0N/A/*
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0N/A
0N/A/*
0N/A * @test
40N/A * @bug 4992438 6633113
0N/A * @summary Checks that fairness setting is respected.
0N/A */
0N/A
0N/Aimport java.util.concurrent.*;
40N/Aimport java.util.concurrent.locks.*;
0N/A
0N/Apublic class Fairness {
0N/A private static void testFairness(boolean fair,
0N/A final BlockingQueue<Integer> q)
40N/A throws Throwable
0N/A {
40N/A final ReentrantLock lock = new ReentrantLock();
40N/A final Condition ready = lock.newCondition();
40N/A final int threadCount = 10;
40N/A final Throwable[] badness = new Throwable[1];
40N/A lock.lock();
40N/A for (int i = 0; i < threadCount; i++) {
40N/A final Integer I = i;
40N/A Thread t = new Thread() { public void run() {
40N/A try {
40N/A lock.lock();
40N/A ready.signal();
40N/A lock.unlock();
40N/A q.put(I);
40N/A } catch (Throwable t) { badness[0] = t; }}};
40N/A t.start();
40N/A ready.await();
40N/A // Probably unnecessary, but should be bullet-proof
40N/A while (t.getState() == Thread.State.RUNNABLE)
40N/A Thread.yield();
0N/A }
40N/A for (int i = 0; i < threadCount; i++) {
40N/A int j = q.take();
0N/A // Non-fair queues are lifo in our implementation
40N/A if (fair ? j != i : j != threadCount - 1 - i)
40N/A throw new Error(String.format("fair=%b i=%d j=%d%n",
40N/A fair, i, j));
0N/A }
40N/A if (badness[0] != null) throw new Error(badness[0]);
0N/A }
0N/A
40N/A public static void main(String[] args) throws Throwable {
0N/A testFairness(false, new SynchronousQueue<Integer>());
0N/A testFairness(false, new SynchronousQueue<Integer>(false));
0N/A testFairness(true, new SynchronousQueue<Integer>(true));
0N/A }
0N/A}