Java tutorial
/** * Copyright (C) 2012 - present by OpenGamma Inc. and the OpenGamma group of companies * * Please see distribution for license. */ package com.opengamma.engine.depgraph; import java.util.Arrays; import java.util.Comparator; import java.util.Iterator; import org.apache.commons.lang.ObjectUtils; import com.opengamma.engine.ComputationTargetSpecification; import com.opengamma.engine.target.ComputationTargetReference; import com.opengamma.engine.target.ComputationTargetRequirement; import com.opengamma.engine.target.ComputationTargetType; import com.opengamma.engine.target.ComputationTargetTypeMap; import com.opengamma.util.ArgumentChecker; /** * Run queue implementation based on sorting the runnable tasks. When the run queue is small, this is comparable to {@link ConcurrentLinkedQueueRunQueue} or {@link StackRunQueue} implementations as * the sorting operation is not performed. As the run queue length grows and exceeds the capacity of the target resolution cache, the cost of ordering the operations may be offset by better use of the * cache. Some function repositories and graph structures may still benefit from the simpler {@link StackRunQueue} implementation which can give good cache performance without any ordering costs. */ /* package */final class OrderedRunQueue implements RunQueue, Comparator<ContextRunnable> { // TODO: Note that this might not be correct with regard to the Java Memory Model. private static final ComputationTargetTypeMap<Integer> s_priority; private final int _maxUnsorted; private ContextRunnable[] _buffer; private int _length; private int _sorted; private boolean _sorting; private final Object _sortingLock = new Object(); static { s_priority = new ComputationTargetTypeMap<Integer>(); s_priority.put(ComputationTargetType.PORTFOLIO_NODE, 1); s_priority.put(ComputationTargetType.NULL, 2); s_priority.put(ComputationTargetType.ANYTHING, 3); s_priority.put(ComputationTargetType.SECURITY, 4); s_priority.put(ComputationTargetType.TRADE, 5); s_priority.put(ComputationTargetType.POSITION, 6); } public OrderedRunQueue(final int initialBuffer, final int maxUnsorted) { ArgumentChecker.isTrue(initialBuffer > 0, "initialBuffer"); ArgumentChecker.isTrue(maxUnsorted > 0, "maxUnsorted"); _maxUnsorted = maxUnsorted; _buffer = new ContextRunnable[(initialBuffer < 2) ? 2 : initialBuffer]; } @Override public synchronized boolean isEmpty() { return _length == 0; } @Override public synchronized int size() { return _length; } @Override public Iterator<ContextRunnable> iterator() { return new Iterator<ContextRunnable>() { private int _count; @Override public boolean hasNext() { return _count < size(); } @Override public ContextRunnable next() { return _buffer[_count++]; } @Override public void remove() { throw new UnsupportedOperationException(); } }; } @Override public void add(final ContextRunnable runnable) { int sorted; synchronized (this) { if (_length >= _buffer.length) { // Can't enlarge the buffer if there is a sort operation outstanding synchronized (_sortingLock) { final ContextRunnable[] newBuffer = new ContextRunnable[_length + (_length >> 1)]; System.arraycopy(_buffer, 0, newBuffer, 0, _length); _buffer = newBuffer; } } _buffer[_length++] = runnable; if ((_sorting) || (_length - _sorted <= _maxUnsorted)) { return; } sorted = _sorted; _sorted = (_length + _sorted) >> 1; _sorting = true; } synchronized (_sortingLock) { if (sorted < _sorted) { Arrays.sort(_buffer, sorted, _sorted, this); if (sorted > 0) { // We now have two sorted fragments; merge them together final ContextRunnable[] newBuffer = new ContextRunnable[_sorted]; int i = 0, j = sorted, n = 0; while ((i < sorted) && (j < _sorted)) { final int c = compare(_buffer[i], _buffer[j]); if (c < 0) { newBuffer[n++] = _buffer[i++]; } else if (c > 0) { newBuffer[n++] = _buffer[j++]; } else { newBuffer[n++] = _buffer[i++]; newBuffer[n++] = _buffer[j++]; } } if (i < sorted) { assert n + sorted - i == _sorted; System.arraycopy(_buffer, i, _buffer, n, sorted - i); System.arraycopy(newBuffer, 0, _buffer, 0, n); } else if (j < _sorted) { assert n + _sorted - j == _sorted; System.arraycopy(_buffer, j, _buffer, n, _sorted - j); System.arraycopy(newBuffer, 0, _buffer, 0, n); } else { System.arraycopy(newBuffer, 0, _buffer, 0, _sorted); } } } } synchronized (this) { _sorting = false; } } @Override public synchronized ContextRunnable take() { if (_length == 0) { return null; } final int index = --_length; final ContextRunnable runnable; if (!_sorting && (index < _sorted)) { _sorted = index; } if (index >= _sorted) { runnable = _buffer[index]; _buffer[index] = null; } else { // Need to acquire the "sorting" lock to read into the sorted data synchronized (_sortingLock) { runnable = _buffer[index]; _buffer[index] = null; if (index < _sorted) { _sorted = index; } } } return runnable; } /** * Runnable task comparison. In runnable priority order (most preferable to run first): * <ul> * <li>PORTFOLIO_NODE</li> * <li>PRIMITIVE</li> * <li>SECURITY</li> * <li>TRADE</li> * <li>POSITION</li> * </ul> * Within a given computation target type, ordering is based on the unique identifier. The aim is to get tasks that will "complete" running sooner (i.e. the primitive and security level functions) * to reduce the live memory footprint during a graph build. Portfolio node targets are performed at a high priority so that if individual positions are also requested then the graph build for both * should run in parallel if the node function is a basic aggregation. Ordering the unique identifiers should group values on the same target to give better utilization of the computation target * resolver cache. * <p> * Note this sorts into reverse order so that the most preferable to run are at the end of the array. */ @Override public int compare(final ContextRunnable r1, final ContextRunnable r2) { if (r1 instanceof ResolveTask) { if (r2 instanceof ResolveTask) { final ResolveTask rt1 = (ResolveTask) r1; final ResolveTask rt2 = (ResolveTask) r2; final ComputationTargetReference ctr1 = rt1.getValueRequirement().getTargetReference(); final ComputationTargetReference ctr2 = rt2.getValueRequirement().getTargetReference(); final Integer p1 = s_priority.get(ctr1.getType()); final Integer p2 = s_priority.get(ctr2.getType()); if (p1.intValue() < p2.intValue()) { return 1; } else if (p1.intValue() > p2.intValue()) { return -1; } else { if (ctr1 instanceof ComputationTargetSpecification) { if (ctr2 instanceof ComputationTargetSpecification) { return ObjectUtils.compare(ctr2.getSpecification().getUniqueId(), ctr1.getSpecification().getUniqueId()); } else { // Do requirement -> specification resolution (r2) first return -1; } } else { if (ctr2 instanceof ComputationTargetRequirement) { return ctr2.getRequirement().getIdentifiers() .compareTo(ctr1.getRequirement().getIdentifiers()); } else { // Do requirement -> specification resolution (r1) first return 1; } } } } else { // Do non-ResolveTask (r2) first return -1; } } else { if (r2 instanceof ResolveTask) { // Do non-ResolveTask (r1) first return 1; } else { // Don't care return 0; } } } }