Fix data race related to RCTNetworkTask.status (#44694)

Summary:
Fix entails using non-synthesized getter, such that underlying backing is an std::atomic<RCTNetworkTaskStatus>.

In the greater scheme of things, I believe `RCTNetworkTask` should be improved as it has several `nonatomic` properties that are read and written to on different threads. Thread safety of this class seems to have been addressed on a per property basis, judging from the employment of `std::mutex` elsewhere in the implementation.

This is an attempt at fixing https://github.com/facebook/react-native/issues/44687.

## Changelog:

[iOS][FIXED] - Fix data race related to access on `RCTNetworkTask.status`.

Pull Request resolved: https://github.com/facebook/react-native/pull/44694

Test Plan: Added unit test in class `RCTNetworkTaskTests`.

Reviewed By: cortinico

Differential Revision: D59217353

Pulled By: javache

fbshipit-source-id: 1af77238ddd99db21e2e53f174a81e207d5832b2

packages/react-native/Libraries/Network/RCTNetworkTask.h

@@ -35,7 +35,7 @@ typedef NS_ENUM(NSInteger, RCTNetworkTaskStatus) {
 @property (nonatomic, copy) RCTURLRequestResponseBlock responseBlock;
 @property (nonatomic, copy) RCTURLRequestProgressBlock uploadProgressBlock;
 
-@property (nonatomic, readonly) RCTNetworkTaskStatus status;
+@property (atomic, readonly) RCTNetworkTaskStatus status;
 
 - (instancetype)initWithRequest:(NSURLRequest *)request
                         handler:(id<RCTURLRequestHandler>)handler

packages/react-native/Libraries/Network/RCTNetworkTask.mm

@@ -17,7 +17,7 @@
   id<RCTURLRequestHandler> _handler;
   dispatch_queue_t _callbackQueue;
   std::mutex _mutex;
-
+  std::atomic<RCTNetworkTaskStatus> _atomicStatus;
   RCTNetworkTask *_selfReference;
 }
 
@@ -36,7 +36,7 @@ static auto currentRequestId = std::atomic<NSUInteger>(0);
     _request = request;
     _handler = handler;
     _callbackQueue = callbackQueue;
-    _status = RCTNetworkTaskPending;
+    _atomicStatus = RCTNetworkTaskPending;
 
     dispatch_queue_set_specific(callbackQueue, (__bridge void *)self, (__bridge void *)self, NULL);
   }
@@ -45,6 +45,11 @@ static auto currentRequestId = std::atomic<NSUInteger>(0);
 
 RCT_NOT_IMPLEMENTED(-(instancetype)init)
 
+- (RCTNetworkTaskStatus)status
+{
+  return _atomicStatus;
+}
+
 - (void)invalidate
 {
   _selfReference = nil;
@@ -67,7 +72,7 @@ RCT_NOT_IMPLEMENTED(-(instancetype)init)
 
 - (void)start
 {
-  if (_status != RCTNetworkTaskPending) {
+  if (_atomicStatus != RCTNetworkTaskPending) {
     RCTLogError(@"RCTNetworkTask was already started or completed");
     return;
   }
@@ -76,18 +81,17 @@ RCT_NOT_IMPLEMENTED(-(instancetype)init)
     id token = [_handler sendRequest:_request withDelegate:self];
     if ([self validateRequestToken:token]) {
       _selfReference = self;
-      _status = RCTNetworkTaskInProgress;
+      _atomicStatus = RCTNetworkTaskInProgress;
     }
   }
 }
 
 - (void)cancel
 {
-  if (_status == RCTNetworkTaskFinished) {
+  if (_atomicStatus.exchange(RCTNetworkTaskFinished) == RCTNetworkTaskFinished) {
     return;
   }
 
-  _status = RCTNetworkTaskFinished;
   id token = _requestToken;
   if (token && [_handler respondsToSelector:@selector(cancelRequest:)]) {
     [_handler cancelRequest:token];
@@ -108,7 +112,7 @@ RCT_NOT_IMPLEMENTED(-(instancetype)init)
   }
 
   if (!valid) {
-    _status = RCTNetworkTaskFinished;
+    _atomicStatus = RCTNetworkTaskFinished;
     if (_completionBlock) {
       RCTURLRequestCompletionBlock completionBlock = _completionBlock;
       [self dispatchCallback:^{
@@ -168,7 +172,7 @@ RCT_NOT_IMPLEMENTED(-(instancetype)init)
     @try {
       [_data appendData:data];
     } @catch (NSException *exception) {
-      _status = RCTNetworkTaskFinished;
+      _atomicStatus = RCTNetworkTaskFinished;
       if (_completionBlock) {
         RCTURLRequestCompletionBlock completionBlock = _completionBlock;
         [self dispatchCallback:^{
@@ -205,7 +209,7 @@ RCT_NOT_IMPLEMENTED(-(instancetype)init)
     return;
   }
 
-  _status = RCTNetworkTaskFinished;
+  _atomicStatus = RCTNetworkTaskFinished;
   if (_completionBlock) {
     RCTURLRequestCompletionBlock completionBlock = _completionBlock;
     NSData *dataCopy = nil;

packages/rn-tester/RNTesterPods.xcodeproj/project.pbxproj

@@ -15,6 +15,7 @@
 		5C60EB1C226440DB0018C04F /* AppDelegate.mm in Sources */ = {isa = PBXBuildFile; fileRef = 5C60EB1B226440DB0018C04F /* AppDelegate.mm */; };
 		8145AE06241172D900A3F8DA /* LaunchScreen.storyboard in Resources */ = {isa = PBXBuildFile; fileRef = 8145AE05241172D900A3F8DA /* LaunchScreen.storyboard */; };
 		832F45BB2A8A6E1F0097B4E6 /* SwiftTest.swift in Sources */ = {isa = PBXBuildFile; fileRef = 832F45BA2A8A6E1F0097B4E6 /* SwiftTest.swift */; };
+		A975CA6C2C05EADF0043F72A /* RCTNetworkTaskTests.m in Sources */ = {isa = PBXBuildFile; fileRef = A975CA6B2C05EADE0043F72A /* RCTNetworkTaskTests.m */; };
 		BEB82277FE76227A15DED9EF /* libPods-RNTesterIntegrationTests.a in Frameworks */ = {isa = PBXBuildFile; fileRef = 77E101C7D8E22A8E70EE76DF /* libPods-RNTesterIntegrationTests.a */; };
 		CD10C7A5290BD4EB0033E1ED /* RCTEventEmitterTests.m in Sources */ = {isa = PBXBuildFile; fileRef = CD10C7A4290BD4EB0033E1ED /* RCTEventEmitterTests.m */; };
 		D626973C1F0D4ABDE2F9028A /* libPods-RNTesterUnitTests.a in Frameworks */ = {isa = PBXBuildFile; fileRef = D8DE57E3292D41E28251988A /* libPods-RNTesterUnitTests.a */; };
@@ -98,6 +99,7 @@
 		832F45BA2A8A6E1F0097B4E6 /* SwiftTest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; name = SwiftTest.swift; path = RNTester/SwiftTest.swift; sourceTree = "<group>"; };
 		8BFB9C61D7BDE894E24BF24F /* Pods-RNTesterUnitTests.release.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-RNTesterUnitTests.release.xcconfig"; path = "Target Support Files/Pods-RNTesterUnitTests/Pods-RNTesterUnitTests.release.xcconfig"; sourceTree = "<group>"; };
 		9B8542B8C590B51BD0588751 /* Pods-RNTester.release.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-RNTester.release.xcconfig"; path = "Target Support Files/Pods-RNTester/Pods-RNTester.release.xcconfig"; sourceTree = "<group>"; };
+		A975CA6B2C05EADE0043F72A /* RCTNetworkTaskTests.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = RCTNetworkTaskTests.m; sourceTree = "<group>"; };
 		AC474BFB29BBD4A1002BDAED /* RNTester.xctestplan */ = {isa = PBXFileReference; lastKnownFileType = text; name = RNTester.xctestplan; path = RNTester/RNTester.xctestplan; sourceTree = "<group>"; };
 		CD10C7A4290BD4EB0033E1ED /* RCTEventEmitterTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = RCTEventEmitterTests.m; sourceTree = "<group>"; };
 		D74056A5352F0925816E50E0 /* libPods-RNTester.a */ = {isa = PBXFileReference; explicitFileType = archive.ar; includeInIndex = 0; path = "libPods-RNTester.a"; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -341,6 +343,7 @@
 				E7DB20B022B2BAA4005AC45F /* RCTModuleInitTests.m */,
 				E7DB20CB22B2BAA5005AC45F /* RCTModuleMethodTests.mm */,
 				E7DB20CF22B2BAA5005AC45F /* RCTMultipartStreamReaderTests.m */,
+				A975CA6B2C05EADE0043F72A /* RCTNetworkTaskTests.m */,
 				E7DB20BE22B2BAA4005AC45F /* RCTNativeAnimatedNodesManagerTests.m */,
 				E7DB20AD22B2BAA3005AC45F /* RCTPerformanceLoggerTests.m */,
 				E7DB20C422B2BAA4005AC45F /* RCTShadowViewTests.m */,
@@ -724,6 +727,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				A975CA6C2C05EADF0043F72A /* RCTNetworkTaskTests.m in Sources */,
 				E7DB20DF22B2BAA6005AC45F /* RCTImageLoaderTests.m in Sources */,
 				E7DB20D222B2BAA6005AC45F /* RCTModuleInitNotificationRaceTests.m in Sources */,
 				E7DB20D522B2BAA6005AC45F /* RCTPerformanceLoggerTests.m in Sources */,

packages/rn-tester/RNTesterUnitTests/RCTNetworkTaskTests.m

@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#import <React/RCTNetworkTask.h>
+#import <React/RCTURLRequestHandler.h>
+#import <XCTest/XCTest.h>
+
+@interface TestHandler<RCTURLRequestHandler> : NSObject
+@end
+
+@implementation TestHandler
+- (BOOL)canHandleRequest:(NSURLRequest *)request
+{
+  return YES;
+}
+- (id)sendRequest:(NSURLRequest *)request withDelegate:(id<RCTURLRequestDelegate>)delegate
+{
+  return [[NSUUID UUID] UUIDString];
+}
+@end
+
+@interface RCTNetworkTaskTests : XCTestCase
+
+@end
+
+@implementation RCTNetworkTaskTests
+
+- (void)testCanReadTaskStatus
+{
+  NSURL *url = [[NSURL alloc] initWithString:@"https://developers.facebook.com"];
+  NSURLRequest *request = [[NSURLRequest alloc] initWithURL:url];
+  dispatch_queue_t callbackQueue =
+      dispatch_queue_create("RCTNetworkTaskTests-testCanReadTaskStatus", DISPATCH_QUEUE_SERIAL);
+  id<RCTURLRequestHandler> testHandler = (id<RCTURLRequestHandler>)[[TestHandler alloc] init];
+  RCTNetworkTask *task = [[RCTNetworkTask alloc] initWithRequest:request
+                                                         handler:testHandler
+                                                   callbackQueue:callbackQueue];
+  XCTAssertEqual(task.status, RCTNetworkTaskPending);
+  [task start];
+  XCTAssertEqual(task.status, RCTNetworkTaskInProgress);
+  [task cancel];
+  XCTAssertEqual(task.status, RCTNetworkTaskFinished);
+}
+
+@end