1.fear resulting from the awareness of danger
2.a device that signals the occurrence of some undesirable event
3.an automatic signal (usually a sound) warning of danger
4.a clock that wakes sleeper at preset time
1.fill with apprehension or alarm; cause to be unpleasantly surprised;
I was horrified at the thought of being late for my interview
2.warn or arouse to a sense of danger or call to a state of preparedness;
The empty house alarmed him
Linux C alarm函数 alarm也称为闹钟函数,它可以在进程中设置一个定时器,当定时器指定的时间到时,它向进程发送SIGALRM信号。要注意的是,一个进程只能有一个闹钟时间,如果在调用alarm之前已设置过闹钟时间,则任何以前的闹钟时间都被新值所代替。需要注意的是,经过指定的秒数后,信号由内核产生,由于进程调度的延迟,所以进程得到控制从而能够处理该信号还需要一些时间。 如果有以前为进程登记的尚未超时的闹钟时钟,而且本