SLEEP.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 edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.TimeUnit;
import org.spf4j.base.Arrays;
import org.spf4j.concurrent.DefaultScheduler;
import org.spf4j.zel.vm.ExecutionContext;
import org.spf4j.zel.vm.SuspendedException;
import org.spf4j.zel.vm.VMASyncFuture;

/**
 *
 * @author zoly
 */
@SuppressFBWarnings("MDM_THREAD_YIELD")
public final class SLEEP extends Instruction {

  private static final long serialVersionUID = 1L;

  public static final Instruction INSTANCE = new SLEEP();

  private SLEEP() {
  }

  @Override
  public int execute(final ExecutionContext context)
          throws SuspendedException, InterruptedException, ExecutionException {
    Number param = (Number) context.popSyncStackVal();
    final long sleepMillis = param.longValue();
    if (sleepMillis > 0) {
      if (context.getExecService() == null) {
        Thread.sleep(sleepMillis);
      } else {
        final VMASyncFuture<Object> future = new VMASyncFuture<>();
        DefaultScheduler.INSTANCE.schedule(
                new RunnableImpl(context, future), sleepMillis, TimeUnit.MILLISECONDS);
        context.incrementInstructionPointer();
        context.suspend(future);
      }
    }
    return 1;

  }

  @Override
  public Object[] getParameters() {
    return Arrays.EMPTY_OBJ_ARRAY;
  }

  private static final class RunnableImpl implements Runnable {

    private final ExecutionContext context;
    private final VMASyncFuture<Object> future;

    RunnableImpl(final ExecutionContext context, final VMASyncFuture<Object> future) {
      this.context = context;
      this.future = future;
    }

    @Override
    public void run() {
      Object stuff;
      do {
        stuff = context.getExecService().resumeSuspendables(future);
      } while (stuff == null);
    }
  }

}