my_lock.cpp

来自「液晶电视完整代码可实现人机界面」· C++ 代码 · 共 64 行

#include "my_lock.h"

static int lock_fd = -1;
int errno;
#define LOCK_FILE "LOCKFILE.LOC"
//static char *tmp_file;

int operFilelock(int fd, int cmd, int type, off_t offset, int whence, off_t len)
{
	struct flock	lock;
	lock.l_type	= type;
	lock.l_start	= offset;
	lock.l_whence	= whence;
	lock.l_len	= len;
	return ( fcntl(fd, cmd, &lock) );
}

//int my_lock_init(char* lock_file)
//{
//	tmp_file = new char[20];
//	sprintf( tmp_file, lock_file);
//		
//	return 0;
//}

int my_lock_wait(char *runlock)
{
	long	rc	= 0;
	char    lockfile[50];

	memset( lockfile, 0x0, sizeof(lockfile));
	if( strlen(runlock)==0 )
		exit(-1);
	sprintf( lockfile,"%s/bin/%s", getenv("HOME"),runlock);
	
	lock_fd = open( lockfile, O_RDWR|O_CREAT, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP);
	rc = filelockW(lock_fd, 0, SEEK_SET, 0);
	if (rc < 0) 
	{
		if (lock_fd > 0)
		{ 
			close(lock_fd);
		}
		if ((EACCES == errno) || (EAGAIN == errno)) 
		{
			return ( 0 );
		} 
		else 
		{
			return ( -1 );
		}
	}
	return lock_fd;
}

int my_lock_release()
{
	
	filelockU(lock_fd, 0, SEEK_SET, 0);
	close(lock_fd);
	
	return 0;
}