2018-2019-1 20165229 20165306 實驗三 實時系統

實驗三-並發程序-1

• 學習使用Linux命令wc(1)。

-c 統計字節數

-m 統計字符數，這個標誌不能與 -c 標誌一起使用

-l 統計行數

-L 打印最長行的長度

-w 統計字數，一個字被定義為由空白、跳格或換行字符分隔的字符串

• 基於Linux Socket程序設計實現wc（1）服務器(端口號是你學號的後6位)和客戶端， 客戶端傳一個文本文件給服務器，服務器返加文本文件中的單詞數。

• server.c

#include<netinet/in.h>  // sockaddr_in
#include<sys/types.h>   // socket
#include<sys/socket.h>  // socket
#include<stdio.h>       // printf
#include<stdlib.h>      // exit
#include<string.h>      // bzero
#include<unistd.h>
#define SERVER_PORT 155316
#define LENGTH_OF_LISTEN_QUEUE 20
#define BUFFER_SIZE 1024
#define FILE_NAME_MAX_SIZE 512
int CountWordsOfEuropeanTxtFile(char *szFileName);
int CountWordsInOneLine(const char *szLine);
int main(void)
{
    // 聲明並初始化一個服務器端的socket地址結構
    struct sockaddr_in server_addr;
    bzero(&server_addr, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    server_addr.sin_addr.s_addr = htons(INADDR_ANY);
    server_addr.sin_port = htons(SERVER_PORT);
   // 創建socket，若成功，返回socket描述符
    int server_socket_fd = socket(PF_INET, SOCK_STREAM, 0);
    if(server_socket_fd < 0)
    {
        perror("Create Socket Failed:");
        exit(1);
    }
    int opt = 1;
    setsockopt(server_socket_fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
 // 綁定socket和socket地址結構
    if(-1 == (bind(server_socket_fd, (struct sockaddr*)&server_addr, sizeof(server_addr))))
    {
        perror("Server Bind Failed:");
        exit(1);
    }
     // socket監聽
    if(-1 == (listen(server_socket_fd, LENGTH_OF_LISTEN_QUEUE)))
    {
        perror("Server Listen Failed:");
        exit(1);
    }
while(1)
    {
        // 定義客戶端的socket地址結構
        struct sockaddr_in client_addr;
        socklen_t client_addr_length = sizeof(client_addr);
 // 接受連接請求，返回一個新的socket(描述符)，這個新socket用於同連接的客戶端通信
        // accept函數會把連接到的客戶端信息寫到client_addr中
        int new_server_socket_fd = accept(server_socket_fd, (struct sockaddr*)&client_addr, &client_addr_length);
        if(new_server_socket_fd < 0)
        {
            perror("Server Accept Failed:");
            break;
        }
        // recv函數接收數據到緩沖區buffer中
        char buffer[BUFFER_SIZE];
        bzero(buffer, BUFFER_SIZE);
        if(recv(new_server_socket_fd, buffer, BUFFER_SIZE, 0) < 0)
        {
            perror("Server Recieve Data Failed:");
            break;
        }
        // 然後從buffer(緩沖區)拷貝到file_name中
        char file_name[FILE_NAME_MAX_SIZE+1];
        bzero(file_name, FILE_NAME_MAX_SIZE+1);
        strncpy(file_name, buffer, strlen(buffer)>FILE_NAME_MAX_SIZE?FILE_NAME_MAX_SIZE:strlen(buffer));
        printf("5316:%s\n", file_name);
    int count=0;
    bzero(buffer, BUFFER_SIZE);
    count = CountWordsOfEuropeanTxtFile(file_name);
    sprintf(buffer,"%d", count);
        if(send(new_server_socket_fd, buffer, sizeof(buffer), 0) < 0)
        {
               printf("Send File:%s Failed./n", file_name);
        }
    bzero(buffer, BUFFER_SIZE); 
        /*/ 打開文件並讀取文件數據
        FILE *fp = fopen(file_name, "r");
        if(NULL == fp)
        {
            printf("File:%s Not Found\n", file_name);
        }
        else
        {
            bzero(buffer, BUFFER_SIZE);
            int length = 0;
            / 每讀取一段數據，便將其發送給客戶端，循環直到文件讀完為止
            while((length = fread(buffer, sizeof(char), BUFFER_SIZE, fp)) > 0)
            {
                if(send(new_server_socket_fd, buffer, length, 0) < 0)
                {
                    printf("Send File:%s Failed./n", file_name);
                    break;
                }
                bzero(buffer, BUFFER_SIZE);
            }
            / 關閉文件
            fclose(fp);
            printf("File:%s Transfer Successful!\n", file_name);
        }*/
        // 關閉與客戶端的連接
        close(new_server_socket_fd);
    }
    // 關閉監聽用的socket
    close(server_socket_fd);
    return 0;
}
int CountWordsOfEuropeanTxtFile(char *szFileName)
{
    int nWords = 0;//詞計數變量，初始值為0
    FILE *fp; //文件指針
    char carrBuffer[1024];//每行字符緩沖，每行最多1024個字符
    //打開文件
    if ((fp = fopen(szFileName,  "r")) == NULL)
    {
        return -1;  //文件打開不成功是返回-1
    }
    while (!feof(fp))//如果沒有讀到文件末尾 
    {
        //從文件中讀一行
        if (fgets(carrBuffer, sizeof(carrBuffer),fp) != NULL)
            //統計每行詞數
            nWords += CountWordsInOneLine(carrBuffer);
    }
    //關閉文件
    fclose(fp);
    return nWords;
}
int CountWordsInOneLine(const char *szLine)
{
    int nWords = 0;
    int i=0;
    for (;i<strlen(szLine);i++)
    {
        if (*(szLine+i)!=‘ ‘)
        {
            nWords++;
            while ((*(szLine+i)!=‘ ‘)&&(*(szLine+i)!=‘\0‘))
            {
                i++;
            }
        }

    }
            //printf("%d\t",nWords);
    
    return nWords;
}
 

• client.c

#include<netinet/in.h>   // sockaddr_in
#include<sys/types.h>    // socket
#include<sys/socket.h>   // socket
#include<stdio.h>        // printf
#include<stdlib.h>       // exit
#include<string.h>       // bzero
#include<unistd.h>
#include<stdlib.h>
#define SERVER_PORT 155316
#define BUFFER_SIZE 1024
#define FILE_NAME_MAX_SIZE 512
int main()
{
    // 聲明並初始化一個客戶端的socket地址結構
    struct sockaddr_in client_addr;
    bzero(&client_addr, sizeof(client_addr));
    client_addr.sin_family = AF_INET;
    client_addr.sin_addr.s_addr = htons(INADDR_ANY);
    client_addr.sin_port = htons(0);
    // 創建socket，若成功，返回socket描述符
    int client_socket_fd = socket(AF_INET, SOCK_STREAM, 0);
    if(client_socket_fd < 0)
    {
        perror("Create Socket Failed:");
        exit(1);
    }
    // 綁定客戶端的socket和客戶端的socket地址結構 非必需
    if(-1 == (bind(client_socket_fd, (struct sockaddr*)&client_addr, sizeof(client_addr))))
    {
        perror("Client Bind Failed:");
        exit(1);
    }
    // 聲明一個服務器端的socket地址結構，並用服務器那邊的IP地址及端口對其進行初始化，用於後面的連接
    struct sockaddr_in server_addr;
    bzero(&server_addr, sizeof(server_addr));
    server_addr.sin_family = AF_INET;
    if(inet_pton(AF_INET, "127.0.0.1", &server_addr.sin_addr) == 0)
    {
        perror("Server IP Address Error:");
        exit(1);
    }
    server_addr.sin_port = htons(SERVER_PORT);
    socklen_t server_addr_length = sizeof(server_addr);
    // 向服務器發起連接，連接成功後client_socket_fd代表了客戶端和服務器的一個socket連接
    if(connect(client_socket_fd, (struct sockaddr*)&server_addr, server_addr_length) < 0)
    {
        perror("Can Not Connect To Server IP:");
        exit(0);
    }
    // 輸入文件名 並放到緩沖區buffer中等待發送
    char file_name[FILE_NAME_MAX_SIZE+1];
    bzero(file_name, FILE_NAME_MAX_SIZE+1);
    printf("Please Input File Name On Server:\t");
    scanf("%s", file_name);
    char buffer[BUFFER_SIZE];
    bzero(buffer, BUFFER_SIZE);
    strncpy(buffer, file_name, strlen(file_name)>BUFFER_SIZE?BUFFER_SIZE:strlen(file_name));   
    // 向服務器發送buffer中的數據
    if(send(client_socket_fd, buffer, BUFFER_SIZE, 0) < 0)
    {
        perror("Send File Name Failed:");
        exit(1);
    }   
    //int count=0;
    int length=0;
    bzero(buffer, BUFFER_SIZE);
    length = recv(client_socket_fd, buffer, BUFFER_SIZE, 0);
    buffer[length] = ‘\0‘;
    printf("count=%s\n", buffer);
    bzero(buffer, BUFFER_SIZE);   
    /* / 打開文件，準備寫入
     / FILE *fp = fopen(file_name, "w");
    if(NULL == fp)
    {
        printf("File:\t%s Can Not Open To Write\n", file_name);
        exit(1);
    }
    / 從服務器接收數據到buffer中    
    / 每接收一段數據，便將其寫入文件中，循環直到文件接收完並寫完為止
    bzero(buffer, BUFFER_SIZE);
    int length = 0;
    while((length = recv(client_socket_fd, buffer, BUFFER_SIZE, 0)) > 0)
    {
        if(fwrite(buffer, sizeof(char), length, fp) < length)
        {
            printf("File:\t%s Write Failed\n", file_name);
            break;
        }
        bzero(buffer, BUFFER_SIZE);
    }
    / 接收成功後，關閉文件，關閉socket
    printf("Receive File:\t%s From Server IP Successful!\n", file_name);
    fclose(fp);
    */
    close(client_socket_fd);
    return 0;
}
 

實驗三-並發程序-2

• 使用多線程實現wc服務器並使用同步互斥機制保證計數正確

• 對比單線程版本的性能，並分析原因

線程本身由於創建和切換的開銷，采用多線程不會提高程序的執行速度，反而會降低速度，但是對於頻繁IO操作的程序，多線程可以有效的並發。對於包含不同任務的程序,可以考慮每個任務使用一個線程。這樣的程序在設計上相對於單線程做所有事的程序來說，更為清晰明了，比如生產、消費者問題。在實際的開發中對於性能優化的問題需要考慮到具體的場景來考慮是否使用多線程技術。

• 遇到的問題

解決：雖然程序包含了線程的頭文件 <pthread.h> ，但是由於pthread庫不是Linux系統默認的庫，連接時需要使用庫libpthread.a，所以在使用pthread_create創建線程時，在編譯中要加 -lpthread

• server2.c

#include<stdlib.h>
#include<pthread.h>
#include<sys/socket.h>
#include<sys/types.h>       //pthread_t , pthread_attr_t and so on.
#include<stdio.h>
#include<netinet/in.h>      //structure sockaddr_in
#include<arpa/inet.h>       //Func : htonl; htons; ntohl; ntohs
#include<assert.h>          //Func :assert
#include<string.h>          //Func :memset bzero
#include<unistd.h>          //Func :close,write,read
#define SOCK_PORT 9988
#define BUFFER_LENGTH 1024
#define MAX_CONN_LIMIT 512     //MAX connection limit
static void Data_handle(void * sock_fd);   //Only can be seen in the file
int CountWordsOfEuropeanTxtFile(char *szFileName);
int CountWordsInOneLine(const char *szLine);
int main()
{
    int sockfd_server;
    int sockfd;
    int fd_temp;
    struct sockaddr_in s_addr_in;
    struct sockaddr_in s_addr_client;
    int client_length;
    sockfd_server = socket(AF_INET,SOCK_STREAM,0);  //ipv4,TCP
    assert(sockfd_server != -1);
    //before bind(), set the attr of structure sockaddr.
    memset(&s_addr_in,0,sizeof(s_addr_in));
    s_addr_in.sin_family = AF_INET;
    s_addr_in.sin_addr.s_addr = htonl(INADDR_ANY);  //trans addr from uint32_t host byte order to network byte order.
    s_addr_in.sin_port = htons(SOCK_PORT);          //trans port from uint16_t host byte order to network byte order.
    fd_temp = bind(sockfd_server,(const struct sockaddr *)(&s_addr_in),sizeof(s_addr_in));
    if(fd_temp == -1)
    {
        fprintf(stderr,"bind error!\n");
        exit(1);
    }
    fd_temp = listen(sockfd_server,MAX_CONN_LIMIT);
    if(fd_temp == -1)
    {
        fprintf(stderr,"listen error!\n");
        exit(1);
    }
    while(1)
    {
        printf("waiting for new connection...\n");
        pthread_t thread_id;
        client_length = sizeof(s_addr_client);
        //Block here. Until server accpets a new connection.
        sockfd = accept(sockfd_server,(struct sockaddr * restrict)(&s_addr_client),(socklen_t *)(&client_length));
        if(sockfd == -1)
        {
            fprintf(stderr,"Accept error!\n");
            continue;                               //ignore current socket ,continue while loop.
        }
        printf("A new connection occurs!\n");
        if(pthread_create(&thread_id,NULL,(void *)(&Data_handle),(void *)(&sockfd)) == -1)
        {
            fprintf(stderr,"pthread_create error!\n");
            break;                                  //break while loop
        }
    }
    //Clear
    int ret = shutdown(sockfd_server,SHUT_WR); //shut down the all or part of a full-duplex connection.
    assert(ret != -1);
    printf("Server shuts down\n");
    return 0;
}
static void Data_handle(void * sock_fd)
{
    int fd = *((int *)sock_fd);
    int i_recvBytes;
    char data_recv[BUFFER_LENGTH];
    const char * data_send = "Server has received your request!\n";
    while(1)
    {
        printf("waiting for file_name...\n");
        //Reset data.
        memset(data_recv,0,BUFFER_LENGTH);
        i_recvBytes = read(fd,data_recv,BUFFER_LENGTH);
        if(i_recvBytes == 0)
        {
            printf("Maybe the client has closed\n");
            break;
        }
        if(i_recvBytes == -1)
        {
            fprintf(stderr,"read error!\n");
            break;
        }
        if(strcmp(data_recv,"quit")==0)
        {
            printf("Quit command!\n");
            break;                           //Break the while loop.
        }
        printf("read from client : %s\n",data_recv);
        
    char buffer[BUFFER_LENGTH];
    int count=0;
    bzero(buffer, BUFFER_LENGTH);
    count = CountWordsOfEuropeanTxtFile(data_recv);
    sprintf(buffer,"%d", count);
        send(fd, buffer, sizeof(buffer), 0);
        if(write(fd,data_send,strlen(data_send)) == -1)
        {
            break;
        }
    }
    //Clear
    printf("terminating current client_connection...\n");
    close(fd);            //close a file descriptor.
    pthread_exit(NULL);   //terminate calling thread!
}
int CountWordsOfEuropeanTxtFile(char *szFileName)
{
    int nWords = 0;//詞計數變量，初始值為0
    FILE *fp; //文件指針
    char carrBuffer[1024];//每行字符緩沖，每行最多1024個字符
    //打開文件
    if ((fp = fopen(szFileName,  "r")) == NULL)
    {
        return -1;  //文件打開不成功是返回-1
    }
    while (!feof(fp))//如果沒有讀到文件末尾 
    {
        //從文件中讀一行
        if (fgets(carrBuffer, sizeof(carrBuffer),fp) != NULL)
            //統計每行詞數
            nWords += CountWordsInOneLine(carrBuffer);
    }

    //關閉文件
    fclose(fp);
    return nWords;
}
int CountWordsInOneLine(const char *szLine)
{
    int nWords = 0;
    int i=0;
    for (;i<strlen(szLine);i++)
    {
        if (*(szLine+i)!=‘ ‘)
        {
            nWords++;
            while ((*(szLine+i)!=‘ ‘)&&(*(szLine+i)!=‘\0‘))
            {
                i++;
            }
        }

    }
            //printf("%d\t",nWords);
    
    return nWords;
}

• client2.c

#include<stdlib.h>
#include<sys/socket.h>
#include<sys/types.h>       //pthread_t , pthread_attr_t and so on.
#include<stdio.h>
#include<netinet/in.h>      //structure sockaddr_in
#include<arpa/inet.h>       //Func : htonl; htons; ntohl; ntohs
#include<assert.h>          //Func :assert
#include<string.h>          //Func :memset bzero
#include<unistd.h>          //Func :close,write,read
#define SOCK_PORT 9988
#define BUFFER_LENGTH 1024
int main()
{
    int sockfd;
    int tempfd;
    struct sockaddr_in s_addr_in;
    char data_send[BUFFER_LENGTH];
    char data_recv[BUFFER_LENGTH];
    memset(data_send,0,BUFFER_LENGTH);
    memset(data_recv,0,BUFFER_LENGTH);
    sockfd = socket(AF_INET,SOCK_STREAM,0);       //ipv4,TCP
    if(sockfd == -1)
    {
        fprintf(stderr,"socket error!\n");
        exit(1);
    }
    //before func connect, set the attr of structure sockaddr.
    memset(&s_addr_in,0,sizeof(s_addr_in));
    s_addr_in.sin_addr.s_addr = inet_addr("127.0.0.1");      //trans char * to in_addr_t
    s_addr_in.sin_family = AF_INET;
    s_addr_in.sin_port = htons(SOCK_PORT);
    tempfd = connect(sockfd,(struct sockaddr *)(&s_addr_in),sizeof(s_addr_in));
    if(tempfd == -1)
    {
        fprintf(stderr,"Connect error! \n");
        exit(1);
    }
    while(1)
    {
        printf("Please Input File Name On Server(input \"quit\" to quit):\t");
    scanf("%s", data_send);        
    //gets(data_send);
        //scanf("%[^\n]",data_send);         //or you can also use this
        tempfd = write(sockfd,data_send,BUFFER_LENGTH);
        if(tempfd == -1)
        {
            fprintf(stderr,"write error\n");
            exit(0);
        }

        if(strcmp(data_send,"quit") == 0)  //quit,write the quit request and shutdown client
        {
            break;
        }
        else
        {
            tempfd = read(sockfd,data_recv,BUFFER_LENGTH);
            assert(tempfd != -1);
            printf("%s\n",data_recv);
            memset(data_send,0,BUFFER_LENGTH);
            memset(data_recv,0,BUFFER_LENGTH);
        }
    char buffer[BUFFER_LENGTH];
    int length=0;
    bzero(buffer, BUFFER_LENGTH);
        length = recv(sockfd, buffer, BUFFER_LENGTH, 0);
        buffer[length] = ‘\0‘;
        printf("count=%s\n", buffer);
        bzero(buffer, BUFFER_LENGTH);
    }
    int ret = shutdown(sockfd,SHUT_WR);       //or you can use func close()--<unistd.h> to close the fd
    assert(ret != -1);
    return 0;
}

2018-2019-1 20165229 20165306 實驗三 實時系統