Track native modules which use the main thread for initialization or gathering constants

Reviewed By: majak

Differential Revision: D3054146

fb-gh-sync-id: fd4f4c0dff3144d22357ea798d3131aee578d509
shipit-source-id: fd4f4c0dff3144d22357ea798d3131aee578d509

React/Base/RCTBatchedBridge.m

@@ -364,6 +364,7 @@ RCT_EXTERN NSArray<Class> *RCTGetModuleClasses(void);
 
   // Set up modules that require main thread init or constants export
   RCTPerformanceLoggerSet(RCTPLNativeModuleMainThread, 0);
+  NSUInteger modulesOnMainThreadCount = 0;
   for (RCTModuleData *moduleData in _moduleDataByID) {
     __weak RCTBatchedBridge *weakSelf = self;
     if (moduleData.requiresMainThreadSetup) {
@@ -380,6 +381,7 @@ RCT_EXTERN NSArray<Class> *RCTGetModuleClasses(void);
           RCTPerformanceLoggerAppendEnd(RCTPLNativeModuleMainThread);
         }
       });
+      modulesOnMainThreadCount++;
     } else if (moduleData.hasConstantsToExport) {
       // Constants must be exported on the main thread, but module setup can
       // be done on any queue
@@ -391,10 +393,12 @@ RCT_EXTERN NSArray<Class> *RCTGetModuleClasses(void);
           RCTPerformanceLoggerAppendEnd(RCTPLNativeModuleMainThread);
         }
       });
+      modulesOnMainThreadCount++;
     }
   }
 
   RCTPerformanceLoggerEnd(RCTPLNativeModuleInit);
+  RCTPerformanceLoggerSet(RCTPLNativeModuleMainThreadUsesCount, modulesOnMainThreadCount);
 }
 
 - (void)setUpExecutor

React/Base/RCTPerformanceLogger.h

@@ -18,6 +18,7 @@ typedef NS_ENUM(NSUInteger, RCTPLTag) {
   RCTPLNativeModuleMainThread,
   RCTPLNativeModulePrepareConfig,
   RCTPLNativeModuleInjectConfig,
+  RCTPLNativeModuleMainThreadUsesCount,
   RCTPLJSCExecutorSetup,
   RCTPLTTI,
   RCTPLBundleSize,

React/Base/RCTPerformanceLogger.m

@@ -78,6 +78,8 @@ NSArray<NSNumber *> *RCTPerformanceLoggerOutput(void)
     @(RCTPLData[RCTPLNativeModulePrepareConfig][1]),
     @(RCTPLData[RCTPLNativeModuleInjectConfig][0]),
     @(RCTPLData[RCTPLNativeModuleInjectConfig][1]),
+    @(RCTPLData[RCTPLNativeModuleMainThreadUsesCount][0]),
+    @(RCTPLData[RCTPLNativeModuleMainThreadUsesCount][1]),
     @(RCTPLData[RCTPLJSCExecutorSetup][0]),
     @(RCTPLData[RCTPLJSCExecutorSetup][1]),
     @(RCTPLData[RCTPLTTI][0]),