f7345d9a00
A wake's handoff waited until every runnable higher-priority thread pinned to the caller's core was blocked, not only the ones the wake made runnable. The host runs a lower-priority thread beside such threads at all other times, and a core's busy loaders, workers and pollers are seldom all blocked at once, so the wait had no bound. Tears of the Kingdom 1.4.3 (issue #247) stayed on an empty scene after the boot logos: on82ab25b, 84 functions / 771 NVN calls a frame, no packaged texture uploaded, 250,008 ms of handoff waits in a 180 s run; a temporary log showed BootupBackgroundWorkThread (priority 58) waiting 200-290 ms at a time for ARes Loading 1, Presentation Thread and BaseProcExecutor. Donkey Kong Country: Tropical Freeze's priority-58 job thread waited the same way for pollers (issue #259, section 6). A wake now records the woken thread in the waker's current handoff and in those the waker belongs to (note_runnable, at most four), so Metroid Dread's main thread still waits for its movie dispatcher and for the worker the dispatcher wakes. Blocking, a sleep, YieldToAnyThread (SleepThread -2, which on Horizon takes the thread off its core so that lower-priority threads run there), exit, suspension and host GPU work end a thread's hold; a handoff ends when its caller's thread SVC returns (hand_epoch). There is still no timeout, and core_preempt keeps checking every runnable peer. Checked on the Mac, without shader libraries for chain 8393d85a4eae (draws skipped): TotK on the issue #70 route for 180 s, 1,221 ms of handoff waits and the same per-frame NVN call counts and texture first uploads as9feac2f(before the unbounded handoff). Dread, fresh saves, DM_KEYS=4:A*20/0.7, 60 s: a control host with the handoff off crashed in 1 of 3 runs at sdk+0x347eb4 from main+0x225338; the limited handoff passed 12 of 12 runs, each through three decoders and two teardowns with about 12,400 handoffs. t_preempt adds three handoff-scope cases: a busy peer nobody woke (main's code never returns), a worker woken by the woken dispatcher (fails without the recorded chain), a woken thread yielding to any thread (never returns without that rule). Host tests, docs tests and an iOS syntax check of hle_thread.c pass. Gameplay with shaders, iOS and DKC itself are not checked here. Co-authored-by: HougeLangley <1161594+HougeLangley@users.noreply.github.com> Co-authored-by: aurlight <120410928+aurlight@users.noreply.github.com>
Subsystem references
How the host meets each part of a Switch game, and every failure met so far, one entry per mechanism: symptom, cause, fix (file and function), the games it was found on (linked to their notes in dm/games/<id>/README.md). Start from the symptom index when you have a log line or a visible result; the workflows that lead here are in docs/agents.
| File | Covers |
|---|---|
| packing.md | NSP script, compressed inputs and build artifacts |
| rewriter.md | The NSO rewriter patch_nso.py: jump tables, exclusive windows, patch area reach, cuts and observation gates, functions without unwind entries, stack and system registers, relocations |
| memory.md | Guest layout, heap and application pool, virtual address memory and the alias region (the SDK's node area), engine allocators, mapping SVCs, running out of memory |
| threads.md | Thread creation and cores, address arbitration, yields and spin waits, events |
| services.md | SDK calls and system services: sm connections, names that changed between SDKs, file system and saves, add-on content, input, keyboard and applets, display and operation mode, accounts and network, settings and fonts, C library and time, modules |
| movies.md | The SDK's movie library: decoder lifecycle, output slots, native-texture output, demuxers and codecs, game movie players |
| audio.md | The audio renderer and its command lists by SDK, AudioOut and devices, codecs, timing |
| frame-rate.md | The host's frame step, engine frame limiters, present intervals and display rates, CPU cost |
| nvn-objects.md | NVN object sizes, memory pools, command memory, queues and syncs, CPU-written textures, NVN entry points |
| rendering.md | The replay on Metal: textures, passes and clears, blend / depth / stencil, vertex input, uniforms and ordering, conditional rendering; the Vulkan and OpenGL layers |
| shaders.md | Shader containers by engine, control sections and code, translation, bindings and handles, shaders compiled at run time, pipelines and caches |
| game-state.md | Saves, scripted state, and game behaviour that looks like a host bug but is not |
A new general finding goes into the file and section it belongs to, in the same form, with a line in the symptom index; a fact about one game goes into that game's note.