//
//  MainViewController.m
//  GCD
//
//  Created by hejin on 13-12-29.
//  Copyright (c) 2013年 e世雕龍. All rights reserved.
//

#import "MainViewController.h"

@interface MainViewController ()

@property (strong, nonatomic) IBOutlet UIProgressView *myProgress;//進度條
@property (strong, nonatomic) IBOutlet UITextView *textView;//多行文本框

@end

@implementation MainViewController
//GCD方式更新進度條
- (IBAction)updateProgress:(id)sender {
    dispatch_async(dispatch_get_global_queue(0, 0), ^{
        for (int i=0; i<100; i++) {
            [NSThread sleepForTimeInterval:0.02];
            dispatch_async(dispatch_get_main_queue(), ^{
                self.myProgress.progress += 0.01;
            });
        }
    });
}
//GCD並發多線程完成任務
- (IBAction)asynDowork:(id)sender {
    self.textView.text = @"";
    NSMutableString *strWork = [NSMutableString stringWithCapacity:20];
    //不使用多線程
    /*[strWork appendFormat:@"%@\n",[self doWork1]];
    [strWork appendFormat:@"%@\n",[self doWork2]];
    [strWork appendFormat:@"%@\n",[self doWork3]];
    self.textView.text = strWork;*/
    //獲取已經存在並始終可用的全局隊列
    dispatch_queue_t globalQueue = dispatch_get_global_queue(0, 0);
    //獲取主線程隊列
    dispatch_queue_t mainQueue = dispatch_get_main_queue();
    //並發多線程完成任務
    dispatch_async(globalQueue, ^{
        [strWork appendFormat:@"%@\n",[self doWork1]];
        NSLog(@"doWork1");
        dispatch_async(mainQueue, ^{
            self.textView.text = strWork;
            NSLog(@"updateUI");
        });
    });
    dispatch_async(globalQueue, ^{
        [strWork appendFormat:@"%@\n",[self doWork2]];
        NSLog(@"doWork2");
        dispatch_async(mainQueue, ^{
            self.textView.text = strWork;
            NSLog(@"updateUI");
        });
    });
    dispatch_async(globalQueue, ^{
        [strWork appendFormat:@"%@\n",[self doWork3]];
        NSLog(@"doWork3");
        dispatch_async(mainQueue, ^{
            self.textView.text = strWork;
            NSLog(@"updateUI");
        });
    });
}
//GCD同步完成任務
- (IBAction)synDowork:(id)sender {
    self.textView.text = @"";
    NSMutableString *strWork = [NSMutableString stringWithCapacity:20];
    //獲取已經存在並始終可用的全局隊列
    dispatch_queue_t globalQueue = dispatch_get_global_queue(0, 0);
    //獲取主線程隊列
    dispatch_queue_t mainQueue = dispatch_get_main_queue();
    //同步完成任務
    dispatch_sync(globalQueue, ^{
        [strWork appendFormat:@"%@\n",[self doWork1]];
        NSLog(@"doWork1");
    });
    dispatch_sync(globalQueue, ^{
        [strWork appendFormat:@"%@\n",[self doWork2]];
        NSLog(@"doWork2");
    });
    dispatch_sync(globalQueue, ^{
        [strWork appendFormat:@"%@\n",[self doWork3]];
        NSLog(@"doWork3");
    });
    //在主線程中更新UI,如下代碼同步等待主線程中按鈕點擊事件完成才進行，主線程中按鈕點擊事件等待如下代碼完成，造成阻塞
    /*dispatch_sync(globalQueue, ^{
        dispatch_sync(mainQueue, ^{
            self.textView.text = strWork;
        });
    });*/
    dispatch_async(globalQueue, ^{
        dispatch_async(mainQueue, ^{
            self.textView.text = strWork;
        });
    });
}
//使用GCD推薦的分組派發同步完成任務
- (IBAction)groupSynDowork:(id)sender {
    self.textView.text = @"";
    NSMutableString *strWork = [NSMutableString stringWithCapacity:20];
    //創建組和隊列
    dispatch_group_t group = dispatch_group_create();
    dispatch_queue_t globalQueue = dispatch_get_global_queue(0, 0);
    //隊列在組中執行操作
    dispatch_group_async(group, globalQueue, ^{
        [strWork appendFormat:@"%@\n",[self doWork1]];
        NSLog(@"doWork1");
    });
    dispatch_group_async(group, globalQueue, ^{
        [strWork appendFormat:@"%@\n",[self doWork2]];
        NSLog(@"doWork2");
    });
    dispatch_group_async(group, globalQueue, ^{
        [strWork appendFormat:@"%@\n",[self doWork3]];
        NSLog(@"doWork3");
    });
    //通知組中任務完成在主線程中更新UI
    dispatch_group_notify(group, dispatch_get_main_queue(), ^{
        self.textView.text = strWork;
    });
}
//任務1
- (NSString *)doWork1 {
    [NSThread sleepForTimeInterval:2];
    return @"任務1完成！";
}
//任務2
- (NSString *)doWork2 {
    [NSThread sleepForTimeInterval:3];
    return @"任務2完成！";
}
//任務3
- (NSString *)doWork3 {
    [NSThread sleepForTimeInterval:4];
    return @"任務3完成！";
}
@end