Mega Code Archive
Another way to suspend and resume
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public class AlternateSuspendResume extends Object implements Runnable {
private volatile int firstVal;
private volatile int secondVal;
private volatile boolean suspended;
public boolean areValuesEqual() {
return (firstVal == secondVal);
}
public void run() {
try {
suspended = false;
firstVal = 0;
secondVal = 0;
workMethod();
} catch (InterruptedException x) {
System.out.println("interrupted in workMethod()");
}
}
private void workMethod() throws InterruptedException {
int val = 1;
while (true) {
// blocks if suspended is true
waitWhileSuspended();
stepOne(val);
stepTwo(val);
val++;
// blocks if suspended is true
waitWhileSuspended();
Thread.sleep(200); // pause before looping again
}
}
private void stepOne(int newVal) throws InterruptedException {
firstVal = newVal;
// simulate some other lengthy process
Thread.sleep(300);
}
private void stepTwo(int newVal) {
secondVal = newVal;
}
public void suspendRequest() {
suspended = true;
}
public void resumeRequest() {
suspended = false;
}
private void waitWhileSuspended() throws InterruptedException {
while (suspended) {
Thread.sleep(200);
}
}
public static void main(String[] args) {
AlternateSuspendResume asr = new AlternateSuspendResume();
Thread t = new Thread(asr);
t.start();
try {
Thread.sleep(1000);
} catch (InterruptedException x) {
}
for (int i = 0; i < 10; i++) {
asr.suspendRequest();
try {
Thread.sleep(350);
} catch (InterruptedException x) {
}
System.out.println("dsr.areValuesEqual()=" + asr.areValuesEqual());
asr.resumeRequest();
try {
Thread.sleep((long) (Math.random() * 2000.0));
} catch (InterruptedException x) {
}
}
System.exit(0);
}
}
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