Revert "Refactor connectivity monitor on iOS"

1 files changed, 50 insertions, 86 deletions

diff --git a/src/objective-c/GRPCClient/GRPCCall.m b/src/objective-c/GRPCClient/GRPCCall.m
index 02492607cd..ac4596da25 100644
--- a/src/objective-c/GRPCClient/GRPCCall.m
+++ b/src/objective-c/GRPCClient/GRPCCall.m
@@ -108,9 +108,6 @@ static NSString * const kBearerPrefix = @"Bearer ";
   // The dispatch queue to be used for enqueuing responses to user. Defaulted to the main dispatch
   // queue
   dispatch_queue_t _responseQueue;
-
-  // Whether the call is finished. If it is, should not call finishWithError again.
-  BOOL _finished;
 }
 
 @synthesize state = _state;
@@ -209,8 +206,6 @@ static NSString * const kBearerPrefix = @"Bearer ";
   } else {
     [_responseWriteable enqueueSuccessfulCompletion];
   }
-
-  [GRPCConnectivityMonitor unregisterObserver:self];
 }
 
 - (void)cancelCall {
@@ -219,10 +214,9 @@ static NSString * const kBearerPrefix = @"Bearer ";
 }
 
 - (void)cancel {
-  [self maybeFinishWithError:[NSError errorWithDomain:kGRPCErrorDomain
-                                                 code:GRPCErrorCodeCancelled
-                                             userInfo:@{NSLocalizedDescriptionKey: @"Canceled by app"}]];
-
+  [self finishWithError:[NSError errorWithDomain:kGRPCErrorDomain
+                                            code:GRPCErrorCodeCancelled
+                                        userInfo:@{NSLocalizedDescriptionKey: @"Canceled by app"}]];
   if (!self.isWaitingForToken) {
     [self cancelCall];
   } else {
@@ -230,19 +224,6 @@ static NSString * const kBearerPrefix = @"Bearer ";
   }
 }
 
-- (void)maybeFinishWithError:(NSError *)errorOrNil {
-  BOOL toFinish = NO;
-  @synchronized(self) {
-    if (_finished == NO) {
-      _finished = YES;
-      toFinish = YES;
-    }
-  }
-  if (toFinish == YES) {
-    [self finishWithError:errorOrNil];
-  }
-}
-
 - (void)dealloc {
   __block GRPCWrappedCall *wrappedCall = _wrappedCall;
   dispatch_async(_callQueue, ^{
@@ -269,13 +250,11 @@ static NSString * const kBearerPrefix = @"Bearer ";
   if (self.state == GRXWriterStatePaused) {
     return;
   }
+  __weak GRPCCall *weakSelf = self;
+  __weak GRXConcurrentWriteable *weakWriteable = _responseWriteable;
 
   dispatch_async(_callQueue, ^{
-    __weak GRPCCall *weakSelf = self;
-    __weak GRXConcurrentWriteable *weakWriteable = self->_responseWriteable;
-    [self startReadWithHandler:^(grpc_byte_buffer *message) {
-      __strong GRPCCall *strongSelf = weakSelf;
-      __strong GRXConcurrentWriteable *strongWriteable = weakWriteable;
+    [weakSelf startReadWithHandler:^(grpc_byte_buffer *message) {
       if (message == NULL) {
         // No more messages from the server
         return;
@@ -287,14 +266,14 @@ static NSString * const kBearerPrefix = @"Bearer ";
         // don't want to throw, because the app shouldn't crash for a behavior
         // that's on the hands of any server to have. Instead we finish and ask
         // the server to cancel.
-        [strongSelf maybeFinishWithError:[NSError errorWithDomain:kGRPCErrorDomain
-                                                             code:GRPCErrorCodeResourceExhausted
-                                                         userInfo:@{NSLocalizedDescriptionKey: @"Client does not have enough memory to hold the server response."}]];
-        [strongSelf cancelCall];
+        [weakSelf finishWithError:[NSError errorWithDomain:kGRPCErrorDomain
+                                                      code:GRPCErrorCodeResourceExhausted
+                                                  userInfo:@{NSLocalizedDescriptionKey: @"Client does not have enough memory to hold the server response."}]];
+        [weakSelf cancelCall];
         return;
       }
-      [strongWriteable enqueueValue:data completionHandler:^{
-        [strongSelf startNextRead];
+      [weakWriteable enqueueValue:data completionHandler:^{
+        [weakSelf startNextRead];
       }];
     }];
   });
@@ -354,17 +333,12 @@ static NSString * const kBearerPrefix = @"Bearer ";
     _requestWriter.state = GRXWriterStatePaused;
   }
 
+  __weak GRPCCall *weakSelf = self;
   dispatch_async(_callQueue, ^{
-    __weak GRPCCall *weakSelf = self;
-    [self writeMessage:value withErrorHandler:^{
-      __strong GRPCCall *strongSelf = weakSelf;
-      if (strongSelf != nil) {
-        [strongSelf maybeFinishWithError:[NSError errorWithDomain:kGRPCErrorDomain
-                                                             code:GRPCErrorCodeInternal
-                                                         userInfo:nil]];
-        // Wrapped call must be canceled when error is reported to upper layers
-        [strongSelf cancelCall];
-      }
+    [weakSelf writeMessage:value withErrorHandler:^{
+      [weakSelf finishWithError:[NSError errorWithDomain:kGRPCErrorDomain
+                                                    code:GRPCErrorCodeInternal
+                                                userInfo:nil]];
     }];
   });
 }
@@ -386,15 +360,12 @@ static NSString * const kBearerPrefix = @"Bearer ";
   if (errorOrNil) {
     [self cancel];
   } else {
+    __weak GRPCCall *weakSelf = self;
     dispatch_async(_callQueue, ^{
-      __weak GRPCCall *weakSelf = self;
-      [self finishRequestWithErrorHandler:^{
-        __strong GRPCCall *strongSelf = weakSelf;
-        [strongSelf maybeFinishWithError:[NSError errorWithDomain:kGRPCErrorDomain
-                                                             code:GRPCErrorCodeInternal
-                                                         userInfo:nil]];
-        // Wrapped call must be canceled when error is reported to upper layers
-        [strongSelf cancelCall];
+      [weakSelf finishRequestWithErrorHandler:^{
+        [weakSelf finishWithError:[NSError errorWithDomain:kGRPCErrorDomain
+                                                      code:GRPCErrorCodeInternal
+                                                  userInfo:nil]];
       }];
     });
   }
@@ -416,37 +387,30 @@ static NSString * const kBearerPrefix = @"Bearer ";
 }
 
 - (void)invokeCall {
-  __weak GRPCCall *weakSelf = self;
   [self invokeCallWithHeadersHandler:^(NSDictionary *headers) {
     // Response headers received.
-    __strong GRPCCall *strongSelf = weakSelf;
-    if (strongSelf) {
-      strongSelf.responseHeaders = headers;
-      [strongSelf startNextRead];
-    }
+    self.responseHeaders = headers;
+    [self startNextRead];
   } completionHandler:^(NSError *error, NSDictionary *trailers) {
-    __strong GRPCCall *strongSelf = weakSelf;
-    if (strongSelf) {
-      strongSelf.responseTrailers = trailers;
+    self.responseTrailers = trailers;
 
-      if (error) {
-        NSMutableDictionary *userInfo = [NSMutableDictionary dictionary];
-        if (error.userInfo) {
-          [userInfo addEntriesFromDictionary:error.userInfo];
-        }
-        userInfo[kGRPCTrailersKey] = strongSelf.responseTrailers;
-        // TODO(jcanizales): The C gRPC library doesn't guarantee that the headers block will be
-        // called before this one, so an error might end up with trailers but no headers. We
-        // shouldn't call finishWithError until ater both blocks are called. It is also when this is
-        // done that we can provide a merged view of response headers and trailers in a thread-safe
-        // way.
-        if (strongSelf.responseHeaders) {
-          userInfo[kGRPCHeadersKey] = strongSelf.responseHeaders;
-        }
-        error = [NSError errorWithDomain:error.domain code:error.code userInfo:userInfo];
+    if (error) {
+      NSMutableDictionary *userInfo = [NSMutableDictionary dictionary];
+      if (error.userInfo) {
+        [userInfo addEntriesFromDictionary:error.userInfo];
+      }
+      userInfo[kGRPCTrailersKey] = self.responseTrailers;
+      // TODO(jcanizales): The C gRPC library doesn't guarantee that the headers block will be
+      // called before this one, so an error might end up with trailers but no headers. We
+      // shouldn't call finishWithError until ater both blocks are called. It is also when this is
+      // done that we can provide a merged view of response headers and trailers in a thread-safe
+      // way.
+      if (self.responseHeaders) {
+        userInfo[kGRPCHeadersKey] = self.responseHeaders;
       }
-      [strongSelf maybeFinishWithError:error];
+      error = [NSError errorWithDomain:error.domain code:error.code userInfo:userInfo];
     }
+    [self finishWithError:error];
   }];
   // Now that the RPC has been initiated, request writes can start.
   @synchronized(_requestWriter) {
@@ -475,8 +439,16 @@ static NSString * const kBearerPrefix = @"Bearer ";
     // TODO(jcanizales): Check this on init.
     [NSException raise:NSInvalidArgumentException format:@"host of %@ is nil", _host];
   }
-  [GRPCConnectivityMonitor registerObserver:self
-                                   selector:@selector(connectivityChanged:)];
+  _connectivityMonitor = [GRPCConnectivityMonitor monitorWithHost:host];
+  __weak typeof(self) weakSelf = self;
+  void (^handler)(void) = ^{
+    typeof(self) strongSelf = weakSelf;
+    [strongSelf finishWithError:[NSError errorWithDomain:kGRPCErrorDomain
+                                                    code:GRPCErrorCodeUnavailable
+                                                userInfo:@{ NSLocalizedDescriptionKey : @"Connectivity lost." }]];
+  };
+  [_connectivityMonitor handleLossWithHandler:handler
+                      wifiStatusChangeHandler:nil];
 }
 
 - (void)startWithWriteable:(id<GRXWriteable>)writeable {
@@ -540,12 +512,4 @@ static NSString * const kBearerPrefix = @"Bearer ";
   }
 }
 
-- (void)connectivityChanged:(NSNotification *)note {
-  [self maybeFinishWithError:[NSError errorWithDomain:kGRPCErrorDomain
-                                                 code:GRPCErrorCodeUnavailable
-                                             userInfo:@{ NSLocalizedDescriptionKey : @"Connectivity lost." }]];
-  // Cancel underlying call upon this notification
-  [self cancelCall];
-}
-
 @end