Re: Bug in TypeInfoCache causes getObject to fail

[Kris Jurka <books(at)ejurka(dot)com>]

On Thu, 9 Feb 2006, till toenges wrote:

> i have found a race condition in org.postgresql.jdbc2.TypeInfoCache. A Map is 
> created as a static member, but reinitialized for every new instance of 
> TypeInfoCache. That causes a race condition in ResultSet.getObject(...), 
> which then returns PGobject instead of the correct type. Probably causes 
> other problems as well. I have attached a test case. The test case works best 
> on smp machines (tested on a 4 way), where it fails almost every time.

Nice work.  Applied to 8.1 and HEAD.

> Also the maps in TypeInfoCache are created as synchronizedMaps, which is 
> unneccessary, slow and a potential source for further side effects. I have 
> removed that as well, and attached a fixed version of TypeInfoCache from 
> build 404. I leave the application of the fixes to the current and other 
> versions as an exercise to the committer ;-)

Actually it is necessary for the maps to be synchronized because at any 
time a client may call PGConnection.addDataType which will modify the 
maps.

Kris Jurka