src: stop leaking a CppHeap in CommonEnvironmentSetup - #65792
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nodejs-github-bot merged 1 commit intoSep 7, 2026
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`CommonEnvironmentSetup` created a `CppHeap` for its `CreateParams` before deciding how to create the isolate, but `NewIsolate()` ignores `params->cpp_heap` and attaches a heap of its own (or the one from `IsolateSettings`). The first heap was never attached or destroyed, so every non-snapshotting setup leaked one `CppHeap`; cppgc's heap registry keeps it reachable, which is why LSAN stays quiet about it. Only create the heap on the snapshotting path, where the params go to the `SnapshotCreator` directly. Refs: nodejs#55337 Signed-off-by: Shelley Vohr <shelley.vohr@gmail.com>
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Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## main #65792 +/- ##
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+ Coverage 89.99% 90.15% +0.15%
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Files 757 769 +12
Lines 257739 261448 +3709
Branches 48881 49661 +780
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+ Hits 231961 235715 +3754
+ Misses 16861 16749 -112
- Partials 8917 8984 +67
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Every
CommonEnvironmentSetup::Create()andCreateFromSnapshot()leaks onev8::CppHeap: the constructor created a heap for itsCreateParamsup front, but the non-snapshotting path then callsNewIsolate(), which ignoresparams->cpp_heapand attaches its own, so the first heap was never attached or destroyed (LSAN stays quiet because cppgc's heap registry still points at it).The heap is now created only on the snapshotting path, where the params go to the
SnapshotCreatorand V8 takes ownership.Tests:
test/embeddingpasses; no new test, since detachedCppHeaps cannot be enumerated.Refs: #55337
Disclosure: the code and this description were written by Claude Code, directed and reviewed by @codebytere.