final public Session session;
final public ResourceSupport resourceSupport;
+ final public Semaphore requests = new Semaphore(1);
+
final public QueryListening listening = new QueryListening(this);
QueryThread[] executors;
-
-// public ArrayList<SessionTask>[] queues;
public LinkedList<SessionTask> freeScheduling = new LinkedList<SessionTask>();
+
+ public LinkedList<SessionTask> topLevelTasks = new LinkedList<SessionTask>();
enum ThreadState {
}
public ThreadState[] threadStates;
-// public ReentrantLock[] threadLocks;
-// public Condition[] threadConditions;
-
- //public ArrayList<SessionTask>[] ownTasks;
-
- //public ArrayList<SessionTask>[] ownSyncTasks;
-
- //ArrayList<SessionTask>[] delayQueues;
final Object querySupportLock;
public void close() {
}
- public SessionTask getOwnTask(ReadGraphImpl impl) {
- Set<ReadGraphImpl> ancestors = impl.ancestorSet();
- synchronized(querySupportLock) {
- int index = 0;
- while(index < freeScheduling.size()) {
- SessionTask task = freeScheduling.get(index);
- if(task.hasCommonParent(ancestors)) {
- return freeScheduling.remove(index);
- }
- index++;
- }
- }
- return null;
- }
-
- public SessionTask getSubTask(ReadGraphImpl impl) {
- Set<ReadGraphImpl> onlyThis = Collections.singleton(impl);
+ public SessionTask getSubTask(ReadGraphImpl parent) {
synchronized(querySupportLock) {
int index = 0;
while(index < freeScheduling.size()) {
SessionTask task = freeScheduling.get(index);
- if(task.hasCommonParent(onlyThis)) {
+ if(task.isSubtask(parent) && task.maybeReady()) {
return freeScheduling.remove(index);
}
index++;
return null;
}
- public boolean performPending(ReadGraphImpl graph) {
- SessionTask task = getOwnTask(graph);
+ /*
+ * We are running errands while waiting for requests to complete.
+ * We can only run work that is part of the current root request to avoid any deadlocks
+ */
+ public boolean performPending(ReadGraphImpl under) {
+ SessionTask task = getSubTask(under);
if(task != null) {
- task.run(QueryProcessor.thread.get());
+ task.run(thread.get());
return true;
- } else {
- return false;
}
+ return false;
}
+
+ final public void scheduleNow(SessionTask request) {
+ SessionTask toExecute = scheduleOrReturnForExecution(request);
+ if(toExecute != null)
+ toExecute.run(thread.get());
+ }
-// final public void scheduleOwn(int caller, SessionTask request) {
-// ownTasks[caller].add(request);
-// }
+ final public SessionTask scheduleOrReturnForExecution(SessionTask request) {
- final public void schedule(SessionTask request) {
-
- //int performer = request.thread;
+ assert(request != null);
-// if(DebugPolicy.SCHEDULE)
-// System.out.println("schedule " + request + " " + " -> " + performer);
-
- //assert(performer >= 0);
+ synchronized(querySupportLock) {
- assert(request != null);
+ LinkedList<SessionTask> queue = request.rootGraph != null ? freeScheduling : topLevelTasks;
+
+ if(BarrierTracing.BOOKKEEPING) {
+ Exception current = new Exception();
+ Exception previous = BarrierTracing.tasks.put(request, current);
+ if(previous != null) {
+ previous.printStackTrace();
+ current.printStackTrace();
+ }
+ }
-// if(caller == performer) {
-// request.run(caller);
-// } else {
-
-// if(performer == THREADS) {
-
- synchronized(querySupportLock) {
-
- if(BarrierTracing.BOOKKEEPING) {
- Exception current = new Exception();
- Exception previous = BarrierTracing.tasks.put(request, current);
- if(previous != null) {
- previous.printStackTrace();
- current.printStackTrace();
- }
- }
-
- freeScheduling.add(request);
-
- querySupportLock.notifyAll();
+ queue.addFirst(request);
+ requests.release();
- }
+ }
- return;
-
-// }
-//
-// ReentrantLock queueLock = threadLocks[performer];
-// queueLock.lock();
-// queues[performer].add(request);
-// // This thread could have been sleeping
-// if(queues[performer].size() == 1) {
-// //if(ThreadState.SLEEP == threadStates[performer]) sleepers.decrementAndGet();
-// threadConditions[performer].signalAll();
-// }
-// queueLock.unlock();
-// }
+ return null;
- }
+ }
final int THREADS;
public static abstract class SessionTask {
- public final ReadGraphImpl graph;
- private Set<ReadGraphImpl> ancestors;
+ final protected ReadGraphImpl rootGraph;
private int counter = 0;
+ protected int position = 1;
private Exception trace;
- public SessionTask(ReadGraphImpl graph) {
- this.graph = graph;
- if(graph != null) graph.asyncBarrier.inc();
- }
-
- public boolean hasCommonParent(Set<ReadGraphImpl> otherAncestors) {
- if(graph == null) return false;
- if(ancestors == null) ancestors = graph.ancestorSet();
- return !Collections.disjoint(ancestors, otherAncestors);
+ public SessionTask() {
+ this(null);
}
+
+ public SessionTask(ReadGraphImpl rootGraph) {
+ this.rootGraph = rootGraph;
+ }
+
+ public boolean isSubtask(ReadGraphImpl graph) {
+ return graph.isParent(rootGraph);
+ }
- public abstract void run0(int thread);
+ public abstract void run0(int thread);
public final void run(int thread) {
if(counter++ > 0) {
trace = new Exception();
}
run0(thread);
- if(graph != null) graph.asyncBarrier.dec();
+ }
+
+ public boolean maybeReady() {
+ return true;
}
@Override
public String toString() {
- return "SessionTask[" + graph.parent + "]";
+ if(rootGraph == null)
+ return "SessionTask[no graph]";
+ else
+ return "SessionTask[" + rootGraph.parent + "]";
}
}
}
- long waitingTime = 0;
-
- static int koss = 0;
- static int koss2 = 0;
-
public boolean resume(ReadGraphImpl graph) {
return executors[0].runSynchronized();
}
-
- //private WeakReference<GarbageTracker> garbageTracker;
-
- private class GarbageTracker {
-
- @Override
- protected void finalize() throws Throwable {
-
-// System.err.println("GarbageTracker");
-//
-// garbageTracker = new WeakReference<GarbageTracker>(new GarbageTracker());
-
- super.finalize();
-
- }
-
- }
public QueryProcessor(final int threads, QuerySupport core, Set<Thread> threadSet)
throws DatabaseException {
- //garbageTracker = new WeakReference<GarbageTracker>(new GarbageTracker());
-
THREADS = threads;
THREAD_MASK = threads - 1;
querySupportLock = core.getLock();
executors = new QueryThread[THREADS];
-// queues = new ArrayList[THREADS];
-// threadLocks = new ReentrantLock[THREADS];
-// threadConditions = new Condition[THREADS];
threadStates = new ThreadState[THREADS];
-// ownTasks = new ArrayList[THREADS];
-// ownSyncTasks = new ArrayList[THREADS];
-// delayQueues = new ArrayList[THREADS * THREADS];
-
- // freeSchedule = new AtomicInteger(0);
-
-// for (int i = 0; i < THREADS * THREADS; i++) {
-// delayQueues[i] = new ArrayList<SessionTask>();
-// }
for (int i = 0; i < THREADS; i++) {
-
- // tasks[i] = new ArrayList<Runnable>();
-// ownTasks[i] = new ArrayList<SessionTask>();
-// ownSyncTasks[i] = new ArrayList<SessionTask>();
-// queues[i] = new ArrayList<SessionTask>();
-// threadLocks[i] = new ReentrantLock();
-// threadConditions[i] = threadLocks[i].newCondition();
- // limits[i] = false;
threadStates[i] = ThreadState.INIT;
-
}
for (int i = 0; i < THREADS; i++) {
@Override
protected void doDispose() {
+ requests.release(Integer.MAX_VALUE / 2);
+
for(int index = 0; index < THREADS; index++) {
executors[index].dispose();
}