进程池实现客户端连接请求程序
服务端通过进程池实现处理并发连接逻辑：服务端主进程先创建进程池(这里没有显示给出进程池类但是逻辑上是采用多个子进程模拟进程池)，服务端监听端口若有连接请求则服务端将连接请求分发给子进程(简单的循环分发)，子进程收到父进程的指示(有新的客户连接请求要你处理)时建立该客户连接并再fork子进程处理客户端的连接处理逻辑。
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <assert.h>
#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/epoll.h>
#include <signal.h>
#include <sys/wait.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#define BUFFER_SIZE 1024
#define MAX_EVENT_NUMBER 1024
#define PROCESS_COUNT 5
#define USER_PER_PROCESS 65535
struct process_in_pool//进程池中子进程属性：进程pid、与父进程通信用管道
{
pid_t pid;
int pipefd[2];
};
struct client_data//客户数据：客户地址、缓冲区、
{
sockaddr_in address;
char buf[ BUFFER_SIZE ];//客户指定连接处理逻辑，即客户向服务器发送可执行文件名然后服务器运行该可执行文件
int read_idx;
};
int sig_pipefd[2];//信号值传递管道：用于将信号值传递给进程
int epollfd;//事件表
int listenfd;//监听端口
process_in_pool sub_process[ PROCESS_COUNT ];//所有子进程都可以通过下标索引到相应的进程属性
bool stop_child = false;
int setnonblocking( int fd )//将fd设置为非阻塞
{
int old_option = fcntl( fd, F_GETFL );
int new_option = old_option | O_NONBLOCK;
fcntl( fd, F_SETFL, new_option );
return old_option;
}
void addfd( int epollfd, int fd )//将fd添加到事件表epollfd
{
epoll_event event;
event.data.fd = fd;
event.events = EPOLLIN | EPOLLET;
epoll_ctl( epollfd, EPOLL_CTL_ADD, fd, &event );
setnonblocking( fd );
}
void sig_handler( int sig )//信号处理函数：将信号值通过管道sig_pipefd发送给进程
{
int save_errno = errno;
int msg = sig;
send( sig_pipefd[1], ( char* )&msg, 1, 0 );
errno = save_errno;
}
void addsig( int sig, void(*handler)(int), bool restart = true )//信号安装函数
{
struct sigaction sa;
memset( &sa, '\0', sizeof( sa ) );
sa.sa_handler = handler;//handler为sig_handler
if( restart )
{
sa.sa_flags |= SA_RESTART;
}
sigfillset( &sa.sa_mask );
assert( sigaction( sig, &sa, NULL ) != -1 );
}
void del_resource()//关闭描述符
{
close( sig_pipefd[0] );
close( sig_pipefd[1] );
close( listenfd );
close( epollfd );
}
void child_term_handler( int sig )//将子进程终止标志置为true
{
stop_child = true;
}
void child_child_handler( int sig )//等待子进程
{
pid_t pid;
int stat;
while ( ( pid = waitpid( -1, &stat, WNOHANG ) ) > 0 )
{
continue;
}
}
int run_child( int idx )//子进程运行逻辑
{
epoll_event events[ MAX_EVENT_NUMBER ];
int child_epollfd = epoll_create( 5 );//子进程创建事件表
assert( child_epollfd != -1 );
int pipefd = sub_process[idx].pipefd[1];//获取子进程与父进程通信用的管道描述符
addfd( child_epollfd, pipefd );//注册事件(可读)
int ret;
addsig( SIGTERM, child_term_handler, false );//安装信号
addsig( SIGCHLD, child_child_handler );
client_data* users = new client_data[ USER_PER_PROCESS ];//每个子进程都处理大量客户连接
while( !stop_child )
{
int number = epoll_wait( child_epollfd, events, MAX_EVENT_NUMBER, -1 );//无限期等待注册事件发生
if ( ( number < 0 ) && ( errno != EINTR ) )
{
printf( "epoll failure\n" );
break;
}
for ( int i = 0; i < number; i++ )
{
int sockfd = events[i].data.fd;//获取就绪事件的描述符
if( ( sockfd == pipefd ) && ( events[i].events & EPOLLIN ) )//若与父进程通信用的管道可读事件发生则表示：父进程有客户连接交给子进程
{
int client = 0;
ret = recv( sockfd, ( char* )&client, sizeof( client ), 0 );
if( ret < 0 )
{
if( errno != EAGAIN )
{
stop_child = true;
}
}
else if( ret == 0 )
{
stop_child = true;
}
else
{
struct sockaddr_in client_address;
socklen_t client_addrlength = sizeof( client_address );
int connfd = accept( listenfd, ( struct sockaddr* )&client_address, &client_addrlength );//子进程接受客户连接
if ( connfd < 0 )
{
printf( "errno is: %d\n", errno );
continue;
}
memset( users[connfd].buf, '\0', BUFFER_SIZE );//初始化客户连接数据
users[connfd].address = client_address;
users[connfd].read_idx = 0;//缓冲区读的位置
addfd( child_epollfd, connfd );//将客户连接加入子进程侦听事件表
}
}
else if( events[i].events & EPOLLIN )//若有可读事件表示有客户端fd发送数据到来
{
int idx = 0;
while( true )
{
idx = users[sockfd].read_idx;//获取客户连接读冲区位置
ret = recv( sockfd, users[sockfd].buf + idx, BUFFER_SIZE-1-idx, 0 );//将客户数据直接写到相应的客户缓冲区
if( ret < 0 )
{
if( errno != EAGAIN )//非EAGAIN错误表示网络出错需要断开连接
{
epoll_ctl( child_epollfd, EPOLL_CTL_DEL, sockfd, 0 );//关闭连接前需要将注册事件清除
close( sockfd );
}
break;
}
else if( ret == 0 )//客户端关闭连接则将注册事件清除
{
epoll_ctl( child_epollfd, EPOLL_CTL_DEL, sockfd, 0 );
close( sockfd );
break;
}
else
{
users[sockfd].read_idx += ret;//客户缓冲区读位置加上刚写入的数据大小
printf( "user content is: %s\n", users[sockfd].buf );
idx = users[sockfd].read_idx;//获取新的读位置
if( ( idx < 2 ) || ( users[sockfd].buf[idx-2] != '\r' ) || ( users[sockfd].buf[idx-1] != '\n' ) )
{
continue;
}
users[sockfd].buf[users[sockfd].read_idx-2] = '\0';
char* file_name = users[sockfd].buf;
if( access( file_name, F_OK ) == -1 )
{
epoll_ctl( child_epollfd, EPOLL_CTL_DEL, sockfd, 0 );
close( sockfd );
break;
}
ret = fork();
if( ret == -1 )
{
epoll_ctl( child_epollfd, EPOLL_CTL_DEL, sockfd, 0 );
close( sockfd );
break;
}
else if( ret > 0 )//父进程继续跳出本次循环执行下次循环逻辑即：建立新的客户连接
{
epoll_ctl( child_epollfd, EPOLL_CTL_DEL, sockfd, 0 );
close( sockfd );
break;
}
else//这里建立新的子进程真正处理客户连接逻辑
{
close( STDOUT_FILENO );
dup( sockfd );
execl( users[sockfd].buf, users[sockfd].buf, 0 );//执行buf指定的可执行文件
exit( 0 );
}
}
}
}
else
{
continue;
}
}
}
delete [] users;
close( pipefd );
close( child_epollfd );
return 0;
}
int main( int argc, char* argv[] )
{
if( argc <= 2 )
{
printf( "usage: %s ip_address port_number\n", basename( argv[0] ) );
return 1;
}
const char* ip = argv[1];
int port = atoi( argv[2] );
int ret = 0;
struct sockaddr_in address;
bzero( &address, sizeof( address ) );
address.sin_family = AF_INET;
inet_pton( AF_INET, ip, &address.sin_addr );
address.sin_port = htons( port );
listenfd = socket( PF_INET, SOCK_STREAM, 0 );
assert( listenfd >= 0 );
ret = bind( listenfd, ( struct sockaddr* )&address, sizeof( address ) );
assert( ret != -1 );
ret = listen( listenfd, 5 );
assert( ret != -1 );
for( int i = 0; i < PROCESS_COUNT; ++i )//i为子进程索引下标
{
ret = socketpair( PF_UNIX, SOCK_STREAM, 0, sub_process[i].pipefd );
assert( ret != -1 );
sub_process[i].pid = fork();
if( sub_process[i].pid < 0 )
{
continue;
}
else if( sub_process[i].pid > 0 )//父进程继续fork子进程
{
close( sub_process[i].pipefd[1] );
setnonblocking( sub_process[i].pipefd[0] );
continue;
}
else//子进程执行run_child逻辑
{
close( sub_process[i].pipefd[0] );
setnonblocking( sub_process[i].pipefd[1] );
run_child( i );
exit( 0 );
}
}
epoll_event events[ MAX_EVENT_NUMBER ];
epollfd = epoll_create( 5 );
assert( epollfd != -1 );
addfd( epollfd, listenfd );
ret = socketpair( PF_UNIX, SOCK_STREAM, 0, sig_pipefd );//信号值通信管道(统一事件源)
assert( ret != -1 );
setnonblocking( sig_pipefd[1] );
addfd( epollfd, sig_pipefd[0] );
addsig( SIGCHLD, sig_handler );
addsig( SIGTERM, sig_handler );
addsig( SIGINT, sig_handler );
addsig( SIGPIPE, SIG_IGN );
bool stop_server = false;
int sub_process_counter = 0;
while( !stop_server )
{
int number = epoll_wait( epollfd, events, MAX_EVENT_NUMBER, -1 );//父进程监听信号管道、监听端口事件
if ( ( number < 0 ) && ( errno != EINTR ) )
{
printf( "epoll failure\n" );
break;
}
for ( int i = 0; i < number; i++ )
{
int sockfd = events[i].data.fd;
if( sockfd == listenfd )//监听端口可读事件：有新的客户连接请求
{
int new_conn = 1;
send( sub_process[sub_process_counter++].pipefd[0], ( char* )&new_conn, sizeof( new_conn ), 0 );//通知子进程建立客户连接并处理该连接
printf( "send request to child %d\n", sub_process_counter-1 );
sub_process_counter %= PROCESS_COUNT;//循环将连接请求发送给子进程
}
else if( ( sockfd == sig_pipefd[0] ) && ( events[i].events & EPOLLIN ) )//有信号产生
{
int sig;
char signals[1024];
ret = recv( sig_pipefd[0], signals, sizeof( signals ), 0 );
if( ret == -1 )
{
continue;
}
else if( ret == 0 )
{
continue;
}
else
{
for( int i = 0; i < ret; ++i )
{
switch( signals[i] )
{
case SIGCHLD:
{
pid_t pid;
int stat;
while ( ( pid = waitpid( -1, &stat, WNOHANG ) ) > 0 )
{
for( int i = 0; i < PROCESS_COUNT; ++i )
{
if( sub_process[i].pid == pid )
{
close( sub_process[i].pipefd[0] );
sub_process[i].pid = -1;
}
}
}
stop_server = true;
for( int i = 0; i < PROCESS_COUNT; ++i )
{
if( sub_process[i].pid != -1 )
{
stop_server = false;
}
}
break;
}
case SIGTERM:
case SIGINT:
{
printf( "kill all the clild now\n" );
for( int i = 0; i < PROCESS_COUNT; ++i )
{
int pid = sub_process[i].pid;
kill( pid, SIGTERM );
}
break;
}
default:
{
break;
}
}
}
}
}
else
{
continue;
}
}
}
del_resource();
return 0;
}