il.ac.bgu.cs.bp.bpjs.model.ForkStatement Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of BPjs Show documentation
Provides runtime and analysis for behavioral programs written in JavaScript. It can run stand-alone (from the commmandline) or be embedded in larger JVM-based systems.
The newest version!
/*
 * The MIT License
 *
 * Copyright 2018 BPjs team.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
package il.ac.bgu.cs.bp.bpjs.model;

import il.ac.bgu.cs.bp.bpjs.bprogramio.BPJSStubInputStream;
import il.ac.bgu.cs.bp.bpjs.bprogramio.BPJSStubOutputStream;
import il.ac.bgu.cs.bp.bpjs.bprogramio.StreamObjectStub;
import il.ac.bgu.cs.bp.bpjs.bprogramio.StubProvider;
import il.ac.bgu.cs.bp.bpjs.execution.jsproxy.BProgramJsProxy;
import il.ac.bgu.cs.bp.bpjs.execution.jsproxy.MapProxy;
import il.ac.bgu.cs.bp.bpjs.execution.jsproxy.MapProxy.Modification;
import il.ac.bgu.cs.bp.bpjs.execution.tasks.BPEngineTask;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Map;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Data required for performing {@code bp.fork}.
 * 
 * TODO: Add array of parameters such that each for gets it's own value (parent should get {@code undefined}).
 * 
 * @author michael
 */
public class ForkStatement {
    
    private Object bthreadData;
    private Map> storageModifications;
    private Object continuation;
    
    private BThreadSyncSnapshot forkingBThread;

    public ForkStatement(Object aContinuation) {
        continuation = aContinuation;        
    }
    
    /**
     * Clones the data of the forked b-thread, so that the original thread can 
     * continue without changing the fork's data.
     * @param syncOrigin The b-program sync snapshot out of which the forking b-thread started
     */
    public void cloneBThreadData(BProgramSyncSnapshot syncOrigin){
        byte[] serializedForm;
        
        try ( ByteArrayOutputStream baos = new ByteArrayOutputStream();
            BPJSStubOutputStream btos = new BPJSStubOutputStream(baos, syncOrigin.getBProgram().getGlobalScope()) ) {
            btos.writeObject(bthreadData);
            btos.writeObject(storageModifications);
            btos.writeObject(continuation);
            btos.flush();
            baos.flush();
            serializedForm = baos.toByteArray();
        } catch (IOException ex) {
            Logger.getLogger(BPEngineTask.class.getName()).log(Level.SEVERE, "Error while serializing continuation during fork:" + ex.getMessage(), ex);
            throw new RuntimeException("Error while serializing continuation during fork:" + ex.getMessage(), ex);
        }
        
        final BProgramJsProxy bpProxy = new BProgramJsProxy(syncOrigin.getBProgram());

        StubProvider stubPrv = (StreamObjectStub stub) -> {
            if (stub == StreamObjectStub.BP_PROXY) {
                return bpProxy;
            }
            throw new IllegalArgumentException("Unknown stub " + stub);
        };
        
        try ( ByteArrayInputStream bais = new ByteArrayInputStream(serializedForm);
              BPJSStubInputStream btis = new BPJSStubInputStream(bais, syncOrigin.getBProgram().getGlobalScope(), stubPrv)
            ) {
            
            bthreadData = btis.readObject();
            storageModifications = (Map>) btis.readObject();
            continuation = btis.readObject();
            
        } catch (IOException | ClassNotFoundException ex) {
            Logger.getLogger(BPEngineTask.class.getName()).log(Level.SEVERE, "Error while serializing continuation during fork:" + ex.getMessage(), ex);
            throw new RuntimeException("Error while serializing continuation during fork:" + ex.getMessage(), ex);
        }
    }
    
    public BThreadSyncSnapshot makeSnapshot(String aName, BProgramSyncSnapshot syncOrigin) {
        return new BThreadSyncSnapshot(
            aName,
            forkingBThread.getEntryPoint(),
            forkingBThread.getInterrupt().orElse(null),
            continuation,
            null,
            bthreadData,
            new MapProxy(syncOrigin.getDataStore(), storageModifications)
        );
    }
    
    public Object getContinuation() {
        return continuation;
    }

    public void setForkingBThread(BThreadSyncSnapshot forkingBThread) {
        this.forkingBThread = forkingBThread;
        setBthreadData(forkingBThread.getData());
        storageModifications = forkingBThread.getStorageModifications();
    }

    public BThreadSyncSnapshot getForkingBThread() {
        return forkingBThread;
    }

    public Object getBthreadData() {
        return bthreadData;
    }

    public void setBthreadData(Object bthreadData) {
        this.bthreadData = bthreadData;
    }
    
}