surefire-booter/src/main/java/org/apache/maven/surefire/booter/PpidChecker.java - maven-surefire - Git at Google

 package org.apache.maven.surefire.booter;

 /*
  * 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.apache.maven.surefire.api.booter.DumpErrorSingleton;

 import javax.annotation.Nonnull;
 import java.io.File;
 import java.io.IOException;
 import java.nio.charset.Charset;
 import java.text.SimpleDateFormat;
 import java.util.Queue;
 import java.util.Scanner;
 import java.util.TimeZone;
 import java.util.concurrent.ConcurrentLinkedQueue;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;

 import static java.lang.Integer.parseInt;
 import static java.lang.Long.parseLong;
 import static java.util.concurrent.TimeUnit.DAYS;
 import static java.util.concurrent.TimeUnit.HOURS;
 import static java.util.concurrent.TimeUnit.MINUTES;
 import static java.util.regex.Pattern.compile;
 import static org.apache.maven.surefire.shared.io.IOUtils.closeQuietly;
 import static org.apache.maven.surefire.shared.lang3.StringUtils.isNotBlank;
 import static org.apache.maven.surefire.shared.lang3.SystemUtils.IS_OS_HP_UX;
 import static org.apache.maven.surefire.shared.lang3.SystemUtils.IS_OS_LINUX;
 import static org.apache.maven.surefire.shared.lang3.SystemUtils.IS_OS_UNIX;
 import static org.apache.maven.surefire.shared.lang3.SystemUtils.IS_OS_WINDOWS;
 import static org.apache.maven.surefire.booter.ProcessInfo.unixProcessInfo;
 import static org.apache.maven.surefire.booter.ProcessInfo.windowsProcessInfo;
 import static org.apache.maven.surefire.booter.ProcessInfo.ERR_PROCESS_INFO;
 import static org.apache.maven.surefire.booter.ProcessInfo.INVALID_PROCESS_INFO;
 import static org.apache.maven.surefire.api.util.internal.StringUtils.NL;

 /**
  * Recognizes PID of Plugin process and determines lifetime.
  *
  * @author <a href="mailto:tibordigana@apache.org">Tibor Digana (tibor17)</a>
  * @since 2.20.1
  */
 final class PpidChecker
 {
     private static final int MINUTES_TO_MILLIS = 60 * 1000;
     // 25 chars https://superuser.com/questions/937380/get-creation-time-of-file-in-milliseconds/937401#937401
     private static final int WMIC_CREATION_DATE_VALUE_LENGTH = 25;
     private static final int WMIC_CREATION_DATE_TIMESTAMP_LENGTH = 18;
     private static final SimpleDateFormat WMIC_CREATION_DATE_FORMAT =
             IS_OS_WINDOWS ? createWindowsCreationDateFormat() : null;
     private static final String WMIC_CREATION_DATE = "CreationDate";
     private static final String WINDOWS_SYSTEM_ROOT_ENV = "SystemRoot";
     private static final String RELATIVE_PATH_TO_WMIC = "System32\\Wbem";
     private static final String SYSTEM_PATH_TO_WMIC =
             "%" + WINDOWS_SYSTEM_ROOT_ENV + "%\\" + RELATIVE_PATH_TO_WMIC + "\\";
     private static final String PS_ETIME_HEADER = "ELAPSED";
     private static final String PS_PID_HEADER = "PID";

     private final Queue<Process> destroyableCommands = new ConcurrentLinkedQueue<>();

     /**
      * The etime is in the form of [[dd-]hh:]mm:ss on Unix like systems.
      * See the workaround https://issues.apache.org/jira/browse/SUREFIRE-1451.
      */
     static final Pattern UNIX_CMD_OUT_PATTERN = compile( "^(((\\d+)-)?(\\d{1,2}):)?(\\d{1,2}):(\\d{1,2})\\s+(\\d+)$" );

     static final Pattern BUSYBOX_CMD_OUT_PATTERN = compile( "^(\\d+)[hH](\\d{1,2})\\s+(\\d+)$" );

     private final String ppid;

     private volatile ProcessInfo parentProcessInfo;
     private volatile boolean stopped;

     PpidChecker( @Nonnull String ppid )
     {
         this.ppid = ppid;
     }

     boolean canUse()
     {
         if ( isStopped() )
         {
             return false;
         }
         final ProcessInfo ppi = parentProcessInfo;
         return ppi == null ? IS_OS_WINDOWS || IS_OS_UNIX && canExecuteUnixPs() : ppi.canUse();
     }

     /**
      * This method can be called only after {@link #canUse()} has returned {@code true}.
      *
      * @return {@code true} if parent process is alive; {@code false} otherwise
      * @throws IllegalStateException if {@link #canUse()} returns {@code false}, error to read process
      *                               or this object has been {@link #destroyActiveCommands() destroyed}
      * @throws NullPointerException if extracted e-time is null
      */
     boolean isProcessAlive()
     {
         if ( !canUse() )
         {
             throw new IllegalStateException( "irrelevant to call isProcessAlive()" );
         }

         final ProcessInfo previousInfo = parentProcessInfo;
         if ( IS_OS_WINDOWS )
         {
             parentProcessInfo = windows();
             checkProcessInfo();

             // let's compare creation time, should be same unless killed or PID is reused by OS into another process
             return !parentProcessInfo.isInvalid()
                     && ( previousInfo == null || parentProcessInfo.isTimeEqualTo( previousInfo ) );
         }
         else if ( IS_OS_UNIX )
         {
             parentProcessInfo = unix();
             checkProcessInfo();

             // let's compare elapsed time, should be greater or equal if parent process is the same and still alive
             return !parentProcessInfo.isInvalid()
                     && ( previousInfo == null || !parentProcessInfo.isTimeBefore( previousInfo ) );
         }
         parentProcessInfo = ERR_PROCESS_INFO;
         throw new IllegalStateException( "unknown platform or you did not call canUse() before isProcessAlive()" );
     }

     private void checkProcessInfo()
     {
         if ( isStopped() )
         {
             throw new IllegalStateException( "error [STOPPED] to read process " + ppid );
         }

         if ( !parentProcessInfo.canUse() )
         {
             throw new IllegalStateException( "Cannot use PPID " + ppid + " process information. "
                     + "Going to use NOOP events." );
         }
     }

     // https://www.freebsd.org/cgi/man.cgi?ps(1)
     // etimes elapsed running time, in decimal integer seconds

     // http://manpages.ubuntu.com/manpages/xenial/man1/ps.1.html
     // etimes elapsed time since the process was started, in seconds.

     // http://hg.openjdk.java.net/jdk7/jdk7/jdk/file/9b8c96f96a0f/test/java/lang/ProcessBuilder/Basic.java#L167
     ProcessInfo unix()
     {
         ProcessInfoConsumer reader = new ProcessInfoConsumer( Charset.defaultCharset().name() )
         {
             @Override
             @Nonnull
             ProcessInfo consumeLine( String line, ProcessInfo previousOutputLine )
             {
                 if ( previousOutputLine.isInvalid() )
                 {
                     if ( hasHeader )
                     {
                         Matcher matcher = UNIX_CMD_OUT_PATTERN.matcher( line );
                         if ( matcher.matches() && ppid.equals( fromPID( matcher ) ) )
                         {
                             long pidUptime = fromDays( matcher )
                                                      + fromHours( matcher )
                                                      + fromMinutes( matcher )
                                                      + fromSeconds( matcher );
                             return unixProcessInfo( ppid, pidUptime );
                         }
                         matcher = BUSYBOX_CMD_OUT_PATTERN.matcher( line );
                         if ( matcher.matches() && ppid.equals( fromBusyboxPID( matcher ) ) )
                         {
                             long pidUptime = fromBusyboxHours( matcher ) + fromBusyboxMinutes( matcher );
                             return unixProcessInfo( ppid, pidUptime );
                         }
                     }
                     else
                     {
                         hasHeader = line.contains( PS_ETIME_HEADER ) && line.contains( PS_PID_HEADER );
                     }
                 }
                 return previousOutputLine;
             }
         };
         String cmd = unixPathToPS() + " -o etime,pid " + ( IS_OS_LINUX ? "" : "-p " ) + ppid;
         return reader.execute( "/bin/sh", "-c", cmd );
     }

     ProcessInfo windows()
     {
         ProcessInfoConsumer reader = new ProcessInfoConsumer( "US-ASCII" )
         {
             @Override
             @Nonnull
             ProcessInfo consumeLine( String line, ProcessInfo previousProcessInfo ) throws Exception
             {
                 if ( previousProcessInfo.isInvalid() && !line.isEmpty() )
                 {
                     if ( hasHeader )
                     {
                         // now the line is CreationDate, e.g. 20180406142327.741074+120
                         if ( line.length() != WMIC_CREATION_DATE_VALUE_LENGTH )
                         {
                             throw new IllegalStateException( "WMIC CreationDate should have 25 characters "
                                     + line );
                         }
                         String startTimestamp = line.substring( 0, WMIC_CREATION_DATE_TIMESTAMP_LENGTH );
                         int indexOfTimeZone = WMIC_CREATION_DATE_VALUE_LENGTH - 4;
                         long startTimestampMillisUTC =
                                 WMIC_CREATION_DATE_FORMAT.parse( startTimestamp ).getTime()
                                         - parseInt( line.substring( indexOfTimeZone ) ) * MINUTES_TO_MILLIS;
                         return windowsProcessInfo( ppid, startTimestampMillisUTC );
                     }
                     else
                     {
                         hasHeader = WMIC_CREATION_DATE.equals( line );
                     }
                 }
                 return previousProcessInfo;
             }
         };
         String wmicPath = hasWmicStandardSystemPath() ? SYSTEM_PATH_TO_WMIC : "";
         return reader.execute( "CMD", "/A", "/X", "/C",
                 wmicPath + "wmic process where (ProcessId=" + ppid + ") get " + WMIC_CREATION_DATE
         );
     }

     void destroyActiveCommands()
     {
         stopped = true;
         for ( Process p = destroyableCommands.poll(); p != null; p = destroyableCommands.poll() )
         {
             p.destroy();
         }
     }

     private boolean isStopped()
     {
         return stopped;
     }

     private static String unixPathToPS()
     {
         return canExecuteLocalUnixPs() ? "/usr/bin/ps" : "/bin/ps";
     }

     static boolean canExecuteUnixPs()
     {
         return canExecuteLocalUnixPs() || canExecuteStandardUnixPs();
     }

     private static boolean canExecuteLocalUnixPs()
     {
         try
         {
             return new File( "/usr/bin/ps" ).canExecute();
         }
         catch ( SecurityException e )
         {
             return false;
         }
     }

     private static boolean canExecuteStandardUnixPs()
     {
         try
         {
             return new File( "/bin/ps" ).canExecute();
         }
         catch ( SecurityException e )
         {
             return false;
         }
     }

     private static boolean hasWmicStandardSystemPath()
     {
         String systemRoot = System.getenv( WINDOWS_SYSTEM_ROOT_ENV );
         return isNotBlank( systemRoot ) && new File( systemRoot, RELATIVE_PATH_TO_WMIC + "\\wmic.exe" ).isFile();
     }

     static long fromDays( Matcher matcher )
     {
         String s = matcher.group( 3 );
         return s == null ? 0L : DAYS.toSeconds( parseLong( s ) );
     }

     static long fromHours( Matcher matcher )
     {
         String s = matcher.group( 4 );
         return s == null ? 0L : HOURS.toSeconds( parseLong( s ) );
     }

     static long fromMinutes( Matcher matcher )
     {
         String s = matcher.group( 5 );
         return s == null ? 0L : MINUTES.toSeconds( parseLong( s ) );
     }

     static long fromSeconds( Matcher matcher )
     {
         String s = matcher.group( 6 );
         return s == null ? 0L : parseLong( s );
     }

     static String fromPID( Matcher matcher )
     {
         return matcher.group( 7 );
     }

     static long fromBusyboxHours( Matcher matcher )
     {
         String s = matcher.group( 1 );
         return s == null ? 0L : HOURS.toSeconds( parseLong( s ) );
     }

     static long fromBusyboxMinutes( Matcher matcher )
     {
         String s = matcher.group( 2 );
         return s == null ? 0L : MINUTES.toSeconds( parseLong( s ) );
     }

     static String fromBusyboxPID( Matcher matcher )
     {
         return matcher.group( 3 );
     }

     private static void checkValid( Scanner scanner )
             throws IOException
     {
         IOException exception = scanner.ioException();
         if ( exception != null )
         {
             throw exception;
         }
     }

     /**
      * The beginning part of Windows WMIC format yyyymmddHHMMSS.xxx <br>
      * https://technet.microsoft.com/en-us/library/ee198928.aspx <br>
      * We use UTC time zone which avoids DST changes, see SUREFIRE-1512.
      *
      * @return Windows WMIC format yyyymmddHHMMSS.xxx
      */
     private static SimpleDateFormat createWindowsCreationDateFormat()
     {
         SimpleDateFormat formatter = new SimpleDateFormat( "yyyyMMddHHmmss'.'SSS" );
         formatter.setTimeZone( TimeZone.getTimeZone( "UTC" ) );
         return formatter;
     }

     public void stop()
     {
         stopped = true;
     }

     /**
      * Reads standard output from {@link Process}.
      * <br>
      * The artifact maven-shared-utils has non-daemon Threads which is an issue in Surefire to satisfy System.exit.
      * This implementation is taylor made without using any Thread.
      * It's easy to destroy Process from other Thread.
      */
     private abstract class ProcessInfoConsumer
     {
         private final String charset;

         boolean hasHeader;

         ProcessInfoConsumer( String charset )
         {
             this.charset = charset;
         }

         abstract @Nonnull ProcessInfo consumeLine( String line, ProcessInfo previousProcessInfo ) throws Exception;

         ProcessInfo execute( String... command )
         {
             ProcessBuilder processBuilder = new ProcessBuilder( command );
             processBuilder.redirectErrorStream( true );
             Process process = null;
             ProcessInfo processInfo = INVALID_PROCESS_INFO;
             StringBuilder out = new StringBuilder( 64 );
             try
             {
                 if ( IS_OS_HP_UX ) // force to run shell commands in UNIX Standard mode on HP-UX
                 {
                     processBuilder.environment().put( "UNIX95", "1" );
                 }
                 process = processBuilder.start();
                 destroyableCommands.add( process );
                 Scanner scanner = new Scanner( process.getInputStream(), charset );
                 while ( scanner.hasNextLine() )
                 {
                     String line = scanner.nextLine();
                     out.append( line ).append( NL );
                     processInfo = consumeLine( line.trim(), processInfo );
                 }
                 checkValid( scanner );
                 int exitCode = process.waitFor();
                 if ( exitCode != 0 || isStopped() )
                 {
                     out.append( "<<exit>> <<" ).append( exitCode ).append( ">>" ).append( NL );
                     DumpErrorSingleton.getSingleton()
                             .dumpText( out.toString() );
                 }
                 return isStopped() ? ERR_PROCESS_INFO : exitCode == 0 ? processInfo : INVALID_PROCESS_INFO;
             }
             catch ( Exception e )
             {
                 if ( !( e instanceof InterruptedException ) && !( e.getCause() instanceof InterruptedException ) )
                 {
                     DumpErrorSingleton.getSingleton()
                             .dumpText( out.toString() );

                     DumpErrorSingleton.getSingleton()
                             .dumpException( e );
                 }

                 return ERR_PROCESS_INFO;
             }
             finally
             {
                 if ( process != null )
                 {
                     destroyableCommands.remove( process );
                     process.destroy();
                     closeQuietly( process.getInputStream() );
                     closeQuietly( process.getErrorStream() );
                     closeQuietly( process.getOutputStream() );
                 }
             }
         }
     }

     @Override
     public String toString()
     {
         String args = "ppid=" + ppid
                 + ", stopped=" + stopped;

         ProcessInfo processInfo = parentProcessInfo;
         if ( processInfo != null )
         {
             args += ", invalid=" + processInfo.isInvalid()
                     + ", error=" + processInfo.isError();
         }

         if ( IS_OS_UNIX )
         {
             args += ", canExecuteLocalUnixPs=" + canExecuteLocalUnixPs()
                     + ", canExecuteStandardUnixPs=" + canExecuteStandardUnixPs();
         }

         return "PpidChecker{" + args + '}';
     }
 }
	package org.apache.maven.surefire.booter;

	/*
	* 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.apache.maven.surefire.api.booter.DumpErrorSingleton;

	import javax.annotation.Nonnull;
	import java.io.File;
	import java.io.IOException;
	import java.nio.charset.Charset;
	import java.text.SimpleDateFormat;
	import java.util.Queue;
	import java.util.Scanner;
	import java.util.TimeZone;
	import java.util.concurrent.ConcurrentLinkedQueue;
	import java.util.regex.Matcher;
	import java.util.regex.Pattern;

	import static java.lang.Integer.parseInt;
	import static java.lang.Long.parseLong;
	import static java.util.concurrent.TimeUnit.DAYS;
	import static java.util.concurrent.TimeUnit.HOURS;
	import static java.util.concurrent.TimeUnit.MINUTES;
	import static java.util.regex.Pattern.compile;
	import static org.apache.maven.surefire.shared.io.IOUtils.closeQuietly;
	import static org.apache.maven.surefire.shared.lang3.StringUtils.isNotBlank;
	import static org.apache.maven.surefire.shared.lang3.SystemUtils.IS_OS_HP_UX;
	import static org.apache.maven.surefire.shared.lang3.SystemUtils.IS_OS_LINUX;
	import static org.apache.maven.surefire.shared.lang3.SystemUtils.IS_OS_UNIX;
	import static org.apache.maven.surefire.shared.lang3.SystemUtils.IS_OS_WINDOWS;
	import static org.apache.maven.surefire.booter.ProcessInfo.unixProcessInfo;
	import static org.apache.maven.surefire.booter.ProcessInfo.windowsProcessInfo;
	import static org.apache.maven.surefire.booter.ProcessInfo.ERR_PROCESS_INFO;
	import static org.apache.maven.surefire.booter.ProcessInfo.INVALID_PROCESS_INFO;
	import static org.apache.maven.surefire.api.util.internal.StringUtils.NL;

	/**
	* Recognizes PID of Plugin process and determines lifetime.
	*
	* @author <a href="mailto:tibordigana@apache.org">Tibor Digana (tibor17)</a>
	* @since 2.20.1
	*/
	final class PpidChecker
	{
	private static final int MINUTES_TO_MILLIS = 60 * 1000;
	// 25 chars https://superuser.com/questions/937380/get-creation-time-of-file-in-milliseconds/937401#937401
	private static final int WMIC_CREATION_DATE_VALUE_LENGTH = 25;
	private static final int WMIC_CREATION_DATE_TIMESTAMP_LENGTH = 18;
	private static final SimpleDateFormat WMIC_CREATION_DATE_FORMAT =
	IS_OS_WINDOWS ? createWindowsCreationDateFormat() : null;
	private static final String WMIC_CREATION_DATE = "CreationDate";
	private static final String WINDOWS_SYSTEM_ROOT_ENV = "SystemRoot";
	private static final String RELATIVE_PATH_TO_WMIC = "System32\\Wbem";
	private static final String SYSTEM_PATH_TO_WMIC =
	"%" + WINDOWS_SYSTEM_ROOT_ENV + "%\\" + RELATIVE_PATH_TO_WMIC + "\\";
	private static final String PS_ETIME_HEADER = "ELAPSED";
	private static final String PS_PID_HEADER = "PID";

	private final Queue<Process> destroyableCommands = new ConcurrentLinkedQueue<>();

	/**
	* The etime is in the form of [[dd-]hh:]mm:ss on Unix like systems.
	* See the workaround https://issues.apache.org/jira/browse/SUREFIRE-1451.
	*/
	static final Pattern UNIX_CMD_OUT_PATTERN = compile( "^(((\\d+)-)?(\\d{1,2}):)?(\\d{1,2}):(\\d{1,2})\\s+(\\d+)$" );

	static final Pattern BUSYBOX_CMD_OUT_PATTERN = compile( "^(\\d+)[hH](\\d{1,2})\\s+(\\d+)$" );

	private final String ppid;

	private volatile ProcessInfo parentProcessInfo;
	private volatile boolean stopped;

	PpidChecker( @Nonnull String ppid )
	{
	this.ppid = ppid;
	}

	boolean canUse()
	{
	if ( isStopped() )
	{
	return false;
	}
	final ProcessInfo ppi = parentProcessInfo;
	return ppi == null ? IS_OS_WINDOWS \|\| IS_OS_UNIX && canExecuteUnixPs() : ppi.canUse();
	}

	/**
	* This method can be called only after {@link #canUse()} has returned {@code true}.
	*
	* @return {@code true} if parent process is alive; {@code false} otherwise
	* @throws IllegalStateException if {@link #canUse()} returns {@code false}, error to read process
	* or this object has been {@link #destroyActiveCommands() destroyed}
	* @throws NullPointerException if extracted e-time is null
	*/
	boolean isProcessAlive()
	{
	if ( !canUse() )
	{
	throw new IllegalStateException( "irrelevant to call isProcessAlive()" );
	}

	final ProcessInfo previousInfo = parentProcessInfo;
	if ( IS_OS_WINDOWS )
	{
	parentProcessInfo = windows();
	checkProcessInfo();

	// let's compare creation time, should be same unless killed or PID is reused by OS into another process
	return !parentProcessInfo.isInvalid()
	&& ( previousInfo == null \|\| parentProcessInfo.isTimeEqualTo( previousInfo ) );
	}
	else if ( IS_OS_UNIX )
	{
	parentProcessInfo = unix();
	checkProcessInfo();

	// let's compare elapsed time, should be greater or equal if parent process is the same and still alive
	return !parentProcessInfo.isInvalid()
	&& ( previousInfo == null \|\| !parentProcessInfo.isTimeBefore( previousInfo ) );
	}
	parentProcessInfo = ERR_PROCESS_INFO;
	throw new IllegalStateException( "unknown platform or you did not call canUse() before isProcessAlive()" );
	}

	private void checkProcessInfo()
	{
	if ( isStopped() )
	{
	throw new IllegalStateException( "error [STOPPED] to read process " + ppid );
	}

	if ( !parentProcessInfo.canUse() )
	{
	throw new IllegalStateException( "Cannot use PPID " + ppid + " process information. "
	+ "Going to use NOOP events." );
	}
	}

	// https://www.freebsd.org/cgi/man.cgi?ps(1)
	// etimes elapsed running time, in decimal integer seconds

	// http://manpages.ubuntu.com/manpages/xenial/man1/ps.1.html
	// etimes elapsed time since the process was started, in seconds.

	// http://hg.openjdk.java.net/jdk7/jdk7/jdk/file/9b8c96f96a0f/test/java/lang/ProcessBuilder/Basic.java#L167
	ProcessInfo unix()
	{
	ProcessInfoConsumer reader = new ProcessInfoConsumer( Charset.defaultCharset().name() )
	{
	@Override
	@Nonnull
	ProcessInfo consumeLine( String line, ProcessInfo previousOutputLine )
	{
	if ( previousOutputLine.isInvalid() )
	{
	if ( hasHeader )
	{
	Matcher matcher = UNIX_CMD_OUT_PATTERN.matcher( line );
	if ( matcher.matches() && ppid.equals( fromPID( matcher ) ) )
	{
	long pidUptime = fromDays( matcher )
	+ fromHours( matcher )
	+ fromMinutes( matcher )
	+ fromSeconds( matcher );
	return unixProcessInfo( ppid, pidUptime );
	}
	matcher = BUSYBOX_CMD_OUT_PATTERN.matcher( line );
	if ( matcher.matches() && ppid.equals( fromBusyboxPID( matcher ) ) )
	{
	long pidUptime = fromBusyboxHours( matcher ) + fromBusyboxMinutes( matcher );
	return unixProcessInfo( ppid, pidUptime );
	}
	}
	else
	{
	hasHeader = line.contains( PS_ETIME_HEADER ) && line.contains( PS_PID_HEADER );
	}
	}
	return previousOutputLine;
	}
	};
	String cmd = unixPathToPS() + " -o etime,pid " + ( IS_OS_LINUX ? "" : "-p " ) + ppid;
	return reader.execute( "/bin/sh", "-c", cmd );
	}

	ProcessInfo windows()
	{
	ProcessInfoConsumer reader = new ProcessInfoConsumer( "US-ASCII" )
	{
	@Override
	@Nonnull
	ProcessInfo consumeLine( String line, ProcessInfo previousProcessInfo ) throws Exception
	{
	if ( previousProcessInfo.isInvalid() && !line.isEmpty() )
	{
	if ( hasHeader )
	{
	// now the line is CreationDate, e.g. 20180406142327.741074+120
	if ( line.length() != WMIC_CREATION_DATE_VALUE_LENGTH )
	{
	throw new IllegalStateException( "WMIC CreationDate should have 25 characters "
	+ line );
	}
	String startTimestamp = line.substring( 0, WMIC_CREATION_DATE_TIMESTAMP_LENGTH );
	int indexOfTimeZone = WMIC_CREATION_DATE_VALUE_LENGTH - 4;
	long startTimestampMillisUTC =
	WMIC_CREATION_DATE_FORMAT.parse( startTimestamp ).getTime()
	- parseInt( line.substring( indexOfTimeZone ) ) * MINUTES_TO_MILLIS;
	return windowsProcessInfo( ppid, startTimestampMillisUTC );
	}
	else
	{
	hasHeader = WMIC_CREATION_DATE.equals( line );
	}
	}
	return previousProcessInfo;
	}
	};
	String wmicPath = hasWmicStandardSystemPath() ? SYSTEM_PATH_TO_WMIC : "";
	return reader.execute( "CMD", "/A", "/X", "/C",
	wmicPath + "wmic process where (ProcessId=" + ppid + ") get " + WMIC_CREATION_DATE
	);
	}

	void destroyActiveCommands()
	{
	stopped = true;
	for ( Process p = destroyableCommands.poll(); p != null; p = destroyableCommands.poll() )
	{
	p.destroy();
	}
	}

	private boolean isStopped()
	{
	return stopped;
	}

	private static String unixPathToPS()
	{
	return canExecuteLocalUnixPs() ? "/usr/bin/ps" : "/bin/ps";
	}

	static boolean canExecuteUnixPs()
	{
	return canExecuteLocalUnixPs() \|\| canExecuteStandardUnixPs();
	}

	private static boolean canExecuteLocalUnixPs()
	{
	try
	{
	return new File( "/usr/bin/ps" ).canExecute();
	}
	catch ( SecurityException e )
	{
	return false;
	}
	}

	private static boolean canExecuteStandardUnixPs()
	{
	try
	{
	return new File( "/bin/ps" ).canExecute();
	}
	catch ( SecurityException e )
	{
	return false;
	}
	}

	private static boolean hasWmicStandardSystemPath()
	{
	String systemRoot = System.getenv( WINDOWS_SYSTEM_ROOT_ENV );
	return isNotBlank( systemRoot ) && new File( systemRoot, RELATIVE_PATH_TO_WMIC + "\\wmic.exe" ).isFile();
	}

	static long fromDays( Matcher matcher )
	{
	String s = matcher.group( 3 );
	return s == null ? 0L : DAYS.toSeconds( parseLong( s ) );
	}

	static long fromHours( Matcher matcher )
	{
	String s = matcher.group( 4 );
	return s == null ? 0L : HOURS.toSeconds( parseLong( s ) );
	}

	static long fromMinutes( Matcher matcher )
	{
	String s = matcher.group( 5 );
	return s == null ? 0L : MINUTES.toSeconds( parseLong( s ) );
	}

	static long fromSeconds( Matcher matcher )
	{
	String s = matcher.group( 6 );
	return s == null ? 0L : parseLong( s );
	}

	static String fromPID( Matcher matcher )
	{
	return matcher.group( 7 );
	}

	static long fromBusyboxHours( Matcher matcher )
	{
	String s = matcher.group( 1 );
	return s == null ? 0L : HOURS.toSeconds( parseLong( s ) );
	}

	static long fromBusyboxMinutes( Matcher matcher )
	{
	String s = matcher.group( 2 );
	return s == null ? 0L : MINUTES.toSeconds( parseLong( s ) );
	}

	static String fromBusyboxPID( Matcher matcher )
	{
	return matcher.group( 3 );
	}

	private static void checkValid( Scanner scanner )
	throws IOException
	{
	IOException exception = scanner.ioException();
	if ( exception != null )
	{
	throw exception;
	}
	}

	/**
	* The beginning part of Windows WMIC format yyyymmddHHMMSS.xxx <br>
	* https://technet.microsoft.com/en-us/library/ee198928.aspx <br>
	* We use UTC time zone which avoids DST changes, see SUREFIRE-1512.
	*
	* @return Windows WMIC format yyyymmddHHMMSS.xxx
	*/
	private static SimpleDateFormat createWindowsCreationDateFormat()
	{
	SimpleDateFormat formatter = new SimpleDateFormat( "yyyyMMddHHmmss'.'SSS" );
	formatter.setTimeZone( TimeZone.getTimeZone( "UTC" ) );
	return formatter;
	}

	public void stop()
	{
	stopped = true;
	}

	/**
	* Reads standard output from {@link Process}.
	* <br>
	* The artifact maven-shared-utils has non-daemon Threads which is an issue in Surefire to satisfy System.exit.
	* This implementation is taylor made without using any Thread.
	* It's easy to destroy Process from other Thread.
	*/
	private abstract class ProcessInfoConsumer
	{
	private final String charset;

	boolean hasHeader;

	ProcessInfoConsumer( String charset )
	{
	this.charset = charset;
	}

	abstract @Nonnull ProcessInfo consumeLine( String line, ProcessInfo previousProcessInfo ) throws Exception;

	ProcessInfo execute( String... command )
	{
	ProcessBuilder processBuilder = new ProcessBuilder( command );
	processBuilder.redirectErrorStream( true );
	Process process = null;
	ProcessInfo processInfo = INVALID_PROCESS_INFO;
	StringBuilder out = new StringBuilder( 64 );
	try
	{
	if ( IS_OS_HP_UX ) // force to run shell commands in UNIX Standard mode on HP-UX
	{
	processBuilder.environment().put( "UNIX95", "1" );
	}
	process = processBuilder.start();
	destroyableCommands.add( process );
	Scanner scanner = new Scanner( process.getInputStream(), charset );
	while ( scanner.hasNextLine() )
	{
	String line = scanner.nextLine();
	out.append( line ).append( NL );
	processInfo = consumeLine( line.trim(), processInfo );
	}
	checkValid( scanner );
	int exitCode = process.waitFor();
	if ( exitCode != 0 \|\| isStopped() )
	{
	out.append( "<<exit>> <<" ).append( exitCode ).append( ">>" ).append( NL );
	DumpErrorSingleton.getSingleton()
	.dumpText( out.toString() );
	}
	return isStopped() ? ERR_PROCESS_INFO : exitCode == 0 ? processInfo : INVALID_PROCESS_INFO;
	}
	catch ( Exception e )
	{
	if ( !( e instanceof InterruptedException ) && !( e.getCause() instanceof InterruptedException ) )
	{
	DumpErrorSingleton.getSingleton()
	.dumpText( out.toString() );

	DumpErrorSingleton.getSingleton()
	.dumpException( e );
	}

	return ERR_PROCESS_INFO;
	}
	finally
	{
	if ( process != null )
	{
	destroyableCommands.remove( process );
	process.destroy();
	closeQuietly( process.getInputStream() );
	closeQuietly( process.getErrorStream() );
	closeQuietly( process.getOutputStream() );
	}
	}
	}
	}

	@Override
	public String toString()
	{
	String args = "ppid=" + ppid
	+ ", stopped=" + stopped;

	ProcessInfo processInfo = parentProcessInfo;
	if ( processInfo != null )
	{
	args += ", invalid=" + processInfo.isInvalid()
	+ ", error=" + processInfo.isError();
	}

	if ( IS_OS_UNIX )
	{
	args += ", canExecuteLocalUnixPs=" + canExecuteLocalUnixPs()
	+ ", canExecuteStandardUnixPs=" + canExecuteStandardUnixPs();
	}

	return "PpidChecker{" + args + '}';
	}
	}