下面的程式碼手動建立了兩個執行緒，一個執行緒是讀取串列埠的資料，另一個執行緒是通過UDP來讀取網路通訊收到的資料。加上main函式的執行緒，一共三個執行緒。

先簡單講一下多執行緒的建立，

    pthread_t serial;
    int ser = pthread_create(&serial,NULL,connectSerial,NULL);
    if(ser != 0)
    {
        std::cout << "pthread creat serial error"<<std::endl;
    }

connectSerial是建立的執行緒的入口函式。

void *connectSerial(void *args)
{
    int fd;
    if(wiringPiSetup() < 0)
        exit(1);  

    if((fd = serialOpen("/dev/ttyAMA0",115200)) < 0)
        exit(1);  

    //long int i = 0;
    int datareceive = 0;
    while(1)
    {
        datareceive = serialGetchar(fd);
        intToHex(datareceive,&basebuff[baselen],2
 
);
        baselen += 2;
    }
    serialClose(fd);

}

完整程式碼：

#include <stdio.h>
#include <iostream>
#include <wiringPi.h>
#include <wiringSerial.h>
#include <vector>
#include <unistd.h>
#include <sys/types.h>  
#include <sys/socket.h>  
#include <pthread.h>  
 

#include <netinet/in.h>  
#include <string.h>  
#include <stdlib.h>  
#include <arpa/inet.h>

std::vector<char> basebuff(1024*1024*10,0);
std::vector<char> roverbuff(1024*1024*10,0);
long int baselen = 0;
long int roverlen = 0;

void *creatWiFi(void *args)
{
    struct sockaddr_in addr;  
    addr.sin_family = AF_INET;  
    addr.sin_port = htons(8000);  
    addr.sin_addr.s_addr = htonl(INADDR_ANY);  

    int sock;  
    if ( (sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0)  
    {  
        perror("socket");  
        exit(1);  
    }  
    if (bind(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0)  
    {  
        perror("bind");  
        exit(1);  
    }  
    //long int roverptr = 0;
    struct sockaddr_in clientAddr;  
    int n;  
    int len = sizeof(clientAddr);  
    while (1)  
    {  
        n = recvfrom(sock,&roverbuff[roverlen], 511, 0, (struct sockaddr*)&clientAddr, (socklen_t*)&len);  
        if (n>0)  
        {  
            roverlen += n;
        }  
        else  
        {  
            perror("recv");  
            break;  
        }  
    }  
}
void intToHex(int dec,char *output,int length)
{
    const char * hex = "0123456789ABCDEF";
    for(int i = 0;i < length;i++)
    {
        output[length-i-1] = hex[(dec >> i * 4) & 0x0F];
    }
}
void *connectSerial(void *args)
{
    int fd;
    if(wiringPiSetup() < 0)
        exit(1);  

    if((fd = serialOpen("/dev/ttyAMA0",115200)) < 0)
        exit(1);  

    //long int i = 0;
    int datareceive = 0;
    while(1)
    {
        datareceive = serialGetchar(fd);
        intToHex(datareceive,&basebuff[baselen],2);
        baselen += 2;
    }
    serialClose(fd);

}

int main()
{
    pthread_t serial;
    int ser = pthread_create(&serial,NULL,connectSerial,NULL);
    if(ser != 0)
    {
        std::cout << "pthread creat serial error"<<std::endl;
    }

    pthread_t wifi;
    int wif = pthread_create(&wifi,NULL,creatWiFi,NULL);
    if(wif != 0)
    {
        std::cout << "pthread creat serial error"<<std::endl;
    }

    FILE *base;
    base = fopen("/home/pi/wifi/base.txt","w+");
    if(base == NULL)
    {   
        std::cout << "basefileerror";
        return 1;
    }
    FILE *rover;
    rover = fopen("/home/pi/wifi/rover.txt","w+");
    if(rover == NULL)
    {   
        std::cout << "roverfileerror";
        return 1;
    }
    long int blen = 0;
    long int rlen = 0;

    while(1)
    {
        if(baselen - blen >= 100)
        {
            std::cout<<"savebasebuff!"<<std::endl;
            fwrite(&basebuff[blen],sizeof(char),100,base);
        }
        if(roverlen - rlen >= 100)
        {
            std::cout<<"saveroverbuff!"<<std::endl;
            fwrite(&roverbuff[rlen],sizeof(char),100,rover);
        }
    }
    pthread_exit(NULL);
    return 0;
}

上面的程式碼用到了Wiring Pi庫，所以編譯語句：

g++ -Wall serial.cpp -o serial -lwiringPi -lpthread

如果沒有使用wiringPi庫的編譯時去掉-lwiringPi。