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fix(perf): eliminate the main-thread App Hangs (Sentry triage)#83

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caezium merged 1 commit into
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fix/sentry-hangs
Jun 17, 2026
Merged

fix(perf): eliminate the main-thread App Hangs (Sentry triage)#83
caezium merged 1 commit into
mainfrom
fix/sentry-hangs

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@caezium caezium commented Jun 16, 2026

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What

Every unresolved Burrow Sentry issue is an AppHang (main thread blocked ≥2 s) — zero real crashes. The 40 issues are ~5 root causes wearing different top-frame hats; the two dominant buckets (BURROW-1 layout, BURROW-N generic app.run()) both regressed after a prior 0.7.1 resolve. This PR fixes the structural root causes.

Changes

A. App icons off the main thread — StatusView.swift (BURROW-R, BURROW-T)

AppIcon.image(for:) walked NSWorkspace.runningApplications on the main thread on every cache miss, once per process row, each 2 s refresh — hundreds of O(running-apps) walks. Now:

  • AppIcon.resolve(for:) runs inside the existing off-main process pass, walking the app list at most once and indexing it (O(apps + procs), not O(apps × procs)).
  • Views read cachedImage(for:) — a pure, lock-guarded cache read; glyph fallback until the icon lands.
  • The popup's handful of rows use image(for:) = cache read + async off-main fill.
  • The main thread never walks the app list again.

B. Bounded process table — StatusView.swift, MoleStatus.swift (BURROW-1 + layout tail)

The table's ForEach iterated the full process set (hundreds), rebuilding/diffing every identity each tick and forcing repeated sizeThatFits over the nested ScrollViews (the ScrollViewLayoutComputer → placeChildren recursion in the trace). Now:

  • ForEach is capped to the top 100 rows by the current sort, with a "Show all (N more)" affordance.
  • ProcRow has a fixed .frame(height: 30) so LazyVStack skips per-child measurement and the ScrollView size cache stays stable.
  • ProcessInfo is now Equatable so unchanged rows don't re-render.

C. Throttled clean/optimize report — OperationFlow.swift (BURROW-1G, BURROW-1F)

OperationFlow (@MainActor) re-parsed the whole accumulated transcript (parseTaskReport/mergeSummaryFields) on the main actor for every streamed line — O(n²) over a long run. The live re-parse is now throttled to ~4×/s; terminal events still do a final, authoritative reduce, so the result screen is never stale.

Audited — no change needed

  • Modals (BURROW-1K): every NSAlert.runModal() already routes through runModalQuiet(), which pauses Sentry ANR tracking for user-paced modals.
  • Blocking waits: the disk-scan (group.wait) and CLI-process (waitUntilExit) calls run off-main.
  • Sparklines (BURROW-1M): MiniChart already caps to 120 drawn points; this fingerprint is downstream of the main-thread pressure that A/B/C relieve.
  • The framework-frame singletons (CharacterSet, swift_slowAlloc, _platform_memmove, chkstk, AGGraph…) are symptoms of a busy main thread and should shrink as a side effect — not worth chasing individually.

Test plan

  • xcodebuild Debug build succeeds, no new warnings.
  • Hand-test: open the window with many processes; confirm scrolling/refresh stays smooth, "Show all" works, icons appear.
  • Instruments (Hangs + Time Profiler): confirm main-thread time per 2 s tick drops sharply.
  • Run a long mo clean and confirm the live report still updates and the final result is correct.

Notes

  • ⚠️ Do not auto-resolve the Sentry issues until a release soaks — the top two regressed after a prior resolve; let production confirm.
  • Branched off origin/main. Companion PR (customizable menu-bar metrics, 关于菜单栏可以自定义指标的建议 #82) to follow.

@caezium
fix(perf): kill main-thread hangs in process table, app icons, and cl…
1c75cae 
…ean reports

Every unresolved Burrow Sentry issue is an AppHang (main thread blocked >=2s), not a crash. This addresses the structural root causes behind the top buckets:

- App icons (BURROW-R/T): AppIcon walked NSWorkspace.runningApplications on the MAIN thread on every cache miss, once per process row, each 2s refresh - hundreds of O(running-apps) walks. Now resolved off-main in the existing process pass (AppIcon.resolve) which walks the app list at most once; views read a pure cache (cachedImage). The popup's few rows use a cache+async-fill path. The main thread never walks the app list.

- Process table (BURROW-1, the regressed #1, + layout-frame tail): the table's ForEach iterated the FULL process set (hundreds), rebuilding/diffing every identity each tick and forcing repeated sizeThatFits over the nested ScrollViews. Cap the ForEach to the top 100 by the current sort (with a 'Show all' affordance), fix ProcRow at 30pt so LazyVStack skips child measurement and the size cache stays stable, and make ProcessInfo Equatable so unchanged rows don't re-render.

- Clean/optimize reports (BURROW-1G/1F): OperationFlow is @mainactor and re-parsed the whole accumulated transcript (parseTaskReport/mergeSummaryFields) on the main actor for EVERY streamed line - O(n^2). Throttle the live re-parse to ~4x/s; terminal events still do a final authoritative reduce.

Audited the rest: all NSAlert.runModal() already route through runModalQuiet() (pauses Sentry ANR tracking during user-paced modals); the disk-scan and CLI-process waits run off-main; sparklines are already capped at 120 drawn points (BURROW-1M is downstream of the main-thread pressure the above fix). The framework-frame singletons (CharacterSet, swift_slowAlloc, etc.) are symptoms that shrink as a side effect.

Verified: xcodebuild Debug build succeeds with no new warnings. Do NOT auto-resolve the Sentry issues until a release soaks - the top two regressed after a prior resolve.
This was referenced Jun 16, 2026
Merged
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@caezium caezium merged commit d99be0e into main Jun 17, 2026
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@caezium caezium deleted the fix/sentry-hangs branch June 17, 2026 09:15
pull Bot pushed a commit to CrazyForks/Burrow that referenced this pull request Jun 17, 2026
@caezium
fix(perf): pre-warm software-list icons off-main (Sentry BURROW-20)
9280a36 
The uninstall/software list rendered each AppRow by calling
SoftwareIcons.icon()/version() in the row body on the main thread:
NSWorkspace.icon(forFile:) hits the app bundle and version() reads
Info.plist, so the first paint of a large /Applications list did
O(rows) disk reads on the main thread during layout — an App Hang
(Sentry BURROW-20, top frame "InstalledApp").

- SoftwareIcons is now NSLock-guarded and resolves icons + versions on
  a utility queue; icon()/version() are main-safe cache reads that
  return a placeholder/nil and fill asynchronously on a miss.
- fetch() pre-warms the cache off-main (it always runs on a background
  queue), so rows render from a pure cache read.
- InstalledApp is Equatable so unchanged rows diff cheaply.

Mirrors the off-main app-icon resolution for the process table in caezium#83.
pull Bot pushed a commit to gclm/Burrow that referenced this pull request Jun 17, 2026
@caezium
feat(menubar): customizable metric widgets in the status item (caeziu…
3574e98 
…m#82)

Replaces the fixed "42% · 5.2G" metrics string with a configurable, reorderable row of metric widgets, the way a desktop system monitor lets you pick what to glance at.

- Store.menuBarItems: an ordered [MenuBarItem] (metric + style + colour), JSON-persisted. Defaults to the historical CPU + memory pair, and only ever shows in Metrics mode (which stays opt-in - the default is still the icon), so nothing changes for existing users until they customise.

- MenuBarWidgets.swift (new): MenuBarMetric (CPU/RAM/GPU/disk/net/IO/fan/temp/battery), MenuBarWidgetStyle (value / label+value / bar / sparkline / speed-down-up / battery glyph), MenuBarColorMode (utilization/accent/mono/pressure), and MenuBarRenderer which draws the whole row into an NSImage via a drawing handler so monochrome text tracks the light/dark menu bar. Re-implemented in our own MIT Swift + Brand tokens.

- StatusBarController renders the row from the live feed: a snapshot sink (CPU/RAM/GPU/disk/fan/temp/battery + cpu/mem/gpu sparkline rings) and a 1 Hz sink (live net/disk rates + their sparklines off the ring). Drawing is a few strings + shapes; it never walks the running-app list or does other blocking work on main - consistent with the hang fixes in caezium#83.

- SettingsView > Menu Bar gains a metrics editor (add / remove / reorder, per-metric style + colour pickers) shown when Display = Metrics; edits persist and re-render the status item live.

Build: xcodebuild Debug succeeds, no new warnings. Satisfies caezium#82.
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