Comment 6 for bug 379452

On Wed, Jun 24, 2009 at 23:28, Yann Leboulanger<email address hidden> wrote:
> Damien Thébault wrote:
>> On Wed, May 27, 2009 at 07:22, Yann Leboulanger<email address hidden> wrote:
>>> Lennart Poettering wrote:
>>>> On Fri, 22.05.09 18:27, Damien Thébault (<email address hidden>) wrote:
>>>>
>>>>> On Fri, May 22, 2009 at 18:16, Damien Thébault
>>>>> <email address hidden> wrote:
>>>>>> That's right, it happens with the attached simple C code too, which is equivalent to the given python code.
>>>>>> So the problem is in the underlying libasyncns library.
>>>>>>
>>>>>> ** Attachment added: "asyncns-0.7-load.c"
>>>>>>   http://launchpadlibrarian.net/27057398/asyncns-0.7-load.c
>>>>>>
>>>>>>
>>>>>> Status in Python bindings for libasyncns: New
>>>>>>
>>>>>> Bug description:
>>>>>> Load goes high (4) when using this module. To reproduce, just open a python console, and type:
>>>>>>>>> import libasyncns
>>>>>>>>> asyncns = libasyncns.Asyncns()
>>>>>> Now in another console look at your load increasing.
>>>>>>
>>>>> CC'ing libasyncns' author Lennart Poettering about this bug.
>>>>> Lennart, what do you think about this?
>>>> Hmm, no clue.
>>>>
>>>> If you can get me a simple test use case using just the C API I'd be
>>>> happy to take a closer look!
>>>>
>>>> Lennart
>>
>> Look like recv() shouldn't be called from multiple threads on the same socket.
>> (See the attached file for a similar behaviour.)
>>
>> If I understand it, some worker threads are created, and they wait a message
>> with recv() on the same fd.
>> Then, when a new request comes, send() is used on the connected socket,
>> and is picked by one of the worker threads.
>>
>> Maybe a worker thread system could be implemented with queues
>> and pthread mutexes/conds, but it's less generic (harder to be compatible with
>> process workers).
>> Another way may be to use pipe() and select()?
>>
>> The strange thing is that the same load increases with the fork() method too,
>> but I didn't looked at this part.
>>
>> Regards,
>>
>
> Will there be any attempt to fix this or is the development of this
> library dead?

I was thinking about fixing it myself but I don't have a lot of time these days,
and I don't really know the code of libasyncns.
I started doing it anyway, maybe it'll give something working in the end.

--
Damien Thebault