MI有一个以for循环开始的程序,它旋转10次,一个循环持续1秒。我需要处理一个信号(CTRL + C)并在处理它时,它应该自己进行循环,并且在它停止之后,我应该返回主循环。我已经成功完成了上面的所有操作,但循环不会单独执行。他们并行做。希望你能帮忙......谢谢:)。
BTW,我的代码是:
import sun.misc.Signal;
import sun.misc.SignalHandler;
public class MySig {
public static void shhh(int s){ //s -> seconds :)
s = s*1000;
try{
Thread.sleep(s);
}catch(InterruptedException e){
System.out.println("Uh-oh :(");
}
}
public static void main(String[] args){
Signal.handle(new Signal("INT"), new SignalHandler () {
public void handle(Signal sig) {
for(int i=0; i<5; i++){
System.out.println("+");
shhh(1);
}
}
});
for(int i=0; i<10; i++) {
shhh(1);
System.out.println(i+"/10");
}
}
}
答案 0 :(得分:1)
是的,根据文档,SignalHandler在一个单独的线程中执行:
...当VM收到信号时,特殊的C信号处理程序会创建一个 新线程(优先级为Thread.MAX_PRIORITY)运行已注册的 Java信号处理程序..
如果要在执行处理程序时停止主循环,可以添加锁定机制,如下所示:
private static final ReentrantLock lock = new ReentrantLock(true);
private static AtomicInteger signalCount = new AtomicInteger(0);
public static void shhh(int s) { // s -> seconds :)
s = s * 1000;
try {
System.out.println(Thread.currentThread().getName() + " sleeping for "
+ s + "s...");
Thread.sleep(s);
} catch (InterruptedException e) {
System.out.println("Uh-oh :(");
}
}
public static void main(String[] args) throws Exception {
Signal.handle(new Signal("INT"), new SignalHandler() {
public void handle(Signal sig) {
// increment the signal counter
signalCount.incrementAndGet();
// Acquire lock and do all work
lock.lock();
try {
for (int i = 0; i < 5; i++) {
System.out.println("+");
shhh(1);
}
} finally {
// decrement signal counter and unlock
signalCount.decrementAndGet();
lock.unlock();
}
}
});
int i = 0;
while (i < 10) {
try {
lock.lock();
// go back to wait mode if signals have arrived
if (signalCount.get() > 0)
continue;
System.out.println(i + "/10");
shhh(1);
i++;
} finally {
// release lock after each unit of work to allow handler to jump in
lock.unlock();
}
}
}
可能有更好的锁定策略。