The core and the headless tools no longer use mutexes, condition variables,
spinlocks, std::atomic, std::thread or volatile flags. Threads hand off through
libretro-common's retro_atomic and rthreads plus a few small pieces on top of
them in Common/Thread: Thread, MpscQueue, EventCounter, ParkingLot waits and
ReaderGate. Every wait blocks until it's woken; nothing polls on a timer.
State that only one thread touches just loses its lock. The PSP filesystem,
sceIo and the savedata dialog now belong to the emulation thread: async reads
and writes run when they're queued and complete later in emulated time, and
the IO and savedata threads are gone. The friend finder only talks to the
adhoc server and hands what it gets to the emulation thread. GPU init always
runs on the thread that starts the game.
The Vulkan render and compile queues, pipeline and render pass caches, delete
list and SPIR-V cache, the GL render queue, the software renderer's jit caches,
the file loader caches, the web debugger, UPnP, input, savestates, logging and
the GE debugger all hand off through queues and atomics. The IR jit's spinning
profiler thread goes.
A CPU thread with nothing to run now sleeps until work is queued instead of
spinning. Headless with --debugger waits for a client while stopped, and ends
the run once every client that connected has left. Web server shutdown keeps
servicing the CPU queue until the server has finished.
The WebSocket debugger reads it from its own thread (input.buttons.press counts
down frames against it) while the CPU thread bumps it.
Note the input subscriber and broadcaster need no other changes for thread
safety: __CtrlUpdateButtons, __CtrlSetAnalogXY, __CtrlPeekButtons and
__CtrlPeekAnalog all take ctrlMutex internally, so routing them through
Core_RunOnCPUThread() would only add a blocking round trip.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GZq8ZtJmFY7bkX5FVkr3P9
This needs kind of a different type of cleanup, actually, but that's for
later (I want to get rid of this registration mechanism entirely).
Fixes#21239
This adds a per-game graphics option, `DisplayRefreshRate`, to override the display refresh rate.
It defaults to 60 Hz, and is located in Dev tools.
Games using variable timesteps benefit from higher refresh rates.
Closes#19319
libretroadmin