On 16.05.2012 13:25, Mark Cave-Ayland wrote:
One of the issues we've been looking at with PostGIS is how to interrupt long-running processing tasks in external libraries, particularly GEOS. After a few tests here, it seems that even the existing SIGALRM handler doesn't get called if statement_timeout is reached when in an external library, e.g. with PostgreSQL 9.0/PostGIS 2.0 trunk/GEOS:
If you interrupt an external library call, it might leave memory in an inconsistent state, or some other such thing. It's not generally safe to interrupt arbitrary 3rd party code.
However, if you're absolutely positively sure that the library function can tolerate that, you can set "ImmediateInterruptOK = true" before calling it. See e.g PGSemaphoreLock() on how that's done before starting to sleep on a semapgore.
-- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
