AsyncWaitForConditionWithCountDownLatch

AsyncWaitForConditionWithCountDownLatch.java

/**
 * Generic method that properly awaits a given condition to become true within a given timeout.
 * This is superior to {@code sleep()} methods because it returns early when the condition is met.
 * 
 * @param boolSupplier the supplier for evaluating the condition, should return {@code true} if condition is met, {@code false} otherwise
 * @param timeout timeout number
 * @param timeUnit timeout unit
 * @return {@code true} if condition is met within given time, {@code false} otherwise
 */
private boolean waitForCondition(final BooleanSupplier boolSupplier, long timeout, final TimeUnit timeUnit) {
    final CountDownLatch conditionMetLatch = new CountDownLatch(1);
    final Runnable checkConditionMetRunner = () -> {
        do {
            if (boolSupplier.getAsBoolean()) {
                conditionMetLatch.countDown();
            }
        } while (conditionMetLatch.getCount() != 0 && !Thread.currentThread().isInterrupted());
    };
    final ExecutorService executor = Executors.newSingleThreadExecutor();
    try {
        executor.execute(checkConditionMetRunner);
        return conditionMetLatch.await(timeout, timeUnit);
    } catch (InterruptedException e) {
        Thread.currentThread().interrupt();
        return false;
    } finally {
        executor.shutdownNow();
    }
}