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             return processor.scheduling.pumpTask(tasks);
 102         }
 103
 104         ArrayList<SessionTask> newTasks(boolean doWait, ArrayList<SessionTask> tasks) {
 105
 106                 try {
 107
 108                         while(true) {
 109
 110                                 // Return tasks if some were found
 111                                 if(!tasks.isEmpty()) return tasks;
 112
 113                                 if(!doWait) return null;
 114
 115                                 synchronized (querySupportLock) {
 116
 117                                         if(pumpTask())
 118                                                 return tasks;
 119
 120 //                                      lock.lock();
 121
 122                                         // We are the last one awake
 123                                         if(sleepers.incrementAndGet() == THREADS) {
 124
 125                                                 // Do not indicate sleeping yet
 126                                                 sleepers.decrementAndGet();
 127                                                 // Ceased can create new own tasks
 128                                                 if(querySupport == null) System.err.println("null qs");
 129                                                 querySupport.ceased(index);
 130
 131                                                 if(pumpTask()) {
 132 //                                                      lock.unlock();
 133                                                         return tasks;
 134                                                 }
 135
 136                                                 // OK, now we are going to sleep
 137                                                 sleepers.incrementAndGet();
 138
 139                                         }
 140
 141                                 }
 142
 143                                 // Nope nothing. Sleep & wait
 144                                 // Whoever releases this calls sleepers.decrementAndGet()
 145
 146                                 // We are done
 147                                 if(isDisposed()) {
 148                                         threadStates[index] = ThreadState.DISPOSED;
 149 //                                      lock.unlock();
 150                                         return null;
 151                                 }
 152
 153
 154                                 threadStates[index] = ThreadState.SLEEP;
 155
 156                                 requests.acquire();
 157
 158                                 sleepers.decrementAndGet();
 159
 160                                 // We are done
 161                                 if(isDisposed()) {
 162                                         threadStates[index] = ThreadState.DISPOSED;
 163                                         //lock.unlock();
 164                                         return null;
 165                                 }
 166
 167                                 threadStates[index] = ThreadState.RUN;
 168
 169                                 //lock.unlock();
 170
 171                         }
 172
 173                 } catch (InterruptedException e) {
 174
 175                         LOGGER.error("Query handling (newTasks) was interrupted", e);
 176                         throw new RuntimeException("Querying was interrupted.", e);
 177
 178                 }
 179
 180         }
 181
 182         public boolean runSynchronized() {
 183
 184                 boolean didExecute = false;
 185
 186 //              for(int performer=0;performer<THREADS;performer++) {
 187 //                      if(!delayQueues[index * THREADS + performer].isEmpty()) {
 188 //                              synchronized(executors[performer]) {
 189 //                                      threadLocks[performer].lock();
 190 //                                      queues[performer].addAll(delayQueues[index * THREADS + performer]);
 191 //                                      delayQueues[index * THREADS + performer].clear();
 192 //                                      executors[performer].notify();
 193 //                                      threadLocks[performer].unlock();
 194 //                              }
 195 //                      }
 196 //              }
 197
 198                 if(tasks.isEmpty()) {
 199                         ArrayList<SessionTask> finished = newTasks(false, tasks);
 200                         if(finished == null) return didExecute;
 201                 }
 202
 203                 while(!tasks.isEmpty()) {
 204
 205                         SessionTask task = tasks.remove(tasks.size() - 1);
 206
 207 //                      if(task.syncCaller == index) {
 208 //                              ownSyncTasks[index].add(task);
 209 //                      } else {
 210                                 task.run(index);
 211 //                              System.err.println("QT(s) " + index + " runs " + task);
 212                                 didExecute = true;
 213 //                      }
 214
 215                 }
 216
 217                 return didExecute;
 218
 219         }
 220
 221         @Override
 222         public void run() {
 223
 224                 QuerySupport support = this.querySupport;
 225
 226                 try {
 227
 228                         while (true) {
 229
 230                                 boolean finished = newTasks(true, tasks) == null;
 231                                 if(finished) {
 232                                         return;
 233                                 }
 234
 235                                 while(!tasks.isEmpty()) {
 236
 237                                         SessionTask task = tasks.remove(tasks.size()-1);
 238                                         task.run(0);
 239
 240                                 }
 241
 242                         }
 243
 244                 } catch (Throwable t) {
 245
 246                         LOGGER.error("FATAL BUG: QueryThread task processing caused unexpected exception.", t);
 247                         support.exit(t);
 248
 249                 } finally {
 250
 251                         exited.release();
 252
 253                 }
 254
 255         }
 256
 257 }