/** * @throws UnsupportedOperationException {@inheritDoc} * @throws ClassCastException {@inheritDoc} * @throws NullPointerException {@inheritDoc} * @throws IllegalArgumentException {@inheritDoc} */ public int drainTo(Collection<? super E> c, int maxElements) { if (c == null) throw new NullPointerException(); if (c == this) throw new IllegalArgumentException(); if (maxElements <= 0) return 0; final E[] items = this.items; final ReentrantLock lock = this.lock; lock.lock(); try { int i = takeIndex; int n = 0; int sz = count; int max = (maxElements < count) ? maxElements : count; while (n < max) { c.add(items[i]); items[i] = null; i = inc(i); ++n; } if (n > 0) { count -= n; takeIndex = i; notFull.signalAll(); } return n; } finally { lock.unlock(); } }
/** * Retrieves and removes the head of this queue, waiting if necessary until an element with an * expired delay is available on this queue, or the specified wait time expires. * * @return the head of this queue, or <tt>null</tt> if the specified waiting time elapses before * an element with an expired delay becomes available * @throws InterruptedException {@inheritDoc} */ public E poll(long timeout, TimeUnit unit) throws InterruptedException { long nanos = unit.toNanos(timeout); final ReentrantLock lock = this.lock; lock.lockInterruptibly(); try { for (; ; ) { E first = q.peek(); if (first == null) { if (nanos <= 0) return null; else nanos = available.awaitNanos(nanos); } else { long delay = first.getDelay(TimeUnit.NANOSECONDS); if (delay <= 0) return q.poll(); if (nanos <= 0) return null; if (nanos < delay || leader != null) nanos = available.awaitNanos(nanos); else { Thread thisThread = Thread.currentThread(); leader = thisThread; try { long timeLeft = available.awaitNanos(delay); nanos -= delay - timeLeft; } finally { if (leader == thisThread) leader = null; } } } } } finally { if (leader == null && q.peek() != null) available.signal(); lock.unlock(); } }
/** * Retrieves and removes the head of this queue, waiting if necessary until an element with an * expired delay is available on this queue, or the specified wait time expires. * * @return the head of this queue, or <tt>null</tt> if the specified waiting time elapses before * an element with an expired delay becomes available * @throws InterruptedException {@inheritDoc} */ public E poll(long timeout, TimeUnit unit) throws InterruptedException { long nanos = unit.toNanos(timeout); final ReentrantLock lock = this.lock; lock.lockInterruptibly(); try { for (; ; ) { E first = q.peek(); if (first == null) { if (nanos <= 0) return null; else nanos = available.awaitNanos(nanos); } else { long delay = first.getDelay(TimeUnit.NANOSECONDS); if (delay > 0) { if (nanos <= 0) return null; if (delay > nanos) delay = nanos; long timeLeft = available.awaitNanos(delay); nanos -= delay - timeLeft; } else { E x = q.poll(); assert x != null; if (q.size() != 0) available.signalAll(); return x; } } } } finally { lock.unlock(); } }
/** * Retrieves and removes the head of this queue, waiting if necessary until an element with an * expired delay is available on this queue. * * @return the head of this queue * @throws InterruptedException {@inheritDoc} */ public E take() throws InterruptedException { final ReentrantLock lock = this.lock; lock.lockInterruptibly(); try { for (; ; ) { E first = q.peek(); if (first == null) available.await(); else { long delay = first.getDelay(TimeUnit.NANOSECONDS); if (delay <= 0) return q.poll(); else if (leader != null) available.await(); else { Thread thisThread = Thread.currentThread(); leader = thisThread; try { available.awaitNanos(delay); } finally { if (leader == thisThread) leader = null; } } } } } finally { if (leader == null && q.peek() != null) available.signal(); lock.unlock(); } }
public E peek() { final ReentrantLock lock = this.lock; lock.lock(); try { return (count == 0) ? null : items[takeIndex]; } finally { lock.unlock(); } }
/** * Returns an array containing all of the elements in this queue. The returned array elements are * in no particular order. * * <p>The returned array will be "safe" in that no references to it are maintained by this queue. * (In other words, this method must allocate a new array). The caller is thus free to modify the * returned array. * * <p>This method acts as bridge between array-based and collection-based APIs. * * @return an array containing all of the elements in this queue */ public Object[] toArray() { final ReentrantLock lock = this.lock; lock.lock(); try { return q.toArray(); } finally { lock.unlock(); } }
/** * Returns an array containing all of the elements in this queue; the runtime type of the returned * array is that of the specified array. The returned array elements are in no particular order. * If the queue fits in the specified array, it is returned therein. Otherwise, a new array is * allocated with the runtime type of the specified array and the size of this queue. * * <p>If this queue fits in the specified array with room to spare (i.e., the array has more * elements than this queue), the element in the array immediately following the end of the queue * is set to <tt>null</tt>. * * <p>Like the {@link #toArray()} method, this method acts as bridge between array-based and * collection-based APIs. Further, this method allows precise control over the runtime type of the * output array, and may, under certain circumstances, be used to save allocation costs. * * <p>The following code can be used to dump a delay queue into a newly allocated array of * <tt>Delayed</tt>: * * <pre> * Delayed[] a = q.toArray(new Delayed[0]);</pre> * * Note that <tt>toArray(new Object[0])</tt> is identical in function to <tt>toArray()</tt>. * * @param a the array into which the elements of the queue are to be stored, if it is big enough; * otherwise, a new array of the same runtime type is allocated for this purpose * @return an array containing all of the elements in this queue * @throws ArrayStoreException if the runtime type of the specified array is not a supertype of * the runtime type of every element in this queue * @throws NullPointerException if the specified array is null */ public <T> T[] toArray(T[] a) { final ReentrantLock lock = this.lock; lock.lock(); try { return q.toArray(a); } finally { lock.unlock(); } }
/** * Removes a single instance of the specified element from this queue, if it is present, whether * or not it has expired. */ public boolean remove(Object o) { final ReentrantLock lock = this.lock; lock.lock(); try { return q.remove(o); } finally { lock.unlock(); } }
/** * Returns the number of additional elements that this queue can ideally (in the absence of memory * or resource constraints) accept without blocking. This is always equal to the initial capacity * of this queue less the current <tt>size</tt> of this queue. * * <p>Note that you <em>cannot</em> always tell if an attempt to insert an element will succeed by * inspecting <tt>remainingCapacity</tt> 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 items.length - count; } finally { lock.unlock(); } }
/** * Atomically removes all of the elements from this delay queue. The queue will be empty after * this call returns. Elements with an unexpired delay are not waited for; they are simply * discarded from the queue. */ public void clear() { final ReentrantLock lock = this.lock; lock.lock(); try { q.clear(); } finally { lock.unlock(); } }
/** * Returns an iterator over the elements in this queue in proper sequence. The returned * <tt>Iterator</tt> is a "weakly consistent" iterator that will never throw {@link * ConcurrentModificationException}, and guarantees to traverse elements as they existed upon * construction of the iterator, and may (but is not guaranteed to) reflect any modifications * subsequent to construction. * * @return an iterator over the elements in this queue in proper sequence */ public Iterator<E> iterator() { final ReentrantLock lock = this.lock; lock.lock(); try { return new Itr(); } finally { lock.unlock(); } }
/** * Retrieves, but does not remove, the head of this queue, or returns <tt>null</tt> if this queue * is empty. Unlike <tt>poll</tt>, if no expired elements are available in the queue, this method * returns the element that will expire next, if one exists. * * @return the head of this queue, or <tt>null</tt> if this queue is empty. */ public E peek() { final ReentrantLock lock = this.lock; lock.lock(); try { return q.peek(); } finally { lock.unlock(); } }
public String toString() { final ReentrantLock lock = this.lock; lock.lock(); try { return super.toString(); } finally { lock.unlock(); } }
public int size() { final ReentrantLock lock = this.lock; lock.lock(); try { return q.size(); } finally { lock.unlock(); } }
/** * Retrieves and removes the head of this queue, or returns <tt>null</tt> if this queue has no * elements with an expired delay. * * @return the head of this queue, or <tt>null</tt> if this queue has no elements with an expired * delay */ public E poll() { final ReentrantLock lock = this.lock; lock.lock(); try { E first = q.peek(); if (first == null || first.getDelay(TimeUnit.NANOSECONDS) > 0) return null; else return q.poll(); } finally { lock.unlock(); } }
public E poll() { final ReentrantLock lock = this.lock; lock.lock(); try { if (count == 0) return null; E x = extract(); return x; } finally { lock.unlock(); } }
/** * Inserts the specified element into this delay queue. * * @param e the element to add * @return <tt>true</tt> * @throws NullPointerException if the specified element is null */ public boolean offer(E e) { final ReentrantLock lock = this.lock; lock.lock(); try { E first = q.peek(); q.offer(e); if (first == null || e.compareTo(first) < 0) available.signalAll(); return true; } finally { lock.unlock(); } }
public E next() { final ReentrantLock lock = ArrayBlockingQueue.this.lock; lock.lock(); try { if (nextIndex < 0) throw new NoSuchElementException(); lastRet = nextIndex; E x = nextItem; nextIndex = inc(nextIndex); checkNext(); return x; } finally { lock.unlock(); } }
/** * Inserts the specified element into this delay queue. * * @param e the element to add * @return <tt>true</tt> * @throws NullPointerException if the specified element is null */ public boolean offer(E e) { final ReentrantLock lock = this.lock; lock.lock(); try { q.offer(e); if (q.peek() == e) { leader = null; available.signal(); } return true; } finally { lock.unlock(); } }
/** * Inserts the specified element at the tail of this queue if it is possible to do so immediately * without exceeding the queue's capacity, returning <tt>true</tt> upon success and <tt>false</tt> * if this queue is full. This method is generally preferable to method {@link #add}, which can * fail to insert an element only by throwing an exception. * * @throws NullPointerException if the specified element is null */ public boolean offer(E e) { if (e == null) throw new NullPointerException(); final ReentrantLock lock = this.lock; lock.lock(); try { if (count == items.length) return false; else { insert(e); return true; } } finally { lock.unlock(); } }
@Override public void setChainHead(StoredBlock chainHead) throws BlockStoreException { final MappedByteBuffer buffer = this.buffer; if (buffer == null) throw new BlockStoreException("Store closed"); lock.lock(); try { lastChainHead = chainHead; byte[] headHash = chainHead.getHeader().getHash().getBytes(); buffer.position(8); buffer.put(headHash); } finally { lock.unlock(); } }
public final Object call() throws Exception { barrier.await(); int sum = v; int x = 0; int n = ITERS; while (n-- > 0) { lock.lockInterruptibly(); try { v = x = LoopHelpers.compute1(v); } finally { lock.unlock(); } sum += LoopHelpers.compute2(LoopHelpers.compute2(x)); } return new Integer(sum); }
/** * Retrieves and removes the head of this queue, or returns <tt>null</tt> if this queue has no * elements with an expired delay. * * @return the head of this queue, or <tt>null</tt> if this queue has no elements with an expired * delay */ public E poll() { final ReentrantLock lock = this.lock; lock.lock(); try { E first = q.peek(); if (first == null || first.getDelay(TimeUnit.NANOSECONDS) > 0) return null; else { E x = q.poll(); assert x != null; if (q.size() != 0) available.signalAll(); return x; } } finally { lock.unlock(); } }
private void initNewStore(NetworkParameters params) throws Exception { byte[] header; header = HEADER_MAGIC.getBytes("US-ASCII"); buffer.put(header); // Insert the genesis block. lock.lock(); try { setRingCursor(buffer, FILE_PROLOGUE_BYTES); } finally { lock.unlock(); } Block genesis = params.getGenesisBlock().cloneAsHeader(); StoredBlock storedGenesis = new StoredBlock(genesis, genesis.getWork(), 0); put(storedGenesis); setChainHead(storedGenesis); }
public E take() throws InterruptedException { final ReentrantLock lock = this.lock; lock.lockInterruptibly(); try { try { while (count == 0) notEmpty.await(); } catch (InterruptedException ie) { notEmpty.signal(); // propagate to non-interrupted thread throw ie; } E x = extract(); return x; } finally { lock.unlock(); } }
/** * Inserts the specified element at the tail of this queue, waiting for space to become available * if the queue is full. * * @throws InterruptedException {@inheritDoc} * @throws NullPointerException {@inheritDoc} */ public void put(E e) throws InterruptedException { if (e == null) throw new NullPointerException(); final E[] items = this.items; final ReentrantLock lock = this.lock; lock.lockInterruptibly(); try { try { while (count == items.length) notFull.await(); } catch (InterruptedException ie) { notFull.signal(); // propagate to non-interrupted thread throw ie; } insert(e); } finally { lock.unlock(); } }
/** * Returns <tt>true</tt> if this queue contains the specified element. More formally, returns * <tt>true</tt> if and only if this queue contains at least one element <tt>e</tt> such that * <tt>o.equals(e)</tt>. * * @param o object to be checked for containment in this queue * @return <tt>true</tt> if this queue contains the specified element */ public boolean contains(Object o) { if (o == null) return false; final E[] items = this.items; final ReentrantLock lock = this.lock; lock.lock(); try { int i = takeIndex; int k = 0; while (k++ < count) { if (o.equals(items[i])) return true; i = inc(i); } return false; } finally { lock.unlock(); } }
/** * Returns an array containing all of the elements in this queue, in proper sequence. * * <p>The returned array will be "safe" in that no references to it are maintained by this queue. * (In other words, this method must allocate a new array). The caller is thus free to modify the * returned array. * * <p>This method acts as bridge between array-based and collection-based APIs. * * @return an array containing all of the elements in this queue */ public Object[] toArray() { final E[] items = this.items; final ReentrantLock lock = this.lock; lock.lock(); try { Object[] a = new Object[count]; int k = 0; int i = takeIndex; while (k < count) { a[k++] = items[i]; i = inc(i); } return a; } finally { lock.unlock(); } }
public void remove() { final ReentrantLock lock = ArrayBlockingQueue.this.lock; lock.lock(); try { int i = lastRet; if (i == -1) throw new IllegalStateException(); lastRet = -1; int ti = takeIndex; removeAt(i); // back up cursor (reset to front if was first element) nextIndex = (i == ti) ? takeIndex : i; checkNext(); } finally { lock.unlock(); } }
@Override @Nullable public StoredBlock get(Sha256Hash hash) throws BlockStoreException { final MappedByteBuffer buffer = this.buffer; if (buffer == null) throw new BlockStoreException("Store closed"); lock.lock(); try { StoredBlock cacheHit = blockCache.get(hash); if (cacheHit != null) return cacheHit; if (notFoundCache.get(hash) != null) return null; // Starting from the current tip of the ring work backwards until we have either found the // block or // wrapped around. int cursor = getRingCursor(buffer); final int startingPoint = cursor; final int fileSize = getFileSize(); final byte[] targetHashBytes = hash.getBytes(); byte[] scratch = new byte[32]; do { cursor -= RECORD_SIZE; if (cursor < FILE_PROLOGUE_BYTES) { // We hit the start, so wrap around. cursor = fileSize - RECORD_SIZE; } // Cursor is now at the start of the next record to check, so read the hash and compare it. buffer.position(cursor); buffer.get(scratch); if (Arrays.equals(scratch, targetHashBytes)) { // Found the target. StoredBlock storedBlock = StoredBlock.deserializeCompact(params, buffer); blockCache.put(hash, storedBlock); return storedBlock; } } while (cursor != startingPoint); // Not found. notFoundCache.put(hash, notFoundMarker); return null; } catch (ProtocolException e) { throw new RuntimeException(e); // Cannot happen. } finally { lock.unlock(); } }