Hi
A while ago I noticed that the current error messages when the
memory_limit is reached / when an OOM condition is encountered are
misleading, because PHP allocates memory from the operating systems in
bulk in larger chunks and the size of the chunk is what is checked
against the memory limit. However the error message reports the much
smaller actual allocation, leading to confusion, because the last known
memory usage + the reported allocation would be smaller than the memory
limit.
I've created a PR to improve the error message to include all relevant
sizes:
https://github.com/php/php-src/pull/11763
Unfortunately that PR did not get much discussion, much less a decision
whether or not it makes the situation better.
I believe it does and thus I'm sending this email to solicit additional
opinion. Please check the PR for additional information about the
proposed rephrased message. You can see the example output from the
adjusted tests.
Before merging the PR will likely require some cleanup and there are two
different tests that fail in CI due to a different allocation path being
hit compared to my local machine. Someone more knowledgeable will need
to decide if the behavior is correct, especially since one of the
outputs indicates an uint64 underflow (18446744073707454792) somewhere.
However I'd first like to gauge some opinions before spending more time
on investigating that.
Best regards
Tim Düsterhus
