Hi,
I've now protected the code with a ReadWriteLock:
https://github.com/sampov2/geotools/commit/c3b41de9217a6b14d15700f3a2d07de88480c4ce
The String intern() pattern was actually a common pattern used in other
places in WFSDataStore. If you accept my implementation, it would make
sense to use the pattern in the other methods as well.
Sampo
On Thu, Nov 13, 2014 at 4:02 PM, Jody Garnett <[email protected]>
wrote:
> We tend to use the java concurrency API, for an example a ReadWrite lock
> if that is appropriate.
>
> Jody Garnett
>
> On Mon, Nov 10, 2014 at 11:26 PM, Sampo Savolainen <
> [email protected]> wrote:
>
>> Hi,
>>
>> Last spring I worked on creating Cascaded WFS 2.0.0 Stored Query support
>> into GeoTools and GeoServer. This work has been done for the Finnish
>> Meteorological Institute. I've now resumed my work after GeoServer 2.6 got
>> released and development stabilized (and my schedule freed up), and I'm
>> working on a pull request for GeoTools. I've been discussing the changes
>> with Jody and I and/or we have two questions for all of you regarding our
>> conversation. I've split these two questions into separate emails so the
>> discussion won't get confused.
>>
>> Also, if anyone else wants to check out the pull request, please do.
>> Given enough eyeballs, and so on.
>>
>>
>> In wfs-ng WFSDataStore, I have a Map for caching StoredQueryDescriptions.
>> The key for the map is the id of the stored query in question (as a
>> String). The Map is populated lazily and it's entirely possible that
>> multiple threads might access the same stored query at the same time. I use
>> a ConcurrentHashMap to avoid basic synchronization issues, but this
>> particular code is to safeguard GeoTools from querying the same information
>> from the WFS in multiple threads at the same time.
>>
>>
>> https://github.com/sampov2/geotools/commit/f8a7d7cfe9c3c75e5619d9960a6747a220af1e43#commitcomment-8379257
>>
>> The current strategy is very naive (synchronized(id.intern()) { }) and as
>> Jody correctly points out, other bits of code might be synchronizing on
>> these interned Strings.
>>
>> My question is if there is a preferred and often used locking strategy in
>> GeoTools that fits the bill here?
>>
>>
>> Thanks,
>> Sampo
>>
>> --
>> Sampo Savolainen
>> R&D Director, Spatineo Oy
>> [email protected]
>> +358-407555649
>> Linnankoskenkatu 16 A 17, 00250 Helsinki, Finland
>> www.spatineo.com, twitter.com/#!/spatineo
>> www.linkedin.com/company/spatineo-inc
>>
>> This message may contain privileged and/or confidential information. If
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>
--
Sampo Savolainen
R&D Director, Spatineo Oy
[email protected]
+358-407555649
Linnankoskenkatu 16 A 17, 00250 Helsinki, Finland
www.spatineo.com, twitter.com/#!/spatineo
www.linkedin.com/company/spatineo-inc
This message may contain privileged and/or confidential information. If you
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may not use, copy, disseminate, or distribute it; do not open any
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