Standardize property attributes and refactor private properties.

Channel/Sources/EDOBlockingQueue.h

@@ -31,10 +31,10 @@ NS_ASSUME_NONNULL_BEGIN
 @interface EDOBlockingQueue<ObjectType> : NSObject
 
 /** Whether the queue has any objects. */
-@property(readonly, getter=isEmpty) BOOL empty;
+@property(atomic, readonly, getter=isEmpty) BOOL empty;
 
 /** The number of objects in the queue. */
-@property(readonly) NSUInteger count;
+@property(atomic, readonly) NSUInteger count;
 
 /** Appends the @c object to the end of the queue.
  *

Channel/Sources/EDOChannelMultiplexer.h

@@ -39,7 +39,7 @@ NS_ASSUME_NONNULL_BEGIN
 @property(readonly, nonatomic) EDOHostPort *port;
 
 /** The number of channels that are set up with the forwarder and ready to connect. */
-@property(readonly) NSUInteger numberOfChannels;
+@property(readonly, nonatomic) NSUInteger numberOfChannels;
 
 /**
  * Starts the multiplexer on the given @c port.

Channel/Sources/EDOChannelPool.h

@@ -32,13 +32,13 @@ NS_ASSUME_NONNULL_BEGIN
 @interface EDOChannelPool : NSObject
 
 /** The singleton of @c EDOChannelPool. */
-@property(class, readonly) EDOChannelPool *sharedChannelPool;
+@property(atomic, class, readonly) EDOChannelPool *sharedChannelPool;
 
 /**
  * A port for clients to accept connection, and receive host name to register as service. This port
  * will lazily create a listen socket when accessed.
  */
-@property(readonly) UInt16 serviceConnectionPort;
+@property(nonatomic, readonly) UInt16 serviceConnectionPort;
 
 /**
  * Fetches an already-connected channel from the pool, keyed by the host @c port.

Channel/Sources/EDOHostPort.h

@@ -31,7 +31,7 @@ NS_ASSUME_NONNULL_BEGIN
  * TODO(haowoo): This will be used to identify whether the host is on a real device or a machine
  *               later, to replace deviceSerialNumber.
  */
-@property(readonly, class) NSString *deviceIdentifier;
+@property(readonly, class, nonatomic) NSString *deviceIdentifier;
 
 /** The listen port number of the host. 0 if the host port is identified by name. */
 @property(readonly, nonatomic) UInt16 port;

Device/Sources/EDODeviceConnector.h

@@ -40,9 +40,9 @@ extern NSString *const EDODeviceIDKey;
 @interface EDODeviceConnector : NSObject
 
 /** The serial numbers of connected devices. */
-@property(readonly) NSArray<NSString *> *connectedDevices;
+@property(nonatomic, readonly) NSArray<NSString *> *connectedDevices;
 /** Shared device connector. */
-@property(readonly, class) EDODeviceConnector *sharedConnector;
+@property(atomic, readonly, class) EDODeviceConnector *sharedConnector;
 
 - (instancetype)init NS_UNAVAILABLE;
 

Device/Sources/EDODeviceDetector.m

@@ -25,8 +25,6 @@ @interface EDODeviceDetector ()
  * is called.
  */
 @property(nonatomic) EDODeviceChannel *channel;
-/** @c YES if the detector has already started to listen to broadcast. */
-@property(readonly) BOOL started;
 
 @end
 
@@ -37,7 +35,7 @@ - (BOOL)listenToBroadcastWithError:(NSError **)error
   __block NSError *resultError;
   EDODeviceChannel *deviceChannel;
   @synchronized(self) {
-    if (!self.started) {
+    if (!self.channel) {
       deviceChannel = [EDODeviceChannel channelWithError:&resultError];
       self.channel = deviceChannel;
     } else {
@@ -93,10 +91,6 @@ - (void)cancel {
   }
 }
 
-- (BOOL)started {
-  return self.channel != nil;
-}
-
 #pragma mark - Private
 
 - (void)edo_scheduleReadBroadcastPacketWithHandler:(EDOBroadcastHandler)handler {

Service/Sources/EDOHostNamingService.h

@@ -32,16 +32,16 @@ NS_ASSUME_NONNULL_BEGIN
 @interface EDOHostNamingService : NSObject
 
 /** The default port number 11237 which the naming service will be listening on. */
-@property(class, readonly) UInt16 namingServerPort;
+@property(nonatomic, class, readonly) UInt16 namingServerPort;
 
 /** Shared singleton instance. */
-@property(class, readonly) EDOHostNamingService *sharedService;
+@property(atomic, class, readonly) EDOHostNamingService *sharedService;
 
 /**
  * The port for service registration. Clients can connect to this port to register their
  * services by name.
  */
-@property(readonly) UInt16 serviceConnectionPort;
+@property(nonatomic, readonly) UInt16 serviceConnectionPort;
 
 - (instancetype)init NS_UNAVAILABLE;
 

Service/Sources/EDORemoteException.h

@@ -24,7 +24,7 @@ NS_ASSUME_NONNULL_BEGIN
 @interface EDORemoteException : NSException <NSSecureCoding>
 
 /** The merged call stack traces of both client process and host process. */
-@property(readonly, copy) NSArray<NSString *> *callStackSymbols;
+@property(atomic, readonly, copy) NSArray<NSString *> *callStackSymbols;
 
 /** EDORemoteException cannot be initialized with default data members. */
 - (instancetype)init NS_UNAVAILABLE;

Service/Sources/EDOServiceRequest.h

@@ -45,7 +45,7 @@ typedef EDOServiceResponse *_Nonnull (^EDORequestHandler)(EDOServiceRequest *req
  * The sub classes should override this and provide its own handler. The default implementation
  * returns an EDOErrorRequestNotHandled response.
  */
-@property(readonly, class) EDORequestHandler requestHandler;
+@property(readonly, class, nonatomic) EDORequestHandler requestHandler;
 
 - (instancetype)initWithMessageID:(NSString *)messageID NS_UNAVAILABLE;