1 files changed, 88 insertions, 0 deletions

diff --git a/Solvers/VIATRA-Solver/org.eclipse.viatra.dse/src/org/eclipse/viatra/dse/base/ExplorerThread.java b/Solvers/VIATRA-Solver/org.eclipse.viatra.dse/src/org/eclipse/viatra/dse/base/ExplorerThread.java
new file mode 100644
index 00000000..f2231e5c
--- /dev/null
+++ b/Solvers/VIATRA-Solver/org.eclipse.viatra.dse/src/org/eclipse/viatra/dse/base/ExplorerThread.java
@@ -0,0 +1,88 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2014, Miklos Foldenyi, Andras Szabolcs Nagy, Abel Hegedus, Akos Horvath, Zoltan Ujhelyi and Daniel Varro
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-v20.html.
+ * 
+ * SPDX-License-Identifier: EPL-2.0
+ *******************************************************************************/
+package org.eclipse.viatra.dse.base;
+
+import org.apache.log4j.Logger;
+import org.eclipse.viatra.dse.api.strategy.interfaces.IStrategy;
+import org.eclipse.viatra.query.runtime.api.ViatraQueryEngine;
+import org.eclipse.viatra.transformation.evm.api.RuleEngine;
+
+/**
+ * This class implements the {@link Runnable} interface, to able to run an exploration strategy in a separate thread. It
+ * is also responsible to initialize the exploration, start the exploration (call the {@link IStrategy#explore()}
+ * method), catch any exception during exploration and to shutdown the thread correctly.
+ * 
+ * @author Földenyi Miklos & Nagy Andras Szabolcs
+ * 
+ */
+public class ExplorerThread implements Runnable {
+
+    private final ThreadContext threadContext;
+
+    private IStrategy strategy;
+
+    public ExplorerThread(final ThreadContext context) {
+        this.threadContext = context;
+        strategy = threadContext.getStrategy();
+    }
+
+    /**
+     * Signals the {@link IStrategy} instance that execution should be stopped. By contract, the strategy is to
+     * stop execution at the next stage of execution where stopping and exiting is appropriate.
+     */
+    public void stopRunning() {
+        strategy.interruptStrategy();
+    }
+
+    /**
+     * Starts the design space exploration. Returns only when the {@link IStrategy#explore()} method returns.
+     */
+    public void run() {
+        GlobalContext globalContext = threadContext.getGlobalContext();
+        try {
+            
+            threadContext.init();
+
+            strategy.initStrategy(threadContext);
+
+            strategy.explore();
+
+            threadContext.backtrackUntilRoot();
+
+        } catch (Throwable e) {
+            Logger.getLogger(IStrategy.class).error("Thread stopped unexpectedly!", e);
+            globalContext.registerException(e);
+        } finally {
+            globalContext.strategyFinished(this);
+            dispose();
+        }
+    }
+
+    /**
+     * Disposes of this strategy. Recursively calls dispose on the underlying {@link RuleEngine} and
+     * {@link ViatraQueryEngine}. Calling this is only required if the design space exploration was launched in thread, as
+     * the underlying engines get collected on the stop of the running {@link Thread}.
+     */
+    public void dispose() {
+        threadContext.getRuleEngine().dispose();
+        DseIdPoolHelper.INSTANCE.disposeByThread();
+    }
+
+    /**
+     * Returns the associated {@link ThreadContext} that houses all the thread specific data about the exploration
+     * process, and is also the gateway to the {@link GlobalContext} which stores data relevant to the design space
+     * exploration process as a whole.
+     * 
+     * @return the relevant {@link ThreadContext}.
+     */
+    public ThreadContext getThreadContext() {
+        return threadContext;
+    }
+
+}