Add MessageQueue method for executing function and returning its result

Reviewed By: majak

Differential Revision: D3175793

fbshipit-source-id: e1e66e3dcde8b1fb35973340e12d947a0e955775

Examples/UIExplorer/UIExplorerIntegrationTests/RCTLoggingTests.m

@@ -38,11 +38,10 @@
   if (getenv("CI_USE_PACKAGER")) {
     NSString *app = @"IntegrationTests/IntegrationTestsApp";
     scriptURL = [NSURL URLWithString:[NSString stringWithFormat:@"http://localhost:8081/%@.bundle?platform=ios&dev=true", app]];
-    RCTAssert(scriptURL != nil, @"No scriptURL set");
   } else {
     scriptURL = [[NSBundle bundleForClass:[RCTBridge class]] URLForResource:@"main" withExtension:@"jsbundle"];
-    RCTAssert(scriptURL != nil, @"Could not locate main.jsBundle");
   }
+  RCTAssert(scriptURL != nil, @"No scriptURL set");
 
   _bridge = [[RCTBridge alloc] initWithBundleURL:scriptURL moduleProvider:NULL launchOptions:nil];
   NSDate *date = [NSDate dateWithTimeIntervalSinceNow:60];

Examples/UIExplorer/UIExplorerUnitTests/RCTModuleInitNotificationRaceTests.m

@@ -21,6 +21,7 @@
 #import "RCTUtils.h"
 #import "RCTUIManager.h"
 #import "RCTViewManager.h"
+#import "RCTJavaScriptExecutor.h"
 
 #define RUN_RUNLOOP_WHILE(CONDITION) \
 { \

Examples/UIExplorer/UIExplorerUnitTests/RCTModuleInitTests.m

@@ -19,6 +19,7 @@
 #import "RCTBridge+Private.h"
 #import "RCTBridgeModule.h"
 #import "RCTUtils.h"
+#import "RCTJavaScriptExecutor.h"
 
 #define RUN_RUNLOOP_WHILE(CONDITION) \
 { \

Libraries/Image/RCTImageLoader.m

@@ -9,10 +9,12 @@
 
 #import "RCTImageLoader.h"
 
-#import <libkern/OSAtomic.h>
-#import <UIKit/UIKit.h>
 #import <ImageIO/ImageIO.h>
 
+#import <libkern/OSAtomic.h>
+
+#import <objc/runtime.h>
+
 #import "RCTConvert.h"
 #import "RCTDefines.h"
 #import "RCTImageUtils.h"

Libraries/RCTTest/RCTTestRunner.m

@@ -47,11 +47,10 @@ static const NSTimeInterval kTestTeardownTimeoutSeconds = 30;
 
     if (getenv("CI_USE_PACKAGER")) {
       _scriptURL = [NSURL URLWithString:[NSString stringWithFormat:@"http://localhost:8081/%@.bundle?platform=ios&dev=true", app]];
-      RCTAssert(_scriptURL != nil, @"No scriptURL set");
     } else {
       _scriptURL = [[NSBundle bundleForClass:[RCTBridge class]] URLForResource:@"main" withExtension:@"jsbundle"];
-      RCTAssert(_scriptURL != nil, @"Could not locate main.jsBundle");
     }
+    RCTAssert(_scriptURL != nil, @"No scriptURL set");
   }
   return self;
 }

Libraries/Utilities/MessageQueue.js

@@ -68,6 +68,7 @@ class MessageQueue {
     [
       'invokeCallbackAndReturnFlushedQueue',
       'callFunctionReturnFlushedQueue',
+      'callFunction',
       'flushedQueue',
     ].forEach((fn) => (this[fn] = this[fn].bind(this)));
 
@@ -98,6 +99,16 @@ class MessageQueue {
     return this.flushedQueue();
   }
 
+  callFunction(module, method, args) {
+    let result;
+    guard(() => {
+      result = this.__callFunction(module, method, args);
+      this.__callImmediates();
+    });
+
+    return result;
+  }
+
   invokeCallbackAndReturnFlushedQueue(cbID, args) {
     guard(() => {
       this.__invokeCallback(cbID, args);
@@ -190,8 +201,9 @@ class MessageQueue {
       'Module %s is not a registered callable module.',
       module
     );
-    moduleMethods[method].apply(moduleMethods, args);
+    const result = moduleMethods[method].apply(moduleMethods, args);
     Systrace.endEvent();
+    return result;
   }
 
   __invokeCallback(cbID, args) {

Libraries/WebSocket/RCTWebSocketModule.m

@@ -9,6 +9,8 @@
 
 #import "RCTWebSocketModule.h"
 
+#import <objc/runtime.h>
+
 #import "RCTConvert.h"
 #import "RCTUtils.h"
 

React/Base/RCTBatchedBridge.m

@@ -589,7 +589,24 @@ RCT_NOT_IMPLEMENTED(- (instancetype)initWithBundleURL:(__unused NSURL *)bundleUR
                 queue:(dispatch_queue_t)queue
 {
   if (queue == RCTJSThread) {
-    [_javaScriptExecutor executeBlockOnJavaScriptQueue:block];
+    __weak __typeof(self) weakSelf = self;
+    RCTProfileBeginFlowEvent();
+    RCTAssert(_javaScriptExecutor != nil, @"Need JS executor to schedule JS work");
+
+    [_javaScriptExecutor executeBlockOnJavaScriptQueue:^{
+      RCTProfileEndFlowEvent();
+
+      RCTBatchedBridge *strongSelf = weakSelf;
+      if (!strongSelf) {
+        return;
+      }
+
+      if (strongSelf.loading) {
+        [strongSelf->_pendingCalls addObject:block];
+      } else {
+        block();
+      }
+    }];
   } else if (queue) {
     dispatch_async(queue, block);
   }
@@ -680,32 +697,19 @@ RCT_NOT_IMPLEMENTED(- (instancetype)initWithBundleURL:(__unused NSURL *)bundleUR
    */
 
   RCT_PROFILE_BEGIN_EVENT(RCTProfileTagAlways, @"-[RCTBatchedBridge enqueueJSCall:]", nil);
+  if (!_valid) {
+    return;
+  }
 
   NSArray<NSString *> *ids = [moduleDotMethod componentsSeparatedByString:@"."];
 
   NSString *module = ids[0];
   NSString *method = ids[1];
 
-  RCTProfileBeginFlowEvent();
+  __weak __typeof(self) weakSelf = self;
-
+  [self dispatchBlock:^{
-  __weak RCTBatchedBridge *weakSelf = self;
+    [weakSelf _actuallyInvokeAndProcessModule:module method:method arguments:args ?: @[]];
-  [_javaScriptExecutor executeBlockOnJavaScriptQueue:^{
+  } queue:RCTJSThread];
-    RCTProfileEndFlowEvent();
-
-    RCTBatchedBridge *strongSelf = weakSelf;
-    if (!strongSelf || !strongSelf.valid) {
-      return;
-    }
-
-    if (strongSelf.loading) {
-      dispatch_block_t pendingCall = ^{
-        [weakSelf _actuallyInvokeAndProcessModule:module method:method arguments:args ?: @[]];
-      };
-      [strongSelf->_pendingCalls addObject:pendingCall];
-    } else {
-      [strongSelf _actuallyInvokeAndProcessModule:module method:method arguments:args ?: @[]];
-    }
-  }];
 
   RCT_PROFILE_END_EVENT(RCTProfileTagAlways, @"", nil);
 }
@@ -718,27 +722,14 @@ RCT_NOT_IMPLEMENTED(- (instancetype)initWithBundleURL:(__unused NSURL *)bundleUR
   /**
    * AnyThread
    */
+  if (!_valid) {
+    return;
+  }
 
-  RCTProfileBeginFlowEvent();
+  __weak __typeof(self) weakSelf = self;
-
+  [self dispatchBlock:^{
-  __weak RCTBatchedBridge *weakSelf = self;
+    [weakSelf _actuallyInvokeCallback:cbID arguments:args];
-  [_javaScriptExecutor executeBlockOnJavaScriptQueue:^{
+  } queue:RCTJSThread];
-    RCTProfileEndFlowEvent();
-
-    RCTBatchedBridge *strongSelf = weakSelf;
-    if (!strongSelf || !strongSelf.valid) {
-      return;
-    }
-
-    if (strongSelf.loading) {
-      dispatch_block_t pendingCall = ^{
-        [weakSelf _actuallyInvokeCallback:cbID arguments:args ?: @[]];
-      };
-      [strongSelf->_pendingCalls addObject:pendingCall];
-    } else {
-      [strongSelf _actuallyInvokeCallback:cbID arguments:args];
-    }
-  }];
 }
 
 /**
@@ -922,11 +913,7 @@ RCT_NOT_IMPLEMENTED(- (instancetype)initWithBundleURL:(__unused NSURL *)bundleUR
       });
     };
 
-    if (queue == RCTJSThread) {
+    [self dispatchBlock:block queue:queue];
-      [_javaScriptExecutor executeBlockOnJavaScriptQueue:block];
-    } else if (queue) {
-      dispatch_async(queue, block);
-    }
   }
 
   _flowID = callID;

React/Base/RCTBridge+Private.h

@@ -11,6 +11,7 @@
 
 @class RCTModuleData;
 @class RCTPerformanceLogger;
+@protocol RCTJavaScriptExecutor;
 
 @interface RCTBridge ()
 {
@@ -67,7 +68,9 @@
 @interface RCTBridge (RCTBatchedBridge)
 
 /**
- * Used for unit testing, to detect when executor has been invalidated.
+ * Access the underlying JavaScript executor. You can use this in unit tests to detect
+ * when the executor has been invalidated, or when you want to schedule calls on the
+ * JS VM outside of React Native. Use with care!
  */
 @property (nonatomic, weak, readonly) id<RCTJavaScriptExecutor> javaScriptExecutor;
 

React/Base/RCTBridge.h

@@ -14,7 +14,6 @@
 #import "RCTDefines.h"
 #import "RCTFrameUpdate.h"
 #import "RCTInvalidating.h"
-#import "RCTJavaScriptExecutor.h"
 
 @class RCTBridge;
 @class RCTEventDispatcher;

React/Base/RCTJavaScriptExecutor.h

@@ -15,7 +15,7 @@
 #import "RCTInvalidating.h"
 
 typedef void (^RCTJavaScriptCompleteBlock)(NSError *error);
-typedef void (^RCTJavaScriptCallback)(id json, NSError *error);
+typedef void (^RCTJavaScriptCallback)(id result, NSError *error);
 
 /**
  * Abstracts away a JavaScript execution context - we may be running code in a

React/Base/RCTModuleData.m

@@ -9,6 +9,8 @@
 
 #import "RCTModuleData.h"
 
+#import <objc/runtime.h>
+
 #import "RCTBridge.h"
 #import "RCTBridge+Private.h"
 #import "RCTModuleMethod.h"

React/Executors/RCTJSCExecutor.h

@@ -11,6 +11,8 @@
 
 #import "RCTJavaScriptExecutor.h"
 
+typedef void (^RCTJavaScriptValueCallback)(JSValue *result, NSError *error);
+
 /**
  * Default name for the JS thread
  */
@@ -75,4 +77,15 @@ RCT_EXTERN NSString *const RCTJavaScriptContextCreatedNotification;
                                              JSContext:(JSContext **)JSContext
                                                  error:(NSError **)error;
 
+/**
+ * Invokes the given module/method directly. The completion block will be called with the
+ * JSValue returned by the JS context.
+ *
+ * Currently this does not flush the JS-to-native message queue.
+ */
+- (void)callFunctionOnModule:(NSString *)module
+                      method:(NSString *)method
+                   arguments:(NSArray *)args
+             jsValueCallback:(RCTJavaScriptValueCallback)onComplete;
+
 @end

React/Executors/RCTJSCExecutor.mm

@@ -595,16 +595,29 @@ static void installBasicSynchronousHooksOnContext(JSContext *context)
 - (void)flushedQueue:(RCTJavaScriptCallback)onComplete
 {
   // TODO: Make this function handle first class instead of dynamically dispatching it. #9317773
-  [self _executeJSCall:@"flushedQueue" arguments:@[] callback:onComplete];
+  [self _executeJSCall:@"flushedQueue" arguments:@[] unwrapResult:YES callback:onComplete];
 }
 
-- (void)callFunctionOnModule:(NSString *)module
+- (void)_callFunctionOnModule:(NSString *)module
-                      method:(NSString *)method
+                       method:(NSString *)method
-                   arguments:(NSArray *)args
+                    arguments:(NSArray *)args
-                    callback:(RCTJavaScriptCallback)onComplete
+                   flushQueue:(BOOL)flushQueue
+                 unwrapResult:(BOOL)unwrapResult
+                     callback:(RCTJavaScriptCallback)onComplete
 {
   // TODO: Make this function handle first class instead of dynamically dispatching it. #9317773
-  [self _executeJSCall:@"callFunctionReturnFlushedQueue" arguments:@[module, method, args] callback:onComplete];
+  NSString *bridgeMethod = flushQueue ? @"callFunctionReturnFlushedQueue" : @"callFunction";
+  [self _executeJSCall:bridgeMethod arguments:@[module, method, args] unwrapResult:unwrapResult callback:onComplete];
+}
+
+- (void)callFunctionOnModule:(NSString *)module method:(NSString *)method arguments:(NSArray *)args callback:(RCTJavaScriptCallback)onComplete
+{
+  [self _callFunctionOnModule:module method:method arguments:args flushQueue:YES unwrapResult:YES callback:onComplete];
+}
+
+- (void)callFunctionOnModule:(NSString *)module method:(NSString *)method arguments:(NSArray *)args jsValueCallback:(RCTJavaScriptValueCallback)onComplete
+{
+  [self _callFunctionOnModule:module method:method arguments:args flushQueue:NO unwrapResult:NO callback:onComplete];
 }
 
 - (void)invokeCallbackID:(NSNumber *)cbID
@@ -612,11 +625,12 @@ static void installBasicSynchronousHooksOnContext(JSContext *context)
                 callback:(RCTJavaScriptCallback)onComplete
 {
   // TODO: Make this function handle first class instead of dynamically dispatching it. #9317773
-  [self _executeJSCall:@"invokeCallbackAndReturnFlushedQueue" arguments:@[cbID, args] callback:onComplete];
+  [self _executeJSCall:@"invokeCallbackAndReturnFlushedQueue" arguments:@[cbID, args] unwrapResult:YES callback:onComplete];
 }
 
 - (void)_executeJSCall:(NSString *)method
              arguments:(NSArray *)arguments
+          unwrapResult:(BOOL)unwrapResult
               callback:(RCTJavaScriptCallback)onComplete
 {
   RCTAssert(onComplete != nil, @"onComplete block should not be nil");
@@ -673,20 +687,16 @@ static void installBasicSynchronousHooksOnContext(JSContext *context)
         error = RCTNSErrorFromJSError(jscWrapper, contextJSRef, errorJSRef);
       }
       onComplete(nil, error);
-      return;
+    } else {
+      id objcValue = nil;
+      // We often return `null` from JS when there is nothing for native side. [JSValue toValue]
+      // returns [NSNull null] in this case, which we don't want.
+      if (!jscWrapper->JSValueIsNull(contextJSRef, resultJSRef)) {
+        JSValue *result = [jscWrapper->JSValue valueWithJSValueRef:resultJSRef inContext:context];
+        objcValue = unwrapResult ? [result toObject] : result;
+      }
+      onComplete(objcValue, nil);
     }
-
-    // Looks like making lots of JSC API calls is slower than communicating by using a JSON
-    // string. Also it ensures that data stuctures don't have cycles and non-serializable fields.
-    // see [RCTJSCExecutorTests testDeserializationPerf]
-    id objcValue;
-    // We often return `null` from JS when there is nothing for native side. JSONKit takes an extra hundred microseconds
-    // to handle this simple case, so we are adding a shortcut to make executeJSCall method even faster
-    if (!jscWrapper->JSValueIsNull(contextJSRef, resultJSRef)) {
-      objcValue = [[jscWrapper->JSValue valueWithJSValueRef:resultJSRef inContext:context] toObject];
-    }
-
-    onComplete(objcValue, nil);
   }), 0, @"js_call", (@{@"method": method, @"args": arguments}))];
 }