bundles/org.simantics.db.impl/src/org/simantics/db/impl/BlockingAsyncProcedure.java

   1 /*******************************************************************************
   2  * Copyright (c) 2018 Association for Decentralized Information Management
   3  * in Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     Semantum Oy - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.db.impl;
  13
  14 import org.simantics.db.AsyncReadGraph;
  15 import org.simantics.db.common.utils.Logger;
  16 import org.simantics.db.exception.DatabaseException;
  17 import org.simantics.db.impl.graph.AsyncBarrierImpl;
  18 import org.simantics.db.impl.graph.ReadGraphImpl;
  19 import org.simantics.db.procedure.AsyncProcedure;
  20
  21 public class BlockingAsyncProcedure<Result> implements AsyncProcedure<Result> {
  22
  23     private static final Object NO_RESULT = new Object();
  24
  25     private final Object key;
  26     private final AsyncBarrierImpl barrier;
  27     private final ReadGraphImpl procedureGraph;
  28     private final AsyncProcedure<Result> procedure;
  29
  30     private Object result = NO_RESULT;
  31     private Throwable exception = null;
  32
  33     public BlockingAsyncProcedure(AsyncBarrierImpl barrier, ReadGraphImpl procedureGraph, AsyncProcedure<Result> procedure, Object key) {
  34         this.procedure = procedure;
  35         this.key = key;
  36         this.barrier = barrier;
  37         this.barrier.inc();
  38         this.procedureGraph = procedureGraph;
  39     }
  40
  41     @Override
  42     public void execute(AsyncReadGraph graph_, Result result) {
  43         this.result = result;
  44         try {
  45             if(procedure != null) procedure.execute(procedureGraph, result);
  46         } catch (Throwable throwable) {
  47             Logger.defaultLogError("AsyncProcedure.execute threw for " + procedure, throwable);
  48         } finally {
  49             barrier.dec();
  50         }
  51     }
  52
  53     @Override
  54     public void exception(AsyncReadGraph graph_, Throwable t) {
  55         this.exception = t;
  56         try {
  57             if(procedure != null) procedure.exception(procedureGraph, t);
  58         } catch (Throwable throwable) {
  59             Logger.defaultLogError("AsyncProcedure.exception threw for " + procedure, throwable);
  60         } finally {
  61             barrier.dec();
  62         }
  63     }
  64
  65     public void waitBarrier() {
  66         barrier.waitBarrier(key, procedureGraph);
  67     }
  68
  69     @SuppressWarnings("unchecked")
  70     public Result get() throws DatabaseException {
  71
  72         barrier.waitBarrier(key, procedureGraph);
  73
  74         if(exception != null) {
  75             if(exception instanceof DatabaseException) throw (DatabaseException)exception;
  76             throw new DatabaseException(exception);
  77         } else {
  78             return (Result)result;
  79         }
  80
  81     }
  82
  83     public boolean isDone() {
  84         return barrier.get() == 0;
  85     }
  86
  87     @SuppressWarnings("unchecked")
  88     public Result getResult() {
  89         return (Result)result;
  90     }
  91
  92     public Throwable getException() {
  93         return exception;
  94     }
  95
  96     @Override
  97     public String toString() {
  98         return "." + procedure;
  99     }
 100
 101 }