1 extern crate libc;
2 use libc::{signal, sleep, syscall, SYS_alarm, SIGALRM};
3
handle_alarm(_: i32)4 extern "C" fn handle_alarm(_: i32) {
5 println!("Alarm ring!");
6 }
7
main()8 fn main() {
9 // 设置信号处理函数
10 unsafe {
11 signal(SIGALRM, handle_alarm as usize);
12 }
13
14 //test1: alarm系统调用能否正常运行
15 unsafe {
16 syscall(SYS_alarm, 5);
17 }
18 println!("Alarm set for 5 seconds");
19 unsafe {
20 sleep(6);
21 }
22 println!("Test 1 complete");
23
24 //test2：在上一个alarm定时器未完成时重新调用alarm，查看返回值是否为上一个alarm的剩余秒数，
25 //并test第三个alarm定时器能否正常运行
26
27 unsafe {
28 let remaining = syscall(SYS_alarm, 5);
29 println!("Remaining time for previous alarm: {}", remaining);
30 }
31 println!("Alarm set for 5 seconds");
32 unsafe {
33 let remaining = syscall(SYS_alarm, 3);
34 println!("Remaining time for previous alarm: {}", remaining);
35 }
36 unsafe {
37 sleep(4);
38 }
39 println!("Alarm set for 3 seconds");
40
41 println!("Test 2 complete");
42 }
43