Examples with ReentrantLock java.util.concurrent.locks.ReentrantLock used on opensource projects

Example 21 with ReentrantLock

use of java.util.concurrent.locks.ReentrantLock in project druid by druid-io.

the class BlockingPool method take.

private T take() throws InterruptedException {
    final ReentrantLock lock = this.lock;
    lock.lockInterruptibly();
    try {
        while (objects.isEmpty()) {
            notEnough.await();
        }
        return objects.pop();
    } finally {
        lock.unlock();
    }
}

Example 22 with ReentrantLock

use of java.util.concurrent.locks.ReentrantLock in project hadoop by apache.

the class InstrumentationService method init.

@Override
@SuppressWarnings("unchecked")
public void init() throws ServiceException {
    timersSize = getServiceConfig().getInt(CONF_TIMERS_SIZE, 10);
    counterLock = new ReentrantLock();
    timerLock = new ReentrantLock();
    variableLock = new ReentrantLock();
    samplerLock = new ReentrantLock();
    Map<String, VariableHolder> jvmVariables = new ConcurrentHashMap<String, VariableHolder>();
    counters = new ConcurrentHashMap<String, Map<String, AtomicLong>>();
    timers = new ConcurrentHashMap<String, Map<String, Timer>>();
    variables = new ConcurrentHashMap<String, Map<String, VariableHolder>>();
    samplers = new ConcurrentHashMap<String, Map<String, Sampler>>();
    samplersList = new ArrayList<Sampler>();
    all = new LinkedHashMap<String, Map<String, ?>>();
    all.put("os-env", System.getenv());
    all.put("sys-props", (Map<String, ?>) (Map) System.getProperties());
    all.put("jvm", jvmVariables);
    all.put("counters", (Map) counters);
    all.put("timers", (Map) timers);
    all.put("variables", (Map) variables);
    all.put("samplers", (Map) samplers);
    jvmVariables.put("free.memory", new VariableHolder<Long>(new Instrumentation.Variable<Long>() {

        @Override
        public Long getValue() {
            return Runtime.getRuntime().freeMemory();
        }
    }));
    jvmVariables.put("max.memory", new VariableHolder<Long>(new Instrumentation.Variable<Long>() {

        @Override
        public Long getValue() {
            return Runtime.getRuntime().maxMemory();
        }
    }));
    jvmVariables.put("total.memory", new VariableHolder<Long>(new Instrumentation.Variable<Long>() {

        @Override
        public Long getValue() {
            return Runtime.getRuntime().totalMemory();
        }
    }));
}

Example 23 with ReentrantLock

use of java.util.concurrent.locks.ReentrantLock in project XobotOS by xamarin.

the class LinkedBlockingDeque method remainingCapacity.

/**
     * Returns the number of additional elements that this deque can ideally
     * (in the absence of memory or resource constraints) accept without
     * blocking. This is always equal to the initial capacity of this deque
     * less the current {@code size} of this deque.
     *
     * <p>Note that you <em>cannot</em> always tell if an attempt to insert
     * an element will succeed by inspecting {@code remainingCapacity}
     * because it may be the case that another thread is about to
     * insert or remove an element.
     */
public int remainingCapacity() {
    final ReentrantLock lock = this.lock;
    lock.lock();
    try {
        return capacity - count;
    } finally {
        lock.unlock();
    }
}

Example 24 with ReentrantLock

use of java.util.concurrent.locks.ReentrantLock in project XobotOS by xamarin.

the class LinkedBlockingDeque method offerFirst.

/**
     * @throws NullPointerException {@inheritDoc}
     * @throws InterruptedException {@inheritDoc}
     */
public boolean offerFirst(E e, long timeout, TimeUnit unit) throws InterruptedException {
    if (e == null)
        throw new NullPointerException();
    Node<E> node = new Node<E>(e);
    long nanos = unit.toNanos(timeout);
    final ReentrantLock lock = this.lock;
    lock.lockInterruptibly();
    try {
        while (!linkFirst(node)) {
            if (nanos <= 0)
                return false;
            nanos = notFull.awaitNanos(nanos);
        }
        return true;
    } finally {
        lock.unlock();
    }
}

Example 25 with ReentrantLock

use of java.util.concurrent.locks.ReentrantLock in project XobotOS by xamarin.

the class LinkedBlockingDeque method peekLast.

public E peekLast() {
    final ReentrantLock lock = this.lock;
    lock.lock();
    try {
        return (last == null) ? null : last.item;
    } finally {
        lock.unlock();
    }
}