EngineTruffleObject.java

/*
 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
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package com.oracle.truffle.api.vm;

import java.util.Objects;

import com.oracle.truffle.api.CallTarget;
import com.oracle.truffle.api.CompilerDirectives;
import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;
import com.oracle.truffle.api.Truffle;
import com.oracle.truffle.api.frame.VirtualFrame;
import com.oracle.truffle.api.interop.ForeignAccess;
import com.oracle.truffle.api.interop.Message;
import com.oracle.truffle.api.interop.TruffleObject;
import com.oracle.truffle.api.nodes.DirectCallNode;
import com.oracle.truffle.api.nodes.RootNode;

final class EngineTruffleObject implements TruffleObject, ForeignAccess.Factory {
    private final PolyglotEngine engine;
    private final TruffleObject delegate;

    private EngineTruffleObject(PolyglotEngine engine, TruffleObject obj) {
        this.engine = engine;
        this.delegate = obj;
    }

    static Object wrap(PolyglotEngine engine, Object value) {
        Object obj = ConvertedObject.value(value);
        if (obj instanceof TruffleObject) {
            return new EngineTruffleObject(engine, (TruffleObject) obj);
        } else {
            return obj;
        }
    }

    @Override
    public ForeignAccess getForeignAccess() {
        return ForeignAccess.create(this);
    }

    TruffleObject getDelegate() {
        return delegate;
    }

    PolyglotEngine engine() {
        return engine;
    }

    void assertEngine(PolyglotEngine other) {
        if (this.engine != other) {
            throwEngine(other);
        }
    }

    @CompilerDirectives.TruffleBoundary
    private void throwEngine(PolyglotEngine other) throws IllegalArgumentException {
        throw new IllegalArgumentException("This object comes from " + this.engine + " and cannot be sent to " + other);
    }

    @Override
    public boolean canHandle(TruffleObject obj) {
        return obj instanceof EngineTruffleObject;
    }

    @Override
    public CallTarget accessMessage(Message message) {
        return Truffle.getRuntime().createCallTarget(new WrappingRoot(engine, message));
    }

    @Override
    public int hashCode() {
        int hash = 7;
        hash = 89 * hash + Objects.hashCode(this.engine);
        hash = 89 * hash + Objects.hashCode(this.delegate);
        return hash;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj) {
            return true;
        }
        if (obj instanceof EngineTruffleObject) {
            final EngineTruffleObject other = (EngineTruffleObject) obj;
            return engine == other.engine && Objects.equals(this.delegate, other.delegate);
        }
        return false;
    }

    @Override
    public String toString() {
        return delegate.toString();
    }

    /*
     * This wrapper is responsible for unwrapping the receiver, potentially executing on the
     * executor and wrapping again the return value.
     */
    static class WrappingRoot extends RootNode {

        private final PolyglotEngine engine;
        @Child private DirectCallNode messageCallNode;

        WrappingRoot(PolyglotEngine engine, Message foreignMessage) {
            super(null);
            this.engine = engine;
            this.messageCallNode = DirectCallNode.create(PolyglotRootNode.createSend(engine, foreignMessage));
        }

        @Override
        public Object execute(VirtualFrame frame) {
            EngineTruffleObject engineTruffleObject = (EngineTruffleObject) ForeignAccess.getReceiver(frame);
            Object[] oldArguments = frame.getArguments();
            final Object[] arguments = new Object[oldArguments.length];
            TruffleObject delegate = engineTruffleObject.getDelegate();
            arguments[0] = delegate;
            System.arraycopy(oldArguments, 1, arguments, 1, oldArguments.length - 1);
            Object res;
            if (engine.executor() == null) {
                res = messageCallNode.call(arguments);
            } else {
                res = invokeOnExecutor(arguments);
            }
            return wrap(engine, res);
        }

        @TruffleBoundary
        private Object invokeOnExecutor(final Object[] arguments) {
            ComputeInExecutor<Object> compute = new ComputeInExecutor<Object>(engine.executor()) {
                @SuppressWarnings("try")
                @Override
                protected Object compute() {
                    return messageCallNode.call(arguments);
                }
            };
            compute.perform();
            return compute.get();
        }

    }

}