org.apache.hadoop.util

Class ProcessTree

java.lang.Object

org.apache.hadoop.util.ProcessTree

Direct Known Subclasses:

ProcfsBasedProcessTree

public class ProcessTree
extends java.lang.Object

Process tree related operations

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ProcessTree.Signal The constants for the signals.

Field Summary

Fields

Modifier and Type	Field and Description
static long	DEFAULT_SLEEPTIME_BEFORE_SIGKILL
static boolean	isSetsidAvailable

Constructor Summary

Constructors

Constructor and Description
ProcessTree()

Method Summary

Methods

Modifier and Type	Method and Description
static void	destroy(java.lang.String pid, long sleeptimeBeforeSigkill, boolean isProcessGroup, boolean inBackground) Destroy the process-tree.
protected static void	destroyProcess(java.lang.String pid, long sleeptimeBeforeSigkill, boolean inBackground) Destroy the process.
protected static void	destroyProcessGroup(java.lang.String pgrpId, long sleeptimeBeforeSigkill, boolean inBackground) Destroy the process group.
static boolean	isAlive(java.lang.String pid) Is the process with PID pid still alive? This method assumes that isAlive is called on a pid that was alive not too long ago, and hence assumes no chance of pid-wrapping-around.
static boolean	isProcessGroupAlive(java.lang.String pgrpId) Is the process group with still alive? This method assumes that isAlive is called on a pid that was alive not too long ago, and hence assumes no chance of pid-wrapping-around.
static void	killProcess(java.lang.String pid, ProcessTree.Signal signal) Sends signal to process, forcefully terminating the process.
static void	killProcessGroup(java.lang.String pgrpId, ProcessTree.Signal signal) Sends signal to all process belonging to same process group, forcefully terminating the process group.
static void	terminateProcess(java.lang.String pid) Sends terminate signal to the process, allowing it to gracefully exit.
static void	terminateProcessGroup(java.lang.String pgrpId) Sends terminate signal to all the process belonging to the passed process group, allowing the group to gracefully exit.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

DEFAULT_SLEEPTIME_BEFORE_SIGKILL

public static final long DEFAULT_SLEEPTIME_BEFORE_SIGKILL

See Also:

Constant Field Values

isSetsidAvailable

public static final boolean isSetsidAvailable

Constructor Detail

ProcessTree

public ProcessTree()

Method Detail

destroy

public static void destroy(java.lang.String pid,
           long sleeptimeBeforeSigkill,
           boolean isProcessGroup,
           boolean inBackground)

Destroy the process-tree.

Parameters:

pid - process id of the root process of the subtree of processes to be killed

sleeptimeBeforeSigkill - The time to wait before sending SIGKILL after sending SIGTERM

isProcessGroup - pid is a process group leader or not

inBackground - Process is to be killed in the back ground with a separate thread

destroyProcess

protected static void destroyProcess(java.lang.String pid,
                  long sleeptimeBeforeSigkill,
                  boolean inBackground)

Destroy the process.

Parameters:

pid - Process id of to-be-killed-process

sleeptimeBeforeSigkill - The time to wait before sending SIGKILL after sending SIGTERM

inBackground - Process is to be killed in the back ground with a separate thread

destroyProcessGroup

protected static void destroyProcessGroup(java.lang.String pgrpId,
                       long sleeptimeBeforeSigkill,
                       boolean inBackground)

Destroy the process group.

Parameters:

pgrpId - Process group id of to-be-killed-processes

sleeptimeBeforeSigkill - The time to wait before sending SIGKILL after sending SIGTERM

inBackground - Process group is to be killed in the back ground with a separate thread

terminateProcess

public static void terminateProcess(java.lang.String pid)

Sends terminate signal to the process, allowing it to gracefully exit.

Parameters:

pid - pid of the process to be sent SIGTERM

terminateProcessGroup

public static void terminateProcessGroup(java.lang.String pgrpId)

Sends terminate signal to all the process belonging to the passed process group, allowing the group to gracefully exit.

Parameters:

pgrpId - process group id

killProcess

public static void killProcess(java.lang.String pid,
               ProcessTree.Signal signal)

Sends signal to process, forcefully terminating the process.

Parameters:

pid - process id

signal - the signal number to send

killProcessGroup

public static void killProcessGroup(java.lang.String pgrpId,
                    ProcessTree.Signal signal)

Sends signal to all process belonging to same process group, forcefully terminating the process group.

Parameters:

pgrpId - process group id

signal - the signal number to send

isAlive

public static boolean isAlive(java.lang.String pid)

Is the process with PID pid still alive? This method assumes that isAlive is called on a pid that was alive not too long ago, and hence assumes no chance of pid-wrapping-around.

Parameters:

pid - pid of the process to check.

Returns:

true if process is alive.

isProcessGroupAlive

public static boolean isProcessGroupAlive(java.lang.String pgrpId)

Is the process group with still alive? This method assumes that isAlive is called on a pid that was alive not too long ago, and hence assumes no chance of pid-wrapping-around.

Parameters:

pgrpId - process group id

Returns:

true if any of process in group is alive.