Add spinlock support for OSX

src/configure

@@ -1050,17 +1050,30 @@ test_spinlocks()
 		return
 	fi
 
+if darwin
+then
 cat > $TMPC << EOF
-#include <pthread.h>
+#include <libkern/OSAtomic.h>
+int main(void)
+{
+	volatile OSSpinLock lock;
+	OSSpinLockTry(&lock);
+	return 0;
+}
+EOF
+else
+cat > $TMPC << EOF
+#include <pthread.h>	
 int main(void)
 {
 	volatile pthread_spinlock_t lock;
 	pthread_spin_init(&lock, 0);
 	return 0;
 }
 EOF
+fi
 
-	echocheck "Posix thread spinlock support"
+	echocheck "spinlock support"
 	if cc_check $pthr
 	then
 		echores "yes"

src/shogun/base/Parallel.h

@@ -17,11 +17,21 @@
 
 #ifdef HAVE_PTHREAD
 #ifdef USE_SPINLOCKS
+#ifdef DARWIN
+#include <libkern/OSAtomic.h>
+
+ 	#define PTHREAD_LOCK_T OSSpinLock
+	#define PTHREAD_LOCK_INIT(lock) *lock = OS_SPINLOCK_INIT
+	#define PTHREAD_LOCK_DESTROY(lock)
+	#define PTHREAD_LOCK(lock) OSSpinLockLock(lock)
+	#define PTHREAD_UNLOCK(lock) OSSpinLockUnlock(lock) 	
+#else
 	#define PTHREAD_LOCK_T pthread_spinlock_t
 	#define PTHREAD_LOCK_INIT(lock) pthread_spin_init(lock, 0)
 	#define PTHREAD_LOCK_DESTROY(lock) pthread_spin_destroy(lock)
 	#define PTHREAD_LOCK(lock) pthread_spin_lock(lock)
 	#define PTHREAD_UNLOCK(lock) pthread_spin_unlock(lock)
+#endif
 #else
 	#define PTHREAD_LOCK_T pthread_mutex_t
 	#define PTHREAD_LOCK_INIT(lock) pthread_mutex_init(lock, NULL)