PR Feedback: Require main thread for all edit commands, various cleanup.

AsyncDisplayKit/ASCollectionView.h

@@ -79,9 +79,8 @@
 @property (nonatomic, assign) CGFloat leadingScreensForBatching;
 
 /**
- *  Perform a batch of updates asynchronously, optionally disabling all animations in the batch. You can call it from background 
+ *  Perform a batch of updates asynchronously, optionally disabling all animations in the batch. This method must be called from the main thread. 
- *  thread (it is recommendated) and the UI collection view will be updated asynchronously. The asyncDataSource must be updated 
+ *  The asyncDataSource must be updated to reflect the changes before the update block completes.
- *  to reflect the changes before this method is called.
  *
  *  @param animated   NO to disable animations for this batch
  *  @param updates    The block that performs the relevant insert, delete, reload, or move operations.
@@ -92,8 +91,8 @@
 - (void)performBatchAnimated:(BOOL)animated updates:(void (^)())updates completion:(void (^)(BOOL))completion;
 
 /**
- *  Perform a batch of updates asynchronously. You can call it from background thread (it is recommendated) and the UI collection 
+ *  Perform a batch of updates asynchronously.  This method must be called from the main thread.
- *  view will be updated asynchronously. The asyncDataSource must be updated to reflect the changes before this method is called.
+ *  The asyncDataSource must be updated to reflect the changes before update block completes.
  *
  *  @param updates    The block that performs the relevant insert, delete, reload, or move operations.
  *  @param completion A completion handler block to execute when all of the operations are finished. This block takes a single
@@ -123,8 +122,7 @@
  *
  * @param sections An index set that specifies the sections to insert.
  *
- * @discussion This operation is asynchronous and thread safe. You can call it from background thread (it is recommendated)
+ * @discussion This method must be called from the main thread. The asyncDataSource must be updated to reflect the changes
- * and the UI collection view will be updated asynchronously. The asyncDataSource must be updated to reflect the changes
  * before this method is called.
  */
 - (void)insertSections:(NSIndexSet *)sections;
@@ -134,8 +132,7 @@
  *
  * @param sections An index set that specifies the sections to delete.
  *
- * @discussion This operation is asynchronous and thread safe. You can call it from background thread (it is recommendated)
+ * @discussion This method must be called from the main thread. The asyncDataSource must be updated to reflect the changes
- * and the UI collection view will be updated asynchronously. The asyncDataSource must be updated to reflect the changes
  * before this method is called.
  */
 - (void)deleteSections:(NSIndexSet *)sections;
@@ -145,8 +142,7 @@
  *
  * @param sections An index set that specifies the sections to reload.
  *
- * @discussion This operation is asynchronous and thread safe. You can call it from background thread (it is recommendated)
+ * @discussion This method must be called from the main thread. The asyncDataSource must be updated to reflect the changes
- * and the UI collection view will be updated asynchronously. The asyncDataSource must be updated to reflect the changes
  * before this method is called.
  */
 - (void)reloadSections:(NSIndexSet *)sections;
@@ -158,8 +154,7 @@
  *
  * @param newSection The index that is the destination of the move for the section.
  *
- * @discussion This operation is asynchronous and thread safe. You can call it from background thread (it is recommendated)
+ * @discussion This method must be called from the main thread. The asyncDataSource must be updated to reflect the changes
- * and the UI collection view will be updated asynchronously. The asyncDataSource must be updated to reflect the changes
  * before this method is called.
  */
 - (void)moveSection:(NSInteger)section toSection:(NSInteger)newSection;
@@ -169,8 +164,7 @@
  *
  * @param indexPaths An array of NSIndexPath objects, each representing an item index and section index that together identify an item.
  *
- * @discussion This operation is asynchronous and thread safe. You can call it from background thread (it is recommendated)
+ * @discussion This method must be called from the main thread. The asyncDataSource must be updated to reflect the changes
- * and the UI collection view will be updated asynchronously. The asyncDataSource must be updated to reflect the changes
  * before this method is called.
  */
 - (void)insertItemsAtIndexPaths:(NSArray *)indexPaths;
@@ -180,8 +174,7 @@
  *
  * @param indexPaths An array of NSIndexPath objects identifying the items to delete.
  *
- * @discussion This operation is asynchronous and thread safe. You can call it from background thread (it is recommendated)
+ * @discussion This method must be called from the main thread. The asyncDataSource must be updated to reflect the changes
- * and the UI collection view will be updated asynchronously. The asyncDataSource must be updated to reflect the changes
  * before this method is called.
  */
 - (void)deleteItemsAtIndexPaths:(NSArray *)indexPaths;
@@ -191,8 +184,7 @@
  *
  * @param indexPaths An array of NSIndexPath objects identifying the items to reload.
  *
- * @discussion This operation is asynchronous and thread safe. You can call it from background thread (it is recommendated)
+ * @discussion This method must be called from the main thread. The asyncDataSource must be updated to reflect the changes
- * and the UI collection view will be updated asynchronously. The asyncDataSource must be updated to reflect the changes
  * before this method is called.
  */
 - (void)reloadItemsAtIndexPaths:(NSArray *)indexPaths;
@@ -204,8 +196,7 @@
  *
  * @param newIndexPath The index path that is the destination of the move for the item.
  *
- * @discussion This operation is asynchronous and thread safe. You can call it from background thread (it is recommendated)
+ * @discussion This method must be called from the main thread. The asyncDataSource must be updated to reflect the changes
- * and the UI collection view will be updated asynchronously. The asyncDataSource must be updated to reflect the changes
  * before this method is called.
  */
 - (void)moveItemAtIndexPath:(NSIndexPath *)indexPath toIndexPath:(NSIndexPath *)newIndexPath;

AsyncDisplayKit/ASCollectionView.mm

@@ -283,6 +283,8 @@ static BOOL _isInterceptedSelector(SEL sel)
 
 - (void)performBatchAnimated:(BOOL)animated updates:(void (^)())updates completion:(void (^)(BOOL))completion
 {
+  ASDisplayNodeAssertMainThread();
+
   [_dataController beginUpdates];
   updates();
   [_dataController endUpdatesAnimated:animated completion:completion];
@@ -295,41 +297,49 @@ static BOOL _isInterceptedSelector(SEL sel)
 
 - (void)insertSections:(NSIndexSet *)sections
 {
+  ASDisplayNodeAssertMainThread();
   [_dataController insertSections:sections withAnimationOptions:kASCollectionViewAnimationNone];
 }
 
 - (void)deleteSections:(NSIndexSet *)sections
 {
+  ASDisplayNodeAssertMainThread();
   [_dataController deleteSections:sections withAnimationOptions:kASCollectionViewAnimationNone];
 }
 
 - (void)reloadSections:(NSIndexSet *)sections
 {
+  ASDisplayNodeAssertMainThread();
   [_dataController reloadSections:sections withAnimationOptions:kASCollectionViewAnimationNone];
 }
 
 - (void)moveSection:(NSInteger)section toSection:(NSInteger)newSection
 {
+  ASDisplayNodeAssertMainThread();
   [_dataController moveSection:section toSection:newSection withAnimationOptions:kASCollectionViewAnimationNone];
 }
 
 - (void)insertItemsAtIndexPaths:(NSArray *)indexPaths
 {
+  ASDisplayNodeAssertMainThread();
   [_dataController insertRowsAtIndexPaths:indexPaths withAnimationOptions:kASCollectionViewAnimationNone];
 }
 
 - (void)deleteItemsAtIndexPaths:(NSArray *)indexPaths
 {
+  ASDisplayNodeAssertMainThread();
   [_dataController deleteRowsAtIndexPaths:indexPaths withAnimationOptions:kASCollectionViewAnimationNone];
 }
 
 - (void)reloadItemsAtIndexPaths:(NSArray *)indexPaths
 {
+  ASDisplayNodeAssertMainThread();
   [_dataController reloadRowsAtIndexPaths:indexPaths withAnimationOptions:kASCollectionViewAnimationNone];
 }
 
 - (void)moveItemAtIndexPath:(NSIndexPath *)indexPath toIndexPath:(NSIndexPath *)newIndexPath
 {
+  ASDisplayNodeAssertMainThread();
   [_dataController moveRowAtIndexPath:indexPath toIndexPath:newIndexPath withAnimationOptions:kASCollectionViewAnimationNone];
 }
 

AsyncDisplayKit/ASTableView.h

@@ -94,7 +94,7 @@
 - (void)reloadData;
 
 /**
- *  begins a batch of insert, delete reload and move operations. Batches are asynchronous an thread safe.
+ *  begins a batch of insert, delete reload and move operations. This method must be called from the main thread.
  */
 - (void)beginUpdates;
 
@@ -102,7 +102,7 @@
  *  Concludes a series of method calls that insert, delete, select, or reload rows and sections of the table view.
  *  You call this method to bracket a series of method calls that begins with beginUpdates and that consists of operations
  *  to insert, delete, select, and reload rows and sections of the table view. When you call endUpdates, ASTableView begins animating
- *  the operations simultaneously. This method is asynchronous and thread safe. It's important to remeber that the ASTableView will
+ *  the operations simultaneously. This method is must be called from the main thread. It's important to remeber that the ASTableView will
  *  be processing the updates asynchronously after this call is completed.
  *
  *  @param animated   NO to disable all animations.
@@ -116,7 +116,7 @@
  *  Concludes a series of method calls that insert, delete, select, or reload rows and sections of the table view.
  *  You call this method to bracket a series of method calls that begins with beginUpdates and that consists of operations 
  *  to insert, delete, select, and reload rows and sections of the table view. When you call endUpdates, ASTableView begins animating
- *  the operations simultaneously. This method is asynchronous and thread safe. It's important to remeber that the ASTableView will
+ *  the operations simultaneously. This method is must be called from the main thread. It's important to remeber that the ASTableView will
  *  be processing the updates asynchronously after this call and are not guaranteed to be reflected in the ASTableView until
  *  the completion block is executed.
  *
@@ -134,8 +134,7 @@
  * 
  * @param animation A constant that indicates how the insertion is to be animated. See UITableViewRowAnimation.
  *
- * @discussion This operation is asynchronous and thread safe. You can call it from background thread (it is recommendated)
+ * @discussion This method must be called from the main thread. The asyncDataSource must be updated to reflect the changes
- * and the UI table view will be updated asynchronously. The asyncDataSource must be updated to reflect the changes
  * before this method is called.
  */
 - (void)insertSections:(NSIndexSet *)sections withRowAnimation:(UITableViewRowAnimation)animation;
@@ -147,8 +146,7 @@
  *
  * @param animation A constant that indicates how the deletion is to be animated. See UITableViewRowAnimation.
  *
- * @discussion This operation is asynchronous and thread safe. You can call it from background thread (it is recommendated)
+ * @discussion This method must be called from the main thread. The asyncDataSource must be updated to reflect the changes
- * and the UI table view will be updated asynchronously. The asyncDataSource must be updated to reflect the changes
  * before this method is called.
  */
 - (void)deleteSections:(NSIndexSet *)sections withRowAnimation:(UITableViewRowAnimation)animation;
@@ -160,8 +158,7 @@
  *
  * @param animation A constant that indicates how the reloading is to be animated. See UITableViewRowAnimation.
  *
- * @discussion This operation is asynchronous and thread safe. You can call it from background thread (it is recommendated)
+ * @discussion This method must be called from the main thread. The asyncDataSource must be updated to reflect the changes
- * and the UI table view will be updated asynchronously. The asyncDataSource must be updated to reflect the changes
  * before this method is called.
  */
 - (void)reloadSections:(NSIndexSet *)sections withRowAnimation:(UITableViewRowAnimation)animation;
@@ -173,8 +170,7 @@
  *
  * @param newSection The index that is the destination of the move for the section.
  *
- * @discussion This operation is asynchronous and thread safe. You can call it from background thread (it is recommendated)
+ * @discussion This method must be called from the main thread. The asyncDataSource must be updated to reflect the changes
- * and the UI table view will be updated asynchronously. The asyncDataSource must be updated to reflect the changes
  * before this method is called.
  */
 - (void)moveSection:(NSInteger)section toSection:(NSInteger)newSection;
@@ -186,8 +182,7 @@
  *
  * @param animation A constant that indicates how the insertion is to be animated. See UITableViewRowAnimation.
  *
- * @discussion This operation is asynchronous and thread safe. You can call it from background thread (it is recommendated)
+ * @discussion This method must be called from the main thread. The asyncDataSource must be updated to reflect the changes
- * and the UI table view will be updated asynchronously. The asyncDataSource must be updated to reflect the changes
  * before this method is called.
  */
 - (void)insertRowsAtIndexPaths:(NSArray *)indexPaths withRowAnimation:(UITableViewRowAnimation)animation;
@@ -199,8 +194,7 @@
  *
  * @param animation A constant that indicates how the deletion is to be animated. See UITableViewRowAnimation.
  *
- * @discussion This operation is asynchronous and thread safe. You can call it from background thread (it is recommendated)
+ * @discussion This method must be called from the main thread. The asyncDataSource must be updated to reflect the changes
- * and the UI table view will be updated asynchronously. The asyncDataSource must be updated to reflect the changes
  * before this method is called.
  */
 - (void)deleteRowsAtIndexPaths:(NSArray *)indexPaths withRowAnimation:(UITableViewRowAnimation)animation;
@@ -212,8 +206,7 @@
  *
  * @param animation A constant that indicates how the reloading is to be animated. See UITableViewRowAnimation.
  *
- * @discussion This operation is asynchronous and thread safe. You can call it from background thread (it is recommendated)
+ * @discussion This method must be called from the main thread. The asyncDataSource must be updated to reflect the changes
- * and the UI table view will be updated asynchronously. The asyncDataSource must be updated to reflect the changes
  * before this method is called.
  */
 - (void)reloadRowsAtIndexPaths:(NSArray *)indexPaths withRowAnimation:(UITableViewRowAnimation)animation;
@@ -225,8 +218,7 @@
  *
  * @param newIndexPath The index path that is the destination of the move for the row.
  *
- * @discussion This operation is asynchronous and thread safe. You can call it from background thread (it is recommendated)
+ * @discussion This method must be called from the main thread. The asyncDataSource must be updated to reflect the changes
- * and the UI table view will be updated asynchronously. The asyncDataSource must be updated to reflect the changes
  * before this method is called.
  */
 - (void)moveRowAtIndexPath:(NSIndexPath *)indexPath toIndexPath:(NSIndexPath *)newIndexPath;
@@ -249,7 +241,8 @@
 
 /**
  * YES to automatically adjust the contentOffset when cells are inserted or deleted "before"
- * visible cells, maintaining the users' visible scroll position.
+ * visible cells, maintaining the users' visible scroll position. Currently this feature tracks insertions, moves and deletions of
+ * cells, but section edits are ignored.
  *
  * default is NO.
  */

AsyncDisplayKit/ASTableView.mm

@@ -328,6 +328,7 @@ void ASPerformBlockWithoutAnimation(BOOL withoutAnimation, void (^block)()) {
 
 - (void)beginUpdates
 {
+  ASDisplayNodeAssertMainThread();
   [_dataController beginUpdates];
 }
 
@@ -338,6 +339,7 @@ void ASPerformBlockWithoutAnimation(BOOL withoutAnimation, void (^block)()) {
 
 - (void)endUpdatesAnimated:(BOOL)animated completion:(void (^)(BOOL completed))completion;
 {
+  ASDisplayNodeAssertMainThread();
   [_dataController endUpdatesAnimated:animated completion:completion];
 }
 
@@ -346,41 +348,49 @@ void ASPerformBlockWithoutAnimation(BOOL withoutAnimation, void (^block)()) {
 
 - (void)insertSections:(NSIndexSet *)sections withRowAnimation:(UITableViewRowAnimation)animation
 {
+  ASDisplayNodeAssertMainThread();
   [_dataController insertSections:sections withAnimationOptions:animation];
 }
 
 - (void)deleteSections:(NSIndexSet *)sections withRowAnimation:(UITableViewRowAnimation)animation
 {
+  ASDisplayNodeAssertMainThread();
   [_dataController deleteSections:sections withAnimationOptions:animation];
 }
 
 - (void)reloadSections:(NSIndexSet *)sections withRowAnimation:(UITableViewRowAnimation)animation
 {
+  ASDisplayNodeAssertMainThread();
   [_dataController reloadSections:sections withAnimationOptions:animation];
 }
 
 - (void)moveSection:(NSInteger)section toSection:(NSInteger)newSection
 {
+  ASDisplayNodeAssertMainThread();
   [_dataController moveSection:section toSection:newSection withAnimationOptions:UITableViewRowAnimationNone];
 }
 
 - (void)insertRowsAtIndexPaths:(NSArray *)indexPaths withRowAnimation:(UITableViewRowAnimation)animation
 {
+  ASDisplayNodeAssertMainThread();
   [_dataController insertRowsAtIndexPaths:indexPaths withAnimationOptions:animation];
 }
 
 - (void)deleteRowsAtIndexPaths:(NSArray *)indexPaths withRowAnimation:(UITableViewRowAnimation)animation
 {
+  ASDisplayNodeAssertMainThread();
   [_dataController deleteRowsAtIndexPaths:indexPaths withAnimationOptions:animation];
 }
 
 - (void)reloadRowsAtIndexPaths:(NSArray *)indexPaths withRowAnimation:(UITableViewRowAnimation)animation
 {
+  ASDisplayNodeAssertMainThread();
   [_dataController reloadRowsAtIndexPaths:indexPaths withAnimationOptions:animation];
 }
 
 - (void)moveRowAtIndexPath:(NSIndexPath *)indexPath toIndexPath:(NSIndexPath *)newIndexPath
 {
+  ASDisplayNodeAssertMainThread();
   [_dataController moveRowAtIndexPath:indexPath toIndexPath:newIndexPath withAnimationOptions:UITableViewRowAnimationNone];
 }
 
@@ -416,7 +426,7 @@ void ASPerformBlockWithoutAnimation(BOOL withoutAnimation, void (^block)()) {
   CGFloat adjustment = 0;
   NSIndexPath *top = _contentOffsetAdjustmentTopVisibleRow ?: self.indexPathsForVisibleRows.firstObject;
 
-  for (int index=0; index<indexPaths.count; index++) {
+  for (int index = 0; index < indexPaths.count; index++) {
     NSIndexPath *indexPath = indexPaths[index];
     if ([indexPath compare:top] <= 0) { // if this row is before or equal to the topmost visible row, make adjustments...
       ASCellNode *cellNode = nodes[index];

AsyncDisplayKit/Details/ASDataController.mm

@@ -328,8 +328,6 @@ static void *kASSizingQueueContext = &kASSizingQueueContext;
   [_editingTransactionQueue waitUntilAllOperationsAreFinished];
   // Begin queuing up edit calls that happen on the main thread.
   // This will prevent further operations from being scheduled on _editingTransactionQueue.
-  // It's fine if there is an in-flight operation on _editingTransactionQueue,
-  // as once the command queue is unpaused, each edit command will wait for the _editingTransactionQueue to be flushed.
   _batchUpdateCounter++;
 }