1 files changed, 78 insertions, 0 deletions
diff --git a/src/core/hle/kernel/synchronization_object.h b/src/core/hle/kernel/synchronization_object.h
new file mode 100644
index 000000000..a0f891c97
--- /dev/null
+++ b/src/core/hle/kernel/synchronization_object.h
@@ -0,0 +1,78 @@
+// Copyright 2014 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <memory>
+#include <vector>
+
+#include "core/hle/kernel/object.h"
+
+namespace Kernel {
+
+class KernelCore;
+class Thread;
+
+/// Class that represents a Kernel object that a thread can be waiting on
+class SynchronizationObject : public Object {
+public:
+    explicit SynchronizationObject(KernelCore& kernel);
+    ~SynchronizationObject() override;
+
+    /**
+     * Check if the specified thread should wait until the object is available
+     * @param thread The thread about which we're deciding.
+     * @return True if the current thread should wait due to this object being unavailable
+     */
+    virtual bool ShouldWait(const Thread* thread) const = 0;
+
+    /// Acquire/lock the object for the specified thread if it is available
+    virtual void Acquire(Thread* thread) = 0;
+
+    /**
+     * Add a thread to wait on this object
+     * @param thread Pointer to thread to add
+     */
+    void AddWaitingThread(std::shared_ptr<Thread> thread);
+
+    /**
+     * Removes a thread from waiting on this object (e.g. if it was resumed already)
+     * @param thread Pointer to thread to remove
+     */
+    void RemoveWaitingThread(std::shared_ptr<Thread> thread);
+
+    /**
+     * Wake up all threads waiting on this object that can be awoken, in priority order,
+     * and set the synchronization result and output of the thread.
+     */
+    void WakeupAllWaitingThreads();
+
+    /**
+     * Wakes up a single thread waiting on this object.
+     * @param thread Thread that is waiting on this object to wakeup.
+     */
+    void WakeupWaitingThread(std::shared_ptr<Thread> thread);
+
+    /// Obtains the highest priority thread that is ready to run from this object's waiting list.
+    std::shared_ptr<Thread> GetHighestPriorityReadyThread() const;
+
+    /// Get a const reference to the waiting threads list for debug use
+    const std::vector<std::shared_ptr<Thread>>& GetWaitingThreads() const;
+
+private:
+    /// Threads waiting for this object to become available
+    std::vector<std::shared_ptr<Thread>> waiting_threads;
+};
+
+// Specialization of DynamicObjectCast for SynchronizationObjects
+template <>
+inline std::shared_ptr<SynchronizationObject> DynamicObjectCast<SynchronizationObject>(
+    std::shared_ptr<Object> object) {
+    if (object != nullptr && object->IsWaitable()) {
+        return std::static_pointer_cast<SynchronizationObject>(object);
+    }
+    return nullptr;
+}
+
+} // namespace Kernel