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From Felix Meschberger <fmesc...@gmail.com>
Subject Re: [jr3] Synchronized sessions
Date Thu, 25 Feb 2010 18:14:18 GMT
Hi,

On 25.02.2010 17:55, Marcel Reutegger wrote:
> Hi,
> 
> On Thu, Feb 25, 2010 at 15:49, Felix Meschberger <fmeschbe@gmail.com> wrote:
>> Hi,
>>
>> On 24.02.2010 21:19, Thomas Müller wrote:
>>> Hi,
>>>
>>>> deadlocks
>>>
>>> I think it's relatively simple to synchronize all methods on the session.
>>
>> Yes, but this creates a big potential for deadlocks ...
>>
>>>
>>>> If we want to make sessions thread-safe, we should use proper
>>>> implementations.
>>>
>>> Yes, that's what I want to write: a proper implementation.
>>
>> I disagree that this would be a proper implementation.
> 
> can you please elaborate what you think is a proper implementation in
> this context?

Just off-the-top-of-my-head: Using a better read-mostly guarding locking
mechanism (i.e. readers don't block each other, writers need exclusive
access [still not entirely save]); not at the "global" method level, but
more intelligently guarding the shared data; not using the Session
object itself for locking

Regards
Felix

> 
> regards
>  marcel
> 
>>>
>>>> any concurrent use of the same session is unsupported.
>>>
>>> The disadvantage of this is that there is no way to enforce correct
>>> usage. In some cases, incorrect usage leads to data corruption. I
>>> believe data corrupt is not acceptable, even if the user made a
>>> mistake.
>>
>> Anything can go wrong -- and if people do the wrong things, well, fine,
>> let them do ...
>>
>> And I don't say, we should not make Session thread-safe. But if we set
>> out to do it, we should do it right. And just synchronizing all methods
>> is just not right.
>>
>> Regards
>> Felix
>>
>>
> 


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