Pool Proxy trap argument arrays#2675
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CallTrap now rents the trap argument array from the engine's JsValueArrayPool and returns it after the call, following the interpreter call-site pattern (no finally: an exception lets the array fall to the GC, and JsArguments.Materialize protects arrays captured by the callee). The set trap needs four arguments (target, key, value, receiver), so the pool gains a size-4 bucket. Two existing size-4 rent/return sites in IntrinsicTypedArrayPrototype start benefiting as well - until now RentArray(4) always allocated and ReturnArray(4) was a silent no-op. ProxyBenchmark on the same base commit (control vs this change): time flat within run noise, allocations on trapped operations drop to the JS-call floor: | Lane | Allocated | |-------------- |-----------------------------:| | TrapGet | 4,689 KB -> 1.3 KB | | TrapHas | 3,908 KB -> 1.3 KB | | TrapSet | 8,275 KB -> 2,806 KB (-66%) | | ApplyTrap | 25,143 KB -> 20,455 KB (-19%)| | ConstructTrap | 3,048 KB -> 2,579 KB (-15%) | | OwnKeysTrap | -313 KB | Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01EsHuKuE4UihKZp5HYapDHE
lahma
enabled auto-merge (squash)
July 13, 2026 18:32
This was referenced Jul 13, 2026
This was referenced Jul 15, 2026
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Follow-up to #2674.
CallTrapnow rents the trap argument array fromJsValueArrayPooland returns it after the call — the same rent/call/return contract as the interpreter call sites (JintCallExpression), withJsArguments.Materializeprotecting arrays captured by the callee.The
settrap takes four arguments (target, key, value, receiver), so the pool gains a size-4 bucket. Bonus: the two existingRentArray(4)/ReturnArraysites inIntrinsicTypedArrayPrototype(sortcomparers etc.) start actually pooling — until now size-4 rents always allocated and returns were silent no-ops.ProxyBenchmark, control vs change on the same base commit (time flat within run noise; allocation is the win):
Verification: full test262 suite green (99,429 passed / 0 failed), full Jint.Tests + PublicInterface green, ProxyTests 43/43.
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https://claude.ai/code/session_01EsHuKuE4UihKZp5HYapDHE