Merge pull request #656 from kinarob/Fix_properties_thread_safe_issue

Fix `properties` thread safe issue

Author: kinarobin

MJExtension/NSObject+MJProperty.m

@@ -135,8 +135,10 @@ + (Class)propertyObjectClassInArray:(NSString *)propertyName
 + (void)mj_enumerateProperties:(MJPropertiesEnumeration)enumeration
 {
     // 获得成员变量
+    MJExtensionSemaphoreCreate
+    MJExtensionSemaphoreWait
     NSArray *cachedProperties = [self properties];
-    
+    MJExtensionSemaphoreSignal
     // 遍历成员变量
     BOOL stop = NO;
     for (MJProperty *property in cachedProperties) {
@@ -149,11 +151,8 @@ + (void)mj_enumerateProperties:(MJPropertiesEnumeration)enumeration
 + (NSMutableArray *)properties
 {
     NSMutableArray *cachedProperties = [self propertyDictForKey:&MJCachedPropertiesKey][NSStringFromClass(self)];
-    
     if (cachedProperties == nil) {
-        MJExtensionSemaphoreCreate
-        MJExtensionSemaphoreWait
-        
+    
         if (cachedProperties == nil) {
             cachedProperties = [NSMutableArray array];
 
@@ -179,8 +178,6 @@ + (NSMutableArray *)properties
 
             [self propertyDictForKey:&MJCachedPropertiesKey][NSStringFromClass(self)] = cachedProperties;
         }
-        
-        MJExtensionSemaphoreSignal
     }
 
     return cachedProperties;