95 and remote port is 22[func] entering 
> > function ssh_connect line 489 in 
> > /home/public/temp/libssh-0.3.4/libssh/client.c
> > [func]  entering function ssh_connect_host line 184 in 
> > /home/public/temp/libssh-0.3.4/libssh/connect.c
> > [func]  leaving function ssh_connect_host line 249 in 
> > /home/public/temp/libssh-0.3.4/libssh/connect.c
> > [func] leaving function ssh_connect_host line 258 in 
> > /home/public/temp/libssh-0.3.4/libssh/connect.c
> > #
> > # A fatal error has been detected by the Java Runtime Environment:
> > #
> > #  SIGSEGV (0xb) at pc=0xff351040, pid=5438, tid=149
> > #
> > # JRE version: 6.0_16-b01
> > # Java VM: Java HotSpot(TM) Server VM (14.2-b01 mixed mode 
> > solaris-sparc )
> > # Problematic frame:
> > # C  [libc_psr.so.1+0x1040]  memset+0x140
> > #
> > # An error report file with more information is saved as:
> > # /home/IEM/Repository/hs_err_pid5438.log
> > #
> > # If you would like to submit a bug report, please visit:
> > #   http://java.sun.com/webapps/bugreport/crash.jsp
> 
>