Add mesosphere (VERY VERY WIP)

mesosphere/source/threading/KMutex.cpp

@@ -0,0 +1,62 @@
+#include <mesosphere/threading/KMutex.hpp>
+#include <mesosphere/threading/KThread.hpp>
+#include <mesosphere/threading/KScheduler.hpp>
+
+namespace mesosphere
+{
+
+void KMutex::lock_slow_path(KThread &owner, KThread &requester)
+{
+    // Requester is currentThread most of (all ?) the time
+    KCriticalSection &critsec = KScheduler::GetCriticalSection();
+    std::lock_guard criticalSection{critsec};
+    if (KCoreContext::GetCurrentInstance().GetScheduler()->IsActive()) {
+        requester.SetWantedMutex((uiptr)this);
+        owner.AddMutexWaiter(requester);
+
+        // If the requester is/was running, pause it (sets status even if force-paused).
+        requester.RescheduleIfStatusEquals(KThread::SchedulingStatus::Running, KThread::SchedulingStatus::Paused);
+
+        // If the owner is force-paused, temporarily wake it.
+        if (owner.IsForcePaused()) {
+            owner.AdjustScheduling(owner.RevertForcePauseToField());
+        }
+
+        // Commit scheduler changes NOW.
+        critsec.unlock();
+        critsec.lock();
+
+        /*
+            At this point, mutex ownership has been transferred to requester or another thread (false wake).
+            Make sure the requester, now resumed, isn't in any mutex wait list.
+        */
+       owner.RemoveMutexWaiter(requester);
+    }
+}
+
+void KMutex::unlock_slow_path(KThread &owner)
+{
+    std::lock_guard criticalSection{KScheduler::GetCriticalSection()};
+    size_t count;
+    KThread *newOwner = owner.RelinquishMutex(&count, (uiptr)this);
+    native_handle_type newTag;
+
+    if (newOwner != nullptr) {
+        // Wake up new owner
+        newTag = (native_handle_type)newOwner | (count > 1 ? 1 : 0);
+        // Sets status even if force-paused.
+        newOwner->RescheduleIfStatusEquals(KThread::SchedulingStatus::Paused, KThread::SchedulingStatus::Running);
+    } else {
+        // Free the mutex.
+        newTag = 0;
+    }
+
+    // Allow previous owner to get back to forced-sleep, if no other thread wants the kmutexes it is holding.
+    if (!owner.IsDying() && owner.GetNumberOfKMutexWaiters() == 0) {
+        owner.AdjustScheduling(owner.CommitForcePauseToField());
+    }
+
+    tag = newTag;
+}
+
+}