2018-2019-1 20165237 20165227 20165228 實驗三 實時系統

No.1

實驗要求：

• 學習使用Linux命令wc(1)
• 基於Linux Socket程式設計實現wc（1）伺服器(埠號是你學號的後6位)和客戶端
• 客戶端傳一個文字檔案給伺服器
• 伺服器返加文字檔案中的單詞數

實驗截圖

實驗程式碼

客戶端：#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 165237
#define BUFFER_SIZE 1024
#define FILE_NAME_MAX_SIZE 512

int main()
{
   // 宣告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);

   // 建立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);
   }

   // 繫結客戶端的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);
   }

   // 宣告一個伺服器端的socket地址結構，並用伺服器那邊的IP地址及埠對其進行初始化，用於後面的連線
   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);

   // 向伺服器發起連線，連線成功後client_socket_fd代表了客戶端和伺服器的一個socket連線
   if(connect(client_socket_fd, (struct sockaddr*)&server_addr, server_addr_length) < 0)
   {
       perror("Can Not Connect To Server IP:");
       exit(0);
   }

   // 輸入檔名 並放到緩衝區buffer中等待發送
   char file_name[FILE_NAME_MAX_SIZE+1];
   bzero(file_name, FILE_NAME_MAX_SIZE+1);
   printf("The file name u want to send:\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));
   
   // 向伺服器傳送buffer中的資料
   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("The count=%s\n", buffer);
   bzero(buffer, BUFFER_SIZE);
  
   /* / 開啟檔案，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);
   }

   / 從伺服器接收資料到buffer中
   
   / 每接收一段資料，便將其寫入檔案中，迴圈直到檔案接收完並寫完為止
   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，關閉檔案，關閉socket
   printf("Receive File:\t%s From Server IP Successful!\n", file_name);
   fclose(fp);
   */
   close(client_socket_fd);
   return 0;
}
伺服器：
#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 165237
#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)
{
   // 宣告並初始化一個伺服器端的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);

   // 建立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));

   // 繫結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);

       // 接受連線請求，返回一個新的socket(描述符)，這個新socket用於同連線的客戶端通訊
       // accept函式會把連線到的客戶端資訊寫到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函式接收資料到緩衝區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(緩衝區)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("oh yeah!! here: 5237:%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); 


       /*/ 開啟檔案並讀取檔案資料
       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;
           / 每讀取一段資料，便將其傳送給客戶端，迴圈直到檔案讀完為止
   
           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);
           }

           / 關閉檔案
           fclose(fp);
           printf("File:%s Transfer Successful!\n", file_name);
       }*/
       // 關閉與客戶端的連線
       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;//詞計數變數，初始值為0
FILE *fp; //檔案指標
char carrBuffer[1024];//每行字元緩衝，每行最多1024個字元

//開啟檔案
if ((fp = fopen(szFileName,  "r")) == NULL)
{
return -1; //檔案開啟不成功是返回-1
}

while (!feof(fp))//如果沒有讀到檔案末尾 
{
//從檔案中讀一行
if (fgets(carrBuffer, sizeof(carrBuffer),fp) != NULL)
//統計每行詞數
nWords += CountWordsInOneLine(carrBuffer);
}
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++;
}
}

}

return nWords;
}
 

No.2

實驗要求：

• 使用多執行緒實現wc伺服器並使用同步互斥機制保證計數正確

實驗截圖

伺服器：
#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 5237
#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("Loading...... \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("Connecting!!!!\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("Reloading......\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("Get something from the newclient : %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;//詞計數變數，初始值為0
FILE *fp; //檔案指標
char carrBuffer[1024];//每行字元緩衝，每行最多1024個字元

//開啟檔案
if ((fp = fopen(szFileName,  "r")) == NULL)
{
return -1; //檔案開啟不成功是返回-1
}

while (!feof(fp))//如果沒有讀到檔案末尾 
{
//從檔案中讀一行
if (fgets(carrBuffer, sizeof(carrBuffer),fp) != NULL)
//統計每行詞數
nWords += CountWordsInOneLine(carrBuffer);
}

//關閉檔案
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;
}
客戶端：
#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 5237
#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 \"exit\" 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,"exit") == 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;
}
 

遇到的問題

-執行程式碼時出現對“pthread_create” 未定義的引用

• 解決方法：在gcc client.c 後 不能直接加-o ，而是

gcc client.c -lpthread -o client

對比執行緒

• 多執行緒與單執行緒的區別
  生活舉例
  你早上上班，正要打卡的時候，手機響了。。你如果先接了電話，等接完了，在打卡，就是單執行緒。
  如果你一手接電話，一手打卡。就是多執行緒。
  2件事的結果是一樣的。。你接了電話且打了卡。

多執行緒具有的優點:

因為使用者介面可以在其它工作進行的同時一直處於活動狀態，所以多執行緒技術會使程式的響應速度更快一點 ;

當前如果沒有正在進行處理的任務時，可以將處理器多餘的時間讓給其它任務;
 

多執行緒的缺點

等候使用共享資源時造成程式的執行速度變慢。這些共享資源主要是獨佔性的資源 ,如印表機等。

對執行緒進行管理要求額外的 CPU開銷。執行緒的使用會給系統帶來上下文切換的額外負擔。當這種負擔超過一定程度時,多執行緒的特點主要表現在其缺點上,比如用獨立的執行緒來更新陣列內每個元素。

執行緒的死鎖。即較長時間的等待或資源競爭以及死鎖等多執行緒症狀。