Linux_Study/pthread_create_server_safe.c at master · ixuanwu/Linux_Study · GitHub

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/*************************************************************************
	> File Name: pthread_create.c
	> Author: jianghechao
	> Mail: [email protected]
	> Created Time: Sun 01 Jun 2014 11:08:41 PM CST
 ************************************************************************/
#include<stdio.h>
#include<sys/socket.h>
#include<sys/param.h>
#include<arpa/inet.h>
#include<netinet/in.h>
#include<stdlib.h>
#include<string.h>
#include<sys/types.h>
#include<pthread.h>
#include<netdb.h>
#define MAXDATASIZE 8192
#define MAXLINE 255
void * function(void *);
void process_cli(int connfd ,struct sockaddr_in caddr);
void savedata(char *recvbuf,int len,char *cli_data);
void savedata_r(char *recvbuf,int len,char *cli_data);
struct ARG{
	int connfd;
	struct sockaddr_in caddr;//other data
};
pthread_key_t key;
pthread_once_t once = PTHREAD_ONCE_INIT;
static void destructor(void * ptr)
{
	free(ptr);
}
static void creatkey_once(void)
{
	pthread_key_create(&key,destructor);
}
struct ST_DATA{
	int index;
};
int main()
{
	int retval = 0;
	struct ARG *arg;
	int connfd,sockfd;
	struct hostent *hostp;
	char hostname[MAXLINE];
	pthread_t tid;
	int len;
	struct sockaddr_in saddr,caddr;
	memset(&saddr,0,sizeof(saddr));
	saddr.sin_family = AF_INET;
	saddr.sin_port = htons(9999);
	saddr.sin_addr.s_addr = inet_addr("192.168.56.101");
	sockfd = socket(AF_INET,SOCK_STREAM,0);
	bind(sockfd,(struct sockaddr*)&saddr,sizeof(saddr));
	listen(sockfd,5);
	while(1){
		printf("等待客户机连接...\n");
		connfd = accept(sockfd,(struct sockaddr* )&caddr,&len);
		arg = (struct ARG *)malloc(sizeof(arg));
		arg->connfd = connfd;
		memcpy((void *)&arg->caddr,&caddr,sizeof(caddr));
		pthread_create(&tid,NULL,function,(void *)arg);
	}
	close(sockfd);
}
/*
 * 客户请求进行相应的处理
 * 并给予相应的响应
 */
void process_cli(int connfd ,struct sockaddr_in caddr)
{
	int num;
	char cli_data[MAXDATASIZE];
	char recvbuf[MAXDATASIZE],sendbuf[MAXDATASIZE],
		 cli_name[MAXDATASIZE];
	printf("You got a connection from %s.\n",inet_ntoa(caddr.sin_addr));
	num = recv(connfd,cli_name,MAXDATASIZE,0);
	if(num==0)
	{
		close(connfd);
		printf("Client disconnected\n");
		return ;
	}
	cli_name[num-1] = '\0';
	printf("Client's name is %s\n",cli_name);
	while(num=recv(connfd,recvbuf,MAXDATASIZE,0))
	{
		recvbuf[num] = '\0';
		printf("Recvived client (%s) message:%s",cli_name,recvbuf);
		//save user's data
		//savedata(recvbuf,num,cli_data);
		savedata_r(recvbuf,num,cli_data);
		int i;
		for(i = 0;i<num;i++)
		{
			if((recvbuf[i]>='a'&&recvbuf[i]<='z')||(recvbuf[i]>='A'&&recvbuf[i]<='Z'))
			{
				recvbuf[i] = recvbuf[i]+3;
				if((recvbuf[i]>'Z'&&recvbuf[i]<'Z'+3)||(recvbuf[i]>'z'))
				{
					recvbuf[i] = recvbuf[i] - 26;
				}
			}
			sendbuf[i] = recvbuf[i];
		}
		sendbuf[num] = '\0';
		send(connfd,sendbuf,strlen(sendbuf),0);
	}
	printf("有客户退出%s:%d\n",inet_ntoa(caddr.sin_addr),ntohs(caddr.sin_port));
	printf("Client (%s) closed connection.\nUser's data:%s\n",cli_name,cli_data);
	close(connfd);
}


void * function (void * arg)
{
	struct ARG *info ;
	info = (struct ARG*)arg;
	process_cli(info->connfd,info->caddr);
	free(arg);
	pthread_exit(NULL);
}
/*
 * 以下是非线程安全举例
 * 不安全因素为存在静态变量 index
 */
void savedata(char *recvbuf,int len,char * cli_data)
{
	static int index = 0;
	int i = 0;
	while(i<len-1)
	{
		cli_data[index++] = recvbuf[i];
		i++;
	}
	cli_data[index] = 0;
}
/*
 * 以下是线程安全举例
 * 采用TSD(线程特殊数据)实现
 * 通常涉及4个系统调用
 * pthread_key_create
 * pthread_once
 * pthread_setspecific
 * pthread_getspecific
 */


void savedata_r(char * recvbuf,int len,char * cli_data)
{
	struct ST_DATA *data;
	pthread_once(&once,creatkey_once);
	if((data=(struct ST_DATA *)pthread_getspecific(key))==NULL)
	{
		data = (struct ST_DATA *)malloc(sizeof(struct ST_DATA));
		pthread_setspecific(key,data);
		data->index = 0;
	}
	int i = 0;
	while(i<len-1)
	{
		cli_data[data->index++] = recvbuf[i];
		i++;
	}
	cli_data[data->index] = 0;
}