perf(execution): raw wasm module bytes + eager userland compile#216
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NathanFlurry merged 5 commits intoJul 2, 2026
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…s via event The sidecar drains process output before emitting process_exited and the frame stream + event pump are FIFO, so once the exit event is observed no trailing output can follow it; the host-side quiet-turn drain (2 turns at 10ms) only remains for the snapshot-poll fallback exit path. Also stop awaiting signal-state refreshes on the exec critical path (start + first output) — kill paths await the in-flight refresh instead — and clean up the parked refresh in finishProcess so fallback exits release it too. Warm host-driven exec p50: node -e '' 30ms -> ~17ms, wasm true 52ms -> 39ms; whole wasm-command-floor lane down ~13ms/row; bench:gate green. New regression test: 10 sequential fast-exit 64KiB stdout captures.
Bake the constant wasm runner + wasi shim (~300KB of JS previously recompiled per exec) into the per-process V8 userland snapshot via guest_runtime.snapshot_userland_code, keyed and cached process-wide. Mode env AGENTOS_WASM_SNAPSHOT_RUNNER=auto|block|off: auto probes the snapshot cache without blocking (async warm kicked once per process) and falls back to the byte-identical inline runner until ready, so the cold path is unchanged. The sync-RPC glue is re-evaluated per exec (the snapshot-baked copy cannot bind session bridge fns). Module bytes are now base64-encoded once per module in a bounded, fingerprint-validated cache (64 entries, warn on evict, debug log reports per-entry and cumulative cache bytes) instead of fs::read+encode per exec. Adds AGENTOS_V8_SESSION_PHASES timers (snapshot_get / blob_clone / isolate_new / user_code_execute) and a measured NOTE against EagerCompile at snapshot build (moves cost to isolate deserialize). Warm wasm floor p50: true 39->33ms, pwd 48->43ms, ls-empty 81->75ms, date-version 127->115ms (52/62/96/140 before PR #212); cold first-exec improved; wasm suite green; bench:gate green. Remaining floor is isolate-per-exec + module decode — pooling tracked as Stage C.
This was referenced Jul 2, 2026
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The filtered install (--filter @secure-exec/benchmarks...) omitted packages/build-tools, so every bench-gate run died in the v8-bridge build script (missing Node dependencies) before gating anything — the PR gate has never actually run green on CI.
Pre-created V8 session workers (thread + snapshot-restored isolate, keyed by snapshot digest + heap limit) are claimed at session create via a warm hint, taking isolate_new (~4.2ms) and blob_clone off the per-exec critical path. Workers are never reused across guests (each exec still gets a virgin isolate); a wrong hint falls back to the existing lazy-create path. Capacity per key via AGENTOS_V8_WARM_ISOLATES (default 2, 0 disables); refill after claim; pool transitions logged; warm_worker_hit/miss counters in the session phases output. Seeding is deliberately conservative: auto mode stays snapshot-only and only AGENTOS_WASM_SNAPSHOT_RUNNER=block seeds workers (wasm-runner key + default node key). Reason: creating isolates on background threads while other isolates execute guest WebAssembly deterministically SIGSEGVs the pinned V8 130 (WasmCodePointerTable::AllocateUninitializedEntry inside Isolate::New, even under the isolate lifecycle lock — the race is against V8-internal wasm threads). Backtraces + notes in the rusty-v8-upgrade todo; enabling default seeding rides that upgrade. Warm floors (block, this host): node -e '' 17 -> 14.4ms p50, wasm true 33 -> ~30ms (warm_worker_hit 64/67, isolate_new down to 3 background calls); pwd 42.6 -> 37.5ms, printf-0b 44.7 -> 40.2ms, date 115 -> 111ms. wasm suite 8.9s (was 96s, pool+snapshot amortize debug isolates); v8-runtime tests and bench:gate green.
Module bytes now ride the in-process runtime protocol as Arc<Vec<u8>> from a raw-bytes cache (same bounded/fingerprinted semantics as the base64 cache it replaces) and are injected pre-exec as a __agentOSWasmModuleBytes Uint8Array; the runner prefers it over the AGENTOS_WASM_MODULE_BASE64 env fallback, so the per-exec base64 encode/decode (4.3ms @267KB, ~23ms @2.5MB) is gone in both snapshot and inline modes. The userland (wasm-runner) snapshot script is now compiled with EagerCompile: the fatter-blob isolate cost it causes is prepaid by parked warm workers, so the runner function no longer lazy-compiles inside user_code_execute. Warm floors (block, this host): wasm true 30 -> 19.7ms p50 (52ms at the start of the 3.2 campaign), echo hello 24.0ms, pwd 29.3ms, ls-empty ~39ms (was 96), date --version 30.4ms (was 140 — module-size tax eliminated), printf-64k 136ms (stdout streaming path, separate finding). Injection failure fails the exec loudly. wasm + v8-runtime suites green; bench:gate green (require_100_small flaked 4.3x once and passed 1.13x on rerun — bimodal, pre-existing, tracked).
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Module bytes now ride the in-process runtime protocol as Arc<Vec> from a
raw-bytes cache (same bounded/fingerprinted semantics as the base64 cache it
replaces) and are injected pre-exec as a __agentOSWasmModuleBytes Uint8Array;
the runner prefers it over the AGENTOS_WASM_MODULE_BASE64 env fallback, so the
per-exec base64 encode/decode (4.3ms @267KB, ~23ms @2.5MB) is gone in both
snapshot and inline modes. The userland (wasm-runner) snapshot script is now
compiled with EagerCompile: the fatter-blob isolate cost it causes is prepaid
by parked warm workers, so the runner function no longer lazy-compiles inside
user_code_execute.
Warm floors (block, this host): wasm true 30 -> 19.7ms p50 (52ms at the start
of the 3.2 campaign), echo hello 24.0ms, pwd 29.3ms, ls-empty ~39ms (was 96),
date --version 30.4ms (was 140 — module-size tax eliminated), printf-64k 136ms
(stdout streaming path, separate finding). Injection failure fails the exec
loudly. wasm + v8-runtime suites green; bench:gate green (require_100_small
flaked 4.3x once and passed 1.13x on rerun — bimodal, pre-existing, tracked).