--- name: review-resource-leaks-799b879431e3 description: Audit for memory leaks, handle leaks, GDI leaks, and CPU churn user-invocable: true disable-model-invocation: true --- Enter planning mode. Systematically audit the codebase for resource leaks and unnecessary CPU churn. Use maximum parallelism — spawn explore agents for independent areas. ## Resource Categories ### 1. GDI+ object leaks GDI+ objects (brushes, pens, fonts, bitmaps, graphics) that are created but never deleted. Each leaked object consumes a GDI handle — Windows limits these per-process (~10,000). Over time, leaks cause rendering failures or crashes. **Known safe pattern**: `D2D_GetCachedBrush` and `gD2D_Res` cache objects intentionally — these are NOT leaks. The rendering pipeline uses D2D now — look for D2D resource create/release patterns and any remaining GDI+ usage in `src/lib/`. Look for: - Create without matching delete in the same scope or cleanup path - Creates inside loops or per-paint callbacks (should use `static` cached objects per `ahk-patterns.md`) - Error/early-return paths that skip cleanup ### 2. Win32 handle leaks Handles from `DllCall` that require explicit cleanup: - `CreateFile` / `CloseHandle` — named pipe handles, file handles - `OpenProcess` / `CloseHandle` — process handles for icon/info extraction - `DllCall("SetWinEventHook")` / `DllCall("UnhookWinEvent")` — event hooks - `LoadImage` / `DestroyIcon` — icon handles (HICON) - `CreateCompatibleDC` / `DeleteDC` — device contexts Look for handles stored in variables that go out of scope without cleanup, and error paths that skip `CloseHandle`. ### 3. File handle leaks `FileOpen()` calls where the file object is never closed, or where an error path skips `.Close()`. Also check for `FileAppend` in tight loops (each call opens+closes — not a leak, but a performance concern that could be replaced with a single `FileOpen` + `.Write()`). ### 4. Named pipe leaks The IPC system uses named pipes (`ipc_pipe.ahk`). Check that: - Server pipe handles are closed when clients disconnect - Client pipes are closed on process exit or reconnect - Pipe handles in error paths are cleaned up ### 5. Timer leaks `SetTimer` calls without corresponding `SetTimer(callback, 0)` to disable. A timer that fires after its context is gone can cause errors or unnecessary CPU work. Also check for one-shot timers (`SetTimer(cb, -period)`) that should be negative but aren't. ### 6. CPU churn Unnecessary polling or computation when idle: - Timers that fire frequently but do no useful work most of the time (should be adaptive or event-driven) - Polling loops that should be event-driven - Redundant recomputation in paint callbacks (should be cached and invalidated) - String concatenation for logging evaluated when logging is disabled (see `ahk-patterns.md` caller-side log guards) ### 7. Unbounded growth Data structures that grow over time without pruning: - Maps/Arrays that accumulate entries for windows that no longer exist - Caches without eviction (icon cache, process name cache) - Log buffers or event buffers without size limits ## Known Safe Patterns (Do NOT Flag) - `gD2D_Res` brush/font cache — intentional lifetime cache, cleaned up on exit - `static` buffers in hot-path functions — intentional reuse per `ahk-patterns.md` - Flight recorder ring buffer — pre-allocated, fixed size, overwrites oldest entries - Stats `.bak` sentinel files — intentional crash-safety pattern ## Explore Strategy Split by resource type for independent parallel exploration: - **D2D / GDI+** — `src/gui/gui_paint.ahk`, `src/gui/gui_overlay.ahk`, `src/gui/gui_gdip.ahk`, any file using `D2D_*` functions. Some `Gdip_*` may remain in `src/lib/` but the paint pipeline is D2D now - **Win32 handles** — `src/core/` producers, `src/shared/ipc_pipe.ahk`, DllCall-heavy files. Use `query_function_visibility.ps1` to trace cleanup call chains and `query_callchain.ps1 -Reverse` to find all callers that should reach cleanup — verify every Create/Open has a corresponding Close/Delete reachable from all callers. Use `query_global_ownership.ps1 ` to determine who declares and writes resource handles (responsible for cleanup). Use `query_impact.ps1 ` to assess the blast radius if a cleanup function is missing or broken. - **Timers** — use `query_timers.ps1` to inventory all timers, then check each for proper cleanup - **Pipe IPC** — `src/shared/ipc_pipe.ahk`, `src/pump/` files - **Data growth** — `src/shared/window_list.ahk` (window store), icon/process caches - **CPU churn** — timer callbacks, paint functions, producer polling loops ## Validation After explore agents report back, **validate every finding yourself**. Resource "leaks" are frequently false positives where cleanup happens in a different function, on a timer, or at process exit. For each candidate: 1. **Cite evidence**: "I verified by reading `file.ahk` lines X–Y" with actual code quoted. 2. **Trace the lifecycle**: Where is the resource created? Where is it supposed to be freed? Is there a cleanup function called on exit/disconnect/error? 3. **Counter-argument**: "What would make this fix unnecessary?" — Is the resource freed at process exit anyway? Is the "leak" actually a cache with bounded size? Does AHK's garbage collector handle this? 4. **Observed vs inferred**: State whether you saw a missing cleanup directly, or inferred it from the absence of a delete call (absence of evidence is not evidence — the cleanup may be elsewhere). 5. **Impact assessment**: Is this a per-paint leak (catastrophic), per-window leak (slow burn), or per-session leak (negligible)? ## Plan Format Group by severity (per-paint > per-event > per-session > theoretical): | File | Lines | Resource Type | Leak Description | Impact | Fix | |------|-------|--------------|-----------------|--------|-----| | `file.ahk` | 42–58 | D2D Brush | D2D brush created in paint loop, never released | ~60 handles/sec | Use `D2D_GetCachedBrush` or `static` | For CPU churn findings, use a separate table: | File | Lines | Pattern | Frequency | Fix | |------|-------|---------|-----------|-----| | `file.ahk` | 100–120 | Timer polls every 100ms, no-ops 99% of the time | 10/sec idle | Adaptive interval or event-driven | Ignore any existing plans — create a fresh one. --- Source attribution: cwilliams5 Original project: https://github.com/cwilliams5/Alt-Tabby/blob/6e941fe6d8344facc4f24c373f41999ff6da4c04/.claude/skills/review-resource-leaks/SKILL.md License: MIT License information: https://opensource.org/license/mit Original upstream instructions; downloaded from Mega AI Hub. ## Upstream license notice MIT License Copyright (c) 2025 Cody Williams Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. # Mega AI Hub resource metadata Creator / publisher: cwilliams5 Original project: https://github.com/cwilliams5/Alt-Tabby/blob/6e941fe6d8344facc4f24c373f41999ff6da4c04/.claude/skills/review-resource-leaks/SKILL.md Attribution basis: Source repository record Fields of work: Development & Engineering Roles: Backend Developer, DevOps / SRE, QA / Test Engineer Specialties: Backend, Testing Tools: Ahk Country applicability: Country not specified Classification basis: Source catalog labels Instruction SHA-256: 70dc40132931cc007e22c3a475f507fa8b47e3d8bd2a0fae5ae8e0c2fc576b85