Linux Network Programming--tcp Concurrent Server (poll implementation)

To thoroughly understand poll or understand the following code, please refer to the "Linux network programming--i/o multiplexing poll function"

Code:

1#include <string.h>2#include <stdio.h>3#include <stdlib.h>4#include <unistd.h>5#include <sys/Select.h>6#include <sys/time.h>7#include <sys/socket.h>8#include <netinet/inch.h>9#include <arpa/inet.h>Ten#include <poll.h> One#include <errno.h> A #defineOpen_max 100 -    - intMainintargcChar*argv[]) the {   -     //1. Create a TCP listener socket -     intSOCKFD = socket (af_inet, Sock_stream,0);  -        +     //2. Binding SOCKFD -     structsockaddr_in my_addr;  +Bzero (&AMP;MY_ADDR,sizeof(MY_ADDR));  Amy_addr.sin_family =af_inet;  atMy_addr.sin_port = htons (8000);  -MY_ADDR.SIN_ADDR.S_ADDR =htonl (Inaddr_any);  -Bind (SOCKFD, (structSOCKADDR *) &my_addr,sizeof(MY_ADDR));  -        -     //3. Monitoring Listen -Listen (SOCKFD,Ten);  in        -     //4.poll corresponding parameter preparation to     structPOLLFD Client[open_max];  +     inti =0, Maxi =0;  -      for(;i<open_max; i++)   theCLIENT[I].FD =-1;//Initialize the file descriptor in the poll structure FD *        $client[0].FD = SOCKFD;//descriptors that need to be monitoredPanax Notoginsengclient[0].events = Pollin;//Normal or priority with data- readable -        the     //5. Data processing for connected clients +      while(1)   A     {   the         intRET = poll (client, maxi+1, -1);//monitoring of all elements added to the poll structure array +            -         //5.1 monitor SOCKFD (listening sockets) for connectivity $         if((client[0].revents & pollin) = =Pollin) $         {   -             structsockaddr_in cli_addr;  -             intClilen =sizeof(CLI_ADDR);  the             intCONNFD =0;  -             //5.1.1 Extracting the client from the TCP completion connectionWuyiCONNFD = Accept (SOCKFD, (structSOCKADDR *) &cli_addr, &Clilen);  the                -             //5.1.2 The extracted connfd into an array of poll structures for easy poll function monitoring Wu              for(i=1; i<open_max; i++)   -             {   About                 if(Client[i].fd <0)   $                 {   -CLIENT[I].FD =CONNFD;  -Client[i].events =Pollin;  -                      Break;  A                 }   +             }   the                -             //5.1.3 Maxi Update $             if(I >Maxi) theMaxi =i;  the                    the             //5.1.4 If there is no ready descriptor, continue to poll monitoring, otherwise continue to look down the             if(--ret <=0)   -                 Continue;  in         }   the            the         //5.2 Continue response-Ready descriptor About          for(i=1; i<=maxi; i++)   the         {   the             if(Client[i].fd <0)   the                 Continue;  +                -             if(Client[i].revents & (Pollin |Pollerr))  the             {  Bayi                 intLen =0;  the                 Charbuf[ -] ="";  the                    -                 //5.2.1 Accepting client data -                 if(len = recv (CLIENT[I].FD, buf,sizeof(BUF),0)) <0)   the                 {   the                     if(errno = = Econnreset)//TCP connection Timeout, RST the                     {   the Close (CLIENT[I].FD);  -CLIENT[I].FD =-1;  the                     }   the                     Else   thePerror ("Read error:"); 94                        the                 }   the                 Else if(len = =0)//Client closes the connection the                 {  98 Close (CLIENT[I].FD);  AboutCLIENT[I].FD =-1;  -                 }  101                 Else//data that is normally received from the server102Send (CLIENT[I].FD, buf, Len,0); 103                   104                 //5.2.2 All the ready descriptors have been processed, exit the current for loop and continue poll monitoring the                 if(--ret <=0)  106                      Break; 107                   108             }  109         }   the     }  111     return 0;  the}

Operation Result:

Linux Network Programming--tcp Concurrent Server (poll implementation)