多線程

#import "ViewController.h"

@interface ViewController ()

@property(nonatomic,assign)NSInteger count;

@end

@implementation ViewController

- (void)viewDidLoad {

[super viewDidLoad];

//單利

//? ? static dispatch_once_t onceToken;

//? ? dispatch_once(&onceToken,^{

//

//? ? });

//線程互斥

//創(chuàng)建線程鎖

NSLock *lock =[[NSLock alloc]init];

//為了防止循環(huán)引用

self.count =100;//票數(shù)

//創(chuàng)建并行隊列

dispatch_queue_t queue =dispatch_queue_create("com.selltikets.www", DISPATCH_QUEUE_CONCURRENT);

__weak ViewController *weakself = self;

for (int i=0; i<10; i++) {

dispatch_async(queue, ^{

[lock lock];//枷鎖

for (int j =0; j<10; j++) {

NSLog(@"買到了第%ld張票",weakself.count);

weakself.count--;

}

[lock unlock];//解鎖

});

}

// Do any additional setup after loading the view, typically from a nib.

}

/*1.GCD是最簡單的多線程,也是效果最高的一種方式,全部是C語言代碼編碼編寫的API,也是是蘋果公司主推的一種多線程

2.GCD 通過queue來實現(xiàn)多線程

3.GCD里面有多重queue 一種是串行serial一種是并行concurrent.

*/

//串行隊列

- (IBAction)serialqueue:(UIButton *)sender {

//關(guān)鍵字serial 特點,第一個任務(wù)執(zhí)行完成,第二個任務(wù)才開始執(zhí)行,一次類推

//有兩種方式

#pragma? mark ---串行隊列第一種

//? ? dispatch_queue_t? queue =dispatch_get_main_queue();

//? ? //往隊列里面添加任務(wù)

//? ? dispatch_async(queue, ^{

//? ? ? ? NSLog(@"這是第一個任務(wù),當(dāng)前線程%@,是否主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

//? ? });

//? ? dispatch_async(queue, ^{

//? ? ? ? NSLog(@"這是第二個任務(wù),當(dāng)前任務(wù)是%@,是否是主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

//? ? });

//? ? dispatch_async(queue, ^{

//? ? ? ? NSLog(@"這是第三個任務(wù),當(dāng)前任務(wù)是%@,是否是主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

//? ? });

//? ? dispatch_async(queue, ^{

//? ? ? ? NSLog(@"這是第四個任務(wù),這是當(dāng)前線程%@是否是主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

//? ? });

#pragma mark ---串行隊列第二種--------------

/*

獲取串行隊列第二種方式:自己創(chuàng)建隊列,

*

*

穿件串行隊列的第二種方式

@Pram "serialQueue" 隊列的名字(蘋果主推使用反向域名去命名)

@pram DISPATCH_QUEUE_SERIAL 隊列的類型

手動創(chuàng)建的串行不在主線程中

*/

//

//? ? dispatch_queue_t queue =dispatch_queue_create("com.serialQueue.www", DISPATCH_QUEUE_SERIAL);

//? ? dispatch_async(queue, ^{

//? ? ? ? NSLog(@"這是第一個任務(wù),當(dāng)前線程是%@是否是主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

//? ? });

//? ? dispatch_async(queue, ^{

//? ? ? ? NSLog(@"這是第二個任務(wù)呀當(dāng)前線程%@,是否是主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

//? ? });

//? ? dispatch_async(queue, ^{

//? ? ? ? NSLog(@"這是第三個任務(wù),當(dāng)前任務(wù)是:%@是否是主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

//? ? });

//? ? dispatch_async(queue, ^{

//? ? ? ? NSLog(@"這是第四個任務(wù),當(dāng)前任務(wù)是%@是否是主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

//? ? });

}

//并行隊列

- (IBAction)concurrentQueue:(UIButton *)sender {

//concurrent 特點:第一個任務(wù)執(zhí)行開始之后,第二個任務(wù),不等第一個執(zhí)行完畢,直接開始執(zhí)行.依次類推,后面的任務(wù)跟前面的沒有關(guān)系,先添加的任務(wù)不一定先執(zhí)行,后面添加的不一定最后執(zhí)行.并行隊列會根據(jù)隊列里面的任務(wù)數(shù)量CPU使用情況開辟最合適的線程數(shù)量,去完成隊列里的任務(wù).

//創(chuàng)建有兩種方式

#pragma mark -----concurentQueue--第一種方式-------

//? ? dispatch_queue_t queue=dispatch_queue_create("com.concurrentQueue.www", DISPATCH_QUEUE_CONCURRENT);

//? ? dispatch_async(queue, ^{

//? ? ? ? NSLog(@"%@%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

//? ? });

//? ? dispatch_async(queue, ^{

//? ? ? ? NSLog(@"第一個任務(wù)當(dāng)前線程%@是否是主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

//? ? });

//? ? dispatch_async(queue, ^{

//? ? ? ? NSLog(@"第二個任務(wù)當(dāng)前線程%@是否是主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

//? ? });

//? ? dispatch_async(queue, ^{

//? ? ? ? NSLog(@"第三個任務(wù)當(dāng)前線程%@是否是主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

//? ? });

//? ? dispatch_async(queue, ^{

//? ? ? ? NSLog(@"第四個任務(wù),當(dāng)前線程%@是否是主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

//? ? });

#pragma mark -----concurrentQueue__第二種創(chuàng)建方式

//創(chuàng)建globalqueue是蘋果里面的全局隊列,有四個優(yōu)先級 第一個參數(shù)DISPATCH_QUEUE_PRIORITY_DEFAULT? 隊列的優(yōu)先級, 第二個是預(yù)留的參數(shù),為了以后使用,目前還沒使用寫0;

//#define DISPATCH_QUEUE_PRIORITY_HIGH 2

//#define DISPATCH_QUEUE_PRIORITY_DEFAULT 0

//#define DISPATCH_QUEUE_PRIORITY_LOW (-2)

//#define DISPATCH_QUEUE_PRIORITY_BACKGROUND INT16_MIN

dispatch_queue_t queue= dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0);

dispatch_async(queue, ^{

NSLog(@"第一個任務(wù)當(dāng)前線程%@是否主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

dispatch_async(queue, ^{

NSLog(@"第二個任務(wù)當(dāng)前線程%@是否主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

dispatch_async(queue, ^{

NSLog(@"第三任務(wù)當(dāng)前線程%@是否主線稱%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

dispatch_async(queue, ^{

NSLog(@"第四個任務(wù)當(dāng)前 線程%@是否主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

dispatch_async(queue, ^{

NSLog(@"第五個任務(wù)當(dāng)前線程%@是否主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

dispatch_async(queue, ^{

NSLog(@"第六個任務(wù)當(dāng)前線程%@是否主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

dispatch_async(queue, ^{

NSLog(@"第七個任務(wù)當(dāng)前線程%@是否主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

dispatch_async(queue, ^{

NSLog(@"第八個任務(wù)當(dāng)前線程%@是否主線成%d",[NSThread currentThread ],[[NSThread currentThread]isMainThread]);

});

dispatch_async(queue, ^{

NSLog(@"第九個任務(wù)當(dāng)前線程%@是否主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

dispatch_async(queue, ^{

NSLog(@"第十個任務(wù)當(dāng)前線程%@是否主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

}

//延遲執(zhí)行代碼(dispatch_after 可以再任何隊列中執(zhí)行,串行 并行,都可以);

- (IBAction)afterbutton:(UIButton *)sender {

/*

第一種

*/

//? ? dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(3 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{

//? ? ? ? NSLog(@"%@%d",[NSThread currentThread],[NSThread isMainThread]);

//? ? });

//第二種

dispatch_time_t seconds =dispatch_time(DISPATCH_TIME_NOW, (int64_t)(3 * NSEC_PER_SEC));

//創(chuàng)建一個全局隊列

dispatch_queue_t queue =dispatch_get_global_queue(0, 0);

//添加到隊列中

dispatch_after(seconds, queue, ^{

NSLog(@" 我是延遲任務(wù)當(dāng)前任務(wù)線程%@是否是主線程 %d",[NSThread currentThread],[[NSThread currentThread]isMainThread] );

});

}//方法結(jié)尾括號

//線程組

- (IBAction)groupbutton:(UIButton *)sender {

//線程組:disoatch_group_t主要是吧一些不想關(guān)的任務(wù)就歸為一組

//組里面放的是隊列

//dispatch_group_async給組里面的隊列添加任務(wù)

//dispatch_group_notify 作用是監(jiān)聽組里面的任務(wù),等到組里面的任務(wù)全部執(zhí)行完之后,才會執(zhí)行里面的任務(wù).

//1.創(chuàng)建組

dispatch_group_t group = dispatch_group_create();

//2.創(chuàng)建全局隊列

dispatch_queue_t queue =dispatch_get_global_queue(0, 0);

//3.往組里添加隊列

dispatch_group_async(group, queue, ^{

NSLog(@"我是第一個任務(wù)當(dāng)前線程%@是否是主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

dispatch_group_notify(group, queue, ^{

NSLog(@"我是最后一個任務(wù)當(dāng)前線程%@是否主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

dispatch_group_async(group, queue, ^{

NSLog(@"這是第二個任務(wù)當(dāng)前線程%@是否主線程%d",[NSThread currentThread ],[[NSThread currentThread]isMainThread]);

});

dispatch_group_async(group, queue, ^{

NSLog(@"我是第三個任務(wù)當(dāng)前線程%@是否主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

}//方法結(jié)尾括號

//同時進(jìn)行讀寫

- (IBAction)readandwriteatsametime:(UIButton *)sender {

//數(shù)據(jù)庫的讀取 可以并發(fā)執(zhí)行,通過GCD里面的并行去實現(xiàn)

//數(shù)據(jù)庫的寫入,只能串發(fā)執(zhí)行,通過GCD里面的串行隊列去實現(xiàn);

//但是真正的項目肯定是既有數(shù)據(jù)的讀寫也有數(shù)據(jù)的寫入;如何解決" dispatch _barrier_async 在它之前的任務(wù)可以區(qū)域并發(fā)執(zhí)行,在他之后的任務(wù)也可以并發(fā)執(zhí)行

//創(chuàng)建一個并行隊列

dispatch_queue_t queue =dispatch_queue_create("con.concurrent.www", DISPATCH_QUEUE_CONCURRENT);

dispatch_async(queue, ^{

NSLog(@"第一任務(wù)當(dāng)前線程%@是否主線成%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

dispatch_async(queue, ^{

NSLog(@"第二任務(wù),當(dāng)前線程%@是否主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

dispatch_async(queue, ^{

NSLog(@"第三任務(wù)當(dāng)前先成%@是否主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

dispatch_async(queue, ^{

NSLog(@"第四線程當(dāng)前線程%@是否主線成%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

dispatch_async(queue, ^{

NSLog(@"第五任務(wù)當(dāng)前任務(wù)%@是否主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

dispatch_barrier_async(queue, ^{

NSLog(@"我正在讀取數(shù)據(jù)%@是否主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

dispatch_async(queue, ^{

NSLog(@"第六人物當(dāng)前線程%@是否主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

dispatch_async(queue, ^{

NSLog(@"第七任務(wù)當(dāng)前線程%@是否主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

dispatch_async(queue, ^{

NSLog(@"第八任務(wù)呀當(dāng)前線程%@是否主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

dispatch_async(queue, ^{

NSLog(@"第九任務(wù)當(dāng)前線程%@是否主線程%d",[NSThread currentThread],[[NSThread currentThread]isMainThread]);

});

dispatch_async(queue, ^{

NSLog(@"第十個任務(wù)當(dāng)前線程%@是否主線程%d",[NSThread currentThread ],[[NSThread currentThread]isMainThread]);

});

}

//多次執(zhí)行

- (IBAction)moretimes:(UIButton *)sender {

NSArray *array =@[@"1",@"2",@"3"];

//同城和數(shù)組配合使用

dispatch_queue_t queue =dispatch_get_global_queue(0, 0);

/*

第一個參數(shù) 次數(shù)

第二個參數(shù) 隊列

第三個參數(shù) 任務(wù)

*/

//index:記錄當(dāng)前執(zhí)行的第幾次? ,是小于隨機(jī)次數(shù)的

dispatch_apply(3, queue, ^(size_t index ) {

NSLog(@"%@",array[index]);

});

}

//async和sync的區(qū)別

- (IBAction)syncandasyncdiffrent:(UIButton *)sender {

//async不等block體執(zhí)行完畢就去執(zhí)行下面的代碼

//sync 會等block體執(zhí)行完畢之后才會執(zhí)行block;

dispatch_queue_t queue=dispatch_get_global_queue(0, 0);

//? ? dispatch_async(queue, ^{

//? ? ? ? NSLog(@"這是第一個任務(wù)");

//? ? });

//? ? NSLog(@"呵呵");

//? ? dispatch_async(queue, ^{

//? ? ? ? NSLog(@"這是第二個任務(wù)");

//? ? });

//? ? NSLog(@"哦");

dispatch_sync(queue, ^{

NSLog(@"第一個任務(wù)");

});

NSLog(@"heh");

dispatch_sync(queue, ^{

NSLog(@"第二個任務(wù)");

});

NSLog(@"o");

}//

//gcd調(diào)用函數(shù)指針

- (IBAction)functionpointer:(UIButton *)sender {

dispatch_queue_t queue=dispatch_get_global_queue(0, 0);

/*

第二個參數(shù)<#void *context#>函數(shù)參數(shù)的內(nèi)容

第三個參數(shù)<#dispatch_function_t work#> 函數(shù)(函數(shù)的返回值為void 參數(shù)類型必須為void)

*/

dispatch_async_f(queue, @"hehe", function);

}//

void function(void *context){

NSLog(@"%@",context);

printf("o");

}

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