package org.apache.maven.lifecycle.internal;
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
import org.codehaus.plexus.component.annotations.Component;
import org.codehaus.plexus.component.annotations.Requirement;
import org.codehaus.plexus.logging.Logger;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
/**
* @since 3.0
*/
@Component( role = ThreadConfigurationService.class )
public class ThreadConfigurationService
{
@Requirement
private Logger logger;
private final int cpuCores;
public ThreadConfigurationService()
{
cpuCores = Runtime.getRuntime().availableProcessors();
}
public ThreadConfigurationService( Logger logger, int cpuCores )
{
this.logger = logger;
this.cpuCores = cpuCores;
}
public ExecutorService getExecutorService( String threadCountConfiguration, boolean perCoreThreadCount,
int largestBuildListSize )
{
Integer threadCount = getThreadCount( threadCountConfiguration, perCoreThreadCount, largestBuildListSize );
return getExecutorService( threadCount );
}
private ExecutorService getExecutorService( Integer threadCount )
{
if ( threadCount == null )
{
logger.info( "Building with unlimited threads" );
return Executors.newCachedThreadPool();
}
logger.info( "Building with " + threadCount + " threads" );
return Executors.newFixedThreadPool( threadCount );
}
/**
* Returns the thread count to use or null for unlimited threads.
*
* @param threadCountConfiguration The property passed from the command line.
* @param perCoreThreadCount Indicates if the threa count should be scaled per cpu core.
* @param largestBuildListSize the size of the largest module list (the number of modules)
* @return The number of threads to use or null if unlimited
*/
Integer getThreadCount( String threadCountConfiguration, boolean perCoreThreadCount, int largestBuildListSize )
{
// Default to a value that is not larger than what we can use ;)
float threadCount = Math.min( cpuCores, largestBuildListSize );
if ( threadCountConfiguration != null )
{
try
{
threadCount = Float.parseFloat( threadCountConfiguration );
}
catch ( NumberFormatException e )
{
logger.warn(
"Couldn't parse thread count, will default to " + threadCount + ": " + threadCountConfiguration );
}
}
if ( perCoreThreadCount )
{
threadCount = threadCount * cpuCores;
}
final int endResult = Math.round( threadCount );
if ( logger.isDebugEnabled() )
{
logger.debug( "Thread pool size: " + endResult );
}
return endResult;
}
}