关于linux 中的时间

读取时间戳(微秒单位)

long get_timestamp(void)

{

struct timeval now;

long now_usec;

gettimeofday(&now, NULL);

now_usec = now.tv_sec * 1000000;

now_usec += now.tv_usec;

//printf("now.tv_sec=%ld now.tv_usec=%ld\n",now.tv_sec,now.tv_usec);

return now_usec;

}

判断是否超时（微秒单位）

bool is_timestamp_after(long last_usec, long timeout)

{

struct timeval now;

long now_usec, elapsed;

gettimeofday(&now, NULL);

now_usec = now.tv_sec * 1000000;

now_usec += now.tv_usec;

if ((last_usec/1000000) > (now_usec/1000000))

{

//printf("@@@ system time refreshed[%ld %ld] @@@\n",last_usec,now_usec);

return TRUE;

}

else

{

elapsed = now_usec - last_usec;

if (elapsed > timeout) return TRUE;

else return FALSE;

}

}