Use a single CHIPDeviceController for all the views in the iOS app. (#…

…1004)

We don't want to be reinitializing the CHIP stack as the user
navigates through the app.

This also fixes issues where we'd have multiple CHIPDeviceController
instances live at the same time, which would bind to the same
low-level socket and confuse the networking layer into delivering
response notifications to the wrong CHIPDeviceController.

The dealloc block for CHIPDeviceController was removed because now we
always keep it alive in a static, so it would never run anyway.

src/darwin/CHIPTool/CHIPTool/CHIPViewControllerBase.m

@@ -60,9 +60,20 @@ - (void)viewDidLoad
     UITapGestureRecognizer * tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(dismissKeyboard)];
     [self.view addGestureRecognizer:tap];
 
-    self.chipCallbackQueue = dispatch_queue_create("com.zigbee.chip.example.callback", DISPATCH_QUEUE_SERIAL);
     // initialize the device controller
-    self.chipController = [[CHIPDeviceController alloc] initWithCallbackQueue:self.chipCallbackQueue];
+    __weak typeof(self) weakSelf = self;
+    dispatch_queue_t callbackQueue = dispatch_queue_create("com.zigbee.chip.example.callback", DISPATCH_QUEUE_SERIAL);
+    self.chipController = [CHIPDeviceController sharedController];
+    [self.chipController registerCallbacks:callbackQueue
+        onMessage:^(NSData * _Nonnull message, NSString * _Nonnull ipAddress, UInt16 port) {
+            typeof(self) strongSelf = weakSelf;
+            NSString * strMessage = [[NSString alloc] initWithData:message encoding:NSUTF8StringEncoding];
+            [strongSelf postResult:[@"Echo Response: " stringByAppendingFormat:@"%@", strMessage]];
+        }
+        onError:^(NSError * _Nonnull error) {
+            typeof(self) strongSelf = weakSelf;
+            [strongSelf postResult:[@"Error: " stringByAppendingString:error.localizedDescription]];
+        }];
 
     // need to restart connections on background/foreground transitions otherwise the socket can be closed without CHIP knowing
     // about it.
@@ -107,16 +118,7 @@ - (void)_connect
     NSString * inputIPAddress = [[self _getScannedIP] length] > 0 ? [self _getScannedIP] : self.serverIPTextField.text;
     UInt16 inputPort = [self _getScannedPort] > 0 ? [self _getScannedPort] : [self.serverPortTextField.text intValue];
 
-    BOOL didConnect = [self.chipController connect:inputIPAddress
-        port:inputPort
-        error:&error
-        onMessage:^(NSData * _Nonnull message, NSString * _Nonnull ipAddress, UInt16 port) {
-            NSString * strMessage = [[NSString alloc] initWithData:message encoding:NSUTF8StringEncoding];
-            [self postResult:[@"Echo Response: " stringByAppendingFormat:@"%@", strMessage]];
-        }
-        onError:^(NSError * _Nonnull error) {
-            [self postResult:[@"Error: " stringByAppendingString:error.localizedDescription]];
-        }];
+    BOOL didConnect = [self.chipController connect:inputIPAddress port:inputPort error:&error];
     if (!didConnect) {
         [self postResult:[@"Error: " stringByAppendingString:error.localizedDescription]];
     }

src/darwin/Framework/CHIP/CHIPDeviceController.h

@@ -36,12 +36,7 @@ typedef void (^ControllerOnErrorBlock)(NSError * error);
 
 @interface CHIPDeviceController : NSObject
 
-- (nullable instancetype)initWithCallbackQueue:(dispatch_queue_t)appCallbackQueue;
-- (BOOL)connect:(NSString *)ipAddress
-           port:(UInt16)port
-          error:(NSError * __autoreleasing *)error
-      onMessage:(ControllerOnMessageBlock)onMessage
-        onError:(ControllerOnErrorBlock)onError;
+- (BOOL)connect:(NSString *)ipAddress port:(UInt16)port error:(NSError * __autoreleasing *)error;
 - (nullable AddressInfo *)getAddressInfo;
 - (BOOL)sendMessage:(NSData *)message error:(NSError * __autoreleasing *)error;
 // We can't include definitions of ChipZclClusterId_t and ChipZclCommandId_t
@@ -53,6 +48,26 @@ typedef void (^ControllerOnErrorBlock)(NSError * error);
 - (instancetype)init NS_UNAVAILABLE;
 + (instancetype)new NS_UNAVAILABLE;
 
+/**
+ * Return the single CHIPDeviceController we support existing.
+ */
++ (CHIPDeviceController *)sharedController;
+
+/**
+ * Register callbacks for network activity.
+ *
+ * @param[in] appCallbackQueue the queue that should be used to deliver the
+ *                             message/error callbacks for this consumer.
+ *
+ * @param[in] onMessage the block to call when the controller gets a message
+ *                      from the network.
+ *
+ * @param[in] onError the block to call when there is a network error.
+ */
+- (void)registerCallbacks:(dispatch_queue_t)appCallbackQueue
+                onMessage:(ControllerOnMessageBlock)onMessage
+                  onError:(ControllerOnErrorBlock)onError;
+
 @end
 
 NS_ASSUME_NONNULL_END

src/darwin/Framework/CHIP/CHIPDeviceController.mm

@@ -54,19 +54,29 @@ @interface CHIPDeviceController ()
 // primarily used to not block the work queue
 @property (atomic, readonly) dispatch_queue_t chipSelectQueue;
 // queue used to signal callbacks to the application
-@property (readonly) dispatch_queue_t appCallbackQueue;
-@property (readonly) ControllerOnMessageBlock onMessageHandler;
-@property (readonly) ControllerOnErrorBlock onErrorHandler;
+@property (readwrite) dispatch_queue_t appCallbackQueue;
+@property (readwrite) ControllerOnMessageBlock onMessageHandler;
+@property (readwrite) ControllerOnErrorBlock onErrorHandler;
 @property (readonly) chip::DeviceController::ChipDeviceController * cppController;
 
 @end
 
 @implementation CHIPDeviceController
 
-- (instancetype)initWithCallbackQueue:(dispatch_queue_t)appCallbackQueue
++ (CHIPDeviceController *)sharedController
+{
+    static CHIPDeviceController * controller = nil;
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
+        // initialize the device controller
+        controller = [[CHIPDeviceController alloc] init];
+    });
+    return controller;
+}
+
+- (instancetype)init
 {
     if (self = [super init]) {
-        _appCallbackQueue = appCallbackQueue;
         _chipWorkQueue = dispatch_queue_create(CHIP_WORK_QUEUE, DISPATCH_QUEUE_SERIAL);
         if (!_chipWorkQueue) {
             return nil;
@@ -151,11 +161,7 @@ - (void)_dispatchAsyncMessageBlock:(NSData *)data ipAddress:(NSString *)ipAddres
     });
 }
 
-- (BOOL)connect:(NSString *)ipAddress
-           port:(UInt16)port
-          error:(NSError * __autoreleasing *)error
-      onMessage:(ControllerOnMessageBlock)onMessage
-        onError:(ControllerOnErrorBlock)onError
+- (BOOL)connect:(NSString *)ipAddress port:(UInt16)port error:(NSError * __autoreleasing *)error
 {
     __block CHIP_ERROR err = CHIP_NO_ERROR;
 
@@ -178,14 +184,6 @@ - (BOOL)connect:(NSString *)ipAddress
         return NO;
     }
 
-    // Set the callback handlers
-    if (onMessage) {
-        _onMessageHandler = onMessage;
-    }
-    if (onError) {
-        _onErrorHandler = onError;
-    }
-
     // Start the IO pump
     [self _serviceEvents];
 
@@ -353,12 +351,11 @@ - (void)_serviceEvents
     });
 }
 
-- (void)dealloc
+- (void)registerCallbacks:appCallbackQueue onMessage:(ControllerOnMessageBlock)onMessage onError:(ControllerOnErrorBlock)onError
 {
-    // no more references to this object so immediately stop the inner controller
-    _cppController->Shutdown();
-    delete _cppController;
-    _cppController = NULL;
+    self.appCallbackQueue = appCallbackQueue;
+    self.onMessageHandler = onMessage;
+    self.onErrorHandler = onError;
 }
 
 @end

src/darwin/Framework/CHIP/CHIPEchoClient.mm

@@ -39,11 +39,8 @@ - (instancetype)initWithServerAddress:(NSString *)ipAddress port:(UInt16)port
     if (self = [super init]) {
         NSError * error;
         _echoCallbackQueue = dispatch_queue_create("com.zigbee.chip.echo", NULL);
-        _chipController = [[CHIPDeviceController alloc] initWithCallbackQueue:_echoCallbackQueue];
-
-        BOOL didInit = [_chipController connect:ipAddress
-            port:port
-            error:&error
+        _chipController = [CHIPDeviceController sharedController];
+        [self.chipController registerCallbacks:_echoCallbackQueue
             onMessage:^(NSData * _Nonnull message, NSString * _Nonnull ipAddress, UInt16 port) {
                 NSData * sentMessage = [kEchoString dataUsingEncoding:NSUTF8StringEncoding];
                 if ([sentMessage isEqualToData:message]) {
@@ -57,6 +54,8 @@ - (instancetype)initWithServerAddress:(NSString *)ipAddress port:(UInt16)port
                 [self stop];
             }];
 
+        BOOL didInit = [_chipController connect:ipAddress port:port error:&error];
+
         if (!didInit) {
             os_log(OS_LOG_DEFAULT, "Failed to init with error %@", error);
             return nil;