iOS串行发包的技术点

串行发包的技术方案：
（1）条件锁。
（2）信号量。

//
//  HsSplashPage.m
//  CjhPhoneDemo(TzyjApp)
//
//  Created by ChengJh on 2014-11-07.
//  Copyright © 2019年 CompanyName. All rights reserved.
//

#import "HsSplashPage.h"
#import "HsAlertToastWidget.h"

@interface HsSplashPage ()

//@property(nonatomic,strong) NSCondition *condition;//iOS的条件锁。
//@property(nonatomic,assign) NSTimeInterval conditionTimeOut;//等待超时的时长（一般可设置为1(s)）.
@property(nonatomic,strong) dispatch_semaphore_t semaphore;

@property(nonatomic,assign) BOOL requesting;

@end

@implementation HsSplashPage

- (instancetype)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        self.backgroundColor = HsColorWithHexStr(@"#F3F3F4");
        
        
        //Initialize default value.
        //self.condition = [[NSCondition alloc] init];
        //self.conditionTimeOut = 1.0f;
        self.semaphore = dispatch_semaphore_create(1);
        
        
        UILabel *hintLbl = [[UILabel alloc] initWithFrame:CGRectMake(12, 60, 280, 21)];
        hintLbl.font = HsFontRegular(16);
        hintLbl.textColor = HsColorWithHexStr(@"#333333");
        hintLbl.text = [NSString stringWithFormat:@"这里是%@页面。", self.class];
        [self addSubview:hintLbl];
        
        
        UIButton *refreshBtn = [UIButton buttonWithType:UIButtonTypeCustom];
        refreshBtn.frame = CGRectMake(12, 120, 100, 40);
        refreshBtn.layer.cornerRadius = 2.0;
        refreshBtn.layer.borderColor = HsColorWithHexStr(@"#999999").CGColor;
        refreshBtn.layer.borderWidth = 1.0;
        [refreshBtn setTitleColor:HsColorWithHexStr(@"#666666") forState:UIControlStateNormal];
        [refreshBtn setTitle:@"刷新" forState:UIControlStateNormal];
        [refreshBtn addTarget:self action:@selector(clickedRefreshBtn:) forControlEvents:UIControlEventTouchUpInside];
        [self addSubview:refreshBtn];
        
        
        //HsWeakSelf;
        //_tblView.actionForDropDown = ^(BxkjTableView *sender) {
        //    if (YES == weakSelf.refreshingReq) {
        //        return;
        //    }
        //    weakSelf.requesting = YES;
        //    [weakSelf startRequestWithFinish:^(BOOL succ){
        //        weakSelf.requesting = NO;
        //        [weakSelf.tblView finishReqWithIsSucc:succ];
        //    }];
        //};
        
        
    }
    return self;
}

- (void)didMoveToWindow {
    [super didMoveToWindow];
    
    if (self.window != nil) {
        if (NO == _requesting) {
            _requesting = YES;
            
            CjhWeakSelf;
            [self startRequestWithFinish:^(BOOL succ) {
                weakSelf.requesting = NO;
            }];
        }
    }
}

#pragma mark - Setter_/_Getter

#pragma mark - Method
- (void)clickedRefreshBtn:(UIButton *)sender {
    if (YES == _requesting) {
        [HsAlertToastWidget displayNotification:@"请稍候重试。"];
        return;
    }
    
    _requesting = YES;
    
    [HsAlertToastWidget displayNotification:@"开始刷新。"];
    
    CjhWeakSelf;
    [self startRequestWithFinish:^(BOOL succ) {
        [HsAlertToastWidget displayNotification:@"刷新完成。"];
        weakSelf.requesting = NO;
    }];
}

- (void)startRequestWithFinish:(void(^)(BOOL succ))finish {
    NSThread *trd = [[NSThread alloc]initWithTarget:self selector:@selector(threadActionWithFinish:) object:finish];
    [trd start];
}

- (void)threadActionWithFinish:(void(^)(BOOL succ))finish {
    @autoreleasepool {
        
        CjhDispatchMainAsyncSafe(^{
            //UIView *parentView = [UIApplication sharedApplication].delegate.window;
            //[YJProgressHUD showProgress:@"加载中..." inView:parentView];
            //[[YJProgressHUD shareinstance].hud hideAnimated:YES afterDelay:6.0];//最多6.0s后自动消失。
        });
        
        //[_condition lock];//加锁。
        //CjhLog(@"%s --- --- 0", __func__);
        
        
        dispatch_semaphore_wait(_semaphore, DISPATCH_TIME_FOREVER);
        CjhLog(@"%s --- --- 1", __func__);
        [self requestUpdateParam];
        
        dispatch_semaphore_wait(_semaphore, DISPATCH_TIME_FOREVER);
        CjhLog(@"%s --- --- 2", __func__);
        [self requestBasicData];
        
        dispatch_semaphore_wait(_semaphore, DISPATCH_TIME_FOREVER);
        CjhLog(@"%s --- --- 3", __func__);
        [self requestServerTime];
        
        dispatch_semaphore_wait(_semaphore, DISPATCH_TIME_FOREVER);
        CjhLog(@"%s --- --- 4", __func__);
        [self requestDownloadAdImgData];
        
        //Insert code here.
        
        dispatch_semaphore_wait(_semaphore, DISPATCH_TIME_FOREVER);
        CjhLog(@"%s --- --- N", __func__);
        dispatch_semaphore_signal(_semaphore);
        
        
        //[_condition unlock];//解锁。
        
        CjhDispatchMainAsyncSafe(^{
            //[YJProgressHUD hide];
        });
        
        dispatch_async(dispatch_get_main_queue(), ^{
            if (finish != NULL) {
                finish(YES);
            }
        });
    }
}

- (void)requestUpdateParam {
    NSString *httpUrl = @"https://www.baidu.com/";
    NSDictionary *param = nil;
    
    CjhWeakSelf;
    [self simulateSendPacketWithUrl:httpUrl param:param success:^(id responseObj) {
        //do something.
        
        //[weakSelf.condition signal];
        dispatch_semaphore_signal(weakSelf.semaphore);
    } failure:^(NSError *error) {
        //do something.
        
        //[weakSelf.condition signal];
        dispatch_semaphore_signal(weakSelf.semaphore);
    }];
    //[_condition waitUntilDate:[NSDate dateWithTimeIntervalSinceNow:_conditionTimeOut]];
}

- (void)requestBasicData {
    NSString *httpUrl = @"https://www.baidu.com/";
    NSDictionary *param = nil;
    
    CjhWeakSelf;
    [self simulateSendPacketWithUrl:httpUrl param:param success:^(id responseObj) {
        //do something.
        
        //[weakSelf.condition signal];
        dispatch_semaphore_signal(weakSelf.semaphore);
    } failure:^(NSError *error) {
        //do something.
        
        //[weakSelf.condition signal];
        dispatch_semaphore_signal(weakSelf.semaphore);
    }];
    //[_condition waitUntilDate:[NSDate dateWithTimeIntervalSinceNow:_conditionTimeOut]];
}

- (void)requestServerTime {
    NSString *httpUrl = @"https://www.baidu.com/";
    NSDictionary *param = nil;
    
    CjhWeakSelf;
    [self simulateSendPacketWithUrl:httpUrl param:param success:^(id responseObj) {
        //do something.
        
        //[weakSelf.condition signal];
        dispatch_semaphore_signal(weakSelf.semaphore);
    } failure:^(NSError *error) {
        //do something.
        
        //[weakSelf.condition signal];
        dispatch_semaphore_signal(weakSelf.semaphore);
    }];
    //[_condition waitUntilDate:[NSDate dateWithTimeIntervalSinceNow:_conditionTimeOut]];
}

- (void)requestDownloadAdImgData {
    NSString *httpUrl = @"https://www.baidu.com/";
    NSDictionary *param = nil;
    
    CjhWeakSelf;
    [self simulateSendPacketWithUrl:httpUrl param:param success:^(id responseObj) {
        //do something.
        
        //[weakSelf.condition signal];
        dispatch_semaphore_signal(weakSelf.semaphore);
    } failure:^(NSError *error) {
        //do something.
        
        //[weakSelf.condition signal];
        dispatch_semaphore_signal(weakSelf.semaphore);
    }];
    //[_condition waitUntilDate:[NSDate dateWithTimeIntervalSinceNow:_conditionTimeOut]];
}

#pragma mark - SimulateSendPacketMethod
- (void)simulateSendPacketWithUrl:(NSString *)urlStr param:(NSDictionary*)param success:(void(^)(id responseObj))success failure:(void(^)(NSError *error))failure {
    //产生1位的随机数（用于模拟请求所花的时长）。
    NSInteger waitSecs = arc4random_uniform(10);
    if (waitSecs <= 0) {
        waitSecs = 1;
    }
    CjhLog(@"-[%@] simulate waitSecs=%ld.", self.class, (long)waitSecs);
    
    dispatch_async(dispatch_get_global_queue(0, 0), ^{
        [NSThread sleepForTimeInterval:waitSecs];
        if (waitSecs < 5) {//模拟成功回调。
            CjhLog(@"-[%@] simulate callback succ.", self.class);
            dispatch_async(dispatch_get_main_queue(), ^{
                if (success != NULL) {
                    success(nil);
                }
            });
        } else {//模拟失败回调。
            CjhLog(@"-[%@] simulate callback failed.", self.class);
            dispatch_async(dispatch_get_main_queue(), ^{
                if (failure != NULL) {
                    failure(nil);
                }
            });
        }
    });
}

@end