Clear handlers on disconnect

Summary:
A few changes that should make our connect/disconnect more robust:

* Certificate provider handler should be set directly to and managed by the policy.
* Instantiate the socket once, synchronously on the connect method. Explicit deallocation once, synchronously on the disconnect method.
* Clear handlers on disconnect after clearing the delegate.
* Wait for the operation queue to drain before returning.

Reviewed By: passy

Differential Revision: D42664724

fbshipit-source-id: bd482acbb64a9bc9e36fb3418d4c81afa2109305

iOS/FlipperKit/FlipperPlatformWebSocket.h

@@ -23,15 +23,15 @@ NS_ASSUME_NONNULL_BEGIN
 /// A message handler used to dispatch messages received from the server.
 @property(nonatomic) facebook::flipper::SocketMessageHandler messageHandler;
 
-/// A certificate provider used to obtain the client certificate used for
-/// authentication.
-@property(nonatomic)
-    facebook::flipper::SocketCertificateProvider certificateProvider;
-
 /// Initializes an instance of FliperWebSocketTransport with an endpoint URL.
 /// @param url Endpoint URL used to establish the connection.
 - (instancetype)initWithURL:(NSURL* _Nonnull)url;
 
+/// A certificate provider used to obtain the client certificate used for
+/// authentication.
+- (void)setCertificateProvider:
+    (facebook::flipper::SocketCertificateProvider)certificateProvider;
+
 /// Connect to the endpoint.
 - (void)connect;
 

iOS/FlipperKit/FlipperPlatformWebSocket.mm

@@ -144,6 +144,10 @@ static constexpr int connectionKeepaliveSeconds = 10;
     return;
   }
 
+  _socket = [[SRWebSocket alloc] initWithURL:self->_url
+                              securityPolicy:self->_policy];
+  _socket.delegate = self;
+
   __weak auto weakSelf = self;
   [_dispatchQueue addOperationWithBlock:^{
     __strong auto strongSelf = weakSelf;
@@ -158,33 +162,32 @@ static constexpr int connectionKeepaliveSeconds = 10;
       return;
     }
 
-    strongSelf->_socket = [[SRWebSocket alloc] initWithURL:self->_url
-                                            securityPolicy:self->_policy];
-    strongSelf->_socket.delegate = self;
     [strongSelf->_socket open];
   }];
 }
 
 - (void)disconnect {
+  _socket.delegate = nil;
+
+  // Manually trigger a 'close' event as SocketRocket close method will
+  // not notify the delegate. SocketRocket only triggers the close event
+  // when the connection is closed from the server. Furthermore,
+  // we are clearing the delegate above.
+  _eventHandler(facebook::flipper::SocketEvent::CLOSE);
+
+  _eventHandler = [](facebook::flipper::SocketEvent) {};
+  _messageHandler = ^(const std::string&) {
+  };
+  _policy.certificateProvider = [](char* _Nonnull, size_t) { return ""; };
+
   [_dispatchQueue cancelAllOperations];
+  [_dispatchQueue waitUntilAllOperationsAreFinished];
 
   if ([_keepAlive isValid]) {
     [_keepAlive invalidate];
   }
   _keepAlive = nil;
-
-  // Manually trigger a 'close' event as SocketRocket close method will
-  // not notify the delegate. SocketRocket only triggers the close event
-  // when the connection is closed from the server.
-  _eventHandler(facebook::flipper::SocketEvent::CLOSE);
-
-  if (_socket) {
-    // Clear the socket delegate before close. Ensures that we won't get
-    // any messages after the disconnect takes place.
-    _socket.delegate = nil;
-    [_socket close];
-    _socket = nil;
-  };
+  _socket = nil;
 }
 
 - (void)send:(NSString*)message
@@ -202,7 +205,6 @@ static constexpr int connectionKeepaliveSeconds = 10;
 
 - (void)setCertificateProvider:
     (facebook::flipper::SocketCertificateProvider)certificateProvider {
-  _certificateProvider = certificateProvider;
   _policy.certificateProvider = certificateProvider;
 }
 
@@ -241,7 +243,6 @@ static constexpr int connectionKeepaliveSeconds = 10;
   } else {
     _eventHandler(facebook::flipper::SocketEvent::ERROR);
   }
-  _socket = nil;
 }
 
 - (void)_webSocketDidClose {
@@ -251,7 +252,6 @@ static constexpr int connectionKeepaliveSeconds = 10;
   _keepAlive = nil;
 
   _eventHandler(facebook::flipper::SocketEvent::CLOSE);
-  _socket = nil;
 }
 
 - (void)_webSocketDidReceiveMessage:(id)message {

iOS/FlipperKit/FlipperWebSocket.mm

@@ -112,15 +112,15 @@ bool FlipperWebSocket::connect(FlipperConnectionManager* manager) {
   };
 
   if (endpoint_.secure) {
-    socket_.certificateProvider = [this](
-                                      char* _Nonnull password, size_t length) {
-      auto pkcs12 = connectionContextStore_->getCertificate();
-      if (pkcs12.first.length() == 0) {
-        return std::string("");
-      }
-      strncpy(password, pkcs12.second.c_str(), length);
-      return pkcs12.first;
-    };
+    [socket_
+        setCertificateProvider:[this](char* _Nonnull password, size_t length) {
+          auto pkcs12 = connectionContextStore_->getCertificate();
+          if (pkcs12.first.length() == 0) {
+            return std::string("");
+          }
+          strncpy(password, pkcs12.second.c_str(), length);
+          return pkcs12.first;
+        }];
   }
 
   [socket_ connect];