Thread safety (#586)

* New EventEmitter (using NSNotificationCenter)

 - In most ways that matter NSNotificationCenter is thread safe. You
can add/remove observers from any thread and you can post notifications
from any thread.

* Events for the EventEmitter

* Fix: should cancel timers when connection times out

* Fix: new state change can occur before receiving publishing acknowledgement

* Test suite: async forced transitions

* Test suite: ack order

* Test suite: stop when there's no internet

* Fix: instance objects released to soon

* Performed a static analysis from Xcode

* fixup! Test suite: ack order

* Memory leak: call session invalidate to dispose of its strong reference to the delegate

* fixup! Test suite: ack order

* Fix RTN19a: guarantee of a new transport (check transport reference)

* Fix: ACK or NACK has not yet been received for a message, the client should consider the delivery of those messages as failed

* Enhance RTN14b: better timings

* Fix: REST and Realtime, wait for last operation to release the object

* fixup! Test suite: ack order

* Fix: cancel timers when a connection gets closed

* fixup! Test suite: ack order

* Test suite: timings

* fixup! Enhance RTN14b: better timings

* Test suite: close connections

* Fix: turn off immediately reachability when close occurs

* Fix RTC1d: wait for host is not reachable error

* fixup! Test suite: ack order

* Travis update

* Fix RTN19a

.travis.yml

@@ -15,5 +15,5 @@ script:
   # Use `travis_wait` when a long running command or compile step regularly takes longer than 10 minutes without producing any output.
   # It writes a short line to the build log every minute for 20 minutes, extending the amount of time your command has to finish.
   # Prefix `travis_wait` with a greater number to extend the wait time.
-  - travis_wait 30 scan --scheme "Ably" --open_report false
+  - scan --scheme "Ably" --open_report false --devices "iPhone 6s"
   - bash ./Scripts/run_examples_tests.sh

Examples/Tests/TestsTests/TestsTests.swift

@@ -64,17 +64,19 @@ class TestsTests: XCTestCase {
         self.waitForExpectationsWithTimeout(10, handler: nil)
 
         let backgroundRealtimeExpectation = self.expectationWithDescription("Realtime in a Background Queue")
+        var realtime: ARTRealtime! //strong reference
         NSURLSession.sharedSession().dataTaskWithURL(NSURL(string:"https://ably.io")!) { _ in
-            let realtime = ARTRealtime(key: key as String)
+            realtime = ARTRealtime(key: key as String)
             realtime.channels.get("foo").attach { _ in
                 defer { backgroundRealtimeExpectation.fulfill() }
             }
         }.resume()
         self.waitForExpectationsWithTimeout(10, handler: nil)
 
         let backgroundRestExpectation = self.expectationWithDescription("Rest in a Background Queue")
+        var rest: ARTRest! //strong reference
         NSURLSession.sharedSession().dataTaskWithURL(NSURL(string:"https://ably.io")!) { _ in
-            let rest = ARTRest(key: key as String)
+            rest = ARTRest(key: key as String)
             rest.channels.get("foo").history { _ in
                 defer { backgroundRestExpectation.fulfill() }
             }

Source/ARTAuth+Private.h

@@ -18,7 +18,7 @@ ART_ASSUME_NONNULL_BEGIN
 
 /// Messages related to the ARTAuth
 @protocol ARTAuthDelegate <NSObject>
-@property (nonatomic, readonly) __GENERIC(ARTEventEmitter, NSNumber * /*ARTAuthorizationState*/, id) *authorizationEmitter;
+@property (nonatomic, readonly) ARTEventEmitter<ARTEvent *, id> *authorizationEmitter;
 - (void)auth:(ARTAuth *)auth didAuthorize:(ARTTokenDetails *)tokenDetails;
 @end
 
@@ -42,7 +42,7 @@ ART_ASSUME_NONNULL_BEGIN
 - (ARTTokenParams *)mergeParams:(ARTTokenParams *)customParams;
 
 - (NSURL *)buildURL:(ARTAuthOptions *)options withParams:(ARTTokenParams *)params;
-- (NSMutableURLRequest *)buildRequest:(ARTAuthOptions *)options withParams:(ARTTokenParams *)params;
+- (NSMutableURLRequest *)buildRequest:(nullable ARTAuthOptions *)options withParams:(nullable ARTTokenParams *)params;
 
 // Execute the received ARTTokenRequest
 - (void)executeTokenRequest:(ARTTokenRequest *)tokenRequest callback:(void (^)(ARTTokenDetails *__art_nullable tokenDetails, NSError *__art_nullable error))callback;
@@ -70,4 +70,11 @@ ART_ASSUME_NONNULL_BEGIN
 
 @end
 
+#pragma mark - ARTEvent
+
+@interface ARTEvent (AuthorizationState)
+- (instancetype)initWithAuthorizationState:(ARTAuthorizationState)value;
++ (instancetype)newWithAuthorizationState:(ARTAuthorizationState)value;
+@end
+
 ART_ASSUME_NONNULL_END

Source/ARTAuth.m

@@ -377,11 +377,11 @@ - (void)authorize:(ARTTokenParams *)tokenParams options:(ARTAuthOptions *)authOp
     if (lastDelegate) {
         // Only the last request should remain
         [lastDelegate.authorizationEmitter off];
-        [lastDelegate.authorizationEmitter once:[NSNumber numberWithInt:ARTAuthorizationSucceeded] callback:^(id null) {
+        [lastDelegate.authorizationEmitter once:[ARTEvent newWithAuthorizationState:ARTAuthorizationSucceeded] callback:^(id null) {
             successBlock(_tokenDetails);
             [lastDelegate.authorizationEmitter off];
         }];
-        [lastDelegate.authorizationEmitter once:[NSNumber numberWithInt:ARTAuthorizationFailed] callback:^(NSError *error) {
+        [lastDelegate.authorizationEmitter once:[ARTEvent newWithAuthorizationState:ARTAuthorizationFailed] callback:^(NSError *error) {
             failureBlock(error);
             [lastDelegate.authorizationEmitter off];
         }];
@@ -402,7 +402,10 @@ - (void)authorize:(ARTTokenParams *)tokenParams options:(ARTAuthOptions *)authOp
         _tokenDetails = tokenDetails;
         _method = ARTAuthMethodToken;
 
-        if (lastDelegate) {
+        if (!tokenDetails) {
+            failureBlock([ARTErrorInfo createWithCode:0 message:@"Token details are empty"]);
+        }
+        else if (lastDelegate) {
             [lastDelegate auth:self didAuthorize:tokenDetails];
         }
         else {
@@ -506,3 +509,26 @@ - (void)toTokenDetails:(ARTAuth *)auth callback:(void (^)(ARTTokenDetails * _Nul
 }
 
 @end
+
+NSString *ARTAuthorizationStateToStr(ARTAuthorizationState state) {
+    switch (state) {
+        case ARTAuthorizationSucceeded:
+            return @"Succeeded"; //0
+        case ARTAuthorizationFailed:
+            return @"Failed"; //1
+    }
+}
+
+#pragma mark - ARTEvent
+
+@implementation ARTEvent (AuthorizationState)
+
+- (instancetype)initWithAuthorizationState:(ARTAuthorizationState)value {
+    return [self initWithString:[NSString stringWithFormat:@"ARTAuthorizationState%@", ARTAuthorizationStateToStr(value)]];
+}
+
++ (instancetype)newWithAuthorizationState:(ARTAuthorizationState)value {
+    return [[self alloc] initWithAuthorizationState:value];
+}
+
+@end

Source/ARTChannels+Private.h

@@ -17,7 +17,7 @@ extern NSString* (^__art_nullable ARTChannels_getChannelNamePrefix)();
 
 @protocol ARTChannelsDelegate <NSObject>
 
-- (id)makeChannel:(NSString *)channel options:(ARTChannelOptions *)options;
+- (id)makeChannel:(NSString *)channel options:(nullable ARTChannelOptions *)options;
 
 @end
 

Source/ARTConnection+Private.h

@@ -17,7 +17,7 @@ ART_ASSUME_NONNULL_BEGIN
 
 @interface ARTConnection ()
 
-@property (readonly, strong, nonatomic) __GENERIC(ARTEventEmitter, NSNumber *, ARTConnectionStateChange *) *eventEmitter;
+@property (readonly, strong, nonatomic) ARTEventEmitter<ARTEvent *, ARTConnectionStateChange *> *eventEmitter;
 @property(weak, nonatomic) ARTRealtime* realtime;
 
 @end

Source/ARTConnection.h

@@ -35,4 +35,11 @@ ART_EMBED_INTERFACE_EVENT_EMITTER(ARTRealtimeConnectionEvent, ARTConnectionState
 
 @end
 
+#pragma mark - ARTEvent
+
+@interface ARTEvent (ConnectionEvent)
+- (instancetype)initWithConnectionEvent:(ARTRealtimeConnectionEvent)value;
++ (instancetype)newWithConnectionEvent:(ARTRealtimeConnectionEvent)value;
+@end
+
 ART_ASSUME_NONNULL_END

Source/ARTConnection.m

@@ -20,7 +20,7 @@ @implementation ARTConnection {
 }
 
 - (instancetype)initWithRealtime:(ARTRealtime *)realtime {
-    if (self == [super init]) {
+    if (self = [super init]) {
         _queue = dispatch_queue_create("io.ably.realtime.connection", DISPATCH_QUEUE_SERIAL);
         _eventEmitter = [[ARTEventEmitter alloc] initWithQueue:_queue];
         _realtime = realtime;
@@ -78,39 +78,49 @@ - (NSString *)getRecoveryKey {
     }
 }
 
-- (__GENERIC(ARTEventListener, ARTConnectionStateChange *) *)on:(ARTRealtimeConnectionEvent)event callback:(void (^)(ARTConnectionStateChange *))cb {
-    return [_eventEmitter on:[NSNumber numberWithInt:event] callback:cb];
+- (ARTEventListener *)on:(ARTRealtimeConnectionEvent)event callback:(void (^)(ARTConnectionStateChange *))cb {
+    return [_eventEmitter on:[ARTEvent newWithConnectionEvent:event] callback:cb];
 }
 
-- (__GENERIC(ARTEventListener, ARTConnectionStateChange *) *)on:(void (^)(ARTConnectionStateChange *))cb {
+- (ARTEventListener *)on:(void (^)(ARTConnectionStateChange *))cb {
     return [_eventEmitter on:cb];
 }
 
-- (__GENERIC(ARTEventListener, ARTConnectionStateChange *) *)once:(ARTRealtimeConnectionEvent)event callback:(void (^)(ARTConnectionStateChange *))cb {
-    return [_eventEmitter once:[NSNumber numberWithInt:event] callback:cb];
+- (ARTEventListener *)once:(ARTRealtimeConnectionEvent)event callback:(void (^)(ARTConnectionStateChange *))cb {
+    return [_eventEmitter once:[ARTEvent newWithConnectionEvent:event] callback:cb];
 }
 
-- (__GENERIC(ARTEventListener, ARTConnectionStateChange *) *)once:(void (^)(ARTConnectionStateChange *))cb {
+- (ARTEventListener *)once:(void (^)(ARTConnectionStateChange *))cb {
     return [_eventEmitter once:cb];
 }
 
 - (void)off {
     [_eventEmitter off];
 }
-- (void)off:(ARTRealtimeConnectionEvent)event listener:listener {
-    [_eventEmitter off:[NSNumber numberWithInt:event] listener:listener];
+- (void)off:(ARTRealtimeConnectionEvent)event listener:(ARTEventListener *)listener {
+    [_eventEmitter off:[ARTEvent newWithConnectionEvent:event] listener:listener];
 }
 
-- (void)off:(__GENERIC(ARTEventListener, ARTConnectionStateChange *) *)listener {
+- (void)off:(ARTEventListener *)listener {
     [_eventEmitter off:listener];
 }
 
 - (void)emit:(ARTRealtimeConnectionEvent)event with:(ARTConnectionStateChange *)data {
-    [_eventEmitter emit:[NSNumber numberWithInt:event] with:data];
+    [_eventEmitter emit:[ARTEvent newWithConnectionEvent:event] with:data];
 }
 
-- (ARTEventListener *)timed:(ARTEventListener *)listener deadline:(NSTimeInterval)deadline onTimeout:(void (^)())onTimeout {
-    return [_eventEmitter timed:listener deadline:deadline onTimeout:onTimeout];
+@end
+
+#pragma mark - ARTEvent
+
+@implementation ARTEvent (ConnectionEvent)
+
+- (instancetype)initWithConnectionEvent:(ARTRealtimeConnectionEvent)value {
+    return [self initWithString:[NSString stringWithFormat:@"ARTRealtimeConnectionEvent%@", ARTRealtimeConnectionEventToStr(value)]];
+}
+
++ (instancetype)newWithConnectionEvent:(ARTRealtimeConnectionEvent)value {
+    return [[self alloc] initWithConnectionEvent:value];
 }
 
 @end

Source/ARTConnectionDetails.m

@@ -17,7 +17,7 @@ - (instancetype)initWithClientId:(NSString *__art_nullable)clientId
                   maxInboundRate:(NSInteger)maxInboundRate
               connectionStateTtl:(NSTimeInterval)connectionStateTtl
                         serverId:(NSString *)serverId {
-    if (self == [super init]) {
+    if (self = [super init]) {
         _clientId = clientId;
         _connectionKey = connectionKey;
         _maxMessageSize = maxMessageSize;

Source/ARTCrypto+Private.h

@@ -50,7 +50,7 @@ ART_ASSUME_NONNULL_BEGIN
 + (int)defaultKeyLength;
 + (int)defaultBlockLength;
 
-+ (NSData *)generateSecureRandomData:(size_t)length;
++ (nullable NSData *)generateSecureRandomData:(size_t)length;
 
 + (id<ARTChannelCipher>)cipherWithParams:(ARTCipherParams *)params;
 

Source/ARTDataEncoder.h

@@ -37,7 +37,7 @@ ART_ASSUME_NONNULL_BEGIN
 
 + (NSString *)artAddEncoding:(NSString *)encoding toString:(NSString *__art_nullable)s;
 - (NSString *)artLastEncoding;
-- (NSString *)artRemoveLastEncoding;
+- (nullable NSString *)artRemoveLastEncoding;
 
 @end
 

Source/ARTEventEmitter+Private.h

@@ -7,24 +7,18 @@
 //
 
 #include "ARTEventEmitter.h"
-#include "CompatibilityMacros.h"
 
-ART_ASSUME_NONNULL_BEGIN
+NS_ASSUME_NONNULL_BEGIN
 
-@interface __GENERIC(ARTEventEmitterEntry, ItemType) : NSObject
+@interface ARTEventEmitter<EventType, ItemType> ()
 
-@property (readwrite, strong, nonatomic) __GENERIC(ARTEventListener, ItemType) *listener;
-@property (readwrite, nonatomic) BOOL once;
+@property (nonatomic, readonly) NSNotificationCenter *notificationCenter;
+@property (nonatomic, readonly) dispatch_queue_t queue;
 
-- (instancetype)initWithListener:(__GENERIC(ARTEventListener, ItemType) *)listener once:(BOOL)once;
+@property (readonly, atomic) NSMutableDictionary<NSString *, NSMutableArray<ARTEventListener *> *> *listeners;
+@property (readonly, atomic) NSMutableArray<ARTEventListener *> *anyListeners;
 
 @end
 
-@interface __GENERIC(ARTEventEmitter, EventType, ItemType) ()
+NS_ASSUME_NONNULL_END
 
-@property (readwrite, atomic) __GENERIC(NSMutableDictionary, EventType, __GENERIC(NSMutableArray, __GENERIC(ARTEventEmitterEntry, ItemType) *) *) *listeners;
-@property (readwrite, atomic) __GENERIC(NSMutableArray, __GENERIC(ARTEventEmitterEntry, ItemType) *) *anyListeners;
-
-@end
-
-ART_ASSUME_NONNULL_END