[Paraview] vtkSocket bugs

[David Partyka]

Humm, I forgot all about this email. I'll stick it in right now for 3.10.2.
If you don't mind please file a bug so that it isn't forgotten.

On Wed, Apr 13, 2011 at 2:17 PM, Burlen Loring <bloring at lbl.gov> wrote:

>  Hi Dave,
>
> What is the status on this?
>
> Burlen
>
>
> On 02/27/2011 02:53 PM, David Partyka wrote:
>
> Thanks Burlen, We'll take a look.
>
> On Sun, Feb 27, 2011 at 5:18 PM, Burlen Loring <bloring at lbl.gov> wrote:
>
>> Hi,
>>
>> While installing ParaView on Nautilus,
>> http://www.nics.tennessee.edu/computing-resources/nautilus, I hit a bug
>> in vtkSocket that prevents ParaView from running on this machine. While
>> tracking this down I uncovered a couple related issues.
>>
>> The main issue is that vtkSocket does not handle EINTR. EINTR occurs when
>> a signal is caught by the application during a blocking socket call. While
>> ParaView does not make use of signals they are used for asynchronous
>> communication by some SGI specific libraries on Nautilus that are linked in
>> with SGI MPI. Because Rank 0 pvserver spends quite a bit of its time blocked
>> in socket calls it only takes a few 10s of seconds for EINTR to occur. When
>> faced with EINTR ParaView silently exits leaving the user wondering what the
>> heck happened. Which brings me to the second issue, a lack of error
>> reporting in vtkSocket.
>>
>> To solve the first issue vtkSocket has to handle EINTR. How EINTR should
>> be handled depends on the specific socket call. For all calls except connect
>> the call can simply be restarted. For EINTR during connect one can't restart
>> the call on all unix, so instead one must block in a select call when
>> connect fails with EINTR. To be portable across Unix one should handle EINTR
>> in all socket calls, even simple ones like set/getsockopt.
>>
>> The second issue of error reporting applies to all socket related errors
>> in general, my feeling is that when a socket call fails vtkSocket should
>> print a message using vtkErrorMacro, errno, and strerror(or windows
>> equivalent) at the point of failure. I think this should be done inside
>> vtkSocket because this is the only place one can safely assume errno has
>> relevant information and vtkSocket has been implemented returning a single
>> error code, -1, so that returning the real error code would change the API
>> and break existing code, including ParaView. Not to mention that the values
>> for error codes are apparently different on windows and unix.
>>
>> I took a stab at fixing these issues, patches attached. I tested them on
>> my workstation, nautilus, and laptop running xp. I ran a dashboard on my
>> linux workstation and didn't see any related issues. Would someone at KW
>> mind taking a look at the changes and see if it could be made permanent?
>>
>> By the way after testing all socket calls for error returns I uncovered a
>> third bug, vtkSocket::Close didn't set the descriptor ivar to -1 which
>> resulted in vtkSocket::~vtkSocket calling close on a closed socket. Not a
>> disasterous error, but this reinforces my opinion that the returns should be
>> tested and error messages printed.
>>
>> Thanks
>>  Burlen
>>
>>
>>
>>
>>
>>
>>
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