kernel: Eliminate kernel global state

As means to pave the way for getting rid of global state within core,
This eliminates kernel global state by removing all globals. Instead
this introduces a KernelCore class which acts as a kernel instance. This
instance lives in the System class, which keeps its lifetime contained
to the lifetime of the System class.

This also forces the kernel types to actually interact with the main
kernel instance itself instead of having transient kernel state placed
all over several translation units, keeping everything together. It also
has a nice consequence of making dependencies much more explicit.

This also makes our initialization a tad bit more correct. Previously we
were creating a kernel process before the actual kernel was initialized,
which doesn't really make much sense.

The KernelCore class itself follows the PImpl idiom, which allows
keeping all the implementation details sealed away from everything else,
which forces the use of the exposed API and allows us to avoid any
unnecessary inclusions within the main kernel header.

1 files changed, 18 insertions, 101 deletions

diff --git a/src/core/hle/kernel/thread.cpp b/src/core/hle/kernel/thread.cpp
index 4ffd8d5cc..520ea0853 100644
--- a/src/core/hle/kernel/thread.cpp
+++ b/src/core/hle/kernel/thread.cpp
@@ -20,6 +20,7 @@
 #include "core/core_timing_util.h"
 #include "core/hle/kernel/errors.h"
 #include "core/hle/kernel/handle_table.h"
+#include "core/hle/kernel/kernel.h"
 #include "core/hle/kernel/object.h"
 #include "core/hle/kernel/process.h"
 #include "core/hle/kernel/thread.h"
@@ -29,9 +30,6 @@
 
 namespace Kernel {
 
-/// Event type for the thread wake up event
-static CoreTiming::EventType* ThreadWakeupEventType = nullptr;
-
 bool Thread::ShouldWait(Thread* thread) const {
     return status != ThreadStatus::Dead;
 }
@@ -40,32 +38,17 @@ void Thread::Acquire(Thread* thread) {
     ASSERT_MSG(!ShouldWait(thread), "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;
-
-// The first available thread id at startup
-static u32 next_thread_id;
-
-/**
- * Creates a new thread ID
- * @return The new thread ID
- */
-inline static u32 const NewThreadId() {
-    return next_thread_id++;
-}
-
-Thread::Thread() {}
-Thread::~Thread() {}
+Thread::Thread(KernelCore& kernel) : WaitObject{kernel} {}
+Thread::~Thread() = default;
 
 void Thread::Stop() {
     // Cancel any outstanding wakeup events for this thread
-    CoreTiming::UnscheduleEvent(ThreadWakeupEventType, callback_handle);
-    wakeup_callback_handle_table.Close(callback_handle);
+    CoreTiming::UnscheduleEvent(kernel.ThreadWakeupCallbackEventType(), callback_handle);
+    kernel.ThreadWakeupCallbackHandleTable().Close(callback_handle);
     callback_handle = 0;
 
     // Clean up thread from ready queue
-    // This is only needed when the thread is termintated forcefully (SVC TerminateProcess)
+    // This is only needed when the thread is terminated forcefully (SVC TerminateProcess)
     if (status == ThreadStatus::Ready) {
         scheduler->UnscheduleThread(this, current_priority);
     }
@@ -98,63 +81,6 @@ void ExitCurrentThread() {
     Core::System::GetInstance().CurrentScheduler().RemoveThread(thread);
 }
 
-/**
- * Callback that will wake up the thread it was scheduled for
- * @param thread_handle The handle of the thread that's been awoken
- * @param cycles_late The number of CPU cycles that have passed since the desired wakeup time
- */
-static void ThreadWakeupCallback(u64 thread_handle, int cycles_late) {
-    const auto proper_handle = static_cast<Handle>(thread_handle);
-
-    // Lock the global kernel mutex when we enter the kernel HLE.
-    std::lock_guard<std::recursive_mutex> lock(HLE::g_hle_lock);
-
-    SharedPtr<Thread> thread = wakeup_callback_handle_table.Get<Thread>(proper_handle);
-    if (thread == nullptr) {
-        LOG_CRITICAL(Kernel, "Callback fired for invalid thread {:08X}", proper_handle);
-        return;
-    }
-
-    bool resume = true;
-
-    if (thread->status == ThreadStatus::WaitSynchAny ||
-        thread->status == ThreadStatus::WaitSynchAll ||
-        thread->status == ThreadStatus::WaitHLEEvent) {
-        // Remove the thread from each of its waiting objects' waitlists
-        for (auto& object : thread->wait_objects)
-            object->RemoveWaitingThread(thread.get());
-        thread->wait_objects.clear();
-
-        // Invoke the wakeup callback before clearing the wait objects
-        if (thread->wakeup_callback)
-            resume = thread->wakeup_callback(ThreadWakeupReason::Timeout, thread, nullptr, 0);
-    }
-
-    if (thread->mutex_wait_address != 0 || thread->condvar_wait_address != 0 ||
-        thread->wait_handle) {
-        ASSERT(thread->status == ThreadStatus::WaitMutex);
-        thread->mutex_wait_address = 0;
-        thread->condvar_wait_address = 0;
-        thread->wait_handle = 0;
-
-        auto lock_owner = thread->lock_owner;
-        // Threads waking up by timeout from WaitProcessWideKey do not perform priority inheritance
-        // and don't have a lock owner unless SignalProcessWideKey was called first and the thread
-        // wasn't awakened due to the mutex already being acquired.
-        if (lock_owner) {
-            lock_owner->RemoveMutexWaiter(thread);
-        }
-    }
-
-    if (thread->arb_wait_address != 0) {
-        ASSERT(thread->status == ThreadStatus::WaitArb);
-        thread->arb_wait_address = 0;
-    }
-
-    if (resume)
-        thread->ResumeFromWait();
-}
-
 void Thread::WakeAfterDelay(s64 nanoseconds) {
     // Don't schedule a wakeup if the thread wants to wait forever
     if (nanoseconds == -1)
@@ -162,12 +88,12 @@ void Thread::WakeAfterDelay(s64 nanoseconds) {
 
     // This function might be called from any thread so we have to be cautious and use the
     // thread-safe version of ScheduleEvent.
-    CoreTiming::ScheduleEventThreadsafe(CoreTiming::nsToCycles(nanoseconds), ThreadWakeupEventType,
-                                        callback_handle);
+    CoreTiming::ScheduleEventThreadsafe(CoreTiming::nsToCycles(nanoseconds),
+                                        kernel.ThreadWakeupCallbackEventType(), callback_handle);
 }
 
 void Thread::CancelWakeupTimer() {
-    CoreTiming::UnscheduleEventThreadsafe(ThreadWakeupEventType, callback_handle);
+    CoreTiming::UnscheduleEventThreadsafe(kernel.ThreadWakeupCallbackEventType(), callback_handle);
 }
 
 static boost::optional<s32> GetNextProcessorId(u64 mask) {
@@ -294,9 +220,9 @@ static void ResetThreadContext(Core::ARM_Interface::ThreadContext& context, VAdd
     context.fpscr = 0;
 }
 
-ResultVal<SharedPtr<Thread>> Thread::Create(std::string name, VAddr entry_point, u32 priority,
-                                            u64 arg, s32 processor_id, VAddr stack_top,
-                                            SharedPtr<Process> owner_process) {
+ResultVal<SharedPtr<Thread>> Thread::Create(KernelCore& kernel, std::string name, VAddr entry_point,
+                                            u32 priority, u64 arg, s32 processor_id,
+                                            VAddr stack_top, SharedPtr<Process> owner_process) {
     // Check if priority is in ranged. Lowest priority -> highest priority id.
     if (priority > THREADPRIO_LOWEST) {
         LOG_ERROR(Kernel_SVC, "Invalid thread priority: {}", priority);
@@ -316,9 +242,9 @@ ResultVal<SharedPtr<Thread>> Thread::Create(std::string name, VAddr entry_point,
         return ResultCode(-1);
     }
 
-    SharedPtr<Thread> thread(new Thread);
+    SharedPtr<Thread> thread(new Thread(kernel));
 
-    thread->thread_id = NewThreadId();
+    thread->thread_id = kernel.CreateNewThreadID();
     thread->status = ThreadStatus::Dormant;
     thread->entry_point = entry_point;
     thread->stack_top = stack_top;
@@ -333,7 +259,7 @@ ResultVal<SharedPtr<Thread>> Thread::Create(std::string name, VAddr entry_point,
     thread->condvar_wait_address = 0;
     thread->wait_handle = 0;
     thread->name = std::move(name);
-    thread->callback_handle = wakeup_callback_handle_table.Create(thread).Unwrap();
+    thread->callback_handle = kernel.ThreadWakeupCallbackHandleTable().Create(thread).Unwrap();
     thread->owner_process = owner_process;
     thread->scheduler = Core::System::GetInstance().Scheduler(processor_id);
     thread->scheduler->AddThread(thread, priority);
@@ -383,19 +309,19 @@ void Thread::BoostPriority(u32 priority) {
     current_priority = priority;
 }
 
-SharedPtr<Thread> SetupMainThread(VAddr entry_point, u32 priority,
+SharedPtr<Thread> SetupMainThread(KernelCore& kernel, VAddr entry_point, u32 priority,
                                   SharedPtr<Process> owner_process) {
     // Setup page table so we can write to memory
     SetCurrentPageTable(&Core::CurrentProcess()->vm_manager.page_table);
 
     // Initialize new "main" thread
-    auto thread_res = Thread::Create("main", entry_point, priority, 0, THREADPROCESSORID_0,
+    auto thread_res = Thread::Create(kernel, "main", entry_point, priority, 0, THREADPROCESSORID_0,
                                      Memory::STACK_AREA_VADDR_END, std::move(owner_process));
 
     SharedPtr<Thread> thread = std::move(thread_res).Unwrap();
 
     // Register 1 must be a handle to the main thread
-    thread->guest_handle = Kernel::g_handle_table.Create(thread).Unwrap();
+    thread->guest_handle = kernel.HandleTable().Create(thread).Unwrap();
 
     thread->context.cpu_registers[1] = thread->guest_handle;
 
@@ -528,13 +454,4 @@ Thread* GetCurrentThread() {
     return Core::System::GetInstance().CurrentScheduler().GetCurrentThread();
 }
 
-void ThreadingInit() {
-    ThreadWakeupEventType = CoreTiming::RegisterEvent("ThreadWakeupCallback", ThreadWakeupCallback);
-    next_thread_id = 1;
-}
-
-void ThreadingShutdown() {
-    Kernel::ClearProcessList();
-}
-
 } // namespace Kernel