Rewrote scheduler to use concurrent queues instead of atomic waits, added thread priorities

Makefile

@@ -56,8 +56,8 @@ UCRT_DIR      ?= C:\Program Files (x86)\Windows Kits\10\lib\10.0.22000.0\ucrt\x6
 SDK_DIR       ?= C:\Program Files (x86)\Windows Kits\10\lib\10.0.22000.0\um\x64
 
 WARNFLAGS := -Wall -Wextra -Wpedantic -Wno-gnu-anonymous-struct
-CFLAGS    := -ffunction-sections -fdata-sections $(OPTFLAGS) $(WARNFLAGS) -c
-CXXFLAGS  := -ffunction-sections -fdata-sections $(OPTFLAGS) $(WARNFLAGS) -std=c++20 -c
+CFLAGS    := -ffunction-sections -fdata-sections -march=nehalem $(OPTFLAGS) $(WARNFLAGS) -c
+CXXFLAGS  := -ffunction-sections -fdata-sections -march=nehalem $(OPTFLAGS) $(WARNFLAGS) -std=c++20 -c
 CPPFLAGS  := -Iinclude -Ithirdparty
 LDFLAGS   := -v -Wl,/OPT:REF $(OPTFLAGS) $(LIBS) -L"$(LIB_DIR:;=)" -L"$(UCRT_DIR:;=)" -L"$(SDK_DIR:;=)" lib/RT64/$(CONFIG)/RT64.lib
 

portultra/events.cpp

@@ -94,6 +94,10 @@ extern "C" void osViSetEvent(RDRAM_ARG PTR(OSMesgQueue) mq_, OSMesg msg, u32 ret
 }
 
 void vi_thread_func() {
+    Multilibultra::set_native_thread_name("VI Thread");
+    // This thread should be prioritized over every other thread in the application, as it's what allows
+    // the game to generate new audio and gfx lists.
+    Multilibultra::set_native_thread_priority(Multilibultra::ThreadPriority::Critical);
     using namespace std::chrono_literals;
     
     uint64_t total_vis = 0;
@@ -198,6 +202,9 @@ void run_rsp_microcode(uint8_t* rdram, const OSTask* task, RspUcodeFunc* ucode_f
 
 
 void task_thread_func(uint8_t* rdram, uint8_t* rom, std::atomic_flag* thread_ready) {
+    Multilibultra::set_native_thread_name("SP Task Thread");
+    Multilibultra::set_native_thread_priority(Multilibultra::ThreadPriority::Normal);
+
     // Notify the caller thread that this thread is ready.
     thread_ready->test_and_set();
     thread_ready->notify_all();
@@ -230,6 +237,10 @@ void task_thread_func(uint8_t* rdram, uint8_t* rom, std::atomic_flag* thread_rea
 
 void gfx_thread_func(uint8_t* rdram, uint8_t* rom, std::atomic_flag* thread_ready, void* window_handle) {
     using namespace std::chrono_literals;
+
+    Multilibultra::set_native_thread_name("Gfx Thread");
+    Multilibultra::set_native_thread_priority(Multilibultra::ThreadPriority::Normal);
+
     RT64Init(rom, rdram, window_handle);
     
     rsp_constants_init();

portultra/multilibultra.hpp

@@ -34,6 +34,17 @@ void resume_thread_impl(OSThread *t);
 void schedule_running_thread(OSThread *t);
 void pause_self(RDRAM_ARG1);
 void cleanup_thread(OSThread *t);
+
+enum class ThreadPriority {
+    Low,
+    Normal,
+    High,
+    VeryHigh,
+    Critical
+};
+
+void set_native_thread_name(const std::string& name);
+void set_native_thread_priority(ThreadPriority pri);
 PTR(OSThread) this_thread();
 void disable_preemption();
 void enable_preemption();

portultra/scheduler.cpp

@@ -2,7 +2,9 @@
 #include <queue>
 #include <atomic>
 #include <vector>
+#include <variant>
 
+#include "blockingconcurrentqueue.h"
 #include "multilibultra.hpp"
 
 class OSThreadComparator {
@@ -35,51 +37,51 @@ public:
     }
 };
 
+struct NotifySchedulerAction {
+
+};
+
+struct ScheduleThreadAction {
+    OSThread* t;
+};
+
+struct StopThreadAction {
+    OSThread* t;
+};
+
+struct CleanupThreadAction {
+    OSThread* t;
+};
+
+struct ReprioritizeThreadAction {
+    OSThread* t;
+    OSPri pri;
+};
+
+using ThreadAction = std::variant<NotifySchedulerAction, ScheduleThreadAction, StopThreadAction, CleanupThreadAction, ReprioritizeThreadAction>;
+
 static struct {
-    std::vector<OSThread*> to_schedule;
-    std::vector<OSThread*> to_stop;
-    std::vector<OSThread*> to_cleanup;
-    std::vector<std::pair<OSThread*, OSPri>> to_reprioritize;
-    std::mutex mutex;
-    // OSThread* running_thread;
-    std::atomic_int notify_count;
-    std::atomic_int action_count;
+    moodycamel::BlockingConcurrentQueue<ThreadAction> action_queue{};
+    OSThread* running_thread;
 
     bool can_preempt;
     std::mutex premption_mutex;
 } scheduler_context{};
 
-void handle_thread_queueing(thread_queue_t& running_thread_queue) {
-    std::lock_guard lock{scheduler_context.mutex};
-
-    if (!scheduler_context.to_schedule.empty()) {
-        OSThread* to_schedule = scheduler_context.to_schedule.back();
-        scheduler_context.to_schedule.pop_back();
-        scheduler_context.action_count.fetch_sub(1);
+void handle_thread_queueing(thread_queue_t& running_thread_queue, const ScheduleThreadAction& action) {
+    OSThread* to_schedule = action.t;
     debug_printf("[Scheduler] Scheduling thread %d\n", to_schedule->id);
     running_thread_queue.push(to_schedule);
 }
-}
 
-void handle_thread_stopping(thread_queue_t& running_thread_queue) {
-    std::lock_guard lock{scheduler_context.mutex};
-
-    while (!scheduler_context.to_stop.empty()) {
-        OSThread* to_stop = scheduler_context.to_stop.back();
-        scheduler_context.to_stop.pop_back();
-        scheduler_context.action_count.fetch_sub(1);
+void handle_thread_stopping(thread_queue_t& running_thread_queue, const StopThreadAction& action) {
+    OSThread* to_stop = action.t;
     debug_printf("[Scheduler] Stopping thread %d\n", to_stop->id);
     running_thread_queue.remove(to_stop);
 }
-}
 
-void handle_thread_cleanup(thread_queue_t& running_thread_queue, OSThread*& cur_running_thread) {
-    std::lock_guard lock{scheduler_context.mutex};
-
-    while (!scheduler_context.to_cleanup.empty()) {
-        OSThread* to_cleanup = scheduler_context.to_cleanup.back();
-        scheduler_context.to_cleanup.pop_back();
-        scheduler_context.action_count.fetch_sub(1);
+void handle_thread_cleanup(thread_queue_t& running_thread_queue, OSThread*& cur_running_thread, const CleanupThreadAction& action) {
+    OSThread* to_cleanup = action.t;
     
     debug_printf("[Scheduler] Destroying thread %d\n", to_cleanup->id);
     running_thread_queue.remove(to_cleanup);
@@ -98,30 +100,15 @@ void handle_thread_cleanup(thread_queue_t& running_thread_queue, OSThread*& cur_
     delete to_cleanup->context;
     to_cleanup->context = nullptr;
 }
-}
 
-void handle_thread_reprioritization(thread_queue_t& running_thread_queue) {
-    std::lock_guard lock{scheduler_context.mutex};
+void handle_thread_reprioritization(thread_queue_t& running_thread_queue, const ReprioritizeThreadAction& action) {
+    OSThread* to_reprioritize = action.t;
+    OSPri pri = action.pri;
     
-    while (!scheduler_context.to_reprioritize.empty()) {
-        const std::pair<OSThread*, OSPri> to_reprioritize = scheduler_context.to_reprioritize.back();
-        scheduler_context.to_reprioritize.pop_back();
-        scheduler_context.action_count.fetch_sub(1);
-        
-        debug_printf("[Scheduler] Reprioritizing thread %d to %d\n", to_reprioritize.first->id, to_reprioritize.second);
-        running_thread_queue.remove(to_reprioritize.first);
-        to_reprioritize.first->priority = to_reprioritize.second;
-        running_thread_queue.push(to_reprioritize.first);
-    }
-}
-
-void handle_scheduler_notifications() {
-    std::lock_guard lock{scheduler_context.mutex};
-    int32_t notify_count = scheduler_context.notify_count.exchange(0);
-    if (notify_count) {
-        debug_printf("Received %d notifications\n", notify_count);
-        scheduler_context.action_count.fetch_sub(notify_count);
-    }
+    debug_printf("[Scheduler] Reprioritizing thread %d to %d\n", to_reprioritize->id, pri);
+    running_thread_queue.remove(to_reprioritize);
+    to_reprioritize->priority = pri;
+    running_thread_queue.push(to_reprioritize);
 }
 
 void swap_running_thread(thread_queue_t& running_thread_queue, OSThread*& cur_running_thread) {
@@ -148,26 +135,32 @@ void scheduler_func() {
     thread_queue_t running_thread_queue{};
     OSThread* cur_running_thread = nullptr;
 
+    Multilibultra::set_native_thread_name("Scheduler Thread");
+    Multilibultra::set_native_thread_priority(Multilibultra::ThreadPriority::VeryHigh);
+
     while (true) {
+        ThreadAction action;
         OSThread* old_running_thread = cur_running_thread;
-        scheduler_context.action_count.wait(0);
+        scheduler_context.action_queue.wait_dequeue(action);
 
         std::lock_guard lock{scheduler_context.premption_mutex};
 
-        // Handle notifications
-        handle_scheduler_notifications();
-
-        // Handle stopping threads
-        handle_thread_stopping(running_thread_queue);
-
-        // Handle cleaning up threads
-        handle_thread_cleanup(running_thread_queue, cur_running_thread);
-
-        // Handle queueing threads to run
-        handle_thread_queueing(running_thread_queue);
-
-        // Handle threads that have changed priority
-        handle_thread_reprioritization(running_thread_queue);
+        // Determine the action type and act on it
+        if (const auto* cleanup_action = std::get_if<NotifySchedulerAction>(&action)) {
+            // Nothing to do
+        }
+        else if (const auto* stop_action = std::get_if<StopThreadAction>(&action)) {
+            handle_thread_stopping(running_thread_queue, *stop_action);
+        }
+        else if (const auto* cleanup_action = std::get_if<CleanupThreadAction>(&action)) {
+            handle_thread_cleanup(running_thread_queue, cur_running_thread, *cleanup_action);
+        }
+        else if (const auto* schedule_action = std::get_if<ScheduleThreadAction>(&action)) {
+            handle_thread_queueing(running_thread_queue, *schedule_action);
+        }
+        else if (const auto* reprioritize_action = std::get_if<ReprioritizeThreadAction>(&action)) {
+            handle_thread_reprioritization(running_thread_queue, *reprioritize_action);
+        }
 
         // Determine which thread to run, stopping the current running thread if necessary
         swap_running_thread(running_thread_queue, cur_running_thread);
@@ -194,51 +187,35 @@ void init_scheduler() {
 
 void schedule_running_thread(OSThread *t) {
     debug_printf("[Scheduler] Queuing Thread %d to be scheduled\n", t->id);
-    std::lock_guard lock{scheduler_context.mutex};
-    scheduler_context.to_schedule.push_back(t);
-    scheduler_context.action_count.fetch_add(1);
-    scheduler_context.action_count.notify_all();
+    scheduler_context.action_queue.enqueue(ScheduleThreadAction{t});
 }
 
 void swap_to_thread(RDRAM_ARG OSThread *to) {
     OSThread *self = TO_PTR(OSThread, Multilibultra::this_thread());
     debug_printf("[Scheduler] Scheduling swap from thread %d to %d\n", self->id, to->id);
-    {
-        std::lock_guard lock{scheduler_context.mutex};
-        scheduler_context.to_schedule.push_back(to);
+    
     Multilibultra::set_self_paused(PASS_RDRAM1);
-        scheduler_context.action_count.fetch_add(1);
-        scheduler_context.action_count.notify_all();
-    }
+    scheduler_context.action_queue.enqueue(ScheduleThreadAction{to});
     Multilibultra::wait_for_resumed(PASS_RDRAM1);
 }
 
 void reprioritize_thread(OSThread *t, OSPri pri) {
     debug_printf("[Scheduler] Adjusting Thread %d priority to %d\n", t->id, pri);
-    std::lock_guard lock{scheduler_context.mutex};
-    scheduler_context.to_reprioritize.emplace_back(t, pri);
-    scheduler_context.action_count.fetch_add(1);
-    scheduler_context.action_count.notify_all();
+
+    scheduler_context.action_queue.enqueue(ReprioritizeThreadAction{t, pri});
 }
 
 void pause_self(RDRAM_ARG1) {
     OSThread *self = TO_PTR(OSThread, Multilibultra::this_thread());
     debug_printf("[Scheduler] Thread %d pausing itself\n", self->id);
-    {
-        std::lock_guard lock{scheduler_context.mutex};
+
     Multilibultra::set_self_paused(PASS_RDRAM1);
-        scheduler_context.to_stop.push_back(self);
-        scheduler_context.action_count.fetch_add(1);
-        scheduler_context.action_count.notify_all();
-    }
+    scheduler_context.action_queue.enqueue(StopThreadAction{self});
     Multilibultra::wait_for_resumed(PASS_RDRAM1);
 }
 
 void cleanup_thread(OSThread *t) {
-    std::lock_guard lock{scheduler_context.mutex};
-    scheduler_context.to_cleanup.push_back(t);
-    scheduler_context.action_count.fetch_add(1);
-    scheduler_context.action_count.notify_all();
+    scheduler_context.action_queue.enqueue(CleanupThreadAction{t});
 }
 
 void disable_preemption() {
@@ -269,10 +246,7 @@ preemption_guard::~preemption_guard() {
 }
 
 void notify_scheduler() {
-    std::lock_guard lock{scheduler_context.mutex};
-    scheduler_context.notify_count.fetch_add(1);
-    scheduler_context.action_count.fetch_add(1);
-    scheduler_context.action_count.notify_all();
+    scheduler_context.action_queue.enqueue(NotifySchedulerAction{});
 }
 
 }

portultra/threads.cpp

@@ -43,6 +43,45 @@ void run_thread_function(uint8_t* rdram, uint64_t addr, uint64_t sp, uint64_t ar
 
 struct thread_terminated : std::exception {};
 
+#ifdef _WIN32
+void Multilibultra::set_native_thread_name(const std::string& name) {
+    std::wstring wname{name.begin(), name.end()};
+
+    HRESULT r;
+    r = SetThreadDescription(
+        GetCurrentThread(),
+        wname.c_str()
+    );
+}
+
+void Multilibultra::set_native_thread_priority(ThreadPriority pri) {
+    int nPriority = THREAD_PRIORITY_NORMAL;
+
+    // Convert ThreadPriority to Win32 priority
+    switch (pri) {
+        case ThreadPriority::Low:
+            nPriority = THREAD_PRIORITY_BELOW_NORMAL;
+            break;
+        case ThreadPriority::Normal:
+            nPriority = THREAD_PRIORITY_NORMAL;
+            break;
+        case ThreadPriority::High:
+            nPriority = THREAD_PRIORITY_ABOVE_NORMAL;
+            break;
+        case ThreadPriority::VeryHigh:
+            nPriority = THREAD_PRIORITY_HIGHEST;
+            break;
+        case ThreadPriority::Critical:
+            nPriority = THREAD_PRIORITY_TIME_CRITICAL;
+            break;
+        default:
+            throw std::runtime_error("Invalid thread priority!");
+            break;
+    }
+    // SetThreadPriority(GetCurrentThread(), nPriority);
+}
+#endif
+
 static void _thread_func(RDRAM_ARG PTR(OSThread) self_, PTR(thread_func_t) entrypoint, PTR(void) arg) {
     OSThread *self = TO_PTR(OSThread, self_);
     debug_printf("[Thread] Thread created: %d\n", self->id);
@@ -50,23 +89,17 @@ static void _thread_func(RDRAM_ARG PTR(OSThread) self_, PTR(thread_func_t) entry
     is_game_thread = true;
 
     // Set the thread name
-#ifdef _WIN32
-    std::wstring thread_name = L"Game Thread " + std::to_wstring(self->id);
-    HRESULT r;
-    r = SetThreadDescription(
-        GetCurrentThread(),
-        thread_name.c_str()
-    );
-#endif
+    Multilibultra::set_native_thread_name("Game Thread " + std::to_string(self->id));
+    Multilibultra::set_native_thread_priority(Multilibultra::ThreadPriority::High);
 
     // Set initialized to false to indicate that this thread can be started.
+    Multilibultra::set_self_paused(PASS_RDRAM1);
     self->context->initialized.store(true);
     self->context->initialized.notify_all();
 
     debug_printf("[Thread] Thread waiting to be started: %d\n", self->id);
 
     // Wait until the thread is marked as running.
-    Multilibultra::set_self_paused(PASS_RDRAM1);
     Multilibultra::wait_for_resumed(PASS_RDRAM1);
 
     debug_printf("[Thread] Thread started: %d\n", self->id);

portultra/timer.cpp

@@ -61,6 +61,9 @@ uint64_t time_now() {
 }
 
 void timer_thread(RDRAM_ARG1) {
+    Multilibultra::set_native_thread_name("Timer Thread");
+    Multilibultra::set_native_thread_priority(Multilibultra::ThreadPriority::VeryHigh);
+
     // Lambda comparator function to keep the set ordered
     auto timer_sort = [PASS_RDRAM1](PTR(OSTimer) a_, PTR(OSTimer) b_) {
         OSTimer* a = TO_PTR(OSTimer, a_);

src/recomp.cpp

@@ -139,6 +139,8 @@ __declspec(dllexport) extern "C" void start(void* window_handle, const Multilibu
     std::thread game_thread{[](void* window_handle) {
         debug_printf("[Recomp] Starting\n");
         
+        Multilibultra::set_native_thread_name("Game Start Thread");
+
         Multilibultra::preinit(rdram_buffer.get(), rom.get(), window_handle);
 
         recomp_entrypoint(rdram_buffer.get(), &context);

thirdparty/concurrentqueue.h

@@ -378,7 +378,7 @@ struct ConcurrentQueueDefaultTraits
 	// Recommended values are on the order of 1000-10000 unless the number of
 	// consumer threads exceeds the number of idle cores (in which case try 0-100).
 	// Only affects instances of the BlockingConcurrentQueue.
-	static const int MAX_SEMA_SPINS = 10000;
+	static const int MAX_SEMA_SPINS = 100;
 
 	// Whether to recycle dynamically-allocated blocks into an internal free list or
 	// not. If false, only pre-allocated blocks (controlled by the constructor