On Wed, Oct 12, 2022 at 07:24:53PM -0400, Tom Lane wrote: > Pavel Stehule <pavel.steh...@gmail.com> writes: > > I had a talk with Julien about the correct handling of an exception raised > > by pfree function. > > > Currently, this exception (elog(ERROR, "could not find block containing > > chunk %p", chunk);) is not specially handled ever. > > There are hundreds, if not thousands, of "shouldn't ever happen" elogs > in Postgres. We don't make any attempt to trap any of them. Why do > you think this one should be different?
Because session variables are allocated in a persistent memory context, so there's a code doing something like this to implement LET variable: [...] oldctxt = MemoryContextSwitchTo(SomePersistentContext); newval = palloc(...); MemoryContextSwitchTo(oldctxt); /* No error should happen after that point or we leak memory */ pfree(var->val); var->val = newval; return; Any error thrown in pfree would mean leaking memory forever in that backend. Is it ok to leak memory in such should-not-happen case or should there be some safeguard?
