On Thu, 15 Dec 2011 22:02:43 +0800, Craig Ringer wrote:
> On 12/15/2011 07:29 PM, Radosław Smogura wrote:
>> Long, long time ago I've sent implementation with timers, you need
>> to search archive If you need this.
>
> If it was ages ago, you probably used java.util.Timer, right?
>
> java.util.Timer is not suitable for use in a JDBC driver because it
> doesn't do any exception handling on the timer thread, it's subject
> to
> congestion on the timer thread, and it offers no way for the driver
> to
> control the timer thread to cleanly shut it down during unload. It's
> unusable in app servers and not really a great idea anywhere that
> needs to be robust and long-running.
>
> --
> Craig Ringer
Indeed it was Timer with subclassed TimerTask. In any way
implementation was that it was prepared for choosing per connection (and
per connection is used during normal execution), per data source, or per
class loader (this is used in case of data sources).
For shutting down implementation is clear thread associated with Timer
will go away if no more tasks are scheduled and there is no more
references to Timer. Demonizing timer is quite enough.
From implementation if I recall well I used a little bit different
concept to create "atomic" operations chain for query executor protected
in addition with timer - and I think this concept was fully realized.
Regards,
Radosław Smogura
