iOS线程通信和进程通信的例子（NSMachPort和NSTask，NSPipe）

原创：http://blog.youkuaiyun.com/yxh265/article/details/51483822

iOS线程间的通信

iOS中，两个线程之间要想互相通信，可以使用：NSMachPort
下面是例子

#define kMsg1 100
#define kMsg2 101

- (void)viewDidLoad {
    [super viewDidLoad];

    //1. 创建主线程的port
    // 子线程通过此端口发送消息给主线程
    NSPort *myPort = [NSMachPort port];

    //2. 设置port的代理回调对象
    myPort.delegate = self;

    //3. 把port加入runloop，接收port消息
    [[NSRunLoop currentRunLoop] addPort:myPort forMode:NSDefaultRunLoopMode];

    NSLog(@"---myport %@", myPort);
    //4. 启动次线程,并传入主线程的port
    MyWorkerClass *work = [[MyWorkerClass alloc] init];
    [NSThread detachNewThreadSelector:@selector(launchThreadWithPort:)
                             toTarget:work
                           withObject:myPort];
}
- (void)handlePortMessage:(NSMessagePort*)message{

    NSLog(@"接到子线程传递的消息！%@",message);

    //1. 消息id
    NSUInteger msgId = [[message valueForKeyPath:@"msgid"] integerValue];

    //2. 当前主线程的port
    NSPort *localPort = [message valueForKeyPath:@"localPort"];

    //3. 接收到消息的port（来自其他线程）
    NSPort *remotePort = [message valueForKeyPath:@"remotePort"];

    if (msgId == kMsg1)
    {
        //向子线的port发送消息
        [remotePort sendBeforeDate:[NSDate date]
                             msgid:kMsg2
                        components:nil
                              from:localPort
                          reserved:0];

    } else if (msgId == kMsg2){
        NSLog(@"操作2....\n");
    }
}

MyWorkerClass

#import "MyWorkerClass.h"

@interface MyWorkerClass() <NSMachPortDelegate> {
    NSPort *remotePort;
    NSPort *myPort;
}
@end

#define kMsg1 100
#define kMsg2 101

@implementation MyWorkerClass


- (void)launchThreadWithPort:(NSPort *)port {

    @autoreleasepool {

        //1. 保存主线程传入的port
        remotePort = port;

        //2. 设置子线程名字
        [[NSThread currentThread] setName:@"MyWorkerClassThread"];

        //3. 开启runloop
        [[NSRunLoop currentRunLoop] run];

        //4. 创建自己port
        myPort = [NSPort port];

        //5.
        myPort.delegate = self;

        //6. 将自己的port添加到runloop
        //作用1、防止runloop执行完毕之后推出
        //作用2、接收主线程发送过来的port消息
        [[NSRunLoop currentRunLoop] addPort:myPort forMode:NSDefaultRunLoopMode];



        //7. 完成向主线程port发送消息
        [self sendPortMessage];


    }
}

/**
 *   完成向主线程发送port消息
 */
- (void)sendPortMessage {

    NSMutableArray *array  =[[NSMutableArray alloc]initWithArray:@[@"1",@"2"]];
    //发送消息到主线程，操作1
    [remotePort sendBeforeDate:[NSDate date]
                         msgid:kMsg1
                    components:array
                          from:myPort
                      reserved:0];

    //发送消息到主线程，操作2
    //    [remotePort sendBeforeDate:[NSDate date]
    //                         msgid:kMsg2
    //                    components:nil
    //                          from:myPort
    //                      reserved:0];
}


#pragma mark - NSPortDelegate

/**
 *  接收到主线程port消息
 */
- (void)handlePortMessage:(NSPortMessage *)message
{
    NSLog(@"接收到父线程的消息...\n");

    //    unsigned int msgid = [message msgid];
    //    NSPort* distantPort = nil;
    //
    //    if (msgid == kCheckinMessage)
    //    {
    //        distantPort = [message sendPort];
    //
    //    }
    //    else if(msgid == kExitMessage)
    //    {
    //        CFRunLoopStop((__bridge CFRunLoopRef)[NSRunLoop currentRunLoop]);
    //    }
}

@end

以上就可以完成一个线程间的数据通信。

iOS进程间的通信（越狱时用到）

先创建一个命令行工程，建一个简单的子项目。名为：taskchild

#import <UIKit/UIKit.h>
#import <Foundation/Foundation.h>
#include <stdio.h>


int main (int argc, const char * argv[])
{

    NSLog(@"receive value arg %d %s %s", argc, argv[0], argv[1]);

    sleep(10);

    // insert code here...
    printf("Hello, World!\n");
    NSLog(@"Hello, World");
    return 0;
}

再创建一个有界面的主项目。进程通信部分代码。需要引用头文件：NSTask.h见下面的引用

    NSString* string = [[NSBundle mainBundle] pathForResource:@"taskchild" ofType:nil];//taskchild是所要启动的名字二进制文件名,上面建的子项目。
    NSLog(@"%@",string);

    NSTask *task;
    task = [[NSTask alloc ]init];
    [task setLaunchPath:string];

    NSLog(@"This is NSTask with ping command......\n");
    NSArray *arguments;
    arguments = [NSArray arrayWithObjects:@"22", nil];
    [task setArguments:arguments];

    NSPipe *pipe;
    pipe = [NSPipe pipe];
    [task setStandardOutput:pipe];

    NSFileHandle *file;
    file = [pipe fileHandleForReading];

    [task launch];

    NSData *data;
    data = [file readDataToEndOfFile];

    string = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];

    NSLog(@"get child value :%@",string);

引用

RunLoops
NSTask-4-iOS