CALLA.java

/*
 * Copyright (c) 2001-2017, Zoltan Farkas All Rights Reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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 Lesser General Public
 * License along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * Additionally licensed with:
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.spf4j.zel.instr;

import java.util.List;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import org.spf4j.zel.vm.ExecutionContext;
import org.spf4j.zel.vm.Method;
import org.spf4j.zel.vm.Program;
import org.spf4j.zel.vm.SuspendedException;
import org.spf4j.zel.vm.VMExecutor;
import org.spf4j.zel.vm.VMFuture;
import org.spf4j.zel.vm.ZExecutionException;

public final class CALLA extends Instruction {

  private static final long serialVersionUID = 1L;

  private final int nrParameters;

  public CALLA(final int nrParameters) {
    this.nrParameters = nrParameters;
  }

  @Override
  @edu.umd.cs.findbugs.annotations.SuppressFBWarnings("ITC_INHERITANCE_TYPE_CHECKING")
  public int execute(final ExecutionContext context)
          throws ExecutionException, InterruptedException, SuspendedException {
    final Object function = context.peekFromTop(nrParameters);
    if (function instanceof Program) {
      final Program p = (Program) function;
      final ExecutionContext nctx;
      Object obj;
      switch (p.getType()) {
        case DETERMINISTIC:
          nctx = context.getSubProgramContext(p, nrParameters);
          context.pop();
          List<Object> params = CALL.getParameters(nctx, nrParameters);
          obj = context.getResultCache().getResult(p, params, nctx::executeAsync);
          break;
        case NONDETERMINISTIC:
          nctx = context.getSubProgramContext(p, nrParameters);
          context.pop();
          obj = nctx.executeAsync();
          break;
        default:
          throw new UnsupportedOperationException(p.getType().toString());
      }
      context.push(obj);
    } else if (function instanceof Method) {
      Object[] parameters = context.popSyncStackVals(nrParameters);
      context.pop();
      Future<Object> obj = context.getExecService().submit(new MethodVMExecutor(function, context, parameters));
      context.push(obj);
    } else {
      throw new ZExecutionException("cannot invoke " + function);
    }
    return 1;
  }

  @Override
  public Object[] getParameters() {
    return new Object[]{nrParameters};
  }

  private static class MethodVMExecutor implements VMExecutor.Suspendable<Object> {

    private final Object function;
    private final ExecutionContext context;
    private final Object[] parameters;

    MethodVMExecutor(final Object function, final ExecutionContext context, final Object[] parameters) {
      this.function = function;
      this.context = context;
      this.parameters = parameters;
    }

    @Override
    public Object call() {
      return ((Method) function).invoke(context, parameters);
    }

    @Override
    public List<VMFuture<Object>> getSuspendedAt() {
      throw new UnsupportedOperationException("Not supported yet.");
    }
  }
}