On 27.09.2013 14:12, Robert Haas wrote:
On Thu, Sep 26, 2013 at 4:20 PM, Alvaro Herrera
<alvhe...@2ndquadrant.com> wrote:
But how do we ensure that the BMS is allocated in a context? You'd have
to switch contexts each time you call bms_add_member. I don't have a
good answer to this.
The coding of bms_add_member is pretty funky. Why doesn't it just
repalloc() the input argument if it's not big enough? If it did that,
the new allocation would be in the same memory context as the original
one, and we'd not need to care about the memory context when adding an
element to an already non-empty set.
But even if we did decide to switch memory contexts on every call, it
would still be much cleaner than this. It's only three lines of code
(and about as many instructions) to save and restore
CurrentMemoryContext.
[looks] Huh, yeah, as it stands, bms_add_member() is an accident waiting
to happen. It's totally non-obvious that it might cause the BMS to jump
from another memory context to CurrentMemoryContext. Same with
bms_add_members(). And it would be good to Assert in bms_join that both
arguments are in the same from MemoryContext.
Let's fix that...
- Heikki
--
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
