C++ libevent:为什么在他们的示例中evutil_使_socket_非阻塞调用了两次
我正在查看上的LibEvent示例-为什么在该示例中,C++ libevent:为什么在他们的示例中evutil_使_socket_非阻塞调用了两次,c++,libevent,C++,Libevent,我正在查看上的LibEvent示例-为什么在该示例中,evutil\u make\u socket\u nonblocking(make socket non blocking)函数被调用两次 她的代码(我只是从LibEvent页面复制的): 中的sockaddr\u的/**/ #包括 /*用于套接字函数*/ #包括 /*对于fcntl*/ #包括 #包括 #包括 #包括 #包括 #包括 #包括 #包括 #包括 #包括 #定义最大值线16384 void do_read(evutil_socke
evutil\u make\u socket\u nonblocking
(make socket non blocking)函数被调用两次
她的代码(我只是从LibEvent页面复制的):
中的sockaddr\u的/**/
#包括
/*用于套接字函数*/
#包括
/*对于fcntl*/
#包括
#包括
#包括
#包括
#包括
#包括
#包括
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#定义最大值线16384
void do_read(evutil_socket_t fd,短事件,void*arg);
void do_write(evutil_socket_t fd,短事件,void*arg);
烧焦
rot13_字符(字符c)
{
/*我们不想在这里使用isalpha;设置区域设置会改变
*哪些字符按字母顺序排列*/
如果((c>='a'&&c='a'&&c='n'&&c='n'&&c=最大线){
/*太长;只需处理存在的内容并继续,以便缓冲区
*不会无限长*/
char-buf[1024];
while(evbuffer_get_length(输入)){
int n=evbuffer_remove(输入,buf,sizeof(buf));
对于(i=0;ifd_设置大小){
关闭(fd);
}否则{
结构缓冲事件*bev;
evutil_使_插座_非阻塞(fd);
bev=bufferevent\u socket\u new(基本、fd、bev\u OPT\u关闭\u开启\u空闲);
bufferevent_setcb(bev、readcb、NULL、errorcb、NULL);
bufferevent_设置水印(bev、EV_读取、0、最大线);
bufferevent_enable(bev、EV_读、EV_写);
}
}
无效的
运行(无效)
{
evutil_套接字_t侦听器;
sin中的结构sockaddr_;
结构事件库*base;
结构事件*侦听器事件;
base=事件\基础\新();
如果(!base)
返回;/*xxxer*/
sin.sin_family=AF_INET;
sin.sin_addr.s_addr=0;
sin.sin_port=htons(40713);
侦听器=socket(AF_INET,SOCK_STREAM,0);
evutil_使_套接字_非阻塞(侦听器);
#ifndef WIN32
{
int-one=1;
setsockopt(监听器,SOL_套接字,SO_REUSEADDR,&one,sizeof(one));
}
#恩迪夫
if(bind(listener,(struct sockaddr*)&sin,sizeof(sin))<0){
佩罗(“绑定”);
返回;
}
if(listen(listener,16)为侦听套接字调用一次,为每个接受的套接字调用一次
/* For sockaddr_in */
#include <netinet/in.h>
/* For socket functions */
#include <sys/socket.h>
/* For fcntl */
#include <fcntl.h>
#include <event2/event.h>
#include <event2/buffer.h>
#include <event2/bufferevent.h>
#include <assert.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#define MAX_LINE 16384
void do_read(evutil_socket_t fd, short events, void *arg);
void do_write(evutil_socket_t fd, short events, void *arg);
char
rot13_char(char c)
{
/* We don't want to use isalpha here; setting the locale would change
* which characters are considered alphabetical. */
if ((c >= 'a' && c <= 'm') || (c >= 'A' && c <= 'M'))
return c + 13;
else if ((c >= 'n' && c <= 'z') || (c >= 'N' && c <= 'Z'))
return c - 13;
else
return c;
}
void
readcb(struct bufferevent *bev, void *ctx)
{
struct evbuffer *input, *output;
char *line;
size_t n;
int i;
input = bufferevent_get_input(bev);
output = bufferevent_get_output(bev);
while ((line = evbuffer_readln(input, &n, EVBUFFER_EOL_LF))) {
for (i = 0; i < n; ++i)
line[i] = rot13_char(line[i]);
evbuffer_add(output, line, n);
evbuffer_add(output, "\n", 1);
free(line);
}
if (evbuffer_get_length(input) >= MAX_LINE) {
/* Too long; just process what there is and go on so that the buffer
* doesn't grow infinitely long. */
char buf[1024];
while (evbuffer_get_length(input)) {
int n = evbuffer_remove(input, buf, sizeof(buf));
for (i = 0; i < n; ++i)
buf[i] = rot13_char(buf[i]);
evbuffer_add(output, buf, n);
}
evbuffer_add(output, "\n", 1);
}
}
void
errorcb(struct bufferevent *bev, short error, void *ctx)
{
if (error & BEV_EVENT_EOF) {
/* connection has been closed, do any clean up here */
/* ... */
} else if (error & BEV_EVENT_ERROR) {
/* check errno to see what error occurred */
/* ... */
} else if (error & BEV_EVENT_TIMEOUT) {
/* must be a timeout event handle, handle it */
/* ... */
}
bufferevent_free(bev);
}
void
do_accept(evutil_socket_t listener, short event, void *arg)
{
struct event_base *base = arg;
struct sockaddr_storage ss;
socklen_t slen = sizeof(ss);
int fd = accept(listener, (struct sockaddr*)&ss, &slen);
if (fd < 0) {
perror("accept");
} else if (fd > FD_SETSIZE) {
close(fd);
} else {
struct bufferevent *bev;
evutil_make_socket_nonblocking(fd);
bev = bufferevent_socket_new(base, fd, BEV_OPT_CLOSE_ON_FREE);
bufferevent_setcb(bev, readcb, NULL, errorcb, NULL);
bufferevent_setwatermark(bev, EV_READ, 0, MAX_LINE);
bufferevent_enable(bev, EV_READ|EV_WRITE);
}
}
void
run(void)
{
evutil_socket_t listener;
struct sockaddr_in sin;
struct event_base *base;
struct event *listener_event;
base = event_base_new();
if (!base)
return; /*XXXerr*/
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = 0;
sin.sin_port = htons(40713);
listener = socket(AF_INET, SOCK_STREAM, 0);
evutil_make_socket_nonblocking(listener);
#ifndef WIN32
{
int one = 1;
setsockopt(listener, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));
}
#endif
if (bind(listener, (struct sockaddr*)&sin, sizeof(sin)) < 0) {
perror("bind");
return;
}
if (listen(listener, 16)<0) {
perror("listen");
return;
}
listener_event = event_new(base, listener, EV_READ|EV_PERSIST, do_accept, (void*)base);
/*XXX check it */
event_add(listener_event, NULL);
event_base_dispatch(base);
}
int
main(int c, char **v)
{
setvbuf(stdout, NULL, _IONBF, 0);
run();
return 0;
}