Keep the bounded nonblocking sequence protocol, but transfer text through retro_atomic words. Readers may discard overlapping writes without invoking a plain-memory data race. Use unsigned sequence arithmetic at wraparound. This adds bounded atomic word work only to ring logging.
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 libretro core is the frontend, and the headless tools are the test and
debugging hosts. The Windows, UWP, Android, iOS, macOS and SDL apps, the UI
framework and imgui go, along with what only they used: the Win32 debugger
hooks (g_frameMutex, the shutdown lock), JNI thread attachment, the Android
text drawer, RAIntegration, Discord, recent files, game installs, tilt input,
the audio resamplers, the control mapper, memstick moving and the remote ISO
and upload server modes. The web server keeps the debugger. The MSVC, Gradle
and ndk-build projects go too.
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.
Headless is the only thing that uses it, and it had its own shorter format with
no thread, file or line, so a pattern that matched a log from the app quietly
matched nothing in one from headless. Costs a wrong conclusion the first time
you do it.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
The log manager had a single external-callback slot, but the WebSocket
debugger registers one per *connection* - LogBroadcaster is a local in the
per-connection handler. So with two clients attached (the bundled JS debugger
in a browser and Tools/wsdbg, say) the second one to connect silently took the
log stream away from the first, and then whichever disconnected first cleared
the slot and stopped delivery to the other as well. A one-shot wsdbg command is
enough to do it: connect, take the stream, exit, and the long-lived listener
that was watching the log goes quiet with nothing to say why.
Make it a list with add/remove by handle. The dispatch loop holds the lock
across the callbacks so a listener can't be freed while one is running - which
is what lets LogBroadcaster delete its listener straight after removing it.
Enabling and disabling LogOutput::ExternalCallback belongs to the list now, and
disabling only happens when the last callback goes away.
libretro registers one of these too, and never removes it; it just moves to the
new call. It can't actually collide with the debugger - the libretro build
doesn't compile Core/Debugger/WebSocket at all - but there's no reason for it
to keep using an API that only has room for one caller.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
log.channel.set is meant for temporary, session-only diagnostic
tweaks (e.g. quieting a noisy channel while investigating something
over the WebSocket debugger). It was going through the same
SetLogLevel/SetEnabled calls the UI settings use, so a normal app
exit would persist whatever channels/levels the debugger last left
set, silently overwriting the user's real saved log preferences for
future runs - discovered when a later session's default logging
looked "off" for no apparent reason.
LogManager now tracks whether the debugger has touched channel
config this run and skips SaveConfig() entirely if so, leaving
whatever's already on disk untouched.
SetFileLogPath() and Shutdown() closed/reassigned fp_ without holding
logFileLock_, while LogLine() only locked around the actual fprintf,
after already reading fp_ unlocked. A concurrent SetFileLogPath() or
Shutdown() could close the FILE* mid-write from another thread. Now
all three paths hold logFileLock_ across the check-and-use of fp_.
Also fixes fp_ being left dangling (non-null but closed) if
SetFileLogPath() runs while File output is disabled.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01L4QAoxV2KY7ek4PcZw3WvY
Codex