Shell jobs · 32 KiB output

Raw snapshots are private and are not served by this website. Only filtered structural findings are published.

Raw idle observations. These observations are separate from the slope fit; a lower heap after idle does not by itself establish that completed outputs were released.

The process-global Job service stores completed jobs, their deferred results, metadata, and output in its Map. The shipped shell/subagent executors create jobs, but Job has no removal or bounded-exit cache, unlike Shell's 25-entry cache.

• Invoke the installed built-in shell executor, not a replacement.
• Each real command returns exit 0 and exactly 32768 bytes with the fixture prefix and a child PID. The command text stays constant across cycles.
• The fixed session's message history stays empty; the fixture retains only first/last shell IDs, never output history.

control-1

Functional preflight passed (2 case + 2 control cycles).
{"completed":2,"controlCompleted":232,"progressCalls":2,"outputBytes":65536,"bytesPerCommand":32768,"sessionMessages":0,"sessionID":"ses_f9bd8f3a8ffex4jAzFsbt0oq08","firstShellID":"sh_064270c99001CHoLafvmJ94nPg","lastShellID":"sh_064270cd50018QzGmiyjEGlF5i","outputMarker":"JOBMEM_LARGE:"}

case-1

Functional preflight passed (2 case + 2 control cycles).
{"completed":232,"controlCompleted":2,"progressCalls":232,"outputBytes":7602176,"bytesPerCommand":32768,"sessionMessages":0,"sessionID":"ses_f9bd828d1ffeWvb2a0FojcBPzF","firstShellID":"sh_06427d760001GjIqYIPAYtmXvt","lastShellID":"sh_0642845a00019ExXR2GRPMpXTx","outputMarker":"JOBMEM_LARGE:"}

case-2

Functional preflight passed (2 case + 2 control cycles).
{"completed":232,"controlCompleted":2,"progressCalls":232,"outputBytes":7602176,"bytesPerCommand":32768,"sessionMessages":0,"sessionID":"ses_f9bd76fd8ffe3d96H3jcsqV3or","firstShellID":"sh_064289073001JPlZWGl0fygbk9","lastShellID":"sh_06428fedb001pMDEPhokbMbHie","outputMarker":"JOBMEM_LARGE:"}

control-2

Functional preflight passed (2 case + 2 control cycles).
{"completed":2,"controlCompleted":232,"progressCalls":2,"outputBytes":65536,"bytesPerCommand":32768,"sessionMessages":0,"sessionID":"ses_f9bd6b57affelGg1R344V8Yj2I","firstShellID":"sh_064294aba001DXyCJhAyNQq1mc","lastShellID":"sh_064294afd001HpXkgZw6cYakdo","outputMarker":"JOBMEM_LARGE:"}

Control cadence is calibrated from two real preflight cycles in each process and recorded as controlCadenceMs. Both arms get at least 20 seconds of warm-up/settling before the baseline. This approximately matches elapsed time, not every internal allocation or polling read.

Source inspected at 4772b6a3e8; this is the investigation reference, not a claim about the binary’s build commit.

• packages/core/src/job.ts:187 — Completion replaces the Map entry with a completed record and output; it does not remove it.
• packages/core/src/tool/plugin/shell.ts:242 — Every shipped shell-tool execution starts a Job and waits for it.
• packages/core/src/shell.ts:29 — The separate shell-process cache is capped at 25 exits.

One fixed session and one inspector transform remain. Commands finish before measurement; the fixture retains neither results nor a growing ID list. Session context remains empty.

Control. Run the same executable and output through a plain subprocess, without OpenCode's shell/job bookkeeping. Both arms are cadence-matched and warmed beyond the shell service's 25-exit cache.

Metric: target process.memoryUsage().heapUsed after Bun.gc(true). Warm-up excluded. Theil–Sen slope; later-half slope must remain positive. Subtract positive control drift only. A growing control, large baseline drift, or a noise allowance above max(1 MiB, 5% of baseline) that prevents detecting a trend makes attribution inconclusive. Net growth and slope × cycles must both exceed max(128 KiB, 6 × combined robust residual noise). Require agreement across at least two fresh-process repetitions. Heuristic, not a significance test.

OpenCode

0.0.0-dev-18911 · dev channel · installed binary

Drive

1.4.4 · installed package

Runtime

Bun 1.4.0 · linux / x64

Isolation

Private server + file-backed database. TUI closed before warm-up. Measurement plugin remains loaded; no object-level instrumentation.

Checkpoints

Case-specific cleanup checks pass before GC; 300 ms settling allowance. This is not a global background-work barrier.

Snapshots

Disabled. Use --snapshots for a diagnostic rerun.

Run

2026-09-02T22-04-32-353Z-59f2dc · 2026-09-02T22:04:32.354Z

cd /root/projects/opencode-memory-lab && bun run run --case shell-jobs-large --warmup 30 --batches 5 --batch-size 40 --repetitions 2 --settle-ms 300 --warmup-ms 20000 --idle-ms 15000

Includes native allocations and allocator behavior. Not used to classify JS heap growth.