Linux網(wǎng)絡編程之高級并發(fā)服務器

1、1. 介紹在上一節(jié)，我們介紹了Linux簡單的并發(fā)服務器，通過在服務器端建立多個子進程，來接收客戶端的請求，實現(xiàn)并發(fā)處理，但這種方式明顯有缺陷,服務器并不知道客戶端請求的數(shù)量，所以事先建立的進程數(shù)不好確定。所以，這里介紹三種高級并發(fā)服務器模式。第一種是服務器端統(tǒng)一accept,接收客戶端的到來，然后為每個客戶端分配一個進程去處理. 第二種是統(tǒng)一accept接收請求，然后為每個客戶端分配一個線程去處理。第三種建立多個線程去處理客戶端請求，每個線程獨自監(jiān)聽客戶端的請求。顯然，第一種方案解決了簡單服務器的并發(fā)問題。第二種方案其實是對第一種方案的改進，因為線程切換的開銷明顯要小于進程切換的開銷。第三種

2、方案就是原來用進程去處理每個請求，現(xiàn)在換成用線程去處理，個人認為改進不是很大.2. 高級并發(fā)服務器算法流程(1)統(tǒng)一accept,多進程  socket(.);  bind(.);  listen(.);  while(1)  accept(.);  fork(.);/子進程  close(.);/關閉服務器套接字子進程: recv(.); process(.); send(.); close(.);/關閉客戶端(2)統(tǒng)一accept,多線程  socket(.);

3、  bind(.);  listen(.);  while(1)  accept(.);  pthread_create(.);   close(.);/關閉服務器線程1:recv(.);process(.);send(.);close(.);/關閉客戶端(3)accept放入每個線程 socket(.); bind(.); listen(.);pthread_create(.);pthread_join(.);/等待線程結束close(.);/關閉服務器線程1:Mutex_lock/互斥鎖ac

4、cept(.);Mutex_unlock(.);recv(.);process(.);send(.);close(.);/客戶端3. 相關例子TCP服務器:(1)統(tǒng)一accept多進程服務器；#include <stdio.h>#include <string.h>#include <stdlib.h>#include <sys/socket.h>#include <sys/types.h>#include <netinet/in.h>#include <time.h>/*高級并發(fā)服務器TCP統(tǒng)一accept當

5、有客戶端到來時,為每個客戶端建立進程，然后每個進程處理客戶端的請求，動態(tài)的建立進程*/#define PORT 8888#define BUFFERSIZE 1024#define BACKLOG 2static void handle(int sc)/處理客戶端的請求  char bufferBUFFERSIZE;  time_t now;  int size;  memset(buffer,0,BUFFERSIZE);   size=recv(sc,buffer,BUFFERSIZE,0);  if(size>0&

6、amp;&!strncmp(buffer,"TIME",4)/時間服務器，當客戶端請求時間就把時間發(fā)送給客戶端      memset(buffer,0,BUFFERSIZE);      now=time(NULL);      sprintf(buffer,"%24srn",ctime(&now);     send(sc,buffer,strle

7、n(buffer),0); close(sc);int main(int argc,char*argv)  int ret;  int s;  int sc;/用于服務器與客戶端進行數(shù)據(jù)傳輸?shù)奶捉幼?#160; struct sockaddr_in server_addr;  struct sockaddr_in client_addr;  int len;  len=sizeof(client_addr);  /建立流式套接字  s=socket(AF_INET,SOCK_STREAM,0); 

8、; if(s<0)    perror("socket error");   return -1;   /將地址結構綁定到套接字描述符上去 memset(&server_addr,0,sizeof(server_addr); server_addr.sin_family=AF_INET; server_addr.sin_port=htons(PORT); server_addr.sin_addr.s_addr=htonl(INADDR_ANY);

9、60;ret=bind(s,(struct sockaddr*)&server_addr,sizeof(server_addr); if(ret=-1)   perror("bind error");   return -1; ret=listen(s,BACKLOG);if(ret<0)   perror("listen error");  return -1; while(1)   sc=accept(s,(struc

10、t sockaddr*)&client_addr,&len);  if(sc<0)    continue;    if(fork()=0)/子進程  handle(sc);  close(s);/子進程關閉用于監(jiān)聽的套接字  else    close(sc);/父進程關閉客戶端套接字 客戶端:#include <stdio.h>#include <string.h>#include <stdlib.h>#

11、include <sys/socket.h>#include <sys/types.h>#include <time.h>#include <netinet/in.h>#define PORT 8888#define BUFFERSIZE 1024int main(int argc,char*argv) int s; int ret; int size; struct sockaddr_in server_addr; char bufferBUFFERSIZE; s=socket(AF_

12、INET,SOCK_STREAM,0); if(s<0)  perror("socket error");  return -1;bzero(&server_addr,sizeof(server_addr);/將地址結構綁定到套接字server_addr.sin_family=AF_INET;server_addr.sin_port=htons(PORT);server_addr.sin_addr.s_addr=htonl(INADDR_ANY);/連接服務器 ret=connect(s,(struct sockaddr

13、*)&server_addr,sizeof(server_addr); if(ret=-1)  perror("connect error");  return -1;memset(buffer,0,BUFFERSIZE);strcpy(buffer,"TIME");size=send(s,buffer,strlen(buffer),0);if(size<0)  perror("send error");  return -1;memset(buffer,0,BUFFER

14、SIZE);size=recv(s,buffer,BUFFERSIZE,0);if(size<0)  perror("recv error");  return;printf("%s",buffer);close(s);return 0;(2)統(tǒng)一accept多線程服務器:#include <stdio.h>#include <string.h>#include <stdlib.h>#include <sys/socket.h>#include <sys/types.h>

15、;#include <netinet/in.h>#include <time.h>/*TCP并發(fā)服務器，采用多線程，每次客戶端發(fā)送請求，主線程建立一個子線程，用于處理客戶端的請求線程具有速度快，占用資源少，數(shù)據(jù)可以共享等優(yōu)點 統(tǒng)一accept*/#define PORT 8888#define BUFFERSIZE 1024#define BACKLOG 2static void handle(void* sc1) int sc; time_t now; char bufferBUFFERSIZE;  int size; 

16、; sc=*(int*)sc1);/轉(zhuǎn)換成int指針，然后取值,sc1本身就是一個指針 memset(buffer,0,BUFFERSIZE); size=recv(sc,buffer,BUFFERSIZE,0); if(size>0&&!strncmp(buffer,"TIME",4)/請求服務器的時間     memset(buffer,0,BUFFERSIZE);/清0   now=time(NULL);    sprintf(buffe

17、r,"%24srn",ctime(&now);    send(sc,buffer,strlen(buffer),0);/向客戶端發(fā)送數(shù)據(jù)close(sc);/關閉客戶端int main(int argc,char*argv)  int ret;  int s;  int sc;  int len;  pthread_t thread1;/定義線程名   struct sockaddr_in server_addr,client_addr;  len=siz

18、eof(client_addr);  /建立流式套接字  s=socket(AF_INET,SOCK_STREAM,0);  if(s<0)    perror("socket error");    return -1;    /將服務器端的地址結構綁定到套接字描述符  server_addr.sin_family=AF_INET;  server_addr.sin_addr.s_addr=htonl(INADDR_ANY); 

19、 server_addr.sin_port=htons(PORT);  ret=bind(s,(struct sockaddr*)&server_addr,sizeof(struct sockaddr_in);  if(ret<0)    perror("bind error");    return -1;  /監(jiān)聽  ret=listen(s,BACKLOG);  if(ret<0)    perror(&quo

20、t;listen error");    return -1;  /接收客戶端的請求for(;)    sc=accept(s,(struct sockaddr*)&client_addr,&len);    if(sc<0)     continue;    else    pthread_create(&thread1,NULL,handle,(void*)&am

21、p;sc);/建立線程，讓線程去處理,最后一個字段是傳遞給線程處理函數(shù)handle的參數(shù)   close(s);客戶端:#include <stdio.h>#include <string.h>#include <stdlib.h>#include <sys/socket.h>#include <sys/types.h>#include <time.h>#include <netinet/in.h>#define PORT 8888#define BUFFERSIZE 1024int mai

22、n(int argc,char*argv) int s; int ret; int size; struct sockaddr_in server_addr; char bufferBUFFERSIZE; s=socket(AF_INET,SOCK_STREAM,0); if(s<0)  perror("socket error");  return -1;bzero(&server_addr,sizeof(server_addr);/將地址結構綁定到套接字server_

23、addr.sin_family=AF_INET;server_addr.sin_port=htons(PORT);server_addr.sin_addr.s_addr=htonl(INADDR_ANY);/連接服務器 ret=connect(s,(struct sockaddr*)&server_addr,sizeof(server_addr); if(ret=-1)  perror("connect error");  return -1;memset(buffer,0,BUFFERSIZE);strcpy(buffer,

24、"TIME");size=send(s,buffer,strlen(buffer),0);if(size<0)  perror("send error");  return -1;memset(buffer,0,BUFFERSIZE);size=recv(s,buffer,BUFFERSIZE,0);if(size<0)  perror("recv error");  return;printf("%s",buffer);close(s);return 0;(3)

25、單獨線程accept服務器:#include <stdio.h>#include <string.h>#include <stdlib.h>#include <sys/socket.h>#include <sys/types.h>#include <netinet/in.h>#include <time.h>#include <pthread.h>/*多線程TCP并發(fā)服務器主線程創(chuàng)建多個線程，然后每個線程獨立的accept和進行數(shù)據(jù)的發(fā)送與接收多線程，獨立accept*/#define PORT 8

26、888#define BUFFERSIZE 1024#define BACKLOG 2#define CLIENTNUM 3static void *handle(void* s1) int s; int len; int sc; pthread_mutex_t alock=PTHREAD_MUTEX_INITIALIZER; char bufferBUFFERSIZE; int size; struct sockaddr_in client_addr; s=*(int*)s1);/得到服務器端的套接字描述符/等待

27、客戶端連接 len=sizeof(client_addr); for(;)/不停的循環(huán)等待客戶端的連接   time_t now;   /進入互斥區(qū),每次一個線程處理客戶端pthread_mutex_lock(&alock);  sc=accept(s,(struct sockaddr*)&client_addr,&len);pthread_mutex_unlock(&alock);memset(buffer,0,BUFFERSIZE);size=recv(sc,buffer,BUFFERSI

28、ZE,0);if(size>0&&!strncmp(buffer,"TIME",4)  memset(buffer,0,BUFFERSIZE);  now=time(NULL);  sprintf(buffer,"%24srn",ctime(&now);  send(sc,buffer,strlen(buffer),0);close(sc);/關閉客戶端 int main(int argc,char*argv)   int ret;   int

29、s;   int len;   int i;   pthread_t threadCLIENTNUM;   struct sockaddr_in server_addr;   /建立流式套接字   s=socket(AF_INET,SOCK_STREAM,0);   if(s<0)    perror("socket error");    return -1; 

30、;  /將地址結構綁定到套接字上  server_addr.sin_family=AF_INET;  server_addr.sin_addr.s_addr=htonl(INADDR_ANY);  server_addr.sin_port=htons(PORT);  ret=bind(s,(struct sockaddr*)&server_addr,sizeof(struct sockaddr_in);  if(ret=-1)   perror("bind error"); &

31、#160; return -1;  /監(jiān)聽  ret=listen(s,BACKLOG);  if(ret=-1)    perror("listen error");     return -1; /建立3個線程，每個線程獨立的accept  for(i=0;i<CLIENTNUM;i+)    pthread_create(&threadi,NULL,handle,(void*)&s);/線程的處理函

32、數(shù)為handle,傳遞的參數(shù)為套接字描述符s      /while(1);/等待線程結束 for(i=0;i<CLIENTNUM;i+)   pthread_join(threadi,NULL);  /關閉套接字close(s);return 0;客戶端:#include <stdio.h>#include <string.h>#include <stdlib.h>#include <sys/socket.h>#include <sys/types.h>#include <time.h>#include <netinet/in.h>#define PORT 8888#define BUFFERSIZE 1024int main(int argc,char*a