多线程创建 方法一： NSThread 创建线程的三种方式

//
//  RootViewController.m
//  多线程
//
//  Created by zm on 14-11-26.
//  Copyright (c) 2014年 practice. All rights reserved.
//

#import "RootViewController.h"

@interface RootViewController ()
{
UILabel *_textLabel;

//  互斥锁
NSLock *_lock ;

// 条件锁
NSConditionLock *_conditionLock;
}
@end

@implementation RootViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {

[self prepareView];

}
return self;
}

-(void)prepareView
{
_textLabel = [[UILabel alloc] initWithFrame:CGRectMake(100, 100, 100, 30)];
_textLabel.text = @"test";
[self.view addSubview:_textLabel];
}

- (void)viewDidLoad
{
[super viewDidLoad];

/**
*  主线程 有序执行
*  主线程就是 UI 线程
*  官方文档：主线程主要处理：
*  1. UI 界面，刷新
*  2. 用户触摸事件
*/
[self doSomething:@"D"];
[self doSomething:@"E"];
[self doSomething:@"F"];

/**
*   理论上（根据官方文档）子线程不能刷新 UI 界面
*   子线程主要处理：
*   1.耗时操作
*   2.数据库等操作
*
*  实现多线程的方法：   三种
*  1. NSThread         软件模拟实现
*  2.NSOperationQueue  线程池
*  3.GCD               苹果大力推荐的方式!（重点）
*/

/**
*  创建的线程  无序执行
*  线程与主线程之间无序，一个线程可以发生在任意主线程前面执行
*   线程与线程之间也无序，一个线程可以发生在任意子线程前面执行
*/

//[self testNSThreadSimplely];

//[self testNSLock];
[self testConditionLock];

}

// NSThread 三种创建方式，简单介绍
-(void)testNSThreadSimplely
{
/**
*  创建 NSThread   三种方式
*  创建的线程  无序执行
*/

/**
* 1. 创建一个线程，并且运行
*     [self performSelectorInBackground:@selector() withObject:@""];
*/
[self performSelectorInBackground:@selector(doSomething:) withObject:@"A"];
[self performSelectorInBackground:@selector(doSomething:) withObject:@"B"];
[self performSelectorInBackground:@selector(doSomething:) withObject:@"C"];

/**
*  2.创建 NSThread   第二种方式
*   [NSThread detachNewThreadSelector:@selector() toTarget:self withObject:@""];
*/
[NSThread detachNewThreadSelector:@selector(doSomething:) toTarget:self withObject:@"G"];

/**
*  3.创建 NSThread   第三种方式
*  主动创建，调用（启动）线程
*/
NSThread *thread = [[NSThread alloc] initWithTarget:self selector:@selector(doSomething:) object:@"H"];
[thread start];

}

-(void)doSomething:(NSString *)str
{
//当前线程休眠一秒钟
[NSThread sleepForTimeInterval:1.0];
NSLog(@"str = %@",str);
_textLabel.text = str;
}

/**
*  测试 互斥锁 : 买票
*/
-(void)testNSLock
{
_lock = [[NSLock alloc] init];

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

//买票操作
int sum = 10;
int sold = 0;
-(void)getTicket
{
[_lock lock];   //加锁

while (sum > 0) {
sum--;
sold++;
NSLog(@"sum = %d; sold = %d",sum,sold);
}

[_lock unlock];    //解锁
}

/**
*  测试条件锁
*/
-(void)testConditionLock
{
_conditionLock = [[NSConditionLock alloc] init];

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

}

-(void)conditionLockDoSomethingA
{
[_conditionLock lock];

for (int i = 0; i < 10; i++) {
NSLog(@"i = %d",i);
[NSThread sleepForTimeInterval:1];

if (i==5)
[_conditionLock unlockWithCondition:5];

}

}

-(void)conditionLockDoSomethingB
{
[_conditionLock lockWhenCondition:5];

NSLog(@"condition = 5");

[_conditionLock unlock];
}

@end