Delete preemtive view allocation on iOS (microsoft#1495)

Summary: changelog: [internal] preemtive view allocation has been disabled on iOS for over a year. We kept the code in but didn't do anything with it. This diff removes the code and related mobile config. Post where we decided to turn preemtive view allocation off: https://fb.workplace.com/groups/215742978987717/permalink/832644567297552/ jest_e2e[run_all_tests] Reviewed By: mdvacca Differential Revision: D37922589 fbshipit-source-id: 1af8949cbbd9d48a2d80ca238b280178cbe2ead5 Co-authored-by: Samuel Susla <samuelsusla@fb.com>
shwanton · Mar 10, 2023 · 39d50f9 · 39d50f9
1 parent 587a2ed
commit 39d50f9
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Showing 7 changed files with 1 addition and 76 deletions.
diff --git a/React/Base/RCTConstants.h b/React/Base/RCTConstants.h
@@ -10,12 +10,6 @@
 RCT_EXTERN NSString *const RCTUserInterfaceStyleDidChangeNotification;
 RCT_EXTERN NSString *const RCTUserInterfaceStyleDidChangeNotificationTraitCollectionKey;
 
-/*
- * Preemptive View Allocation
- */
-RCT_EXTERN BOOL RCTExperimentGetPreemptiveViewAllocationDisabled(void);
-RCT_EXTERN void RCTExperimentSetPreemptiveViewAllocationDisabled(BOOL value);
-
 /*
  * W3C Pointer Events
  */

diff --git a/React/Base/RCTConstants.m b/React/Base/RCTConstants.m
@@ -10,21 +10,6 @@
 NSString *const RCTUserInterfaceStyleDidChangeNotification = @"RCTUserInterfaceStyleDidChangeNotification";
 NSString *const RCTUserInterfaceStyleDidChangeNotificationTraitCollectionKey = @"traitCollection";
 
-/*
- * Preemptive View Allocation
- */
-static BOOL RCTExperimentPreemptiveViewAllocationDisabled = NO;
-
-BOOL RCTExperimentGetPreemptiveViewAllocationDisabled()
-{
-  return RCTExperimentPreemptiveViewAllocationDisabled;
-}
-
-void RCTExperimentSetPreemptiveViewAllocationDisabled(BOOL value)
-{
-  RCTExperimentPreemptiveViewAllocationDisabled = value;
-}
-
 /*
  * W3C Pointer Events
  */

diff --git a/React/Fabric/Mounting/RCTComponentViewFactory.mm b/React/Fabric/Mounting/RCTComponentViewFactory.mm
@@ -71,13 +71,6 @@ + (RCTComponentViewFactory *)currentComponentViewFactory
   dispatch_once(&onceToken, ^{
     componentViewFactory = [RCTComponentViewFactory new];
     [componentViewFactory registerComponentViewClass:[RCTRootComponentView class]];
-    [componentViewFactory registerComponentViewClass:[RCTViewComponentView class]];
-    [componentViewFactory registerComponentViewClass:[RCTParagraphComponentView class]];
-    [componentViewFactory registerComponentViewClass:[RCTTextInputComponentView class]];
-
-    Class<RCTComponentViewProtocol> imageClass = RCTComponentViewClassWithName("Image");
-    [componentViewFactory registerComponentViewClass:imageClass];
-
     componentViewFactory->_providerRegistry.setComponentDescriptorProviderRequest(
         [](ComponentName requestedComponentName) {
           [componentViewFactory registerComponentIfPossible:requestedComponentName];

diff --git a/React/Fabric/Mounting/RCTComponentViewRegistry.h b/React/Fabric/Mounting/RCTComponentViewRegistry.h
@@ -50,11 +50,6 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (nullable UIView<RCTComponentViewProtocol> *)findComponentViewWithTag:(facebook::react::Tag)tag;
 
-/**
- * Creates a component view with a given type and puts it to the recycle pool.
- */
-- (void)optimisticallyCreateComponentViewWithComponentHandle:(facebook::react::ComponentHandle)componentHandle;
-
 @end
 
 NS_ASSUME_NONNULL_END
diff --git a/React/Fabric/Mounting/RCTComponentViewRegistry.mm b/React/Fabric/Mounting/RCTComponentViewRegistry.mm
@@ -35,42 +35,11 @@ - (instancetype)init
                                              selector:@selector(handleApplicationDidReceiveMemoryWarningNotification)
                                                  name:UIApplicationDidReceiveMemoryWarningNotification
                                                object:nil];
-
-    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.1 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
-      // Calling this a bit later, when the main thread is probably idle while JavaScript thread is busy.
-      [self preallocateViewComponents];
-    });
   }
 
   return self;
 }
 
-- (void)preallocateViewComponents
-{
-  if (RCTExperimentGetPreemptiveViewAllocationDisabled()) {
-    return;
-  }
-
-  // This data is based on empirical evidence which should represent the reality pretty well.
-  // Regular `<View>` has magnitude equals to `1` by definition.
-  std::vector<std::pair<ComponentHandle, float>> componentMagnitudes = {
-      {[RCTViewComponentView componentDescriptorProvider].handle, 1},
-      {[RCTImageComponentView componentDescriptorProvider].handle, 0.3},
-      {[RCTParagraphComponentView componentDescriptorProvider].handle, 0.3},
-  };
-
-  // `complexity` represents the complexity of a typical surface in a number of `<View>` components (with Flattening
-  // enabled).
-  float complexity = 100;
-
-  // The whole process should not take more than 10ms in the worst case, so there is no need to split it up.
-  for (const auto &componentMagnitude : componentMagnitudes) {
-    for (int i = 0; i < complexity * componentMagnitude.second; i++) {
-      [self optimisticallyCreateComponentViewWithComponentHandle:componentMagnitude.first];
-    }
-  }
-}
-
 - (RCTComponentViewDescriptor const &)dequeueComponentViewWithComponentHandle:(ComponentHandle)componentHandle
                                                                           tag:(Tag)tag
 {
@@ -100,14 +69,6 @@ - (void)enqueueComponentViewWithComponentHandle:(ComponentHandle)componentHandle
   [self _enqueueComponentViewWithComponentHandle:componentHandle componentViewDescriptor:componentViewDescriptor];
 }
 
-- (void)optimisticallyCreateComponentViewWithComponentHandle:(ComponentHandle)componentHandle
-{
-  RCTAssertMainQueue();
-  [self _enqueueComponentViewWithComponentHandle:componentHandle
-                         componentViewDescriptor:[self.componentViewFactory
-                                                     createComponentViewWithComponentHandle:componentHandle]];
-}
-
 - (RCTComponentViewDescriptor const &)componentViewDescriptorWithTag:(Tag)tag
 {
   RCTAssertMainQueue();

diff --git a/React/Fabric/RCTSurfacePresenter.mm b/React/Fabric/RCTSurfacePresenter.mm
@@ -252,10 +252,6 @@ - (RCTScheduler *)_createScheduler
 {
   auto reactNativeConfig = _contextContainer->at<std::shared_ptr<ReactNativeConfig const>>("ReactNativeConfig");
 
-  if (reactNativeConfig && reactNativeConfig->getBool("react_fabric:preemptive_view_allocation_disabled_ios")) {
-    RCTExperimentSetPreemptiveViewAllocationDisabled(YES);
-  }
-
   if (reactNativeConfig && reactNativeConfig->getBool("rn_convergence:dispatch_pointer_events")) {
     RCTSetDispatchW3CPointerEvents(YES);
   }

diff --git a/React/Tests/Mounting/RCTComponentViewRegistryTests.mm b/React/Tests/Mounting/RCTComponentViewRegistryTests.mm
@@ -22,6 +22,7 @@ - (void)setUp
 {
   [super setUp];
   _componentViewRegistry = [RCTComponentViewRegistry new];
+  [_componentViewRegistry.componentViewFactory registerComponentViewClass:[RCTViewComponentView class]];
 }
 
 - (void)testComponentViewDescriptorWithTag