Remove legacy RCTTimingModule (#57037)

Summary:
Pull Request resolved: #57037

## Changelog:
[IOS][Fixed] Remove legacy RCTTimingModule

Reviewed By: javache

Differential Revision: D107201906

fbshipit-source-id: 34e006cd046795c80bd234c13979110aadfa9f58

Author: christophpurrer

packages/react-native/React/Base/RCTBridge+Private.h

@@ -86,12 +86,6 @@ RCT_EXTERN void RCTRegisterModule(Class);
  */
 - (void)start;
 
-/**
- * Used by RCTModuleData to register the module for frame updates after it is
- * lazily initialized.
- */
-- (void)registerModuleForFrameUpdates:(id<RCTBridgeModule>)module withModuleData:(RCTModuleData *)moduleData;
-
 /**
  * Dispatch work to a module's queue - this is also supports the fake RCTJSThread
  * queue. Exposed for the RCTProfiler

packages/react-native/React/Base/RCTDisplayLink.h

@@ -7,23 +7,12 @@
 
 #import <Foundation/Foundation.h>
 
-@protocol RCTBridgeModule;
-@class RCTModuleData;
-
-@protocol RCTDisplayLinkModuleHolder
-- (id<RCTBridgeModule>)instance;
-- (Class)moduleClass;
-- (dispatch_queue_t)methodQueue;
-@end
+@protocol RCTFrameUpdateObserver;
 
 @interface RCTDisplayLink : NSObject
 
-- (instancetype)init;
+- (instancetype)initWithFrameUpdateObserver:(id<RCTFrameUpdateObserver>)observer;
 - (void)invalidate;
-- (void)registerModuleForFrameUpdates:(id<RCTBridgeModule>)module
-                     withModuleHolder:(id<RCTDisplayLinkModuleHolder>)moduleHolder
-    __attribute__((deprecated(
-        "registerModuleForFrameUpdates is part of the legacy architecture and will be removed in a future React Native release.")));
 - (void)addToRunLoop:(NSRunLoop *)runLoop;
 
 @end

packages/react-native/React/Base/RCTDisplayLink.m

@@ -11,76 +11,50 @@
 #import <QuartzCore/CADisplayLink.h>
 
 #import "RCTAssert.h"
-#import "RCTBridgeModule.h"
 #import "RCTFrameUpdate.h"
-#import "RCTModuleData.h"
 #import "RCTProfile.h"
 
 #define RCTAssertRunLoop() \
   RCTAssert(_runLoop == [NSRunLoop currentRunLoop], @"This method must be called on the CADisplayLink run loop")
 
 @implementation RCTDisplayLink {
   CADisplayLink *_jsDisplayLink;
-  NSMutableSet<id<RCTDisplayLinkModuleHolder>> *_frameUpdateObservers;
+  id<RCTFrameUpdateObserver> _frameUpdateObserver;
   NSRunLoop *_runLoop;
 }
 
-- (instancetype)init
+- (instancetype)initWithFrameUpdateObserver:(id<RCTFrameUpdateObserver>)observer
 {
   if ((self = [super init])) {
-    _frameUpdateObservers = [NSMutableSet new];
+    _frameUpdateObserver = observer;
     _jsDisplayLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(_jsThreadUpdate:)];
-  }
 
-  return self;
-}
+    __weak typeof(self) weakSelf = self;
+    observer.pauseCallback = ^{
+      typeof(self) strongSelf = weakSelf;
+      if (!strongSelf) {
+        return;
+      }
 
-- (void)registerModuleForFrameUpdates:(id<RCTBridgeModule>)module
-                     withModuleHolder:(id<RCTDisplayLinkModuleHolder>)moduleHolder
-{
-  if (![moduleHolder.moduleClass conformsToProtocol:@protocol(RCTFrameUpdateObserver)] ||
-      [_frameUpdateObservers containsObject:moduleHolder]) {
-    return;
-  }
+      CFRunLoopRef cfRunLoop = [strongSelf->_runLoop getCFRunLoop];
+      if (!cfRunLoop) {
+        return;
+      }
 
-  [_frameUpdateObservers addObject:moduleHolder];
-
-  // Don't access the module instance via moduleHolder, as this will cause deadlock
-  id<RCTFrameUpdateObserver> observer = (id<RCTFrameUpdateObserver>)module;
-  __weak typeof(self) weakSelf = self;
-  observer.pauseCallback = ^{
-    typeof(self) strongSelf = weakSelf;
-    if (!strongSelf) {
-      return;
-    }
-
-    CFRunLoopRef cfRunLoop = [strongSelf->_runLoop getCFRunLoop];
-    if (!cfRunLoop) {
-      return;
-    }
-
-    if ([NSRunLoop currentRunLoop] == strongSelf->_runLoop) {
-      [weakSelf updateJSDisplayLinkState];
-    } else {
-      CFRunLoopPerformBlock(cfRunLoop, kCFRunLoopDefaultMode, ^{
-        @autoreleasepool {
-          [weakSelf updateJSDisplayLinkState];
-        }
-      });
-      CFRunLoopWakeUp(cfRunLoop);
-    }
-  };
-
-  // Assuming we're paused right now, we only need to update the display link's state
-  // when the new observer is not paused. If it not paused, the observer will immediately
-  // start receiving updates anyway.
-  if (![observer isPaused] && _runLoop) {
-    CFRunLoopPerformBlock([_runLoop getCFRunLoop], kCFRunLoopDefaultMode, ^{
-      @autoreleasepool {
-        [self updateJSDisplayLinkState];
+      if ([NSRunLoop currentRunLoop] == strongSelf->_runLoop) {
+        [weakSelf updateJSDisplayLinkState];
+      } else {
+        CFRunLoopPerformBlock(cfRunLoop, kCFRunLoopDefaultMode, ^{
+          @autoreleasepool {
+            [weakSelf updateJSDisplayLinkState];
+          }
+        });
+        CFRunLoopWakeUp(cfRunLoop);
       }
-    });
+    };
   }
+
+  return self;
 }
 
 - (void)addToRunLoop:(NSRunLoop *)runLoop
@@ -96,47 +70,24 @@ - (void)dealloc
 
 - (void)invalidate
 {
-  // ensure observer callbacks do not hold a reference to weak self via pauseCallback
-  for (id<RCTDisplayLinkModuleHolder> moduleHolder in _frameUpdateObservers) {
-    id<RCTFrameUpdateObserver> observer = (id<RCTFrameUpdateObserver>)moduleHolder.instance;
-    [observer setPauseCallback:nil];
-  }
-  [_frameUpdateObservers removeAllObjects]; // just to be explicit
+  // ensure the observer callback does not hold a reference to weak self via pauseCallback
+  [_frameUpdateObserver setPauseCallback:nil];
+  _frameUpdateObserver = nil;
 
   [_jsDisplayLink invalidate];
 }
 
-- (void)dispatchBlock:(dispatch_block_t)block queue:(dispatch_queue_t)queue
-{
-  if (queue == RCTJSThread) {
-    block();
-  } else if (queue) {
-    dispatch_async(queue, block);
-  }
-}
-
 - (void)_jsThreadUpdate:(CADisplayLink *)displayLink
 {
   RCTAssertRunLoop();
 
   RCT_PROFILE_BEGIN_EVENT(RCTProfileTagAlways, @"-[RCTDisplayLink _jsThreadUpdate:]", nil);
 
+  // This always runs on the JS thread run loop, which is the queue the frame
+  // update observer expects its callbacks on, so dispatch inline.
   RCTFrameUpdate *frameUpdate = [[RCTFrameUpdate alloc] initWithDisplayLink:displayLink];
-  for (id<RCTDisplayLinkModuleHolder> moduleHolder in _frameUpdateObservers) {
-    id<RCTFrameUpdateObserver> observer = (id<RCTFrameUpdateObserver>)moduleHolder.instance;
-    if (!observer.paused) {
-      if (moduleHolder.methodQueue) {
-        RCTProfileBeginFlowEvent();
-        [self
-            dispatchBlock:^{
-              RCTProfileEndFlowEvent();
-              [observer didUpdateFrame:frameUpdate];
-            }
-                    queue:moduleHolder.methodQueue];
-      } else {
-        [observer didUpdateFrame:frameUpdate];
-      }
-    }
+  if (!_frameUpdateObserver.paused) {
+    [_frameUpdateObserver didUpdateFrame:frameUpdate];
   }
 
   [self updateJSDisplayLinkState];
@@ -150,16 +101,7 @@ - (void)updateJSDisplayLinkState
 {
   RCTAssertRunLoop();
 
-  BOOL pauseDisplayLink = YES;
-  for (id<RCTDisplayLinkModuleHolder> moduleHolder in _frameUpdateObservers) {
-    id<RCTFrameUpdateObserver> observer = (id<RCTFrameUpdateObserver>)moduleHolder.instance;
-    if (!observer.paused) {
-      pauseDisplayLink = NO;
-      break;
-    }
-  }
-
-  _jsDisplayLink.paused = pauseDisplayLink;
+  _jsDisplayLink.paused = _frameUpdateObserver == nil || _frameUpdateObserver.paused;
 }
 
 @end

packages/react-native/React/CoreModules/RCTTiming.h

@@ -7,7 +7,6 @@
 
 #import <Foundation/Foundation.h>
 
-#import <React/RCTBridgeModule.h>
 #import <React/RCTFrameUpdate.h>
 #import <React/RCTInitializing.h>
 #import <React/RCTInvalidating.h>
@@ -22,7 +21,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 @end
 
-@interface RCTTiming : NSObject <RCTBridgeModule, RCTInvalidating, RCTFrameUpdateObserver, RCTInitializing>
+@interface RCTTiming : NSObject <RCTInvalidating, RCTFrameUpdateObserver, RCTInitializing>
 
 - (instancetype)initWithDelegate:(id<RCTTimingDelegate>)delegate;
 - (void)createTimerForNextFrame:(NSNumber *)callbackID