RunLoop詳解

runloop的本質(zhì)是一個(gè)對(duì)象，這個(gè)對(duì)象有一個(gè)入口函數(shù)，執(zhí)行入口函數(shù)之后就會(huì)進(jìn)入一個(gè)do while循環(huán)，循環(huán)的處理一些事情。

沒(méi)有runloop的情況下，程序運(yùn)行完成就會(huì)退出。
有runloop的時(shí)候程序運(yùn)行完成的時(shí)候不會(huì)退出

runloop的作用

1. 保持程序持續(xù)運(yùn)行
2. 處理app中的各種事件(觸摸、定時(shí)器、performselector等)
3. 節(jié)省cpu資源，提高程序性能(有事件的餓時(shí)候處理事件，沒(méi)事件的時(shí)候休息，可以在main函數(shù)中直接返回1進(jìn)行測(cè)試)

線程和runloop

1. 線程和runloop是一一對(duì)應(yīng)的關(guān)系(內(nèi)部是一個(gè)字典，key為線程，value為runloop)
2. 線程創(chuàng)建的時(shí)候，并沒(méi)有創(chuàng)建runloop對(duì)象，runloop會(huì)在第一次獲取的時(shí)候自動(dòng)創(chuàng)建
3. 主線程默認(rèn)開(kāi)啟了runloop，子線程默認(rèn)沒(méi)有開(kāi)啟runloop

runloop的mode

1. 一個(gè)runloop對(duì)應(yīng)一個(gè)線程
2. 一個(gè)runloop包含多個(gè)mode，每個(gè)mode包含若干個(gè)source、timer、observer
3. source、timer、observer又叫modeitem，不同的mode下mode item 互不影響
4. runloop運(yùn)行過(guò)程中，只會(huì)選擇一種模式運(yùn)行
5. 切換mode，程序退出當(dāng)前mode，再重新制定mode執(zhí)行

ModeItem

source0事件

1. 觸摸事件

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event
{
    NSLog(@"testRunloop"); //打斷點(diǎn)可以看到堆棧信息中 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__
}

2. 自定義輸入園source0

- (void)testAction:(UIButton *)sender
{
    NSThread *subThread = [[NSThread alloc]initWithBlock:^{
        CFRunLoopSourceContext context = {
            0,
            NULL,
            NULL,
            NULL,
            NULL,
            NULL,
            NULL,
            schedule,
            cancel,
            perform
        };
        CFRunLoopSourceRef source0 = CFRunLoopSourceCreate(CFAllocatorGetDefault(), 0, &context);
        //有下面一行才能觸發(fā)schedule回調(diào)
        CFRunLoopAddSource(CFRunLoopGetCurrent(), source0, kCFRunLoopDefaultMode);
        
        //有以下代碼才能觸發(fā)perform回調(diào)
        CFRunLoopSourceSignal(source0);
        CFRunLoopWakeUp(CFRunLoopGetCurrent());
        //觸發(fā)cancel回調(diào)
        CFRunLoopRemoveSource(CFRunLoopGetCurrent(), source0, kCFRunLoopDefaultMode);
        CFRelease(source0); //釋放
    }];
    [subThread start];
}
void schedule(void *info, CFRunLoopRef rl, CFRunLoopMode mode)
{
    NSLog(@"currentThreed ===%s",__func__);
}

void cancel(void *info, CFRunLoopRef rl, CFRunLoopMode mode)
{
    NSLog(@"currentThreedMode ===%s",__func__);
}

void perform(void *info)
{
  NSLog(@"currentThreedInfo ===%s",__func__);
}

4. performSelector:onThread:方法調(diào)用

[self performSelectorOnMainThread:@selector(animation:) withObject:nil waitUntilDone:NO];
- (void)animation:(id)sender
{
    NSLog(@"哈哈"); //此處打斷點(diǎn)可以在堆棧中看到 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__
}

source1

1. 端口(NSPort)----

注意測(cè)試代碼在模擬器上控制臺(tái)能打印出來(lái)在手機(jī)上不行,原因是通過(guò)NSPort的port類(lèi)方法創(chuàng)建出來(lái)的是它的子類(lèi)對(duì)象NSMachPort，而Foundation框架給我們提供的NSPort的三個(gè)子類(lèi)中NSMachPort和NSMessagePort只能用于同一臺(tái)機(jī)器上的通信，NSSocketPort可以用于本地和遠(yuǎn)程通信。

- (void)viewDidLoad
{
    [super viewDidLoad];
    self.mainPort = [NSPort port];
    self.mainPort.delegate = self;
    [[NSRunLoop currentRunLoop] addPort:self.mainPort forMode:NSDefaultRunLoopMode];

    NSThread *testThread = [[NSThread alloc]initWithBlock:^{
        self.subPort = [NSPort port];
        self.subPort.delegate = self;
        [[NSRunLoop currentRunLoop] addPort:self.subPort forMode:NSDefaultRunLoopMode];
        [[NSRunLoop currentRunLoop] run];
    }];
    [testThread setName:@"subThread"];
    [testThread start];
}

- (IBAction)testAction:(UIButton *)sender
{
    NSMutableArray *conmponents = [NSMutableArray array];
    [conmponents addObject:[@"fromMainThread" dataUsingEncoding:NSUTF8StringEncoding]];
    [self.subPort sendBeforeDate:[NSDate date] components:conmponents from:self.mainPort reserved:0];
}

- (void)handlePortMessage:(id)message
{
    NSMutableArray *array = [message valueForKey:@"components"]; //此處打斷點(diǎn)可以在堆棧中看到__CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__說(shuō)明這是一個(gè)source1源
    NSString *password = [[NSString alloc]initWithData:[array  firstObject] encoding:NSUTF8StringEncoding];
    NSLog(@"thread ===%@\tpassword===%@", [NSThread currentThread], password);
    if (![[NSThread currentThread] isMainThread]) {
        NSMutableArray *conmponents = [NSMutableArray array];
        [conmponents addObject:[@"fromSubthread" dataUsingEncoding:NSUTF8StringEncoding]];
        [self.mainPort sendBeforeDate:[NSDate date] components:conmponents from:self.subPort reserved:0];
    }
}

計(jì)時(shí)源

1. NStimer
2. performSelector:withObject:afterDelay

[self performSelector:@selector(animation:) withObject:nil afterDelay:3];
- (void)animation:(id)sender
{
    NSLog(@"哈哈"); //此處打斷點(diǎn)可以在堆棧中看到 __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__
}