1 files changed, 67 insertions, 0 deletions
diff --git a/Runtime/Threads/Semaphore.h b/Runtime/Threads/Semaphore.h
new file mode 100644
index 0000000..151f64d
--- /dev/null
+++ b/Runtime/Threads/Semaphore.h
@@ -0,0 +1,67 @@
+#ifndef __SEMAPHORE_H
+#define __SEMAPHORE_H
+
+#if SUPPORT_THREADS
+
+#if UNITY_WIN || UNITY_XENON
+#	include "Winapi/PlatformSemaphore.h"
+#elif UNITY_LINUX || UNITY_PEPPER || UNITY_ANDROID || UNITY_PS3 || UNITY_BB10 || UNITY_TIZEN
+#	include "Posix/PlatformSemaphore.h"
+#else
+#	include "PlatformSemaphore.h"
+#endif
+
+#include "Runtime/Utilities/NonCopyable.h"
+
+class Semaphore : public NonCopyable
+{
+public:
+	Semaphore() { m_Semaphore.Create(); }
+	~Semaphore() { m_Semaphore.Destroy(); }
+	void Reset() { m_Semaphore.Destroy(); m_Semaphore.Create(); }
+	void WaitForSignal() { m_Semaphore.WaitForSignal(); }
+	void Signal() { m_Semaphore.Signal(); }
+
+private:
+	PlatformSemaphore m_Semaphore;
+};
+
+class SuspendableSemaphore : public NonCopyable
+{
+public:
+	explicit SuspendableSemaphore(bool suspended = true) : m_Suspended(suspended), m_SuspendedIndefinitely(false) { }
+	bool IsSuspended() const { return m_Suspended; }
+	void Reset() { m_Semaphore.Reset(); }
+	void WaitForSignal() { if (!m_Suspended) m_Semaphore.WaitForSignal(); };
+	void Signal() { if (!m_Suspended) m_Semaphore.Signal(); }
+	void Resume(bool reset = true);
+	void Suspend(bool indefinitely = false);
+
+private:
+	volatile bool m_SuspendedIndefinitely;
+	volatile bool m_Suspended;
+	Semaphore m_Semaphore;
+};
+
+inline void SuspendableSemaphore::Resume(bool reset)
+{
+	if (reset)
+		Reset();
+
+	if (!m_SuspendedIndefinitely)
+		m_Suspended = false;
+}
+
+inline void SuspendableSemaphore::Suspend(bool indefinitely)
+{
+	m_Suspended = true;
+	if (indefinitely)
+		m_SuspendedIndefinitely = indefinitely;
+
+	m_Semaphore.Signal(); // release any waiting thread
+}
+
+
+#endif // SUPPORT_THREADS
+
+#endif // __SEMAPHORE_H