检查libevent是否安装，是则会列出清单，否则空白。
ls -al /usr/lib |grep libevent
如果没有安装，请去官网下载源文件http://libevent.org/\
解压libevent-2.1.8-stable.tar.gz，tar xzvf libevent-2.1.8-stable.tar.gz
然后进入目录编译
./configure -prefix=/usr
make
make install
安装完成，会自动把相关头文件拷贝到/usr/inclue，库文件拷贝到/usr/lib。
Qt的编译环境，需要在.pro文件添加LIBS += /usr/lib/libevent.so\
\
1、.pro文件
TEMPLATE = app
CONFIG += console
CONFIG -= app_bundle
CONFIG -= qt
SOURCES += main.c
LIBS += /usr/lib/libevent.so
\
2、main.c文件\
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <stdio.h>
#include <string.h>
#include <event.h>
#include <stdlib.h>
#define PORT 8011
#define BACKLOG 5
#define MEM_SIZE 1024
struct event_base* base;
struct sock_ev
{
struct event* read_ev;
struct event* write_ev;
char* buffer;
};
void release_sock_event(struct sock_ev* ev)
{
event_del(ev->read_ev);
free(ev->read_ev);
free(ev->write_ev);
free(ev->buffer);
free(ev);
}
void on_write(int sock, short event, void* arg)
{
char* buffer = (char*)arg;
send(sock, buffer, strlen(buffer), 0);
free(buffer);
}
void on_read(int sock, short event, void* arg)
{
struct event* write_ev;
int size;
struct sock_ev* ev = (struct sock_ev*)arg;
ev->buffer = (char*)malloc(MEM_SIZE);
bzero(ev->buffer, MEM_SIZE);
size = recv(sock, ev->buffer, MEM_SIZE, 0);
printf("receive data:%s, size:%d\n", ev->buffer, size);
if (size == 0)
{
release_sock_event(ev);
close(sock);
return;
}
event_set(ev->write_ev, sock, EV_WRITE, on_write, ev->buffer);
event_base_set(base, ev->write_ev);
event_add(ev->write_ev, NULL);
}
void on_accept(int sock, short event, void* arg)
{
struct sockaddr_in cli_addr;
int newfd, sin_size;
struct sock_ev* ev = (struct sock_ev*)malloc(sizeof(struct sock_ev));
ev->read_ev = (struct event*)malloc(sizeof(struct event));
ev->write_ev = (struct event*)malloc(sizeof(struct event));
sin_size = sizeof(struct sockaddr_in);
newfd = accept(sock, (struct sockaddr*)&cli_addr, &sin_size);
event_set(ev->read_ev, newfd, EV_READ|EV_PERSIST, on_read, ev);
event_base_set(base, ev->read_ev);
event_add(ev->read_ev, NULL);
}
int main(int argc, char* argv[])
{
struct sockaddr_in my_addr;
int sock;
sock = socket(AF_INET, SOCK_STREAM, 0);
int yes = 1;
setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(int));
memset(&my_addr, 0, sizeof(my_addr));
my_addr.sin_family = AF_INET;
my_addr.sin_port = htons(PORT);
my_addr.sin_addr.s_addr = INADDR_ANY;
bind(sock, (struct sockaddr*)&my_addr, sizeof(struct sockaddr));
listen(sock, BACKLOG);
struct event listen_ev;
base = event_base_new();
event_set(&listen_ev, sock, EV_READ|EV_PERSIST, on_accept, NULL);
event_base_set(base, &listen_ev);
event_add(&listen_ev, NULL);
event_base_dispatch(base);
return 0;
}
———————————
查看当前服务器的链接数
ulimit -a
lsof -p pid\
\
参考文献：\
linux网络编程
blog.csdn.net/feitianxuxu…
linux epoll介绍和程序实例\
select、poll、epoll之间的区别总结
