Reverts "Timing: Fixes timer when app get into background (#24649)" (#27073)

Summary:
This PR reverts commit 338298417f that is causing https://github.com/facebook/react-native/issues/26696 #26995.
> app would be closed immediately after going to background on iOS 13.1/13.2 and was investigated by minhtc https://github.com/facebook/react-native/issues/26696#issuecomment-548056694. The commit that is being reverted is apparently causing the app to be closed immediately. This has to be reverted in master separately as the file differs there.

Similar PR for 0.61. branch https://github.com/facebook/react-native/pull/27065

## Changelog

[iOS] [Fixed] - Fix apps crashing on iOS 13.x when running timer in the background
Pull Request resolved: https://github.com/facebook/react-native/pull/27073

Test Plan: Try [this](338298417f (commitcomment-35745287)) snippet on iOS 13.1/13.2, the app should not crash anymore

Differential Revision: D18323679

Pulled By: cpojer

fbshipit-source-id: 3af7036a0e1d3811924e581c649b16e5a4667e83

React/CoreModules/RCTTiming.mm

@@ -12,9 +12,9 @@
 #import <React/RCTAssert.h>
 #import <React/RCTBridge+Private.h>
 #import <React/RCTBridge.h>
+#import <React/RCTConvert.h>
 #import <React/RCTLog.h>
 #import <React/RCTUtils.h>
-#import <React/RCTConvert.h>
 
 #import "CoreModulesPlugins.h"
 
@@ -75,8 +75,7 @@ static const NSTimeInterval kIdleCallbackFrameDeadline = 0.001;
 @end
 
 // NSTimer retains its target, insert this class to break potential retain cycles
-@implementation _RCTTimingProxy
+@implementation _RCTTimingProxy {
-{
   __weak id _target;
 }
 
@@ -96,16 +95,14 @@ static const NSTimeInterval kIdleCallbackFrameDeadline = 0.001;
 
 @end
 
-@interface RCTTiming() <NativeTimingSpec>
+@interface RCTTiming () <NativeTimingSpec>
 @end
 
-@implementation RCTTiming
+@implementation RCTTiming {
-{
   NSMutableDictionary<NSNumber *, _RCTTimer *> *_timers;
   NSTimer *_sleepTimer;
   BOOL _sendIdleEvents;
   BOOL _inBackground;
-  UIBackgroundTaskIdentifier _backgroundTaskIdentifier;
   id<RCTTimingDelegate> _timingDelegate;
 }
 
@@ -115,7 +112,7 @@ static const NSTimeInterval kIdleCallbackFrameDeadline = 0.001;
 
 RCT_EXPORT_MODULE()
 
-- (instancetype)initWithDelegate:(id<RCTTimingDelegate>) delegate
+- (instancetype)initWithDelegate:(id<RCTTimingDelegate>)delegate
 {
   if (self = [super init]) {
     [self setup];
@@ -136,19 +133,19 @@ RCT_EXPORT_MODULE()
   _paused = YES;
   _timers = [NSMutableDictionary new];
   _inBackground = NO;
-  _backgroundTaskIdentifier = UIBackgroundTaskInvalid;
 
-  for (NSString *name in @[UIApplicationWillResignActiveNotification,
+  for (NSString *name in @[
-                           UIApplicationDidEnterBackgroundNotification,
+         UIApplicationWillResignActiveNotification,
-                           UIApplicationWillTerminateNotification]) {
+         UIApplicationDidEnterBackgroundNotification,
+         UIApplicationWillTerminateNotification
+       ]) {
     [[NSNotificationCenter defaultCenter] addObserver:self
                                              selector:@selector(appDidMoveToBackground)
                                                  name:name
                                                object:nil];
   }
 
-  for (NSString *name in @[UIApplicationDidBecomeActiveNotification,
+  for (NSString *name in @[ UIApplicationDidBecomeActiveNotification, UIApplicationWillEnterForegroundNotification ]) {
-                           UIApplicationWillEnterForegroundNotification]) {
     [[NSNotificationCenter defaultCenter] addObserver:self
                                              selector:@selector(appDidMoveToForeground)
                                                  name:name
@@ -158,34 +155,9 @@ RCT_EXPORT_MODULE()
 
 - (void)dealloc
 {
-  [self markEndOfBackgroundTaskIfNeeded];
   [_sleepTimer invalidate];
 }
 
-- (void)markStartOfBackgroundTaskIfNeeded
-{
-  if (_backgroundTaskIdentifier == UIBackgroundTaskInvalid) {
-    __weak RCTTiming *weakSelf = self;
-    // Marks the beginning of a new long-running background task. We can run the timer in the background.
-    _backgroundTaskIdentifier = [[UIApplication sharedApplication] beginBackgroundTaskWithName:@"rct.timing.gb.task" expirationHandler:^{
-      RCTTiming *strongSelf = weakSelf;
-      if (!strongSelf) {
-        return;
-      }
-      // Mark the end of background task
-      [strongSelf markEndOfBackgroundTaskIfNeeded];
-    }];
-  }
-}
-
-- (void)markEndOfBackgroundTaskIfNeeded
-{
-  if (_backgroundTaskIdentifier != UIBackgroundTaskInvalid) {
-    [[UIApplication sharedApplication] endBackgroundTask:_backgroundTaskIdentifier];
-    _backgroundTaskIdentifier = UIBackgroundTaskInvalid;
-  }
-}
-
 - (dispatch_queue_t)methodQueue
 {
   return RCTJSThread;
@@ -211,7 +183,6 @@ RCT_EXPORT_MODULE()
 
 - (void)appDidMoveToForeground
 {
-  [self markEndOfBackgroundTaskIfNeeded];
   _inBackground = NO;
   [self startTimers];
 }
@@ -246,7 +217,7 @@ RCT_EXPORT_MODULE()
 
 - (BOOL)hasPendingTimers
 {
-  @synchronized (_timers) {
+  @synchronized(_timers) {
     return _sendIdleEvents || _timers.count > 0;
   }
 }
@@ -256,7 +227,7 @@ RCT_EXPORT_MODULE()
   NSDate *nextScheduledTarget = [NSDate distantFuture];
   NSMutableArray<_RCTTimer *> *timersToCall = [NSMutableArray new];
   NSDate *now = [NSDate date]; // compare all the timers to the same base time
-  @synchronized (_timers) {
+  @synchronized(_timers) {
     for (_RCTTimer *timer in _timers.allValues) {
       if ([timer shouldFire:now]) {
         [timersToCall addObject:timer];
@@ -272,7 +243,7 @@ RCT_EXPORT_MODULE()
       return [a.target compare:b.target];
     }] valueForKey:@"callbackID"];
     if (_bridge) {
-      [_bridge enqueueJSCall:@"JSTimers" method:@"callTimers" args:@[sortedTimers] completion:NULL];
+      [_bridge enqueueJSCall:@"JSTimers" method:@"callTimers" args:@[ sortedTimers ] completion:NULL];
     } else {
       [_timingDelegate callTimers:sortedTimers];
     }
@@ -283,7 +254,7 @@ RCT_EXPORT_MODULE()
       [timer reschedule];
       nextScheduledTarget = [nextScheduledTarget earlierDate:timer.target];
     } else {
-      @synchronized (_timers) {
+      @synchronized(_timers) {
         [_timers removeObjectForKey:timer.callbackID];
       }
     }
@@ -294,12 +265,11 @@ RCT_EXPORT_MODULE()
     NSTimeInterval frameElapsed = currentTimestamp - update.timestamp;
     if (kFrameDuration - frameElapsed >= kIdleCallbackFrameDeadline) {
       NSNumber *absoluteFrameStartMS = @((currentTimestamp - frameElapsed) * 1000);
-      if (_bridge){
+      if (_bridge) {
-        [_bridge enqueueJSCall:@"JSTimers" method:@"callIdleCallbacks" args:@[absoluteFrameStartMS] completion:NULL];
+        [_bridge enqueueJSCall:@"JSTimers" method:@"callIdleCallbacks" args:@[ absoluteFrameStartMS ] completion:NULL];
       } else {
         [_timingDelegate callIdleCallbacks:absoluteFrameStartMS];
       }
-
     }
   }
 
@@ -307,12 +277,11 @@ RCT_EXPORT_MODULE()
   // in response to this timer another timer is scheduled, we don't pause and unpause
   // the displaylink frivolously.
   NSUInteger timerCount;
-  @synchronized (_timers) {
+  @synchronized(_timers) {
     timerCount = _timers.count;
   }
   if (_inBackground) {
     if (timerCount) {
-      [self markStartOfBackgroundTaskIfNeeded];
       [self scheduleSleepTimer:nextScheduledTarget];
     }
   } else if (!_sendIdleEvents && timersToCall.count == 0) {
@@ -331,13 +300,13 @@ RCT_EXPORT_MODULE()
 
 - (void)scheduleSleepTimer:(NSDate *)sleepTarget
 {
-  @synchronized (self) {
+  @synchronized(self) {
     if (!_sleepTimer || !_sleepTimer.valid) {
       _sleepTimer = [[NSTimer alloc] initWithFireDate:sleepTarget
-                                            interval:0
+                                             interval:0
-                                              target:[_RCTTimingProxy proxyWithTarget:self]
+                                               target:[_RCTTimingProxy proxyWithTarget:self]
-                                            selector:@selector(timerDidFire)
+                                             selector:@selector(timerDidFire)
-                                            userInfo:nil
+                                             userInfo:nil
                                               repeats:NO];
       [[NSRunLoop currentRunLoop] addTimer:_sleepTimer forMode:NSDefaultRunLoopMode];
     } else {
@@ -367,13 +336,14 @@ RCT_EXPORT_MODULE()
  * calculating the timer's target time. We calculate this by passing in
  * Date.now() from JS and then subtracting that from the current time here.
  */
-RCT_EXPORT_METHOD(createTimer:(double)callbackID
+RCT_EXPORT_METHOD(createTimer
-                  duration:(NSTimeInterval)jsDuration
+                  : (double)callbackID duration
-                  jsSchedulingTime:(double)jsSchedulingTime
+                  : (NSTimeInterval)jsDuration jsSchedulingTime
-                  repeats:(BOOL)repeats)
+                  : (double)jsSchedulingTime repeats
+                  : (BOOL)repeats)
 {
   NSNumber *callbackIdObjc = [NSNumber numberWithDouble:callbackID];
-  NSDate *schedulingTime = [RCTConvert NSDate:[NSNumber numberWithDouble: jsSchedulingTime]];
+  NSDate *schedulingTime = [RCTConvert NSDate:[NSNumber numberWithDouble:jsSchedulingTime]];
   if (jsDuration == 0 && repeats == NO) {
     // For super fast, one-off timers, just enqueue them immediately rather than waiting a frame.
     if (_bridge) {
@@ -384,10 +354,7 @@ RCT_EXPORT_METHOD(createTimer:(double)callbackID
     return;
   }
 
-  [self createTimerForNextFrame:callbackIdObjc
+  [self createTimerForNextFrame:callbackIdObjc duration:jsDuration jsSchedulingTime:schedulingTime repeats:repeats];
-                       duration:jsDuration
-               jsSchedulingTime:schedulingTime
-                        repeats:repeats];
 }
 
 /**
@@ -410,12 +377,11 @@ RCT_EXPORT_METHOD(createTimer:(double)callbackID
                                                   interval:jsDuration
                                                 targetTime:targetTime
                                                    repeats:repeats];
-  @synchronized (_timers) {
+  @synchronized(_timers) {
     _timers[callbackID] = timer;
   }
 
   if (_inBackground) {
-    [self markStartOfBackgroundTaskIfNeeded];
     [self scheduleSleepTimer:timer.target];
   } else if (_paused) {
     if ([timer.target timeIntervalSinceNow] > kMinimumSleepInterval) {
@@ -426,9 +392,9 @@ RCT_EXPORT_METHOD(createTimer:(double)callbackID
   }
 }
 
-RCT_EXPORT_METHOD(deleteTimer:(double)timerID)
+RCT_EXPORT_METHOD(deleteTimer : (double)timerID)
 {
-  @synchronized (_timers) {
+  @synchronized(_timers) {
     [_timers removeObjectForKey:[NSNumber numberWithDouble:timerID]];
   }
   if (![self hasPendingTimers]) {
@@ -436,7 +402,7 @@ RCT_EXPORT_METHOD(deleteTimer:(double)timerID)
   }
 }
 
-RCT_EXPORT_METHOD(setSendIdleEvents:(BOOL)sendIdleEvents)
+RCT_EXPORT_METHOD(setSendIdleEvents : (BOOL)sendIdleEvents)
 {
   _sendIdleEvents = sendIdleEvents;
   if (sendIdleEvents) {
@@ -446,13 +412,15 @@ RCT_EXPORT_METHOD(setSendIdleEvents:(BOOL)sendIdleEvents)
   }
 }
 
-- (std::shared_ptr<facebook::react::TurboModule>)getTurboModuleWithJsInvoker:(std::shared_ptr<facebook::react::CallInvoker>)jsInvoker
+- (std::shared_ptr<facebook::react::TurboModule>)getTurboModuleWithJsInvoker:
+    (std::shared_ptr<facebook::react::CallInvoker>)jsInvoker
 {
   return std::make_shared<facebook::react::NativeTimingSpecJSI>(self, jsInvoker);
 }
 
 @end
 
-Class RCTTimingCls(void) {
+Class RCTTimingCls(void)
+{
   return RCTTiming.class;
 }