On Wed, Sep 20, 2006 at 11:02:46AM -0400, Jack Orenstein wrote: > >http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/mmgr/README?rev=1.9 > > Thank you, that is a useful document. So let me make sure I understand: > > - My C function is invoked in a MessageContext (which you referred to > in an earlier message as a short-lived context). > > - In such a context, I do not need to pfree anything, including memory > that I palloc myself, and plans returned by SPI_prepare invocations, > (assuming that I don't hold onto these things past the function > invocation, e.g. in a static). In general, any memory you allocate in a function will have been free'd by the next time you're called. If you want memory to survive (like in a static) you need to place it in a longer lived context. The SPI reference has some details about how long various bits of memory survive. It's not a garbage collector, everything in a context goes when the context is reset or deleted. If you still have a pointer there, it'll be invalid. If you enable debugging stuff it'll clear freed memory so the error becomes more obvious. Hope this helps, -- Martijn van Oosterhout <kleptog@xxxxxxxxx> http://svana.org/kleptog/ > From each according to his ability. To each according to his ability to litigate.
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