c – 缺少某些东西或者我只是不了解epoll?

前端之家收集整理的这篇文章主要介绍了c – 缺少某些东西或者我只是不了解epoll?前端之家小编觉得挺不错的,现在分享给大家,也给大家做个参考。
完全披露,我是学生,这是一项任务.我已经工作了一个多星期几乎不停(除了以前花的时间),我无法弄清楚我做错了什么.只有“少量”的recvs完成后,我的服务器一直挂在epoll_wait上(“少数”,因为我预计有几GB的数据而且我只得到几十MB).我不认为我的客户端如何工作有任何问题,因为它与我的选择和多线程服务器一起工作得很好.请快速浏览一下,让我知道是否有什么因为我的问题而跳出来.

客户端/服务器的基本思想是使用连接(10k)轰炸服务器并多次传输给定数量的数据.这个epoll服务器在使用2000时遇到了麻烦,当时我的多线程服务器只处理了10k的目标.

我不是要求你为我做任务(我差不多完成了)我只是需要帮助弄清楚我在这里做错了什么.在此先感谢您提供的任何帮助:)

1 #include "common.h"
  2 #include <sys/epoll.h>
  3 
  4 uint16_t ready[MAX_CONNS];
  5 uint16_t next;
  6 pthread_mutex_t mutex;
  7 
  8 void *worker_thread(void *param) {
  9     int my_sock,pos;
 10     struct conn_params *conn_ps = (struct conn_params *)param;
 11 
 12     while (1) {
 13         pthread_mutex_lock(&mutex);
 14 
 15         while (1) {
 16             if (next == MAX_CONNS) {
 17                 printf("balls\n");
 18                 next = 4;
 19             }
 20 
 21             if (ready[next] != 0) {
 22                 pos = next;
 23                 my_sock = ready[pos];
 24                 next++;
 25                 break;
 26             }
 27         }
 28 
 29         pthread_mutex_unlock(&mutex);
 30         /* handle recv/send */
 31         if (echo_recv(&conn_ps[my_sock],MULTIPLE) == 0) { /* closed conn */
 32             shutdown(my_sock,SHUT_RDWR);
 33             close(my_sock);
 34             serv_stats.active_connections--;
 35         }
 36         ready[pos] = 0;
 37 /*      print_conn_stats(&conn_ps[my_sock]);*/
 38     }
 39 }
 40 
 41 void *add_client_thread(void *param) {
 42     struct epoll_accept_thread *eat = (struct epoll_accept_thread *)param;
 43     struct sockaddr client;
 44     struct epoll_event event;
 45     socklen_t client_len;
 46     int new_sock,ret;
 47     char hostbuf[NI_MAXHOST],servbuf[NI_MAXSERV];
 48 
 49     bzero(&client,sizeof(struct sockaddr));
 50     event.events = EPOLLIN | EPOLLERR | EPOLLHUP | EPOLLET;
 51 
 52     while ((new_sock = accept(eat->listen_sock,&client,&client_len)) != -1) {
 53         set_nonblock(new_sock);
 54         event.data.fd = new_sock;
 55         if (epoll_ctl(eat->fd_epoll,EPOLL_CTL_ADD,new_sock,&event) == -1) {
 56             perror("epoll_ctl");
 57             printf("%u\n",new_sock);
 58             continue;
 59         }
 60 
 61         bzero(&(eat->conn_ps[new_sock]),sizeof(struct conn_params));
 62         eat->conn_ps[new_sock].sock = new_sock;
 63         if ((ret = getnameinfo(&client,client_len,hostbuf,NI_MAXHOST,servbuf,NI_MAXSERV,NI_NUMERICHOST)) != 0) {
 64             gai_strerror(ret);
 65         }
 66 
 67         update_server_stats();
 68         printf("added client\n");
 69     }
 70 
 71     if (errno != EAGAIN) {
 72         perror("Couldn't accept connection");
 73     }
 74 
 75     pthread_exit(NULL);
 76 }
 77 
 78 int main(int argc,char **argv) {
 79     char opt,*port = NULL;
 80     struct addrinfo hints,*results,*p;
 81     int listen_sock = new_tcp_sock(),nfds,i,ret;
 82     int fd_epoll,next_avail = 4;
 83     struct conn_params conn_ps[MAX_CONNS];
 84     struct epoll_event evs[MAX_CONNS];
 85     struct epoll_event event;
 86     struct epoll_accept_thread eat;
 87     pthread_t thread;
 88 
 89     while ((opt = getopt(argc,argv,":l:")) != -1) {
 90         switch (opt) {
 91             case 'l': /* port to listen on */
 92                 port = optarg;
 93                 break;
 94             case '?': /* unknown option */
 95                 fprintf(stderr,"The option -%c is not supported.\n",opt);
 96                 exit(1);
 97             case ':': /* required arg not supplied for option */
 98                 fprintf(stderr,"The option -%c requires an argument.\n",opt);
 99                 exit(1);
100         }
101     } /* command line arg processing done */
102 
103     if (port == NULL) {
104         fprintf(stderr,"You must provide the port to listen on (-l).\n");
105         exit(1);
106     }
107 
108     signal(SIGINT,handle_interrupt);
109 
110     bzero(&hints,sizeof(struct addrinfo));
111     hints.ai_family = AF_INET;
112     hints.ai_socktype = SOCK_STREAM;
113     hints.ai_flags = AI_PASSIVE;
114 
115     set_nonblock(listen_sock);
116     set_reuseaddr(listen_sock);
117 
118     if ((ret = getaddrinfo(NULL,port,&hints,&results) != 0)) {
119         gai_strerror(ret);
120         exit(1);
121     }
122 
123     for (p = results; p != NULL; p = p->ai_next) { /* attempt to connect to the host */
124         if (bind(listen_sock,p->ai_addr,p->ai_addrlen) == -1) {
125             perror("Bind Failed");
126         } else {
127             break;
128         }
129     }
130 
131     if (p == NULL) { /* we were unable to connect to anything */
132         fprintf(stderr,"Unable to bind to the specified port. Exiting...\n");
133         exit(1);
134     }
135 
136     freeaddrinfo(results);
137 
138     if (listen(listen_sock,5) == -1) {
139         perror("Listen Failed");
140         exit(1);
141     }
142 
143     /* everything is set up. method-specific code goes below */
144 
145     start_server_stats();
146     next = 4;
147 
148     if ((fd_epoll = epoll_create(MAX_CONNS)) == -1) {
149         perror("epoll_create");
150         exit(1);
151     }
152 
153     event.events = EPOLLIN | EPOLLERR | EPOLLHUP | EPOLLET;
154     event.data.fd = listen_sock;
155     if (epoll_ctl(fd_epoll,listen_sock,&event) == -1) {
156         perror("epoll_ctl");
157         exit(1);
158     }
159 
160     signal(SIGPIPE,SIG_IGN);
161     bzero(ready,MAX_CONNS * sizeof(uint16_t));
162     pthread_mutex_init(&mutex,NULL);
163 
164     for (i = 0; i < 5; i++) { /* five workers should be enough */
165         pthread_create(&thread,NULL,worker_thread,(void *)&conn_ps);
166     }
167 
168     while (1) {
169         if ((nfds = epoll_wait(fd_epoll,evs,MAX_CONNS,-1)) > 0 && errno == EINTR) {
170             continue;
171         }
172         for (i = 0; i < nfds; i++) { /* loop through all FDs */
173             if (evs[i].events & (EPOLLERR | EPOLLHUP)) { /* if there's an error or a hangup */
174                 /*fprintf(stderr,"Error! Danger,Will Robinson! Danger!");*/
175                 close(evs[i].data.fd);
176                 continue;
177             } else if (evs[i].data.fd == listen_sock) { /* we have a new connection coming in */
178                 eat.listen_sock = listen_sock;
179                 eat.fd_epoll = fd_epoll;
180                 eat.conn_ps = conn_ps;
181                 pthread_create(&thread,add_client_thread,(void *)&eat);
182             } else { /* inbound data */
183                 while (ready[next_avail] != 0) {
184                     next_avail++;
185 
186                     if (next_avail == MAX_CONNS) {
187                         next_avail = 4;
188                     }
189                 }
190                 ready[next_avail] = evs[i].data.fd;
191             } /* end inbound data */
192         } /* end iterating through FDs */
193     } /* end epoll_wait loop */
194 
195     perror("epoll_wait");
196 
197     return 0;
198 }

这是echo_recv函数,因为我假设某人也想看到它:

14 int echo_recv(struct conn_params *conn_p,int single) {
 15     char client_buf[CLIENT_BUF_SIZE],buffer[BUF_SIZE];
 16     int nread,nwrite,nsent = 0,i;
 17 
 18     while ((nread = recv(conn_p->sock,client_buf,CLIENT_BUF_SIZE,0)) > 0) {
 19         /* create buffer of MULTIPLIER(int) times what was received */
 20         for (i = 0; i < MULTIPLIER && nread*i < BUF_SIZE; i++) {
 21             memcpy(buffer+(nread*i),nread);
 22         }
 23 
 24         /* send the created buffer */
 25         while ((nwrite = send(conn_p->sock,buffer+nsent,(nread*MULTIPLIER)-nsent,0)) > 0) {
 26             nsent += nwrite;
 27         }
 28 
 29         conn_p->total_recvd += nread; /* update our stats for this conn */
 30         conn_p->total_sent += nsent; /* update our status for this conn */
 31         serv_stats.total_recvd += nread;
 32         serv_stats.total_sent += nsent;
 33         nsent = 0;
 34 
 35         if (single) {
 36             return 1;
 37         }
 38     }
 39 
 40     if (nread == -1 && (errno & EAGAIN)) {
 41         return 1;
 42     }
 43 
 44     if (nread == -1) {
 45         perror("wtf?");
 46     }
 47 
 48     shutdown(conn_p->sock,SHUT_RDWR);
 49     close(conn_p->sock);
 50 
 51     return 0; /* recv Failed */
 52 }

解决方法

以下是一些想法:

>您应该真正了解如何访问共享阵列.在你的工作线程中,你获取了一个互斥体来读取它,但是有时你在锁外部修改它,另外,你没有在轮询循环(主线程)中获得这个锁,你只需要写入数组 – 这是完全错误的.
>你没有保留所有工作线程的线程ID,你如何建议杀死它们(或者等待它们完成 – 通常你需要调用pthread_join)
>您创建一个单独的线程来接受连接,但是再次修改此线程中的共享epoll_accept_thread结构 – 并且没有锁定它.

我会首先解决所有同步问题,然后可能会揭示其他问题.

猜你在找的C&C++相关文章