[macOS] Use native os_sync calls for futexes

Utilities/sync.h

@@ -17,6 +17,8 @@
 #include <sys/time.h>
 #include <unistd.h>
 #include <fcntl.h>
+#elif __APPLE__
+#include <os/os_sync_wait_on_address.h>
 #endif
 
 #ifdef _WIN32
@@ -76,6 +78,46 @@ inline int futex(volatile void* uaddr, int futex_op, uint val, const timespec* t
 {
 #ifdef __linux__
 	return syscall(SYS_futex, uaddr, futex_op, static_cast<int>(val), timeout, nullptr, static_cast<int>(mask));
+#elif __APPLE__
+	switch (futex_op)
+	{
+	case FUTEX_WAIT_PRIVATE:
+	case FUTEX_WAIT_BITSET_PRIVATE:
+	{
+	  if (timeout)
+	  {
+		const uint64_t nsec = timeout->tv_nsec + timeout->tv_sec * 1000000000ull;
+		return os_sync_wait_on_address_with_timeout(const_cast<void*>(uaddr), static_cast<uint64_t>(val), sizeof(uint), OS_SYNC_WAIT_ON_ADDRESS_NONE, OS_CLOCK_MACH_ABSOLUTE_TIME, nsec);
+	  }
+	  else
+	  {
+		return os_sync_wait_on_address(const_cast<void*>(uaddr), static_cast<uint64_t>(val), sizeof(uint), OS_SYNC_WAIT_ON_ADDRESS_NONE);
+	  }
+	}
+
+	case FUTEX_WAKE_PRIVATE:
+	case FUTEX_WAKE_BITSET_PRIVATE:
+	{
+		for (;;)
+		{
+        	int ret = 0;
+			if (val == INT32_MAX)
+			{
+				ret = os_sync_wake_by_address_all(const_cast<void*>(uaddr), sizeof(uint), OS_SYNC_WAKE_BY_ADDRESS_NONE);
+			}
+			else if (val-- >= 0)
+			{
+				ret = os_sync_wake_by_address_any(const_cast<void*>(uaddr), sizeof(uint), OS_SYNC_WAKE_BY_ADDRESS_NONE);
+			}
+			if (val <= 0 || val == INT32_MAX || (ret < 0 && errno == ENOENT))
+			{
+				return ret;
+			}
+		}
+	}
+	}
+	errno = EINVAL;
+	return -1;
 #else
 	static struct futex_manager
 	{