2高并发服务器多线程服务器.docxVIP

1多线程并发服务器多线程服务器模型在使用线程模型开发服务器时需要考虑以下问题：A 调整进程最大文件描述符上限B 线程如有共享数据，考虑线程同步C 服务于客户端线程退出时，退出处理。（退出值，分离态）D 系统负载，随着连接客户端增加，导致其它线程不能及时得到CPU2.案例说明server.c,代码如下：/* server.c */#include stdio.h#include string.h#include netinet/in.h#include arpa/inet.h#include pthread.h#include wrap.h#define MAXLINE 80#define SERV_PORT 8000struct s_info {struct sockaddr_in cliaddr;int connfd;};void *do_work(void *arg){int n,i;struct s_info *ts = (struct s_info*)arg;char buf[MAXLINE];char str[INET_ADDRSTRLEN];/* 可以在创建线程前设置线程创建属性,设为分离态,哪种效率高内？ */pthread_detach(pthread_self());while (1) {n = Read(ts-connfd, buf, MAXLINE);if (n == 0) {printf(the other side has been closed.\n);break;}printf(received from %s at PORT %d\n,inet_ntop(AF_INET, (*ts).cliaddr.sin_addr, str, sizeof(str)),ntohs((*ts).cliaddr.sin_port));for (i = 0; i n; i++) {buf[i] = toupper(buf[i]); }Write(ts-connfd, buf, n);}Close(ts-connfd);}int main(void) {struct sockaddr_in servaddr, cliaddr;socklen_t cliaddr_len;int listenfd, connfd;int i = 0;pthread_t tid;struct s_info ts[383];listenfd = Socket(AF_INET, SOCK_STREAM, 0);bzero(servaddr, sizeof(servaddr));servaddr.sin_family = AF_INET;servaddr.sin_addr.s_addr = htonl(INADDR_ANY);servaddr.sin_port = htons(SERV_PORT);Bind(listenfd, (struct sockaddr *)servaddr, sizeof(servaddr));Listen(listenfd, 20);printf(Accepting connections ...\n);while (1) {cliaddr_len = sizeof(cliaddr);connfd = Accept(listenfd, (struct sockaddr *)cliaddr, cliaddr_len);ts[i].cliaddr = cliaddr;ts[i].connfd = connfd;/* 达到线程最大数时，pthread_create出错处理, 增加服务器稳定性*/pthread_create(tid, NULL, do_work, (void*)ts[i]);i++;}close(listenfd);return 0;}client.c/* client.c */#include stdio.h#include string.h#include unistd.h#include netinet/in.h#include wrap.h#define MAXLINE 80#define SERV_PORT 8000int main(int argc, char *argv[]){struct sockaddr_in servaddr;char buf[MAXLINE];int sockfd, n;sockfd = Socket(AF_INET, SOCK_STREAM, 0);bzero(servaddr, sizeof(servaddr));servaddr.sin_family = AF_INET;inet_pton(AF_INET, 127.0.0.1, servaddr.sin_add