Ensure all kernel objects are released during shutdown

This commit fixes several kernel object leaks. The most severe of them
was threads not being removed from the private handle table used for
CoreTiming events. This resulted in Threads never being released, which
in turn held references to Process, causing CodeSets to never be freed
when loading other applications.

src/core/hle/kernel/thread.cpp

@@ -37,6 +37,10 @@ void Thread::Acquire() {
     ASSERT_MSG(!ShouldWait(), "object unavailable!");
 }
 
+// TODO(yuriks): This can be removed if Thread objects are explicitly pooled in the future, allowing
+//               us to simply use a pool index or similar.
+static Kernel::HandleTable wakeup_callback_handle_table;
+
 // Lists all thread ids that aren't deleted/etc.
 static std::vector<SharedPtr<Thread>> thread_list;
 
@@ -93,6 +97,8 @@ void Thread::Stop() {
 
     // Cancel any outstanding wakeup events for this thread
     CoreTiming::UnscheduleEvent(ThreadWakeupEventType, callback_handle);
+    wakeup_callback_handle_table.Close(callback_handle);
+    callback_handle = 0;
 
     // Clean up thread from ready queue
     // This is only needed when the thread is termintated forcefully (SVC TerminateProcess)
@@ -108,6 +114,7 @@ void Thread::Stop() {
     for (auto& wait_object : wait_objects) {
         wait_object->RemoveWaitingThread(this);
     }
+    wait_objects.clear();
 
     Kernel::g_current_process->used_tls_slots[tls_index] = false;
 
@@ -268,10 +275,6 @@ void WaitCurrentThread_ArbitrateAddress(VAddr wait_address) {
     thread->status = THREADSTATUS_WAIT_ARB;
 }
 
-// TODO(yuriks): This can be removed if Thread objects are explicitly pooled in the future, allowing
-//               us to simply use a pool index or similar.
-static Kernel::HandleTable wakeup_callback_handle_table;
-
 /**
  * Callback that will wake up the thread it was scheduled for
  * @param thread_handle The handle of the thread that's been awoken
@@ -503,12 +506,16 @@ void ThreadingInit() {
 
     current_thread = nullptr;
     next_thread_id = 1;
+}
 
+void ThreadingShutdown() {
+    current_thread = nullptr;
+
+    for (auto& t : thread_list) {
+        t->Stop();
+    }
     thread_list.clear();
     ready_queue.clear();
 }
 
-void ThreadingShutdown() {
-}
-
 } // namespace

src/core/hle/service/apt/apt.cpp

@@ -406,6 +406,9 @@ void Shutdown() {
     lock = nullptr;
     notification_event = nullptr;
     parameter_event = nullptr;
+
+    next_parameter.object = nullptr;
+
     HLE::Applets::Shutdown();
 }
 

src/core/hle/service/dsp_dsp.cpp

@@ -310,4 +310,9 @@ Interface::Interface() {
     Register(FunctionTable);
 }
 
+Interface::~Interface() {
+    semaphore_event = nullptr;
+    interrupt_event = nullptr;
+}
+
 } // namespace

src/core/hle/service/dsp_dsp.h

@@ -16,6 +16,7 @@ namespace DSP_DSP {
 class Interface : public Service::Interface {
 public:
     Interface();
+    ~Interface() override;
 
     std::string GetPortName() const override {
         return "dsp::DSP";

src/core/hle/service/gsp_gpu.cpp

@@ -584,7 +584,7 @@ const Interface::FunctionInfo FunctionTable[] = {
 Interface::Interface() {
     Register(FunctionTable);
 
-    g_interrupt_event = 0;
+    g_interrupt_event = nullptr;
 
     using Kernel::MemoryPermission;
     g_shared_memory = Kernel::SharedMemory::Create(0x1000, MemoryPermission::ReadWrite,
@@ -593,4 +593,9 @@ Interface::Interface() {
     g_thread_id = 0;
 }
 
+Interface::~Interface() {
+    g_interrupt_event = nullptr;
+    g_shared_memory = nullptr;
+}
+
 } // namespace

src/core/hle/service/gsp_gpu.h

@@ -161,6 +161,7 @@ static_assert(sizeof(CommandBuffer) == 0x200, "CommandBuffer struct has incorrec
 class Interface : public Service::Interface {
 public:
     Interface();
+    ~Interface() override;
 
     std::string GetPortName() const override {
         return "gsp::Gpu";

src/core/hle/service/nwm_uds.cpp

@@ -125,4 +125,8 @@ Interface::Interface() {
     Register(FunctionTable);
 }
 
+Interface::~Interface() {
+    handle_event = nullptr;
+}
+
 } // namespace

src/core/hle/service/nwm_uds.h

@@ -16,6 +16,7 @@ namespace NWM_UDS {
 class Interface : public Service::Interface {
 public:
     Interface();
+    ~Interface() override;
 
     std::string GetPortName() const override {
         return "nwm::UDS";

src/core/hle/service/srv.cpp

@@ -68,4 +68,8 @@ Interface::Interface() {
     Register(FunctionTable);
 }
 
+Interface::~Interface() {
+    event_handle = nullptr;
+}
+
 } // namespace

src/core/hle/service/srv.h

@@ -13,6 +13,7 @@ namespace SRV {
 class Interface : public Service::Interface {
 public:
     Interface();
+    ~Interface() override;
 
     std::string GetPortName() const override {
         return "srv:";

src/core/hle/service/y2r_u.cpp

@@ -410,4 +410,8 @@ Interface::Interface() {
     Register(FunctionTable);
 }
 
+Interface::~Interface() {
+    completion_event = nullptr;
+}
+
 } // namespace

src/core/hle/service/y2r_u.h

@@ -112,6 +112,7 @@ struct ConversionConfiguration {
 class Interface : public Service::Interface {
 public:
     Interface();
+    ~Interface() override;
 
     std::string GetPortName() const override {
         return "y2r:u";