iOS多线程总结

// 创建
NSThread *thread = [[NSThread alloc] initWithTarget:self selector:@selector(download:) object:nil];
 
// 启动
[thread start];

[NSThread detachNewThreadSelector:@selector(download:) toTarget:self withObject:nil];

[self performSelectorInBackground:@selector(download:) withObject:nil];

+ (NSThread *)currentThread;

+ (NSThread *)mainThread;

+ (void)sleepUntilDate:(NSDate *)date;
+ (void)sleepForTimeInterval:(NSTimeInterval)ti;

- (void)setName:(NSString *)n;
- (NSString *)name;

@synchronized(self) {
// 被锁住的代码
}

dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);

dispatch_queue_t queue = dispatch_queue_create("cn.heima.queue_name", NULL);

dispatch_queue_t queue = dispatch_get_main_queue();

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
// 执行耗时的异步操作...
 
 
dispatch_async(dispatch_get_main_queue(), ^{
// 回到主线程，执行UI刷新操作
});
});

[self performSelector:@selector(download:) withObject:@"http://xxx.jpg" afterDelay:3];

// 任务放到哪个队列中执行
dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);
double delay = 3; // 延迟多少秒
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delay * NSEC_PER_SEC)), queue, ^{
// 3秒后需要执行的任务
});

static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
// 这里面的代码，在程序运行过程中，永远只会执行1次
});

@interface HMDataTool : NSObject
+ (instancetype)sharedDataTool;
@end
 
@implementation HMDataTool
// 用来保存唯一的单例对象
static id _instace;
 
+ (id)allocWithZone:(struct _NSZone *)zone
{
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
_instace = [super allocWithZone:zone];
});
return _instace;
}
 
+ (instancetype)sharedDataTool
{
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
_instace = [[self alloc] init];
});
return _instace;
}
 
- (id)copyWithZone:(NSZone *)zone
{
return _instace;
}
@end

@interface HMDataTool : NSObject
+ (instancetype)sharedDataTool;
@end
 
@implementation HMDataTool
// 用来保存唯一的单例对象
static id _instace;
 
+ (id)allocWithZone:(struct _NSZone *)zone
{
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
_instace = [super allocWithZone:zone];
});
return _instace;
}
 
+ (instancetype)sharedDataTool
{
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
_instace = [[self alloc] init];
});
return _instace;
}
 
- (id)copyWithZone:(NSZone *)zone
{
return _instace;
}
 
- (oneway void)release {
 
}
 
- (id)retain {
return self;
}
 
- (NSUInteger)retainCount {
return 1;
}
 
- (id)autorelease {
return self;
}
@end

[NSOperationQueue mainQueue];

[[NSOperationQueue alloc] init]

- (void)addOperation:(NSOperation *)op;
- (void)addOperationWithBlock:(void (^)(void))block;

- (NSInteger)maxConcurrentOperationCount;
- (void)setMaxConcurrentOperationCount:(NSInteger)cnt;

- (void)cancelAllOperations;

[queue setSuspended:YES];

[operationB addDependency:operationA];

NSOperationQueue *queue = [[NSOperationQueue alloc] init];
[queue addOperationWithBlock:^{

}];

1 [self performSelectorOnMainThread:<#(SEL)#> withObject:<#(id)#> waitUntilDone:<#(BOOL)#>];

[[NSOperationQueue mainQueue] addOperationWithBlock:^{
 
}];