The core no longer sleeps to pace itself: the frontend runs retro_run at
its own rate, so the frame throttle, the idle-vblank delay and the real
clock sync event (and its core option) are gone, and a stepping CPU hands
straight back instead of waiting 2 ms. Waits that polled now park on a
lock-free eventcount through Common/Thread/ParkingLot and are woken by
whoever changes the state: a paused GL emu thread, which also queues a
marker behind its last frame so pausing runs the render queue up to it
instead of polling; async I/O results; the software renderer when its
queue is full; Vulkan pipeline compiles; and debugger requests once
stepping ends. Boot joins the loader thread, cache shutdown joins its
read-ahead thread, and the slow-I/O simulation is removed.
The path browser, the HTTP and WebSocket servers, the Windows console and
the game info cache are left out of the core build. libretro/test gains
lrgltest, which drives the GL backend on a surfaceless EGL context through
every path that pauses or stops the emu thread; run.sh and the image
checks CI job run it on llvmpipe.
- Wait on actionComplete instead of a bare condition variable wait, which
could miss the wakeup and hang until resume.
- Serialize requesters, so two debuggers can't overwrite each other's
action, and make SetCmdValue/FlushDrawing wait too.
- Give up and withdraw the request when stepping ends, instead of waiting
forever (this deadlocked game shutdown against the Win32 GE debugger).
- Run requests during CPU stepping, which already accepted them.
- Clear the stepping state on Core_Resume from GE stepping and on
GPU_Shutdown.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>