iOS NSThread

作者: 没脑子的程序员 | 来源:发表于2018-11-01 22:54 被阅读0次

iOS多线程篇：NSThread
IOS 中NSThread
iOS 多线程
iOS多线程(三)-NSThread
OC_NSThread
iOS多线程
iOS 多线程初探（二）
iOS NSThread 保活线程代码封装
iOS 多线程面试题（iOS中的多线程）
iOS多线程学习笔记

/*  NSThread.h
    Copyright (c) 1994-2018, Apple Inc. All rights reserved.
*/

#import <Foundation/NSObject.h>
#import <Foundation/NSDate.h>
#import <Foundation/NSNotification.h>

@class NSArray<ObjectType>, NSMutableDictionary, NSDate, NSNumber, NSString;

NS_ASSUME_NONNULL_BEGIN

@interface NSThread : NSObject  {
@private
    id _private;
    uint8_t _bytes[44];
}
//当前线程
@property (class, readonly, strong) NSThread *currentThread;
//使用类方法创建线程并立即执行任务
+ (void)detachNewThreadWithBlock:(void (^)(void))block API_AVAILABLE(macosx(10.12), ios(10.0), watchos(3.0), tvos(10.0));
+ (void)detachNewThreadSelector:(SEL)selector toTarget:(id)target withObject:(nullable id)argument;
//是否为多线程
+ (BOOL)isMultiThreaded;
//指定线程的线程参数，例如设置当前线程的断言处理器。
@property (readonly, retain) NSMutableDictionary *threadDictionary;
//当前线程暂停到某个时间
+ (void)sleepUntilDate:(NSDate *)date;
//当前线程暂停一段时间
+ (void)sleepForTimeInterval:(NSTimeInterval)ti;
//退出当前线程，未完成的任务不再执行
+ (void)exit;
//当前线程优先级
+ (double)threadPriority;
//设置当前线程优先级
+ (BOOL)setThreadPriority:(double)p;
//指定线程对象优先级 0.0～1.0，默认值为0.5
@property double threadPriority API_AVAILABLE(macos(10.6), ios(4.0), watchos(2.0), tvos(9.0)); // To be deprecated; use qualityOfService below
//服务质量
@property NSQualityOfService qualityOfService API_AVAILABLE(macos(10.10), ios(8.0), watchos(2.0), tvos(9.0)); // read-only after the thread is started

@property (class, readonly, copy) NSArray<NSNumber *> *callStackReturnAddresses API_AVAILABLE(macos(10.5), ios(2.0), watchos(2.0), tvos(9.0));
@property (class, readonly, copy) NSArray<NSString *> *callStackSymbols API_AVAILABLE(macos(10.6), ios(4.0), watchos(2.0), tvos(9.0));
//线程名称
@property (nullable, copy) NSString *name API_AVAILABLE(macos(10.5), ios(2.0), watchos(2.0), tvos(9.0));
//栈区大小
@property NSUInteger stackSize API_AVAILABLE(macos(10.5), ios(2.0), watchos(2.0), tvos(9.0));
//是否为主线程
@property (readonly) BOOL isMainThread API_AVAILABLE(macos(10.5), ios(2.0), watchos(2.0), tvos(9.0));
@property (class, readonly) BOOL isMainThread API_AVAILABLE(macos(10.5), ios(2.0), watchos(2.0), tvos(9.0)); // reports whether current thread is main
//获取主线程
@property (class, readonly, strong) NSThread *mainThread API_AVAILABLE(macos(10.5), ios(2.0), watchos(2.0), tvos(9.0));
//初始化线程
- (instancetype)init API_AVAILABLE(macos(10.5), ios(2.0), watchos(2.0), tvos(9.0)) NS_DESIGNATED_INITIALIZER;
//实例方法初始化，需要再调用start方法
- (instancetype)initWithTarget:(id)target selector:(SEL)selector object:(nullable id)argument API_AVAILABLE(macos(10.5), ios(2.0), watchos(2.0), tvos(9.0));
- (instancetype)initWithBlock:(void (^)(void))block API_AVAILABLE(macosx(10.12), ios(10.0), watchos(3.0), tvos(10.0));
//线程状态，正在执行
@property (readonly, getter=isExecuting) BOOL executing API_AVAILABLE(macos(10.5), ios(2.0), watchos(2.0), tvos(9.0));
//线程状态，已经完成
@property (readonly, getter=isFinished) BOOL finished API_AVAILABLE(macos(10.5), ios(2.0), watchos(2.0), tvos(9.0));
//线程状态，已经取消
@property (readonly, getter=isCancelled) BOOL cancelled API_AVAILABLE(macos(10.5), ios(2.0), watchos(2.0), tvos(9.0));
//取消，仅仅改变线程状态，并不能像exit一样真正的终止线程
- (void)cancel API_AVAILABLE(macos(10.5), ios(2.0), watchos(2.0), tvos(9.0));
//开始
- (void)start API_AVAILABLE(macos(10.5), ios(2.0), watchos(2.0), tvos(9.0));
//线程需要执行的代码，一般写子类的时候会用到
- (void)main API_AVAILABLE(macos(10.5), ios(2.0), watchos(2.0), tvos(9.0)); // thread body method

@end

FOUNDATION_EXPORT NSNotificationName const NSWillBecomeMultiThreadedNotification;

FOUNDATION_EXPORT NSNotificationName const NSDidBecomeSingleThreadedNotification;
//线程将要退出通知
FOUNDATION_EXPORT NSNotificationName const NSThreadWillExitNotification;

@interface NSObject (NSThreadPerformAdditions)
/隐式的创建并启动线程，并在指定的线程（主线程或子线程）上执行方法。
- (void)performSelectorOnMainThread:(SEL)aSelector withObject:(nullable id)arg waitUntilDone:(BOOL)wait modes:(nullable NSArray<NSString *> *)array;
- (void)performSelectorOnMainThread:(SEL)aSelector withObject:(nullable id)arg waitUntilDone:(BOOL)wait;
    // equivalent to the first method with kCFRunLoopCommonModes

- (void)performSelector:(SEL)aSelector onThread:(NSThread *)thr withObject:(nullable id)arg waitUntilDone:(BOOL)wait modes:(nullable NSArray<NSString *> *)array API_AVAILABLE(macos(10.5), ios(2.0), watchos(2.0), tvos(9.0));
- (void)performSelector:(SEL)aSelector onThread:(NSThread *)thr withObject:(nullable id)arg waitUntilDone:(BOOL)wait API_AVAILABLE(macos(10.5), ios(2.0), watchos(2.0), tvos(9.0));
    // equivalent to the first method with kCFRunLoopCommonModes
- (void)performSelectorInBackground:(SEL)aSelector withObject:(nullable id)arg API_AVAILABLE(macos(10.5), ios(2.0), watchos(2.0), tvos(9.0));

@end

NS_ASSUME_NONNULL_END

typedef NS_ENUM(NSInteger, NSQualityOfService) {
    NSQualityOfServiceUserInteractive = 0x21,
    NSQualityOfServiceUserInitiated = 0x19,
    NSQualityOfServiceUtility = 0x11,
    NSQualityOfServiceBackground = 0x09,
    NSQualityOfServiceDefault = -1
} API_AVAILABLE(macos(10.10), ios(8.0), watchos(2.0), tvos(9.0));

NSQualityOfServiceUserInteractive
与用户交互的任务，这些任务通常跟UI级别的刷新相关，比如动画，这些任务需要在一瞬间完成
NSQualityOfServiceUserInitiated
由用户发起的并且需要立即得到结果的任务，比如滑动scroll view时去加载数据用于后续cell的显示，这些任务通常跟后续的用户交互相关，在几秒或者更短的时间内完成
NSQualityOfServiceUtility
一些可能需要花点时间的任务，这些任务不需要马上返回结果，比如下载的任务，这些任务可能花费几秒或者几分钟的时间
NSQualityOfServiceBackground
这些任务对用户不可见，比如后台进行备份的操作，这些任务可能需要较长的时间，几分钟甚至几个小时
NSQualityOfServiceDefault
优先级介于user-initiated 和 utility，当没有 QoS信息时默认使用，开发者不应该使用这个值来设置自己的任务

image.png