我会多次调用这个函数read_check(dev, buf, 1或者4), 这个函数跑了大概20次左右就会出现怪事:
res1= -1, 4, 4
res2= -1, 4, 4, 716768201
Failed to read: Interrupted system call
read调用的count值居然被修改了!
"Failed to read:"是我在这个函数失败退出时打印的,请大家帮忙分析一下呀,搞了好几天没搞定.
这样一个函数,linux里的原代码,打印是出现问题后我打印的:
static int read_check(int fd, void *buf, int count)
{
int res;
int cnt=0;
do {
res = read(fd, buf, count);
printf("res1= %d, %d, %d \n", res, errno, EINTR);
if (res != -1) {
buf += res;
count -= res;
}
printf("res2= %d, %d, %d, %d \n", res, errno, EINTR, count);
} while (count && (errno == 0 || errno == EINTR));
if (count)
return -1;
return 0;
} |