[ASDataController] Add an experiment that avoids flushing editing queue before starting the data pipeline pipeline

Source/ASExperimentalFeatures.h

@@ -27,9 +27,10 @@ typedef NS_OPTIONS(NSUInteger, ASExperimentalFeatures) {
   ASExperimentalSkipClearData = 1 << 6,                     // exp_skip_clear_data
   ASExperimentalDidEnterPreloadSkipASMLayout = 1 << 7,      // exp_did_enter_preload_skip_asm_layout
   ASExperimentalDispatchApply = 1 << 8,                     // exp_dispatch_apply
-  ASExperimentalOOMBackgroundDeallocDisable = 1 << 9,      // exp_oom_bg_dealloc_disable
+  ASExperimentalOOMBackgroundDeallocDisable = 1 << 9,       // exp_oom_bg_dealloc_disable
   ASExperimentalRemoveTextKitInitialisingLock = 1 << 10,    // exp_remove_textkit_initialising_lock
   ASExperimentalDrawingGlobal = 1 << 11,                    // exp_drawing_global
+  ASExperimentalOptimizeDataControllerPipeline = 1 << 12,   // exp_optimize_data_controller_pipeline
   ASExperimentalFeatureAll = 0xFFFFFFFF
 };
 

Source/ASExperimentalFeatures.mm

@@ -23,7 +23,8 @@
                                       @"exp_dispatch_apply",
                                       @"exp_oom_bg_dealloc_disable",
                                       @"exp_remove_textkit_initialising_lock",
-                                      @"exp_drawing_global"]));
+                                      @"exp_drawing_global",
+                                      @"exp_optimize_data_controller_pipeline"]));
   if (flags == ASExperimentalFeatureAll) {
     return allNames;
   }

Source/Details/ASDataController.mm

@@ -560,13 +560,15 @@ - (void)updateWithChangeSet:(_ASHierarchyChangeSet *)changeSet
   } else {
     os_log_debug(ASCollectionLog(), "performBatchUpdates %@ %@", ASViewToDisplayNode(ASDynamicCast(self.dataSource, UIView)), changeSet);
   }
-
-  NSTimeInterval transactionQueueFlushDuration = 0.0f;
-  {
-    AS::ScopeTimer t(transactionQueueFlushDuration);
-    dispatch_group_wait(_editingTransactionGroup, DISPATCH_TIME_FOREVER);
+
+  if (!ASActivateExperimentalFeature(ASExperimentalOptimizeDataControllerPipeline)) {
+    NSTimeInterval transactionQueueFlushDuration = 0.0f;
+    {
+      AS::ScopeTimer t(transactionQueueFlushDuration);
+      dispatch_group_wait(_editingTransactionGroup, DISPATCH_TIME_FOREVER);
+    }
   }
-  
+
   // If the initial reloadData has not been called, just bail because we don't have our old data source counts.
   // See ASUICollectionViewTests.testThatIssuingAnUpdateBeforeInitialReloadIsUnacceptable
   // for the issue that UICollectionView has that we're choosing to workaround.

Tests/ASCollectionModernDataSourceTests.mm

@@ -34,6 +34,11 @@ @implementation ASCollectionModernDataSourceTests {
 
 - (void)setUp {
   [super setUp];
+
+  ASConfiguration *config = [ASConfiguration new];
+  config.experimentalFeatures = ASExperimentalOptimizeDataControllerPipeline;
+  [ASConfigurationManager test_resetWithConfiguration:config];
+
   // Default is 2 sections: 2 items in first, 1 item in second.
   sections = [NSMutableArray array];
   [sections addObject:[ASTestSection new]];

Tests/ASCollectionViewTests.mm

@@ -16,7 +16,9 @@
 #import <OCMock/OCMock.h>
 #import <AsyncDisplayKit/ASCollectionView+Undeprecated.h>
 #import <AsyncDisplayKit/ASDisplayNode+FrameworkPrivate.h>
+
 #import "ASDisplayNodeTestsHelper.h"
+#import "ASTestCase.h"
 
 @interface ASTextCellNodeWithSetSelectedCounter : ASTextCellNode
 
@@ -166,12 +168,20 @@ @interface ASCollectionView (InternalTesting)
 
 @end
 
-@interface ASCollectionViewTests : XCTestCase
+@interface ASCollectionViewTests : ASTestCase
 
 @end
 
 @implementation ASCollectionViewTests
 
+- (void)setUp
+{
+  [super setUp];
+  ASConfiguration *config = [ASConfiguration new];
+  config.experimentalFeatures = ASExperimentalOptimizeDataControllerPipeline;
+  [ASConfigurationManager test_resetWithConfiguration:config];
+}
+
 - (void)tearDown
 {
   // We can't prevent the system from retaining windows, but we can at least clear them out to avoid

Tests/ASCollectionViewThrashTests.mm

@@ -12,9 +12,10 @@
 #import <AsyncDisplayKit/ASCollectionView.h>
 #import <stdatomic.h>
 
+#import "ASTestCase.h"
 #import "ASThrashUtility.h"
 
-@interface ASCollectionViewThrashTests : XCTestCase
+@interface ASCollectionViewThrashTests : ASTestCase
 
 @end
 
@@ -25,8 +26,17 @@ @implementation ASCollectionViewThrashTests
   BOOL _failed;
 }
 
+- (void)setUp
+{
+  [super setUp];
+  ASConfiguration *config = [ASConfiguration new];
+  config.experimentalFeatures = ASExperimentalOptimizeDataControllerPipeline;
+  [ASConfigurationManager test_resetWithConfiguration:config];
+}
+
 - (void)tearDown
 {
+  [super tearDown];
   if (_failed && _update != nil) {
     NSLog(@"Failed update %@: %@", _update, _update.logFriendlyBase64Representation);
   }

Tests/ASConfigurationTests.mm

@@ -29,7 +29,8 @@
   ASExperimentalDispatchApply,
   ASExperimentalOOMBackgroundDeallocDisable,
   ASExperimentalRemoveTextKitInitialisingLock,
-  ASExperimentalDrawingGlobal
+  ASExperimentalDrawingGlobal,
+  ASExperimentalOptimizeDataControllerPipeline
 };
 
 @interface ASConfigurationTests : ASTestCase <ASConfigurationDelegate>
@@ -53,11 +54,13 @@ + (NSArray *)names {
     @"exp_dispatch_apply",
     @"exp_oom_bg_dealloc_disable",
     @"exp_remove_textkit_initialising_lock",
-    @"exp_drawing_global"
+    @"exp_drawing_global",
+    @"exp_optimize_data_controller_pipeline"
   ];
 }
 
-- (ASExperimentalFeatures)allFeatures {
+- (ASExperimentalFeatures)allFeatures
+{
   ASExperimentalFeatures allFeatures = 0;
   for (int i = 0; i < sizeof(features)/sizeof(ASExperimentalFeatures); i++) {
     allFeatures |= features[i];

Tests/ASTableViewTests.mm

@@ -22,6 +22,7 @@
 #import <AsyncDisplayKit/ASTableView+Undeprecated.h>
 #import <AsyncDisplayKit/ASInternalHelpers.h>
 
+#import "ASTestCase.h"
 #import "ASXCTExtensions.h"
 
 #define NumberOfSections 10
@@ -217,12 +218,20 @@ - (ASSizeRange)tableView:(ASTableView *)tableView constrainedSizeForRowAtIndexPa
 
 @end
 
-@interface ASTableViewTests : XCTestCase
+@interface ASTableViewTests : ASTestCase
 @property (nonatomic, retain) ASTableView *testTableView;
 @end
 
 @implementation ASTableViewTests
 
+- (void)setUp
+{
+  [super setUp];
+  ASConfiguration *config = [ASConfiguration new];
+  config.experimentalFeatures = ASExperimentalOptimizeDataControllerPipeline;
+  [ASConfigurationManager test_resetWithConfiguration:config];
+}
+
 - (void)testDataSourceImplementsNecessaryMethods
 {
   ASTestTableView *tableView = [[ASTestTableView alloc] __initWithFrame:CGRectMake(0, 0, 100, 400)

Tests/ASTableViewThrashTests.mm

@@ -13,9 +13,10 @@
 #import <AsyncDisplayKit/ASTableView+Undeprecated.h>
 #import <stdatomic.h>
 
+#import "ASTestCase.h"
 #import "ASThrashUtility.h"
 
-@interface ASTableViewThrashTests: XCTestCase
+@interface ASTableViewThrashTests: ASTestCase
 @end
 
 @implementation ASTableViewThrashTests
@@ -27,8 +28,17 @@ @implementation ASTableViewThrashTests
 
 #pragma mark Overrides
 
+- (void)setUp
+{
+  [super setUp];
+  ASConfiguration *config = [ASConfiguration new];
+  config.experimentalFeatures = ASExperimentalOptimizeDataControllerPipeline;
+  [ASConfigurationManager test_resetWithConfiguration:config];
+}
+
 - (void)tearDown
 {
+  [super tearDown];
   if (_failed && _update != nil) {
     NSLog(@"Failed update %@: %@", _update, _update.logFriendlyBase64Representation);
   }