alluxio.hub.agent.util.process

Interface ProcessTable

All Known Implementing Classes:

LinuxProcessTable, MacOsProcessTable

public interface ProcessTable

A process table interface to abstract away the different ways platforms retrieve information about system processes.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	ProcessTable.Factory A factory for creating the process table instances.

Method Summary

Modifier and Type	Method and Description
java.util.stream.Stream<Integer>	getAllPids() Get all PIDs running on the system.
List<Integer>	getJavaPid(java.util.stream.Stream<Integer> possiblePids, Class<?> clazz) Gets a Java PID running with the given class.
java.util.stream.Stream<Integer>	getJavaPids() Gets all the Java PIDs on the system that are readable by the current process.
boolean	isProcessAlive(int pid)
default boolean	isProcessDead(int pid)
default void	stopProcess(int pid, int timeoutMs) Stops a process.

Method Detail

getJavaPids

java.util.stream.Stream<Integer> getJavaPids()
                                      throws IOException

Gets all the Java PIDs on the system that are readable by the current process. In testing on a half-utilized 32-core system, this method takes ~25ms to execute, so use it sparingly.

Returns:

a list of PIDs that belong to java processes

Throws:

IOException - if the /proc filesystem is not available

getAllPids

java.util.stream.Stream<Integer> getAllPids()
                                     throws IOException

Get all PIDs running on the system.

Returns:

a stream of PIDs

Throws:

IOException - if the program cannot read the process table

getJavaPid

List<Integer> getJavaPid(@Nullable
                         java.util.stream.Stream<Integer> possiblePids,
                         Class<?> clazz)
                  throws IOException

Gets a Java PID running with the given class.

Parameters:

possiblePids - a list of PIDs to check. If null, it will check all PIDs on the system

clazz - the main class of the process that should be running

Returns:

a list of PIDs running with that main class

Throws:

IOException

isProcessAlive

boolean isProcessAlive(int pid)

Parameters:

pid - pid to test

Returns:

whether the process is alive

isProcessDead

default boolean isProcessDead(int pid)

Parameters:

pid - pid to test

Returns:

whether this process is currently running

stopProcess

default void stopProcess(int pid,
                         int timeoutMs)
                  throws IOException,
                         InterruptedException,
                         TimeoutException

Stops a process. Blocks until it is dead, or throws an exception.

Parameters:

pid - the PID to kill

timeoutMs - the total amount of time we should wait on the process dying before giving up

Throws:

IOException - If we can't read the process table or send a signal

InterruptedException - if we are interrupted waiting for the process to die

TimeoutException - if we wait too long for the process to die