In my main thread I create two additional threads that I want to use a value from. Basically what I want to do is this:
Threads thread1 = new Threads();
Threads thread2 = new Threads();
Thread.currentThread.wait();
If (thread1 = complete){
var = thread1.getter
//delete thread2
}
If (thread2 == complete){
var = thread2.getter
//delete thread1
}
With thread1 and thread2 having a notify() at the end that wakes up the main thread and the thread that doesn't finish is deleted. But I realise that I don't properly understand wait() and multithreading so the way this is setup may not be correct. I know that Thread.currentThread.wait() is definitely not correct.
I think I may have to synchronize the methods but I have not been able to find any examples that show how to do this in this situation.
Edit: To give more info Thread1 takes input from a scanner and Thread2 takes input from a keylistener and I want to use the first input from 1 of them
I think you are saying that your threads are racing to solve a problem, and you are only interested in whichever solution is produced first. Am I right? If so, then what you need is some shared variables that allow all the threads to know if a solution has been found:
boolean solution_is_found = false;
SolutionType solution;
final Object solution_mutex = new Object();
A worker thread can do this:
while (true) {
synchronized(solution_mutex) {
if (solution_is_found) {
// Some other thread won the race, our solution is not needed.
return;
}
}
...do some increment of work...
if (...this thread found a solution...) {
synchronized(solution_mutex) {
if (! solution_was_found) {
// Only update the variables if this thread won the race.
solution_is_found = true;
solution = ...what this thread found...
solution_mutex.notifyAll();
}
}
return;
}
}
And now, the main thread can await the appearance of the first solution.
synchronized(solution_lock) {
while (! solution_was_found) {
solution_lock.wait();
}
}
...use `solution` here...
If the smallest possible "increment of work" takes a significant chunk of time, then you may want to test solution_is_found
several times within the "increment," and abort if it is true
.