Utilities: Add TryWait and spin waits to semaphore and mutex

common/Darwin/DarwinSemaphore.cpp

@@ -226,6 +226,14 @@ bool Threading::Semaphore::Wait(const wxTimeSpan& timeout)
 #endif
 }
 
+bool Threading::Semaphore::TryWait()
+{
+	int counter = __atomic_load_n(&m_counter, __ATOMIC_RELAXED);
+	while (counter > 0 && !__atomic_compare_exchange_n(&m_counter, &counter, counter - 1, true, __ATOMIC_ACQUIRE, __ATOMIC_RELAXED))
+		;
+	return counter > 0;
+}
+
 // Performs an uncancellable wait on a semaphore; restoring the thread's previous cancel state
 // after the wait has completed.  Useful for situations where the semaphore itself is stored on
 // the stack and passed to another thread via GUI message or such, avoiding complications where

common/Mutex.cpp

@@ -262,6 +262,24 @@ void Threading::Mutex::Wait()
 	Release();
 }
 
+// Like wait but spins for a while before sleeping the thread
+void Threading::Mutex::WaitWithSpin()
+{
+	u32 waited = 0;
+	while (true)
+	{
+		if (TryAcquire())
+		{
+			Release();
+			return;
+		}
+		if (waited >= SPIN_TIME_NS)
+			break;
+		waited += ShortSpin();
+	}
+	Wait();
+}
+
 void Threading::Mutex::WaitWithoutYield()
 {
 	AcquireWithoutYield();

common/Semaphore.cpp

@@ -165,6 +165,11 @@ void Threading::Semaphore::WaitNoCancel(const wxTimeSpan& timeout)
 	pthread_setcancelstate(oldstate, NULL);
 }
 
+bool Threading::Semaphore::TryWait()
+{
+	return sem_trywait(&m_sema) == 0;
+}
+
 int Threading::Semaphore::Count()
 {
 	int retval;

common/Threading.h

@@ -28,6 +28,7 @@
 #endif
 #include "common/Pcsx2Defs.h"
 #include "common/TraceLog.h"
+#include "common/General.h"
 
 #undef Yield // release the burden of windows.h global namespace spam.
 
@@ -256,6 +257,20 @@ namespace Threading
 		bool WaitWithoutYield(const wxTimeSpan& timeout);
 		void WaitNoCancel();
 		void WaitNoCancel(const wxTimeSpan& timeout);
+		void WaitWithoutYieldWithSpin()
+		{
+			u32 waited = 0;
+			while (true)
+			{
+				if (TryWait())
+					return;
+				if (waited >= SPIN_TIME_NS)
+					break;
+				waited += ShortSpin();
+			}
+			WaitWithoutYield();
+		}
+		bool TryWait();
 		int Count();
 
 		void Wait();
@@ -285,6 +300,7 @@ namespace Threading
 		bool AcquireWithoutYield(const wxTimeSpan& timeout);
 
 		void Wait();
+		void WaitWithSpin();
 		bool Wait(const wxTimeSpan& timeout);
 		void WaitWithoutYield();
 		bool WaitWithoutYield(const wxTimeSpan& timeout);