jaspex.speculation.CreateNonSpeculativeMethodsClassVisitor.java Source code

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Here is the source code for jaspex.speculation.CreateNonSpeculativeMethodsClassVisitor.java

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/*
 * jaspex-mls: a Java Software Speculative Parallelization Framework
 * Copyright (C) 2015 Ivo Anjo <ivo.anjo@ist.utl.pt>
 *
 * This file is part of jaspex-mls.
 *
 * jaspex-mls is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * jaspex-mls 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with jaspex-mls.  If not, see <http://www.gnu.org/licenses/>.
 */

package jaspex.speculation;

import org.objectweb.asm.*;

/** ClassVisitor utilizado para copiar todos os mtodos $speculative para uma verso $non_speculative.
  *
  * A verso $non_speculative dos mtodos executa-se com proteco da STM mas nunca tenta fazer
  * especulao (e portanto no sofre o overhead de o tentar fazer).
  *
  * Actualmente, mtodos $non_speculative so usados em dois casos:
  * - oldspec decidiu temporariamente deixar de fazer especulaes
  * - <clinit> est a ser executado
  *
  * No confundir os mtodos $non_speculative com os originais (que no so modificados); os originais so
  * usados apenas em casos muito especiais:
  * - Implementao de interfaces e de mtodos abstractos de superclasses no-transactificveis
  * - Mtodos nativos
  * Portanto  necessria a existncia tanto das verses originais como das $non_speculative.
  *
  * (De notar que a verso original de um mtodo s deve ser chamada numa task onde j tenha ocorrido um
  * nonTransactionalActionAttempted(), e portanto todas as suas operaes j so consideradas seguras.)
  *
  * Ver tambm no wiki em "Transformaes Especulao" algumas notas sobre isto.
  **/
public class CreateNonSpeculativeMethodsClassVisitor extends ClassVisitor {

    public static String convertName(String name) {
        return name.replace("$speculative", "$non_speculative");
    }

    public static String convertDesc(String desc) {
        return desc.replace(CommonTypes.SPECULATIVECTORMARKER.bytecodeName(),
                CommonTypes.NONSPECULATIVECTORMARKER.bytecodeName());
    }

    static class CreateNonSpeculativeMethodVisitor extends MethodVisitor {
        public CreateNonSpeculativeMethodVisitor(int access, String name, String desc, String signature,
                String[] exceptions, ClassVisitor cv) {
            super(Opcodes.ASM4,
                    cv.visitMethod(access, convertName(name), convertDesc(desc), signature, exceptions));
        }

        @Override
        public void visitMethodInsn(int opcode, String owner, String name, String desc) {
            mv.visitMethodInsn(opcode, owner, convertName(name), convertDesc(desc));
        }
    }

    // Excepo ao code style normal para simular o ClassAdapter
    private final ClassVisitor cv;

    public CreateNonSpeculativeMethodsClassVisitor(ClassVisitor cv) {
        super(Opcodes.ASM4);
        this.cv = cv;
    }

    @Override
    public MethodVisitor visitMethod(int access, String name, String desc, String signature, String[] exceptions) {
        if (name.equals("<init>")) {
            if (!desc.contains("/SpeculativeCtorMarker"))
                return null;
        } else {
            if (!name.endsWith("$speculative"))
                return null;
        }
        return new CreateNonSpeculativeMethodVisitor(access, name, desc, signature, exceptions, cv);
    }

    @Override
    public void visitEnd() {
        // Necessrio porque no estamos a funcionar como ClassAdapter, mas como ClassVisitor
        cv.visitEnd();
    }

}