一、RunLoop运行逻辑
-
1.源码分析：精简版（保留了核心代码）
-
2.休眠细节
二、RunLoop在实际开发中的应用
-
1.处理滑动scrollview时NSTimer失效
-
2.线程保活
- 1.在子线程中创建一个RunLoop
- 2.往RunLoop里面添加Source\Timer\Observer保证RunLoop不立刻退出
- 3.[[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]];方法保证RunLoop持续运行
- 4.在子线程调用方法（waitUntilDone设置为YES，代表子线程的代码执行完毕后，这个方法才会往下走）
- 5.只要RunLoop退出，该子线程就不能再用了。
代码：
------------------------------------MJThread.h--------------------------------
#import <Foundation/Foundation.h>
@interface MJThread : NSThread
@end
------------------------------------MJThread.m----------------------------------
#import "MJThread.h"
@implementation MJThread
- (void)dealloc
{
NSLog(@"%s", __func__);
}
@end
----------------------------------------------ViewController.h---------------------------------------
#import <UIKit/UIKit.h>
@interface ViewController : UIViewController
@end
----------------------------------------------ViewController.m---------------------------------------
#import "ViewController.h"
#import "MJThread.h"
@interface ViewController ()
@property (strong, nonatomic) MJThread *thread;
@property (assign, nonatomic, getter=isStoped) BOOL stopped;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
__weak typeof(self) weakSelf = self;
self.stopped = NO;
self.thread = [[MJThread alloc] initWithBlock:^{
NSLog(@"%@----begin----", [NSThread currentThread]);
// 往RunLoop里面添加Source\Timer\Observer保证RunLoop不立刻退出。
[[NSRunLoop currentRunLoop] addPort:[[NSPort alloc] init] forMode:NSDefaultRunLoopMode];
//while这个方法保证RunLoop持续运行，有事情时处理事情，没事情时就休眠。
while (weakSelf && !weakSelf.isStoped) {
//这个方法执行完任务后就退出了
[[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]];
}
NSLog(@"%@----end----", [NSThread currentThread]);
}];
[self.thread start];
}
- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
//只要RunLoop退出，该子线程就不能再用了。
if (!self.thread) return;
[self performSelector:@selector(test) onThread:self.thread withObject:nil waitUntilDone:NO];
}
// 子线程需要执行的任务
- (void)test
{
NSLog(@"%s %@", __func__, [NSThread currentThread]);
}
//控制器中的Button
- (IBAction)stop {
//只要RunLoop退出，该子线程就不能再用了。
if (!self.thread) return;
// 在子线程调用stop（waitUntilDone设置为YES，代表子线程的代码执行完毕后，这个方法才会往下走）
[self performSelector:@selector(stopThread) onThread:self.thread withObject:nil waitUntilDone:YES];
}
// 用于停止子线程的RunLoop
- (void)stopThread
{
// 设置标记为YES
self.stopped = YES;
// 停止RunLoop,
CFRunLoopStop(CFRunLoopGetCurrent());
NSLog(@"%s %@", __func__, [NSThread currentThread]);
// 清空线程
self.thread = nil;
}
- (void)dealloc
{
NSLog(@"%s", __func__);
[self stop];
}
@end
三、线程的封装
- OC
-------------------------------------------------MJPermenantThread.h--------------------------------------------
#import <Foundation/Foundation.h>
typedef void (^MJPermenantThreadTask)(void);
@interface MJPermenantThread : NSObject
/**
开启线程
*/
//- (void)run;
/**
在当前子线程执行一个任务
*/
- (void)executeTask:(MJPermenantThreadTask)task;
/**
结束线程
*/
- (void)stop;
@end
------------------------------------------------MJPermenantThread.m--------------------------------------------
#import "MJPermenantThread.h"
/** MJThread **/
@interface MJThread : NSThread
@end
@implementation MJThread
- (void)dealloc
{
NSLog(@"%s", __func__);
}
@end
/** MJPermenantThread **/
@interface MJPermenantThread()
@property (strong, nonatomic) MJThread *innerThread;
@property (assign, nonatomic, getter=isStopped) BOOL stopped;
@end
@implementation MJPermenantThread
#pragma mark - public methods
- (instancetype)init
{
if (self = [super init]) {
self.stopped = NO;
__weak typeof(self) weakSelf = self;
self.innerThread = [[MJThread alloc] initWithBlock:^{
[[NSRunLoop currentRunLoop] addPort:[[NSPort alloc] init] forMode:NSDefaultRunLoopMode];
while (weakSelf && !weakSelf.isStopped) {
[[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]];
}
}];
[self.innerThread start];
}
return self;
}
//- (void)run
//{
// if (!self.innerThread) return;
//
// [self.innerThread start];
//}
- (void)executeTask:(MJPermenantThreadTask)task
{
if (!self.innerThread || !task) return;
[self performSelector:@selector(__executeTask:) onThread:self.innerThread withObject:task waitUntilDone:NO];
}
- (void)stop
{
if (!self.innerThread) return;
[self performSelector:@selector(__stop) onThread:self.innerThread withObject:nil waitUntilDone:YES];
}
- (void)dealloc
{
NSLog(@"%s", __func__);
[self stop];
}
#pragma mark - private methods
- (void)__stop
{
self.stopped = YES;
CFRunLoopStop(CFRunLoopGetCurrent());
self.innerThread = nil;
}
- (void)__executeTask:(MJPermenantThreadTask)task
{
task();
}
@end
- 2.C
------------------------------------------------MJPermenantThread.h---------------------------------------------
#import <Foundation/Foundation.h>
typedef void (^MJPermenantThreadTask)(void);
@interface MJPermenantThread : NSObject
/**
开启线程
*/
//- (void)run;
/**
在当前子线程执行一个任务
*/
- (void)executeTask:(MJPermenantThreadTask)task;
/**
结束线程
*/
- (void)stop;
@end
---------------------------------------------------MJPermenantThread.m---------------------------------------
#import "MJPermenantThread.h"
/** MJThread **/
@interface MJThread : NSThread
@end
@implementation MJThread
- (void)dealloc
{
NSLog(@"%s", __func__);
}
@end
/** MJPermenantThread **/
@interface MJPermenantThread()
@property (strong, nonatomic) MJThread *innerThread;
@end
@implementation MJPermenantThread
#pragma mark - public methods
- (instancetype)init
{
if (self = [super init]) {
self.innerThread = [[MJThread alloc] initWithBlock:^{
NSLog(@"begin----");
// 创建上下文（要初始化一下结构体）
CFRunLoopSourceContext context = {0};
// 创建source
CFRunLoopSourceRef source = CFRunLoopSourceCreate(kCFAllocatorDefault, 0, &context);
// 往Runloop中添加source
CFRunLoopAddSource(CFRunLoopGetCurrent(), source, kCFRunLoopDefaultMode);
// 销毁source
CFRelease(source);
// 启动
CFRunLoopRunInMode(kCFRunLoopDefaultMode, 1.0e10, false);
// while (weakSelf && !weakSelf.isStopped) {
// // 第3个参数：returnAfterSourceHandled，设置为true，代表执行完source后就会退出当前loop
// CFRunLoopRunInMode(kCFRunLoopDefaultMode, 1.0e10, true);
// }
NSLog(@"end----");
}];
[self.innerThread start];
}
return self;
}
//- (void)run
//{
// if (!self.innerThread) return;
//
// [self.innerThread start];
//}
- (void)executeTask:(MJPermenantThreadTask)task
{
if (!self.innerThread || !task) return;
[self performSelector:@selector(__executeTask:) onThread:self.innerThread withObject:task waitUntilDone:NO];
}
- (void)stop
{
if (!self.innerThread) return;
[self performSelector:@selector(__stop) onThread:self.innerThread withObject:nil waitUntilDone:YES];
}
- (void)dealloc
{
NSLog(@"%s", __func__);
[self stop];
}
#pragma mark - private methods
- (void)__stop
{
CFRunLoopStop(CFRunLoopGetCurrent());
self.innerThread = nil;
}
- (void)__executeTask:(MJPermenantThreadTask)task
{
task();
}
@end
