core: Make CPUBarrier a unique_ptr instead of a shared_ptr

This will always outlive the Cpu instances, since it's destroyed after
we destroy the Cpu instances on shutdown, so there's no need for shared
ownership semantics here.

src/core/core.cpp

@@ -139,10 +139,10 @@ struct System::Impl {
         auto main_process = Kernel::Process::Create(kernel, "main");
         kernel.MakeCurrentProcess(main_process.get());
 
-        cpu_barrier = std::make_shared<CpuBarrier>();
+        cpu_barrier = std::make_unique<CpuBarrier>();
         cpu_exclusive_monitor = Cpu::MakeExclusiveMonitor(cpu_cores.size());
         for (std::size_t index = 0; index < cpu_cores.size(); ++index) {
-            cpu_cores[index] = std::make_shared<Cpu>(cpu_exclusive_monitor, cpu_barrier, index);
+            cpu_cores[index] = std::make_shared<Cpu>(cpu_exclusive_monitor, *cpu_barrier, index);
         }
 
         telemetry_session = std::make_unique<Core::TelemetrySession>();
@@ -283,7 +283,7 @@ struct System::Impl {
     std::unique_ptr<Tegra::GPU> gpu_core;
     std::shared_ptr<Tegra::DebugContext> debug_context;
     std::shared_ptr<ExclusiveMonitor> cpu_exclusive_monitor;
-    std::shared_ptr<CpuBarrier> cpu_barrier;
+    std::unique_ptr<CpuBarrier> cpu_barrier;
     std::array<std::shared_ptr<Cpu>, NUM_CPU_CORES> cpu_cores;
     std::array<std::unique_ptr<std::thread>, NUM_CPU_CORES - 1> cpu_core_threads;
     std::size_t active_core{}; ///< Active core, only used in single thread mode

src/core/core_cpu.cpp

@@ -49,10 +49,9 @@ bool CpuBarrier::Rendezvous() {
     return false;
 }
 
-Cpu::Cpu(std::shared_ptr<ExclusiveMonitor> exclusive_monitor,
-         std::shared_ptr<CpuBarrier> cpu_barrier, std::size_t core_index)
-    : cpu_barrier{std::move(cpu_barrier)}, core_index{core_index} {
-
+Cpu::Cpu(std::shared_ptr<ExclusiveMonitor> exclusive_monitor, CpuBarrier& cpu_barrier,
+         std::size_t core_index)
+    : cpu_barrier{cpu_barrier}, core_index{core_index} {
     if (Settings::values.use_cpu_jit) {
 #ifdef ARCHITECTURE_x86_64
         arm_interface = std::make_unique<ARM_Dynarmic>(exclusive_monitor, core_index);
@@ -83,7 +82,7 @@ std::shared_ptr<ExclusiveMonitor> Cpu::MakeExclusiveMonitor(std::size_t num_core
 
 void Cpu::RunLoop(bool tight_loop) {
     // Wait for all other CPU cores to complete the previous slice, such that they run in lock-step
-    if (!cpu_barrier->Rendezvous()) {
+    if (!cpu_barrier.Rendezvous()) {
         // If rendezvous failed, session has been killed
         return;
     }

src/core/core_cpu.h

@@ -41,8 +41,8 @@ private:
 
 class Cpu {
 public:
-    Cpu(std::shared_ptr<ExclusiveMonitor> exclusive_monitor,
-        std::shared_ptr<CpuBarrier> cpu_barrier, std::size_t core_index);
+    Cpu(std::shared_ptr<ExclusiveMonitor> exclusive_monitor, CpuBarrier& cpu_barrier,
+        std::size_t core_index);
     ~Cpu();
 
     void RunLoop(bool tight_loop = true);
@@ -77,7 +77,7 @@ private:
     void Reschedule();
 
     std::unique_ptr<ARM_Interface> arm_interface;
-    std::shared_ptr<CpuBarrier> cpu_barrier;
+    CpuBarrier& cpu_barrier;
     std::shared_ptr<Kernel::Scheduler> scheduler;
 
     std::atomic<bool> reschedule_pending = false;