bundles/org.simantics.db.impl/src/org/simantics/db/impl/query/QueryThread.java

   1 package org.simantics.db.impl.query;
   2
   3 import java.util.ArrayList;
   4 import java.util.concurrent.Semaphore;
   5 import java.util.concurrent.atomic.AtomicInteger;
   6
   7 import org.simantics.db.Session;
   8 import org.simantics.db.common.SessionThread;
   9 import org.simantics.db.impl.query.QueryProcessor.SessionTask;
  10 import org.simantics.db.impl.query.QueryProcessor.ThreadState;
  11 import org.slf4j.LoggerFactory;
  12
  13 class QueryThread extends Thread implements SessionThread {
  14
  15         private static final org.slf4j.Logger LOGGER = LoggerFactory.getLogger(QueryThread.class);
  16
  17         boolean disposed = false;
  18         private Semaphore exited = new Semaphore(0);
  19
  20         final int index;
  21
  22         private Session session;
  23         private QuerySupport querySupport;
  24         private final QueryProcessor processor;
  25         private final Semaphore requests;
  26
  27         final private ArrayList<SessionTask> tasks = new ArrayList<SessionTask>();
  28 //      final private ArrayList<SessionTask> own;
  29 //      final private ArrayList<SessionTask> ownSync;
  30 //      final private ArrayList<SessionTask> queue;
  31 //      final private ReentrantLock lock;
  32 //      final private Condition condition;
  33         final private Object querySupportLock;
  34         final private int THREADS;
  35         final private AtomicInteger sleepers;
  36         final private ThreadState[] threadStates;
  37 //      final private ArrayList<SessionTask>[] delayQueues;
  38 //      final private QueryThread[] executors;
  39 //      final private ReentrantLock[] threadLocks;
  40 //      final private ArrayList<SessionTask>[] queues;
  41 //      final private ArrayList<SessionTask>[] ownSyncTasks;
  42
  43         public QueryThread(Session session, QueryProcessor processor, int index, String name) {
  44                 super(QueryProcessor.QueryThreadGroup, null, name);
  45                 this.session = session;
  46                 this.processor = processor;
  47                 this.index = index;
  48 //              own = processor.ownTasks[index];
  49 //              ownSync = processor.ownSyncTasks[index];
  50 //              queue = processor.queues[index];
  51 //              lock = processor.threadLocks[index];
  52 //              condition = processor.threadConditions[index];
  53                 querySupportLock = processor.querySupportLock;
  54                 THREADS = processor.THREADS;
  55                 sleepers = processor.sleepers;
  56                 querySupport = processor.querySupport;
  57                 threadStates = processor.threadStates;
  58                 requests = processor.requests;
  59 //              delayQueues = processor.delayQueues;
  60 //              executors = processor.executors;
  61 //              threadLocks = processor.threadLocks;
  62 //              queues = processor.queues;
  63 //              ownSyncTasks = processor.ownSyncTasks;
  64         }
  65
  66         synchronized void dispose() {
  67
  68 //              System.err.println("qt dispose");
  69
  70                 disposed = true;
  71 //              lock.lock();
  72 //              condition.signalAll();
  73 //              lock.unlock();
  74
  75                 try {
  76                         exited.acquire();
  77                 } catch (InterruptedException e) {
  78                         LOGGER.error("dispose was interrupted", e);
  79                 }
  80
  81                 session = null;
  82                 querySupport = null;
  83
  84 //              System.err.println("qt disposed");
  85
  86         }
  87
  88         boolean isDisposed() {
  89
  90                 return disposed;
  91
  92         }
  93
  94         public Session getSession() {
  95
  96                 return session;
  97
  98         }
  99
 100         private boolean pumpTask() {
 101             // First finish existing executions
 102         if(!processor.freeScheduling.isEmpty()) {
 103             tasks.add(processor.freeScheduling.removeFirst());
 104             return true;
 105         }
 106         // Check for new tasks
 107         if(!processor.topLevelTasks.isEmpty()) {
 108             tasks.add(processor.topLevelTasks.removeFirst());
 109             return true;
 110         }
 111                 return false;
 112         }
 113
 114         ArrayList<SessionTask> newTasks(boolean doWait, ArrayList<SessionTask> tasks) {
 115
 116                 try {
 117
 118                         while(true) {
 119
 120                                 // Return tasks if some were found
 121                                 if(!tasks.isEmpty()) return tasks;
 122
 123                                 if(!doWait) return null;
 124
 125                                 synchronized (querySupportLock) {
 126
 127                                         if(pumpTask())
 128                                                 return tasks;
 129
 130 //                                      lock.lock();
 131
 132                                         // We are the last one awake
 133                                         if(sleepers.incrementAndGet() == THREADS) {
 134
 135                                                 // Do not indicate sleeping yet
 136                                                 sleepers.decrementAndGet();
 137                                                 // Ceased can create new own tasks
 138                                                 if(querySupport == null) System.err.println("null qs");
 139                                                 querySupport.ceased(index);
 140
 141                                                 if(pumpTask()) {
 142 //                                                      lock.unlock();
 143                                                         return tasks;
 144                                                 }
 145
 146                                                 // OK, now we are going to sleep
 147                                                 sleepers.incrementAndGet();
 148
 149                                         }
 150
 151                                 }
 152
 153                                 // Nope nothing. Sleep & wait
 154                                 // Whoever releases this calls sleepers.decrementAndGet()
 155
 156                                 // We are done
 157                                 if(isDisposed()) {
 158                                         threadStates[index] = ThreadState.DISPOSED;
 159 //                                      lock.unlock();
 160                                         return null;
 161                                 }
 162
 163
 164                                 threadStates[index] = ThreadState.SLEEP;
 165
 166                                 requests.acquire();
 167
 168                                 sleepers.decrementAndGet();
 169
 170                                 // We are done
 171                                 if(isDisposed()) {
 172                                         threadStates[index] = ThreadState.DISPOSED;
 173                                         //lock.unlock();
 174                                         return null;
 175                                 }
 176
 177                                 threadStates[index] = ThreadState.RUN;
 178
 179                                 //lock.unlock();
 180
 181                         }
 182
 183                 } catch (InterruptedException e) {
 184
 185                         LOGGER.error("Query handling (newTasks) was interrupted", e);
 186                         throw new RuntimeException("Querying was interrupted.", e);
 187
 188                 }
 189
 190         }
 191
 192         public boolean runSynchronized() {
 193
 194                 boolean didExecute = false;
 195
 196 //              for(int performer=0;performer<THREADS;performer++) {
 197 //                      if(!delayQueues[index * THREADS + performer].isEmpty()) {
 198 //                              synchronized(executors[performer]) {
 199 //                                      threadLocks[performer].lock();
 200 //                                      queues[performer].addAll(delayQueues[index * THREADS + performer]);
 201 //                                      delayQueues[index * THREADS + performer].clear();
 202 //                                      executors[performer].notify();
 203 //                                      threadLocks[performer].unlock();
 204 //                              }
 205 //                      }
 206 //              }
 207
 208                 if(tasks.isEmpty()) {
 209                         ArrayList<SessionTask> finished = newTasks(false, tasks);
 210                         if(finished == null) return didExecute;
 211                 }
 212
 213                 while(!tasks.isEmpty()) {
 214
 215                         SessionTask task = tasks.remove(tasks.size() - 1);
 216
 217 //                      if(task.syncCaller == index) {
 218 //                              ownSyncTasks[index].add(task);
 219 //                      } else {
 220                                 task.run(index);
 221 //                              System.err.println("QT(s) " + index + " runs " + task);
 222                                 didExecute = true;
 223 //                      }
 224
 225                 }
 226
 227                 return didExecute;
 228
 229         }
 230
 231         @Override
 232         public void run() {
 233
 234                 QuerySupport support = this.querySupport;
 235
 236                 try {
 237
 238                         while (true) {
 239
 240                                 boolean finished = newTasks(true, tasks) == null;
 241                                 if(finished) {
 242                                         return;
 243                                 }
 244
 245                                 while(!tasks.isEmpty()) {
 246
 247                                         SessionTask task = tasks.remove(tasks.size()-1);
 248                                         task.run(0);
 249
 250                                 }
 251
 252                         }
 253
 254                 } catch (Throwable t) {
 255
 256                         LOGGER.error("FATAL BUG: QueryThread task processing caused unexpected exception.", t);
 257                         support.exit(t);
 258
 259                 } finally {
 260
 261                         exited.release();
 262
 263                 }
 264
 265         }
 266
 267 }