Re: slru.c race condition (was Re: TRAP: FailedAssertion("!((itemid)->lp_flags

Alvaro Herrera <alvherre(at)commandprompt(dot)com> writes:
> May I propose to make Assert() yield only WARNINGs,

That is a horrid idea --- for one thing, it means that Asserts inside
the elog machinery itself would be instant infinite recursion, and even
elsewhere you'd have to think a bit about whether it's ok to call the
elog machinery. Plus, once you *have* detected an assertion failure,
allowing the code to keep running is just silly.

Either they dump core or they're disabled, there is no third option.

I do think it would be reasonable to fix things so that
MEMORY_CONTEXT_CHECKING could be turned on and off at runtime.

Perhaps rather than an all-or-nothing debug_assertions GUC variable,
what we want is something that turns on or off "expensive" assertion
checks at runtime. This could include MEMORY_CONTEXT_CHECKING and
anything else where the actual checking of the condition is nontrivial.
(For instance, there is code in list.c that grovels over the whole
list for a consistency check --- that is "expensive". There is some
code in the bufmgr that scans through all the buffers --- ditto.)

regards, tom lane