- 论坛徽章:
- 0
|
1.问题描述：
程序一开始开一个pthread,用以执行execvp(cmdtemp[0],&cmdtemp[0]);
程序接收client的连接，根据client 发过来的控制命令，关掉上一个线程用execvp开的一个进程spcaview，再重新开一个线程用以执行execvp(cmdtemp1[0],&cmdtemp1[0]);开另一个spcaview，最终完成线程中执行的内容的替换。最终目地其实为了实现在一个主程序A中，执行一个外部程序，给它传入参数，但是在这个外部程序执行过程中要能够控制它的开启与关闭。用fork感觉 不行，就用pthread做了如下更改，就出现了上面的问题。
期待问题解决中...
2.代码：
/* File: server.c */
#include <stdio.h>
#include <pthread.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
char* cmdtemp[6];
char* cmdtemp1[6];
int thread_flag = 0;//flag to exit pthread
//two pthread to start servfox process
void* thread_spcaview(void)
{
execvp(cmdtemp[0],&cmdtemp[0]);
printf("start spcaview-0 pthread ok \n");
if(thread_flag)
{
pthread_exit(NULL);
}
}
void* thread_spcaview1(void)
{
execvp(cmdtemp1[0],&cmdtemp1[0]);
printf("start spcaview-1 pthread ok \n");
if(thread_flag)
{
pthread_exit(NULL);
}
}
int main(int argc, char **argv)
{
int fd;
int address_len;
struct sockaddr_in address;
pthread_t thread_id;
int ret;
cmdtemp[0] = "spcaview";
cmdtemp[1] = "-l";
cmdtemp[2] = "-d";
cmdtemp[3] = "/dev/video0";
cmdtemp[4] = "&";
cmdtemp1[0] = "spcaview";
cmdtemp1[1] = "-l";
cmdtemp1[2] = "-d";
cmdtemp1[3] = "/dev/video0";
cmdtemp1[4] = "&";
//pid_t pid,pid2;
/*************************
if((pid = fork())<0)
{
perror("cannot create the new process");
return -1;
}
else if(pid ==0)
{
execvp(cmdtemp[0],&cmdtemp[0]);
}
if(pid2>0)
{
pid =pid2;
printf("child pid = %d\n",pid);
//execvp(cmdtemp[0],&cmdtemp[0]);
}
//pid = system("/home/lyt/servfox -g -d /dev/video0 -l -w 7070 &");
***************************/
fd = socket(AF_INET, SOCK_DGRAM, 0); //SOCK_DGRAM
bzero(&address, sizeof(address));
address.sin_family = AF_INET;
address.sin_addr.s_addr = htonl(INADDR_ANY);
address.sin_port = htons(5555);
address_len = sizeof(address);
bind(fd, (struct sockaddr *)&address, address_len);
ret = pthread_create(&thread_id,NULL,(void*)thread_spcaview,NULL);
if(ret==-1)
{
//peeror("cannot create new thread");
return -1;
}
while(1) {
struct sockaddr_in client_address;
socklen_t len = sizeof(client_address);
int n;
char line[80];
char cmd[20]="";
printf("waiting...\n");
n = recvfrom(fd, line, 80, 0, (struct sockaddr *)&client_address, &len);
//printf("server received %d:%s\n", n, line);
if(n)
{//kill the old process to switch the channel
if(strcmp(line,"0")==0)
{
//printf("pid = %d\n",pid);
//sprintf(cmd,"kill -9 %d",pid);
//system(cmd);
printf("exec::00000000000\n");
//pid = system("spcaview -w 10.10.19.129:7070 &");
//pid = system("/home/lyt/servfox -g -d /dev/video0 -l -w 7070 &");
/************************
if((pid2 = fork())<0)
{
perror("cannot create the new process");
return -1;
}
else if(pid2 ==0)
{
execvp(cmdtemp[0],&cmdtemp[0]);
printf("I am in child pid\n");
}
if(pid2>0)
{
pid =pid2;
system(cmd);
printf("child pid = %d\n",pid);
//execvp(cmdtemp[0],&cmdtemp[0]);
}
***************************/
thread_flag = 1;
sleep(2);
thread_flag = 0;
ret = pthread_create(&thread_id,NULL,(void*)thread_spcaview,NULL);
if(ret==-1)
{
//peeror("cannot create new thread");
return -1;
}
}
else if(strcmp(line,"1")==0)
{
//printf("pid = %d\n",pid);
//sprintf(cmd,"kill -9 %d",pid);
//system(cmd);
printf("exec::11111111111\n");
//pid = system("/home/lyt/servfox -g -d /dev/video1 -l -w 7070 &");
/*******************************
if((pid2 = fork())<0)
{
perror("cannot create the new process");
return -1;
}
else if(pid2 ==0)
{
execvp(cmdtemp[0],&cmdtemp[0]);
printf("I am in child pid\n");
}
if(pid2>0)
{
pid =pid2;
printf("child pid = %d\n",pid);
//execvp(cmdtemp[0],&cmdtemp[0]);
}
*****************************************/
thread_flag = 1;
sleep(2);
thread_flag = 0;
ret = pthread_create(&thread_id,NULL,(void*)thread_spcaview1,NULL);
if(ret==-1)
{
//peeror("cannot create new thread");
return -1;
}
}
else
{
printf("exec::no such dev\n");
}
}
//send data to client
//sendto(fd, line, n, 0, (struct sockaddr *)&client_address, len);
}
} |
|
免费注册
发表于 2009-01-02 18:09
