src: disable V8 external memory reasonable size check - #65589
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V8 aborts the process when external memory grows by more than --external-memory-max-reasonable-size gigabytes in a single step. The 32 GB default is a Chromium-oriented sanity check; allocating a buffer larger than that is legitimate in Node and should raise a RangeError rather than terminate the process. Default the flag to 0 unless the user supplied a value, alongside the other V8 defaults Node sets explicitly. Fixes: nodejs#65534 Signed-off-by: Paul Bouchon <mail@bitpshr.net>
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Codecov Report❌ Patch coverage is
Additional details and impacted files@@ Coverage Diff @@
## main #65589 +/- ##
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- Coverage 90.07% 90.07% -0.01%
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Files 751 751
Lines 254875 254880 +5
Branches 48108 48126 +18
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- Hits 229579 229574 -5
- Misses 16466 16496 +30
+ Partials 8830 8810 -20
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Fixes: #65534
V8 aborts the process when external memory grows by more than
--external-memory-max-reasonable-sizegigabytes in a single step, which defaults to 32. Allocating a buffer larger than that is a legitimate thing to do in Node, and it should raise aRangeErrorrather than terminate the process:This defaults the flag to 0 unless the user supplied a value, next to the other V8 defaults Node already sets explicitly. Per @Renegade334 on the issue, the 32 GB limit is a Chromium oriented sanity check rather than something Node wants to inherit.
The guard checks both the dashed and underscored spellings, since V8 accepts either, and appends only when neither is present so an explicit
--external-memory-max-reasonable-size=Nstill wins.On testing: reproducing the real thing needs more than 32 GB of RAM, which I do not have, so I verified against a lowered threshold instead.
--external-memory-max-reasonable-size=1plus a 2 GB allocation produces the identical fatal check, and the same allocation succeeds once the flag defaults to 0. The test covers the override path rather than the new default, because asserting the default is gone would need a >32 GB allocation in CI. I confirmed the test fails if the appended flag clobbers a user supplied value, so it does catch the case it is there for.