Fix #9588, 140a96b: [Squirrel] Reaching memory limit during script registration could prevent further script detections #9589
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…ript registration could prevent further script detections Also the memory allocation triggering the limit was never freed. And if the exception was thrown in a constructor using placement new, the pre-allocated memory was not freed either.
LordAro
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Oct 2, 2021
glx22
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the
backport requested
TrueBrain
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Oct 3, 2021
…ript registration could prevent further script detections (OpenTTD#9589) Also the memory allocation triggering the limit was never freed. And if the exception was thrown in a constructor using placement new, the pre-allocated memory was not freed either.
TrueBrain
pushed a commit
to TrueBrain/OpenTTD
that referenced
this pull request
Oct 3, 2021
…ript registration could prevent further script detections (OpenTTD#9589) Also the memory allocation triggering the limit was never freed. And if the exception was thrown in a constructor using placement new, the pre-allocated memory was not freed either.
TrueBrain
pushed a commit
to TrueBrain/OpenTTD
that referenced
this pull request
Oct 3, 2021
…ript registration could prevent further script detections (OpenTTD#9589) Also the memory allocation triggering the limit was never freed. And if the exception was thrown in a constructor using placement new, the pre-allocated memory was not freed either.
TrueBrain
pushed a commit
to TrueBrain/OpenTTD
that referenced
this pull request
Oct 3, 2021
…ript registration could prevent further script detections (OpenTTD#9589) Also the memory allocation triggering the limit was never freed. And if the exception was thrown in a constructor using placement new, the pre-allocated memory was not freed either.
TrueBrain
pushed a commit
to TrueBrain/OpenTTD
that referenced
this pull request
Oct 3, 2021
…ript registration could prevent further script detections (OpenTTD#9589) Also the memory allocation triggering the limit was never freed. And if the exception was thrown in a constructor using placement new, the pre-allocated memory was not freed either.
TrueBrain
pushed a commit
that referenced
this pull request
Oct 3, 2021
…gistration could prevent further script detections (#9589) Also the memory allocation triggering the limit was never freed. And if the exception was thrown in a constructor using placement new, the pre-allocated memory was not freed either.
TrueBrain
removed
the
backport requested
LordAro
added
the
backported
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Motivation / Problem
When a script's
info.nuttriggersMaximum memory allocation exceeded, it can prevent the detection of other scripts of the same type.This happens because the memory allocation triggering the limit is still accounted in the allocator for all other detections.
And that means this memory is also never freed.
Once the
allocated_sizeissue was fixed, another issue appeared, a script failing to register due to memory limit would still be available ingame (and possibly other scripts that should have failed memory check). That's because scripts are scanned multiple times, and the error was not properly reset.Finally another memory leak exists, when the memory limit is triggered in a constructor and using placement new.
Regarding the reported crash, it's because
DummyAIregistration triggers the memory limit due to a previous failing script and incomplete cleaning between registrations.Description
Properly count allocated memory, and free memory not referenced by squirrel before it's lost.
I added an assert to ensure all allocated memory is managed by squirrel and its garbage collector, or is taken care of otherwise.
Limitations
As now the engine is properly reset, the failing scripts are now reported multiple times in debug console, because many rescan happen during startup.
Checklist for review
Some things are not automated, and forgotten often. This list is a reminder for the reviewers.