diff --git a/ios/sdk/WeexSDK/Sources/Component/WXCycleSliderComponent.mm b/ios/sdk/WeexSDK/Sources/Component/WXCycleSliderComponent.mm
index 402e592c7a..ab26bc3655 100644
--- a/ios/sdk/WeexSDK/Sources/Component/WXCycleSliderComponent.mm
+++ b/ios/sdk/WeexSDK/Sources/Component/WXCycleSliderComponent.mm
@@ -73,6 +73,9 @@ - (id)initWithFrame:(CGRect)frame
         _currentIndex = 0;
         _itemViews = [[NSMutableArray alloc] init];
         _scrollView = [[WXRecycleSliderScrollView alloc] init];
+        if (@available(iOS 11.0, *)) {
+            _scrollView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
+        }
         _scrollView.backgroundColor = [UIColor clearColor];
         _scrollView.delegate = self;
         _scrollView.showsHorizontalScrollIndicator = NO;
diff --git a/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.mm b/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.mm
index dfe8824891..a27820222b 100644
--- a/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.mm
+++ b/ios/sdk/WeexSDK/Sources/Component/WXScrollerComponent.mm
@@ -903,7 +903,7 @@ - (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL
     }
     if (!decelerate) {
         _isScrolling = NO;
-        [self performSelector:@selector(scrollViewDidEndDecelerating:) withObject:nil afterDelay:0.1];
+        [self performSelector:@selector(scrollViewDidEndDecelerating:) withObject:scrollView afterDelay:0.1];
     }
     
     NSHashTable *delegates = [_delegates copy];
diff --git a/ios/sdk/WeexSDK/Sources/Engine/WXSDKEngine.h b/ios/sdk/WeexSDK/Sources/Engine/WXSDKEngine.h
index 5e7b1e7db6..ac014a5781 100644
--- a/ios/sdk/WeexSDK/Sources/Engine/WXSDKEngine.h
+++ b/ios/sdk/WeexSDK/Sources/Engine/WXSDKEngine.h
@@ -82,6 +82,20 @@
  */
 + (void)registerService:(NSString *)name withScript:(NSString *)serviceScript withOptions:(NSDictionary *)options;
 
+/**
+ * @abstract Registers a component for a given name, options and js code
+ *
+ * @param name The service name to register
+ *
+ * @param options The service options to register
+ *
+ * @param serviceScript service js code to invoke
+ *
+ * @param completion Completion callback. JS is executed in asynchronously.
+ *
+ */
++ (void)registerService:(NSString *)name withScript:(NSString *)serviceScript withOptions:(NSDictionary *)options completion:(void(^)(BOOL result))completion;
+
 /**
  * @abstract Registers a component for a given name, options and js url
  *
@@ -92,7 +106,21 @@
  * @param serviceScriptUrl The service url to register
  *
  */
-+ (void)registerService:(NSString *)name withScriptUrl:(NSURL *)serviceScriptUrl WithOptions:(NSDictionary *)options;
++ (void)registerService:(NSString *)name withScriptUrl:(NSURL *)serviceScriptUrl withOptions:(NSDictionary *)options;
+
+/**
+ * @abstract Registers a component for a given name, options and js url
+ *
+ * @param name The service name to register
+ *
+ * @param options The service options to register
+ *
+ * @param serviceScriptUrl The service url to register
+ *
+ * @param completion Completion callback. JS is executed in asynchronously.
+ *
+ */
++ (void)registerService:(NSString *)name withScriptUrl:(NSURL *)serviceScriptUrl withOptions:(NSDictionary *)options completion:(void(^)(BOOL result))completion;
 
 /**
  * @abstract Registers a component for a given name, options and js code
diff --git a/ios/sdk/WeexSDK/Sources/Engine/WXSDKEngine.m b/ios/sdk/WeexSDK/Sources/Engine/WXSDKEngine.m
index b5d7e00825..26ca8b7714 100644
--- a/ios/sdk/WeexSDK/Sources/Engine/WXSDKEngine.m
+++ b/ios/sdk/WeexSDK/Sources/Engine/WXSDKEngine.m
@@ -166,14 +166,25 @@ + (void)registerComponent:(NSString *)name withClass:(Class)clazz withProperties
 
 
 # pragma mark Service Register
+
 + (void)registerService:(NSString *)name withScript:(NSString *)serviceScript withOptions:(NSDictionary *)options
 {
-    [[WXSDKManager bridgeMgr] registerService:name withService:serviceScript withOptions:options];
+    [[WXSDKManager bridgeMgr] registerService:name withService:serviceScript withOptions:options completion:nil];
+}
+
++ (void)registerService:(NSString *)name withScript:(NSString *)serviceScript withOptions:(NSDictionary *)options completion:(void(^)(BOOL result))completion
+{
+    [[WXSDKManager bridgeMgr] registerService:name withService:serviceScript withOptions:options completion:completion];
+}
+
++ (void)registerService:(NSString *)name withScriptUrl:(NSURL *)serviceScriptUrl withOptions:(NSDictionary *)options
+{
+    [[WXSDKManager bridgeMgr] registerService:name withServiceUrl:serviceScriptUrl withOptions:options completion:nil];
 }
 
-+ (void)registerService:(NSString *)name withScriptUrl:(NSURL *)serviceScriptUrl WithOptions:(NSDictionary *)options
++ (void)registerService:(NSString *)name withScriptUrl:(NSURL *)serviceScriptUrl withOptions:(NSDictionary *)options completion:(void(^)(BOOL result))completion
 {
-    [[WXSDKManager bridgeMgr] registerService:name withServiceUrl:serviceScriptUrl withOptions:options];
+    [[WXSDKManager bridgeMgr] registerService:name withServiceUrl:serviceScriptUrl withOptions:options completion:completion];
 }
 
 + (void)unregisterService:(NSString *)name
diff --git a/ios/sdk/WeexSDK/Sources/Layout/WXComponent+Layout.h b/ios/sdk/WeexSDK/Sources/Layout/WXComponent+Layout.h
index a33884769c..7a7dc37ff7 100644
--- a/ios/sdk/WeexSDK/Sources/Layout/WXComponent+Layout.h
+++ b/ios/sdk/WeexSDK/Sources/Layout/WXComponent+Layout.h
@@ -26,6 +26,13 @@
 #ifdef __cplusplus
 #include "layout.h"
 
+typedef WeexCore::WXCoreFlexDirection WXCoreFlexDirection;
+typedef WeexCore::WXCoreFlexWrap WXCoreFlexWrap;
+typedef WeexCore::WXCoreJustifyContent WXCoreJustifyContent;
+typedef WeexCore::WXCoreAlignItems WXCoreAlignItems;
+typedef WeexCore::WXCoreAlignSelf WXCoreAlignSelf;
+typedef WeexCore::WXCorePositionType WXCorePositionType;
+
 extern "C" {
 #endif
     bool flexIsUndefined(float value);
@@ -33,6 +40,19 @@ extern "C" {
 }
 #endif
 
+#ifndef __cplusplus
+// Ensure that .m files can use css style enum definitions.
+#include "flex_enum.h"
+
+typedef enum WXCoreFlexDirection WXCoreFlexDirection;
+typedef enum WXCoreFlexWrap WXCoreFlexWrap;
+typedef enum WXCoreJustifyContent WXCoreJustifyContent;
+typedef enum WXCoreAlignItems WXCoreAlignItems;
+typedef enum WXCoreAlignSelf WXCoreAlignSelf;
+typedef enum WXCorePositionType WXCorePositionType;
+
+#endif
+
 @interface WXComponent ()
 {
     @package
@@ -51,9 +71,59 @@ extern "C" {
  * @warning Subclasses must not override this.
  */
 #ifdef __cplusplus
-@property(nonatomic, readonly, assign) WeexCore::WXCoreLayoutNode *flexCssNode;
+@property (nonatomic, readonly, assign) WeexCore::WXCoreLayoutNode *flexCssNode;
 #endif
 
+/**
+ * @abstract Get css style value for key. The key should be of CSS standard form.
+ *  This method is for convenience use in C/ObjC environment. And if you want to
+ *  retrieve all style values or in C++, you could use flexCssNode directly.
+ *
+ *  Thread usage:
+ *      This method should be invoked in component thread by WXPerformBlockOnComponentThread.
+ *      Note that all initWithRef methods of WXComponent and its subclasses are performed in
+ *      component thread by default. Therefore you can call this method directly in initWithRef.
+ *
+ *  Supported keys:
+ *      width, height, min-width, min-height, max-width, max-height,
+ *      margin-(left/right/top/bottom)
+ *      padding-(left/right/top/bottom)
+ *      border-(left/right/top/bottom)-width
+ *      left, right, top, bottom
+ *      flex-grow
+ */
+- (float)getCssStyleValueForKey:(NSString *)key;
+
+/**
+ * @abstract Get css style flex-direction. Thread usage the same as getCssStyleValueForKey.
+ */
+- (WXCoreFlexDirection)getCssStyleFlexDirection;
+
+/**
+ * @abstract Get css style flex-wrap. Thread usage the same as getCssStyleValueForKey.
+ */
+- (WXCoreFlexWrap)getCssStyleFlexWrap;
+
+/**
+ * @abstract Get css style justify-content. Thread usage the same as getCssStyleValueForKey.
+ */
+- (WXCoreJustifyContent)getCssStyleJustifyContent;
+
+/**
+ * @abstract Get css style align-items. Thread usage the same as getCssStyleValueForKey.
+ */
+- (WXCoreAlignItems)getCssStyleAlignItems;
+
+/**
+ * @abstract Get css style align-self. Thread usage the same as getCssStyleValueForKey.
+ */
+- (WXCoreAlignSelf)getCssStyleAlignSelf;
+
+/**
+ * @abstract Get css style position. Thread usage the same as getCssStyleValueForKey.
+ */
+- (WXCorePositionType)getCssStylePositionType;
+
 /**
  * @abstract Convert layout dimension value like 'left', 'width' to style value in js considering viewport and scale.
  */
diff --git a/ios/sdk/WeexSDK/Sources/Layout/WXComponent+Layout.mm b/ios/sdk/WeexSDK/Sources/Layout/WXComponent+Layout.mm
index 18cb24dbb1..8afd225d18 100644
--- a/ios/sdk/WeexSDK/Sources/Layout/WXComponent+Layout.mm
+++ b/ios/sdk/WeexSDK/Sources/Layout/WXComponent+Layout.mm
@@ -366,6 +366,86 @@ - (CGFloat)judgePropValuePropValue:(id)propValue defaultValue:(CGFloat)defaultVa
     return defaultValue;
 }
 
+- (float)getCssStyleValueForKey:(NSString *)key
+{
+    /*
+     *      width, height, min-width, min-height, max-width, max-height,
+     *      margin-(left/right/top/bottom)
+     *      padding-(left/right/top/bottom)
+     *      border-(left/right/top/bottom)-width
+     *      left, right, top, bottom
+     *      flex-grow
+     */
+    WXAssert(_flexCssNode != nullptr, @"Css node is null.");
+    if (_flexCssNode == nullptr) {
+        return NAN;
+    }
+    
+    std::string ckey = [key UTF8String];
+    if (ckey == "width") return _flexCssNode->getStyleWidth();
+    if (ckey == "height") return _flexCssNode->getStyleHeight();
+    if (ckey == "min-width") return _flexCssNode->getMinWidth();
+    if (ckey == "min-height") return _flexCssNode->getMinHeight();
+    if (ckey == "max-width") return _flexCssNode->getMaxWidth();
+    if (ckey == "max-height") return _flexCssNode->getMaxHeight();
+    if (ckey == "margin-left") return _flexCssNode->getMarginLeft();
+    if (ckey == "margin-right") return _flexCssNode->getMarginRight();
+    if (ckey == "margin-top") return _flexCssNode->getMarginTop();
+    if (ckey == "margin-bottom") return _flexCssNode->getMarginBottom();
+    if (ckey == "padding-left") return _flexCssNode->getPaddingLeft();
+    if (ckey == "padding-right") return _flexCssNode->getPaddingRight();
+    if (ckey == "padding-top") return _flexCssNode->getPaddingTop();
+    if (ckey == "padding-bottom") return _flexCssNode->getPaddingBottom();
+    if (ckey == "border-left-width") return _flexCssNode->getBorderWidthLeft();
+    if (ckey == "border-right-width") return _flexCssNode->getBorderWidthRight();
+    if (ckey == "border-top-width") return _flexCssNode->getBorderWidthTop();
+    if (ckey == "border-bottom-width") return _flexCssNode->getBorderWidthBottom();
+    if (ckey == "left") return _flexCssNode->getStylePositionLeft();
+    if (ckey == "right") return _flexCssNode->getStylePositionRight();
+    if (ckey == "top") return _flexCssNode->getStylePositionTop();
+    if (ckey == "bottom") return _flexCssNode->getStylePositionBottom();
+    if (ckey == "flex-grow") return _flexCssNode->getFlex();
+    
+    WXAssert(NO, @"Invalid css style key %@", key);
+    return NAN;
+}
+
+- (WXCoreFlexDirection)getCssStyleFlexDirection
+{
+    WXAssert(_flexCssNode != nullptr, @"Css node is null.");
+    return _flexCssNode ? _flexCssNode->getFlexDirection() : kFlexDirectionColumn;
+}
+
+- (WXCoreFlexWrap)getCssStyleFlexWrap
+{
+    WXAssert(_flexCssNode != nullptr, @"Css node is null.");
+    return _flexCssNode ? _flexCssNode->getFlexWrap() : kNoWrap;
+}
+
+- (WXCoreJustifyContent)getCssStyleJustifyContent
+{
+    WXAssert(_flexCssNode != nullptr, @"Css node is null.");
+    return _flexCssNode ? _flexCssNode->getJustifyContent() : kJustifyFlexStart;
+}
+
+- (WXCoreAlignItems)getCssStyleAlignItems
+{
+    WXAssert(_flexCssNode != nullptr, @"Css node is null.");
+    return _flexCssNode ? _flexCssNode->getAlignItems() : kAlignItemsStretch;
+}
+
+- (WXCoreAlignSelf)getCssStyleAlignSelf
+{
+    WXAssert(_flexCssNode != nullptr, @"Css node is null.");
+    return _flexCssNode ? _flexCssNode->getAlignSelf() : kAlignSelfAuto;
+}
+
+- (WXCorePositionType)getCssStylePositionType
+{
+    WXAssert(_flexCssNode != nullptr, @"Css node is null.");
+    return _flexCssNode ? _flexCssNode->getStylePositionType() : kRelative;
+}
+
 - (NSString*)convertLayoutValueToStyleValue:(NSString*)valueName
 {
     if (_flexCssNode == nullptr) {
diff --git a/ios/sdk/WeexSDK/Sources/Manager/WXBridgeManager.h b/ios/sdk/WeexSDK/Sources/Manager/WXBridgeManager.h
index 3d062774b7..8728161254 100644
--- a/ios/sdk/WeexSDK/Sources/Manager/WXBridgeManager.h
+++ b/ios/sdk/WeexSDK/Sources/Manager/WXBridgeManager.h
@@ -102,8 +102,9 @@ extern void WXPerformBlockOnBridgeThread(void (^block)(void));
  *  @param name      :   service name
  *  @param serviceScript    :   script code
  *  @param options   :   service options
+ *  @param completion : completion callback
  **/
-- (void)registerService:(NSString *)name withService:(NSString *)serviceScript withOptions:(NSDictionary *)options;
+- (void)registerService:(NSString *)name withService:(NSString *)serviceScript withOptions:(NSDictionary *)options completion:(void(^)(BOOL result))completion;
 
 
 /**
@@ -111,9 +112,9 @@ extern void WXPerformBlockOnBridgeThread(void (^block)(void));
  *  @param name         :   service name
  *  @param serviceScriptUrl    :   script url
  *  @param options      :   service options
+ *  @param completion : completion callback
  **/
-
--(void)registerService:(NSString *)name withServiceUrl:(NSURL *)serviceScriptUrl withOptions:(NSDictionary *)options;
+-(void)registerService:(NSString *)name withServiceUrl:(NSURL *)serviceScriptUrl withOptions:(NSDictionary *)options completion:(void(^)(BOOL result))completion;
 
 /**
  *  Unregister JS service Script
diff --git a/ios/sdk/WeexSDK/Sources/Manager/WXBridgeManager.m b/ios/sdk/WeexSDK/Sources/Manager/WXBridgeManager.m
index a0e8e4e2a2..f5c7a47e7d 100644
--- a/ios/sdk/WeexSDK/Sources/Manager/WXBridgeManager.m
+++ b/ios/sdk/WeexSDK/Sources/Manager/WXBridgeManager.m
@@ -288,28 +288,41 @@ - (JSValue *)callJSMethodWithResult:(WXCallJSMethod *)method
     return value;
 }
 
--(void)registerService:(NSString *)name withServiceUrl:(NSURL *)serviceScriptUrl withOptions:(NSDictionary *)options
+- (void)registerService:(NSString *)name withServiceUrl:(NSURL *)serviceScriptUrl withOptions:(NSDictionary *)options completion:(void(^)(BOOL result))completion
 {
-    if (!name || !serviceScriptUrl || !options) return;
+    if (!name || !serviceScriptUrl || !options) {
+        if (completion) {
+            completion(NO);
+        }
+        return;
+    }
     __weak typeof(self) weakSelf = self;
     WXResourceRequest *request = [WXResourceRequest requestWithURL:serviceScriptUrl resourceType:WXResourceTypeServiceBundle referrer:@"" cachePolicy:NSURLRequestUseProtocolCachePolicy];
     WXResourceLoader *serviceBundleLoader = [[WXResourceLoader alloc] initWithRequest:request];;
     serviceBundleLoader.onFinished = ^(WXResourceResponse *response, NSData *data) {
         __strong typeof(weakSelf) strongSelf = weakSelf;
         NSString *jsServiceString = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
-        [strongSelf registerService:name withService:jsServiceString withOptions:options];
+        [strongSelf registerService:name withService:jsServiceString withOptions:options completion:completion];
     };
     
     serviceBundleLoader.onFailed = ^(NSError *loadError) {
         WXLogError(@"No script URL found");
+        if (completion) {
+            completion(NO);
+        }
     };
     
     [serviceBundleLoader start];
 }
 
-- (void)registerService:(NSString *)name withService:(NSString *)serviceScript withOptions:(NSDictionary *)options
+- (void)registerService:(NSString *)name withService:(NSString *)serviceScript withOptions:(NSDictionary *)options completion:(void(^)(BOOL result))completion
 {
-    if (!name || !serviceScript || !options) return;
+    if (!name || !serviceScript || !options) {
+        if (completion) {
+            completion(NO);
+        }
+        return;
+    }
     
     NSString *script = [WXServiceFactory registerServiceScript:name withRawScript:serviceScript withOptions:options];
     
@@ -318,6 +331,9 @@ - (void)registerService:(NSString *)name withService:(NSString *)serviceScript w
         // save it when execute
         [WXDebugTool cacheJsService:name withScript:serviceScript withOptions:options];
         [weakSelf.bridgeCtx executeJsService:script withName:name];
+        if (completion) {
+            completion(YES);
+        }
     });
 }
 
diff --git a/ios/sdk/WeexSDK/Sources/Model/WXSDKInstance.m b/ios/sdk/WeexSDK/Sources/Model/WXSDKInstance.m
index 87bc32650b..613abd59a4 100644
--- a/ios/sdk/WeexSDK/Sources/Model/WXSDKInstance.m
+++ b/ios/sdk/WeexSDK/Sources/Model/WXSDKInstance.m
@@ -78,7 +78,6 @@ @implementation WXSDKInstance
     BOOL _debugJS;
     id<WXBridgeProtocol> _instanceJavaScriptContext; // sandbox javaScript context    
     CGFloat _defaultPixelScaleFactor;
-    BOOL _bReleaseInstanceInMainThread;
     BOOL _defaultDataRender;
 }
 
@@ -118,7 +117,6 @@ - (instancetype)init
         _apmInstance = [[WXApmForInstance alloc] init];
         
         _defaultPixelScaleFactor = CGFLOAT_MIN;
-        _bReleaseInstanceInMainThread = YES;
         _defaultDataRender = NO;
         
         [self addObservers];
@@ -443,9 +441,6 @@ - (BOOL)_handleConfigCenter
         
         BOOL useJSCApiForCreateInstance = [[configCenter configForKey:@"iOS_weex_ext_config.useJSCApiForCreateInstance" defaultValue:@(YES) isDefault:NULL] boolValue];
         [WXUtility setUseJSCApiForCreateInstance:useJSCApiForCreateInstance];
-		
-        //Reading config from orange for Release instance in Main Thread or not
-        _bReleaseInstanceInMainThread = [[configCenter configForKey:@"iOS_weex_ext_config.releaseInstanceInMainThread" defaultValue:@(YES) isDefault:nil] boolValue];
 
         BOOL shoudMultiContext = NO;
         shoudMultiContext = [[configCenter configForKey:@"iOS_weex_ext_config.createInstanceUsingMutliContext" defaultValue:@(YES) isDefault:NULL] boolValue];
@@ -659,13 +654,9 @@ - (void)destroyInstance
         [WXCoreBridge closePage:instanceId];
         
         // Reading config from orange for Release instance in Main Thread or not, for Bug #15172691 +{
-        if (!_bReleaseInstanceInMainThread) {
+        dispatch_async(dispatch_get_main_queue(), ^{
             [WXSDKManager removeInstanceforID:instanceId];
-        } else {
-            dispatch_async(dispatch_get_main_queue(), ^{
-                [WXSDKManager removeInstanceforID:instanceId];
-            });
-        }
+        });
         //+}
     });
     
diff --git a/ios/sdk/WeexSDK/Sources/Module/WXAnimationModule.m b/ios/sdk/WeexSDK/Sources/Module/WXAnimationModule.m
index 70a8feba25..75b09d8d01 100644
--- a/ios/sdk/WeexSDK/Sources/Module/WXAnimationModule.m
+++ b/ios/sdk/WeexSDK/Sources/Module/WXAnimationModule.m
@@ -123,7 +123,7 @@ - (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag
         _animationInfo.target.view.layer.anchorPoint = _animationInfo.originAnchorPoint;
         _animationInfo.target.view.layer.frame = originFrame;
     }
-    [_animationInfo.target.layer removeAllAnimations];
+    [_animationInfo.target.layer removeAnimationForKey:_animationInfo.propertyName];
     
     if (_finishBlock) {
         _finishBlock(flag);
diff --git a/ios/sdk/WeexSDK/Sources/Utility/WXThreadSafeMutableDictionary.m b/ios/sdk/WeexSDK/Sources/Utility/WXThreadSafeMutableDictionary.m
index 3c32292269..6f31fb990e 100644
--- a/ios/sdk/WeexSDK/Sources/Utility/WXThreadSafeMutableDictionary.m
+++ b/ios/sdk/WeexSDK/Sources/Utility/WXThreadSafeMutableDictionary.m
@@ -145,24 +145,30 @@ - (NSEnumerator *)keyEnumerator
 
 - (void)setObject:(id)anObject forKey:(id<NSCopying>)aKey
 {
+    id originalObject = nil; // make sure that object is not released in lock
     @try {
         pthread_mutex_lock(&_safeThreadDictionaryMutex);
+        originalObject = [_dict objectForKey:aKey];
         [_dict setObject:anObject forKey:aKey];
     }
     @finally {
         pthread_mutex_unlock(&_safeThreadDictionaryMutex);
     }
+    originalObject = nil;
 }
 
 - (void)setObject:(id)anObject forKeyedSubscript:(id <NSCopying>)key
 {
+    id originalObject = nil; // make sure that object is not released in lock
     @try {
         pthread_mutex_lock(&_safeThreadDictionaryMutex);
+        originalObject = [_dict objectForKey:key];
         [_dict setObject:anObject forKeyedSubscript:key];
     }
     @finally {
         pthread_mutex_unlock(&_safeThreadDictionaryMutex);
     }
+    originalObject = nil;
 }
 
 - (NSArray *)allKeys
@@ -189,24 +195,32 @@ - (NSArray *)allValues
 
 - (void)removeObjectForKey:(id)aKey
 {
+    id originalObject = nil; // make sure that object is not released in lock
     @try {
         pthread_mutex_lock(&_safeThreadDictionaryMutex);
-        [_dict removeObjectForKey:aKey];
+        originalObject = [_dict objectForKey:aKey];
+        if (originalObject) {
+            [_dict removeObjectForKey:aKey];
+        }
     }
     @finally {
         pthread_mutex_unlock(&_safeThreadDictionaryMutex);
     }
+    originalObject = nil;
 }
 
 - (void)removeAllObjects
 {
+    NSArray* allValues = nil; // make sure that objects are not released in lock
     @try {
         pthread_mutex_lock(&_safeThreadDictionaryMutex);
+        allValues = [_dict allValues];
         [_dict removeAllObjects];
     }
     @finally {
         pthread_mutex_unlock(&_safeThreadDictionaryMutex);
     }
+    allValues = nil;
 }
 
 - (id)copy
diff --git a/weex_core/Source/android/wrap/native_render_object_utils_impl_android.cpp b/weex_core/Source/android/wrap/native_render_object_utils_impl_android.cpp
index 5565075a01..eb30d90d72 100644
--- a/weex_core/Source/android/wrap/native_render_object_utils_impl_android.cpp
+++ b/weex_core/Source/android/wrap/native_render_object_utils_impl_android.cpp
@@ -79,7 +79,7 @@ static jlong CopyRenderObject(JNIEnv* env, jclass jcaller, jlong ptr){
 
 static  void showRenderObjectLayout(RenderObject *renderObject, int level){
     LOGE("RenderObject layout %s %d %p %f %f %f %f ", renderObject->type().c_str(),
-         renderObject->getStypePositionType(),
+         renderObject->getStylePositionType(),
          renderObject, renderObject->getLayoutHeight(), renderObject->getLayoutWidth(),
          renderObject->getLayoutPositionLeft(), renderObject->getLayoutPositionRight());
 
@@ -171,11 +171,11 @@ static void RenderObjectChildWaste(JNIEnv* env, jclass jcaller,
                                    jboolean waster){
     RenderObject* renderObject = convert_long_to_render_object(ptr);
     if(waster){
-        if(renderObject->getStypePositionType() != WXCorePositionType::kFixed){
+        if(renderObject->getStylePositionType() != WXCorePositionType::kFixed){
             renderObject->setStylePositionType(WXCorePositionType::kFixed);
         }
     }else{
-        if(renderObject->getStypePositionType() != WXCorePositionType::kRelative){
+        if(renderObject->getStylePositionType() != WXCorePositionType::kRelative){
             renderObject->setStylePositionType(WXCorePositionType::kRelative);
         }
     }
diff --git a/weex_core/Source/core/layout/flex_enum.h b/weex_core/Source/core/layout/flex_enum.h
index 9eb3676354..7e439b21ed 100644
--- a/weex_core/Source/core/layout/flex_enum.h
+++ b/weex_core/Source/core/layout/flex_enum.h
@@ -16,12 +16,14 @@
  * specific language governing permissions and limitations
  * under the License.
  */
-#ifdef __cplusplus
 
 #ifndef WEEXCORE_FLEXLAYOUT_WXCOREFLEXENUM_H
 #define WEEXCORE_FLEXLAYOUT_WXCOREFLEXENUM_H
 
+/* These enum definitions may also be used by C files. */
+#ifdef __cplusplus
 namespace WeexCore {
+#endif
 
   /**
    * MainAxis direction
@@ -120,6 +122,8 @@ namespace WeexCore {
     kLeft,
   };
 
+#ifdef __cplusplus
 }
+#endif
+
 #endif //WEEXCORE_FLEXLAYOUT_WXCOREFLEXENUM_H
-#endif
\ No newline at end of file
diff --git a/weex_core/Source/core/layout/layout.h b/weex_core/Source/core/layout/layout.h
index 0d62edd1df..4b8f0c54df 100644
--- a/weex_core/Source/core/layout/layout.h
+++ b/weex_core/Source/core/layout/layout.h
@@ -836,7 +836,7 @@ namespace WeexCore {
       }
     }
 
-    inline WXCorePositionType getStypePositionType() const {
+    inline WXCorePositionType getStylePositionType() const {
       return mCssStyle->mPositionType;
     }
 
diff --git a/weex_core/Source/core/render/page/render_page.cpp b/weex_core/Source/core/render/page/render_page.cpp
index 032a0d7aa0..119af879ec 100644
--- a/weex_core/Source/core/render/page/render_page.cpp
+++ b/weex_core/Source/core/render/page/render_page.cpp
@@ -628,13 +628,11 @@ void RenderPage::Batch() {
   if ((kUseVSync && this->need_layout_.load()) || !kUseVSync) {
     LayoutInner();
   }
-  else {
 #if OS_IOS
-    // vsync may stopped, trigger once
-    RenderAction *action = new RenderActionTriggerVSync(page_id());
-    PostRenderAction(action);
+  // vsync may stopped, trigger once
+  RenderAction *action = new RenderActionTriggerVSync(page_id());
+  PostRenderAction(action);
 #endif
-  }
 }
 
 RenderObject *RenderPage::GetRenderObject(const std::string &ref) {