Small code updates

- add a couple of atomics API updates missed from fc4f4a2
- mark C functions taking no arguments as `(void)`

SyphonDispatch.c

@@ -117,7 +117,7 @@ static atomic_uintptr_t mWorkDoneSignal = (uintptr_t)NULL;
 #pragma mark Constructor and Destructor
 
 __attribute__((destructor))
-static void finalizer()
+static void finalizer(void)
 {
 	struct timeval start;
 	if(gettimeofday(&start, NULL) == 0)
@@ -181,7 +181,7 @@ static void *_SyphonDispatchChannelLoop(SyphonDispatchChannel *channel)
 	return NULL;
 }
 
-static dispatch_semaphore_t _SyphonDispatchGetWorkSemaphore()
+static dispatch_semaphore_t _SyphonDispatchGetWorkSemaphore(void)
 {
     dispatch_semaphore_t sem = (dispatch_semaphore_t)atomic_load(&mWorkDoneSignal);
 	if (!sem)

SyphonMessageQueue.m

@@ -28,7 +28,7 @@
 */
 
 #import "SyphonMessageQueue.h"
-#import <libkern/OSAtomic.h>
+#import <stdatomic.h>
 #import <os/lock.h>
 
 /*
@@ -72,7 +72,7 @@ @implementation SyphonMessageQueue
     os_unfair_lock _lock;
     void *_head;
     OSQueueHead _pool; // TODO: or maybe manage our own within the lock as we lock anyway
-    void *_info;
+    atomic_uintptr_t _info;
 }
 
 - (id)init
@@ -186,15 +186,15 @@ - (BOOL)copyAndDequeue:(NSData **)content type:(uint32_t *)type
 
 - (void *)userInfo
 {
-	return _info;
+    return (void *)atomic_load(&_info);
 }
 
 - (void)setUserInfo:(void *)info
 {
 	bool result;
 	do {
-		void *old = _info;
-		result = OSAtomicCompareAndSwapPtrBarrier(old, info, &_info);
+		uintptr_t old = _info;
+        result = atomic_compare_exchange_strong(&_info, &old, (uintptr_t)info);
 	} while (!result);
 }
 @end

SyphonPrivate.h

@@ -31,6 +31,8 @@
 
 #ifdef __OBJC__
 
+#import <stdatomic.h> // For SyphonSafeBool
+
 #define kSyphonIdentifier @"info.v002.Syphon"
 
 // NSNotification names for Syphon's distributed notifications
@@ -60,7 +62,7 @@ extern NSString * const SyphonServerOptionStencilBufferResolution;
 
 NSString *SyphonCreateUUIDString(void) NS_RETURNS_RETAINED;
 
-typedef volatile int32_t SyphonSafeBool;
+typedef atomic_int_fast32_t SyphonSafeBool;
 
 BOOL SyphonSafeBoolGet(SyphonSafeBool *b);
 void SyphonSafeBoolSet(SyphonSafeBool *b, BOOL value);

SyphonPrivate.m

@@ -28,7 +28,6 @@
  */
 
 #import "SyphonPrivate.h"
-#import <libkern/OSAtomic.h> // For SyphonSafeBool
 
 NSString * const SyphonServerDescriptionDictionaryVersionKey = @"SyphonServerDescriptionDictionaryVersionKey";
 NSString * const SyphonServerDescriptionUUIDKey = @"SyphonServerDescriptionUUIDKey";
@@ -67,6 +66,6 @@ void SyphonSafeBoolSet(SyphonSafeBool *b, BOOL value)
 	int32_t new = value ? 1 : 0;
 	do {
 		int32_t old = *b;
-		result = OSAtomicCompareAndSwap32(old, new, b);
+        result = atomic_compare_exchange_strong(b, &old, new);
 	} while (!result);
 }

SyphonServerBase.m

@@ -15,7 +15,7 @@ + (void)retireRemainingServers;
 @end
 
 __attribute__((destructor))
-static void finalizer()
+static void finalizer(void)
 {
     [SyphonServerBase retireRemainingServers];
 }