多线程单例

多线程单例.h

#import <Foundation/Foundation.h>

@interface DataHandle : NSObject

+ (DataHandle *)defaultdataHandle;
@end

多线程单例.m

#import "DataHandle.h"

@implementation DataHandle
+ (DataHandle *)defaultdataHandle
{
    static DataHandle *dataHandle = nil;
    
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        dataHandle = [[DataHandle alloc] init];
    });
    
    return dataHandle;
}

@end