#ifndef PROCESSPOOL_H
#define PROCESSPOOL_H
#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/stat.h>
class process
{
public:
process() : m_pid(-1) {}
public:
pid_t m_pid;
int m_pipefd[2]; // 父进程和子进程通信用管道
};
template <typename T> // 模板参数是处理逻辑任务的类
class processpool
{
private:
// 定义为私有,只能通过create静态函数来创建processpool实例
processpool(int listenfd, int process_number = 8);
public:
// 单例模式,是程序正确处理信号的必要条件
static processpool<T> *create(int listenfd, int process_number = 8)
{
if (!m_instance)
{
m_instance = new processpool<T>(listenfd, process_number);
}
return m_instance;
}
~processpool()
{
delete[] m_sub_process;
}
void run();
private:
void setup_sig_pipe();
void run_parent();
void run_child();
private:
static const int MAX_PROCESS_NUMBER = 16; // 最大子进程数量
static const int USER_PER_PROCESS = 65536; // 每个子进程处理最大客户数量
static const int MAX_EVENT_NUMBER = 10000; // epoll最多能处理的事件数
int m_process_number; // 进程总数
int m_idx; // 子进程在池中序号
int m_epollfd; // 每个进程有个epoll内核事件表
int m_listenfd; // 监听socket
int m_stop; // 子进程通过m_stop判断是否停止运行
process *m_sub_process; // 保存所有子进程描述信息
static processpool<T> *m_instance; // 进程池静态实例
};
template <typename T>
processpool<T> *processpool<T>::m_instance = NULL;
static int sig_pipefd[2]; // 信号管道 统一事件源
static int setnonblocking(int fd)
{
int old_option = fcntl(fd, F_GETFL);
int new_option = old_option | O_NONBLOCK;
fcntl(fd, F_SETFL, new_option);
return old_option;
}
static void addfd(int epollfd, int fd)
{
epoll_event event;
event.data.fd = fd;
event.events = EPOLLIN | EPOLLET;
epoll_ctl(epollfd, EPOLL_CTL_ADD, fd, &event);
setnonblocking(fd);
}
static void removefd(int epollfd, int fd) // 从epollfd表示的内核事件表中删除fd的 所有事件
{
epoll_ctl(epollfd, EPOLL_CTL_DEL, fd, 0);
close(fd);
}
static void sig_handler(int sig)
{
int save_errno = errno;
int msg = sig;
send(sig_pipefd[1], (char *)&msg, 1, 0);
errno = save_errno;
}
static void addsig(int sig, void(handler)(int), bool restart = true)
{
struct sigaction sa;
memset(&sa, '\0', sizeof(sa));
sa.sa_handler = handler;
if (restart)
{
sa.sa_flags |= SA_RESTART;
}
sigfillset(&sa.sa_mask);
assert(sigaction(sig, &sa, NULL) != -1);
}
template <typename T>
processpool<T>::processpool(int listenfd, int process_number) // 进程池构造函数,参数listenfd是监听的socket,必须在创建进程池之前被创建
: m_listenfd(listenfd), m_process_number(process_number), m_idx(-1), m_stop(false)
{
assert((process_number > 0) && (process_number <= MAX_PROCESS_NUMBER));
m_sub_process = new process[process_number];
assert(m_sub_process);
for (int i = 0; i < process_number; ++i)
{
int ret = socketpair(PF_UNIX, SOCK_STREAM, 0, m_sub_process[i].m_pipefd);
assert(ret == 0);
m_sub_process[i].m_pid = fork();
assert(m_sub_process[i].m_pid >= 0);
if (m_sub_process[i].m_pid > 0) // 父进程
{
close(m_sub_process[i].m_pipefd[1]); // 只向子进程写
continue;
}
else // 子进程
{
close(m_sub_process[i].m_pipefd[0]); // 只从父进程读
m_idx = i;
break;
}
}
}
template <typename T>
void processpool<T>::setup_sig_pipe() // 统一事件源
{
m_epollfd = epoll_create(5); // 创建epoll事件监听表和信号管道
assert(m_epollfd != -1);
int ret = socketpair(PF_UNIX, SOCK_STREAM, 0, sig_pipefd);
assert(ret != -1);
setnonblocking(sig_pipefd[1]);
addfd(m_epollfd, sig_pipefd[0]);
addsig(SIGCHLD, sig_handler); // 设置信号处理函数
addsig(SIGTERM, sig_handler);
addsig(SIGINT, sig_handler);
addsig(SIGPIPE, SIG_IGN);
}
template <typename T>
void processpool<T>::run() // 父进程中m_idx值为 -1, 子进程中m_idx值 >= 0,判断接下来运行的是父还是子进程的代码
{
if (m_idx != -1)
{
run_child();
return;
}
run_parent();
}
template <typename T>
void processpool<T>::run_child()
{
setup_sig_pipe();
int pipefd = m_sub_process[m_idx].m_pipefd[1]; // 每个子进程都通过其在进程池中的序号值m_idx找到与父进程通信的管道
addfd(m_epollfd, pipefd); // 子进程需要监听管道文件描述符pipefd 因为父进程将通过它通知子进程accept新连接
epoll_event events[MAX_EVENT_NUMBER];
T *users = new T[USER_PER_PROCESS];
assert(users);
int number = 0; // epoll事件数量
int ret = -1;
while (!m_stop)
{
number = epoll_wait(m_epollfd, events, MAX_EVENT_NUMBER, -1);
if ((number < 0) && (errno != EINTR))
{
printf("epoll failure\n");
break;
}
for (int i = 0; i < number; i++) // 处理每个事件
{
int sockfd = events[i].data.fd;
if ((sockfd == pipefd) && (events[i].events & EPOLLIN)) // 父进程有数据给子进程
{
int client = 0;
ret = recv(sockfd, (char *)&client, sizeof(client), 0); // 从父子进程之间管道读取数据,结果保存client中读取成功有新客户
if (((ret < 0) && (errno != EAGAIN)) || ret == 0)
{
continue;
}
else
{
struct sockaddr_in client_address;
socklen_t client_addrlength = sizeof(client_address);
int connfd = accept(m_listenfd, (struct sockaddr *)&client_address, &client_addrlength);
if (connfd < 0)
{
printf("errno is: %d\n", errno);
continue;
}
addfd(m_epollfd, connfd); // 模板类T必须实现init方法,初始化一个客户连接。我们用connfd来索引处理的逻辑对象 提高效率
users[connfd].init(m_epollfd, connfd, client_address); // 实现在cgi_server.cpp中
}
}
else if ((sockfd == sig_pipefd[0]) && (events[i].events & EPOLLIN)) // 有信号,处理信号
{
int sig;
char signals[1024];
ret = recv(sig_pipefd[0], signals, sizeof(signals), 0);
if (ret <= 0)
{
continue;
}
else
{
for (int i = 0; i < ret; ++i)
{
switch (signals[i])
{
case SIGCHLD: // 回收子进程资源
{
pid_t pid;
int stat;
while ((pid = waitpid(-1, &stat, WNOHANG)) > 0)
{
continue;
}
break;
}
case SIGTERM:
case SIGINT:
{
m_stop = true;
break;
}
default:
{
break;
}
}
}
}
}
else if (events[i].events & EPOLLIN) // 其他数据可读 必然是客户请求到来 调用逻辑处理对象的process方法处理
{
users[sockfd].process(); // 还没实现
}
else
{
continue;
}
}
}
delete[] users;
users = NULL;
close(pipefd);
//close( m_listenfd ); // 应该由m_listenfd的创建者来关闭,所谓的对象由哪个函数创建,就该由那个函数销毁
close(m_epollfd);
}
template <typename T>
void processpool<T>::run_parent()
{
setup_sig_pipe();
addfd(m_epollfd, m_listenfd);
epoll_event events[MAX_EVENT_NUMBER];
int sub_process_counter = 0;
int new_conn = 1;
int number = 0;
int ret = -1;
while (!m_stop)
{
number = epoll_wait(m_epollfd, events, MAX_EVENT_NUMBER, -1);
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 == m_listenfd)
{
int i = sub_process_counter; // 有新连接到来,就采用round robin方式将其分给一个子进程
do
{
if (m_sub_process[i].m_pid != -1) // 选出空闲进程的进程数组索引
{
break;
}
i = (i + 1) % m_process_number;
} while (i != sub_process_counter);
if (m_sub_process[i].m_pid == -1)
{
m_stop = true;
break;
}
sub_process_counter = (i + 1) % m_process_number;
//send( m_sub_process[sub_process_counter++].m_pipefd[0], ( char* )&new_conn, sizeof( new_conn ), 0 );
send(m_sub_process[i].m_pipefd[0], (char *)&new_conn, sizeof(new_conn), 0);
printf("send request to child %d\n", i);
//sub_process_counter %= m_process_number;
}
else if ((sockfd == sig_pipefd[0]) && (events[i].events & EPOLLIN)) // 处理父进程收到的信号
{
int sig;
char signals[1024];
ret = recv(sig_pipefd[0], signals, sizeof(signals), 0);
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 < m_process_number; ++i)
{
if (m_sub_process[i].m_pid == pid) // 如果进程池中第i个子进程退出了,则主进程关闭对应通信管道,并设置m_pid为-1,标记子进程已经退出
{
printf("child %d join\n", i);
close(m_sub_process[i].m_pipefd[0]);
m_sub_process[i].m_pid = -1;
}
}
}
m_stop = true;
for (int i = 0; i < m_process_number; ++i)
{
if (m_sub_process[i].m_pid != -1)
{
m_stop = false;
}
}
break;
}
case SIGTERM:
case SIGINT:
{
printf("kill all the clild now\n"); // 杀了所有子进程
for (int i = 0; i < m_process_number; ++i)
{
int pid = m_sub_process[i].m_pid;
if (pid != -1)
{
kill(pid, SIGTERM);
}
}
break;
}
default:
{
break;
}
}
}
}
}
else
{
continue;
}
}
}
//close( m_listenfd ); // 由创建者关闭 见后文
close(m_epollfd);
}
#endif
此头文件需要传入cgi模板类以进行实例化线程池。模板代码见下一节。
reference:
linux高性能服务器编程——游双