core: hle: kernel: Disable dispatch count tracking on single core.

- This would have limited value, and would be a mess to handle properly.

src/core/cpu_manager.cpp

@@ -33,7 +33,7 @@ void CpuManager::Initialize() {
             core_data[core].host_thread = std::jthread(ThreadStart, std::ref(*this), core);
         }
     } else {
-        core_data[0].host_thread = std::jthread(ThreadStart, std::ref(*this), -1);
+        core_data[0].host_thread = std::jthread(ThreadStart, std::ref(*this), 0);
     }
 }
 

src/core/hle/kernel/k_thread.cpp

@@ -14,6 +14,7 @@
 #include "common/fiber.h"
 #include "common/logging/log.h"
 #include "common/scope_exit.h"
+#include "common/settings.h"
 #include "common/thread_queue_list.h"
 #include "core/core.h"
 #include "core/cpu_manager.h"
@@ -215,9 +216,10 @@ ResultCode KThread::InitializeThread(KThread* thread, KThreadFunction func, uint
     // Initialize the thread.
     R_TRY(thread->Initialize(func, arg, user_stack_top, prio, core, owner, type));
 
-    // Initialize host context.
+    // Initialize emulation parameters.
     thread->host_context =
         std::make_shared<Common::Fiber>(std::move(init_func), init_func_parameter);
+    thread->is_single_core = !Settings::values.use_multi_core.GetValue();
 
     return ResultSuccess;
 }

src/core/hle/kernel/k_thread.h

@@ -454,8 +454,12 @@ public:
         return GetActiveCore() == 3;
     }
 
+    [[nodiscard]] bool IsDispatchTrackingDisabled() const {
+        return is_single_core || IsKernelThread();
+    }
+
     [[nodiscard]] s32 GetDisableDispatchCount() const {
-        if (IsKernelThread()) {
+        if (IsDispatchTrackingDisabled()) {
             // TODO(bunnei): Until kernel threads are emulated, we cannot enable/disable dispatch.
             return 1;
         }
@@ -464,7 +468,7 @@ public:
     }
 
     void DisableDispatch() {
-        if (IsKernelThread()) {
+        if (IsDispatchTrackingDisabled()) {
             // TODO(bunnei): Until kernel threads are emulated, we cannot enable/disable dispatch.
             return;
         }
@@ -474,7 +478,7 @@ public:
     }
 
     void EnableDispatch() {
-        if (IsKernelThread()) {
+        if (IsDispatchTrackingDisabled()) {
             // TODO(bunnei): Until kernel threads are emulated, we cannot enable/disable dispatch.
             return;
         }
@@ -727,6 +731,7 @@ private:
 
     // For emulation
     std::shared_ptr<Common::Fiber> host_context{};
+    bool is_single_core{};
 
     // For debugging
     std::vector<KSynchronizationObject*> wait_objects_for_debugging;