Introducing RCTAssertUIManagerQueue()

Reviewed By: javache

Differential Revision: D4868564

fbshipit-source-id: b9b9f6cf8f31495bb0e82fb60b2402dde460ddb8

React/Base/RCTAssert.h

@@ -85,13 +85,13 @@ typedef void (^RCTFatalHandler)(NSError *error);
  * Convenience macro for asserting that we're running on main queue.
  */
 #define RCTAssertMainQueue() RCTAssert(RCTIsMainQueue(), \
-  @"This function must be called on the main thread")
+  @"This function must be called on the main queue")
 
 /**
  * Convenience macro for asserting that we're running off the main queue.
  */
 #define RCTAssertNotMainQueue() RCTAssert(!RCTIsMainQueue(), \
-@"This function must not be called on the main thread")
+@"This function must not be called on the main queue")
 
 /**
  * Deprecated, do not use

React/Modules/RCTUIManager.h

@@ -25,6 +25,17 @@ RCT_EXTERN dispatch_queue_t RCTGetUIManagerQueue(void);
  */
 RCT_EXTERN char *const RCTUIManagerQueueName;
 
+/**
+ * Check if we are currently on UIManager queue.
+ */
+RCT_EXTERN BOOL RCTIsUIManagerQueue(void);
+
+/**
+ * Convenience macro for asserting that we're running on UIManager queue.
+ */
+#define RCTAssertUIManagerQueue() RCTAssert(RCTIsUIManagerQueue(), \
+@"This function must be called on the UIManager queue")
+
 /**
  * Posted right before re-render happens. This is a chance for views to invalidate their state so
  * next render cycle will pick up updated views and layout appropriately.

React/Modules/RCTUIManager.m

@@ -345,6 +345,16 @@ dispatch_queue_t RCTGetUIManagerQueue(void)
   return shadowQueue;
 }
 
+BOOL RCTIsUIManagerQueue()
+{
+  static void *queueKey = &queueKey;
+  static dispatch_once_t onceToken;
+  dispatch_once(&onceToken, ^{
+    dispatch_queue_set_specific(RCTGetUIManagerQueue(), queueKey, queueKey, NULL);
+  });
+  return dispatch_get_specific(queueKey) == queueKey;
+}
+
 - (dispatch_queue_t)methodQueue
 {
   return RCTGetUIManagerQueue();