On 2019-Mar-13, Robert Haas wrote:
> On Wed, Mar 13, 2019 at 12:42 PM Alvaro Herrera
> <alvherre@2ndquadrant.com> wrote:
> > I remember going over this code's memory allocation strategy a bit to
> > avoid the copy while not incurring potential leaks CacheMemoryContext;
> > as I recall, my idea was to use two contexts, one of which is temporary
> > and used for any potentially leaky callees, and destroyed at the end of
> > the function, and the other contains the good stuff and is reparented to
> > CacheMemoryContext at the end. So if you have any accidental leaks,
> > they don't affect a long-lived context. You have to be mindful of not
> > calling leaky code when you're using the permanent one.
>
> Well, that assumes that the functions which allocate the good stuff do
> not also leak, which seems a bit fragile.
A bit, yes, but not overly so, and it's less fragile that not having
such a protection. Anything that allocates in CacheMemoryContext needs
to be very careful anyway.
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
