Migration from ESR 115 to 128 #85
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ptomato
commented
Jul 27, 2024
Comment on lines
+93
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+128
| Also, note that `JS::GCPolicy<JS::Heap<T>>` does not implement | ||
| `needsSweep()`. | ||
| If you were storing a `JS::Heap` inside `JS::WeakCache<T>`, you will | ||
| need to use a different data structure. | ||
| An easy drop-in replacement for `JS::Heap` suitable for this purpose | ||
| would be something like this: | ||
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| ```c++ | ||
| template <typename T> | ||
| class WeakPtr : public JS::Heap<T> { | ||
| public: | ||
| using JS::Heap<T>::Heap; | ||
| using JS::Heap<T>::operator=; | ||
| }; | ||
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| namespace JS { | ||
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| template <typename T> | ||
| struct GCPolicy<WeakPtr<T>> { | ||
| static void trace(JSTracer* trc, WeakPtr<T>* thingp, const char* name) { | ||
| return JS::TraceEdge(trc, thingp, name); | ||
| } | ||
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| static bool traceWeak(JSTracer* trc, WeakPtr<T>* thingp) { | ||
| return js::gc::TraceWeakEdge(trc, thingp); | ||
| } | ||
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| static bool needsSweep(JSTracer* trc, const WeakPtr<T>* thingp) { | ||
| WeakPtr<T> thing{*thingp}; | ||
| return !js::gc::TraceWeakEdge(trc, &thing); | ||
| } | ||
| }; | ||
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| } // namespace JS | ||
| ``` |
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I was also wondering if this omission was unintentional and we should have JS::Heap's GCPolicy be sweepable after all.
arai-a
reviewed
Jul 28, 2024
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@arai-a Thanks for the review. I've pushed another revision. Any thoughts on whether we should add |
arai-a
reviewed
Jul 28, 2024
Includes updated build instructions and a migration guide. One of the examples needs to be updated, with the new column number API; and the WeakRefs example needs its job queue and realm creation options adjusted. Everything else builds as is.
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Includes updated build instructions and a migration guide. Only one of the examples needs to be updated, with the new column number API; everything else builds as is.