Package org.apache.maven.surefire.booter

Interface ProcessChecker

public interface ProcessChecker

Interface for checking if a process (typically the parent Maven plugin) is still alive.

Implementations allow the forked JVM to detect when its parent Maven process has terminated, enabling cleanup and preventing orphaned processes.

Since:

3.5.5

Method Summary

Modifier and Type	Method	Description
boolean	canUse()	Deprecated. with using ProcessHandleChecker on Java 9+, this method will always return true and can be removed in a future release.
void	destroyActiveCommands()	Destroys any active commands or subprocesses used by this checker.
boolean	isProcessAlive()	Checks if the process is still alive.
static boolean	isProcessHandleSupported()	Returns whether the ProcessHandle API is available in the current JVM.
boolean	isStopped()	Checks if the checker has been stopped.
static ProcessChecker	of(java.lang.String ppid)	Creates the appropriate ProcessChecker implementation for the given parent PID.
org.apache.maven.surefire.booter.ProcessInfo	processInfo()	Returns information about the process being checked.
void	stop()	Stops the checker and releases any resources.

Method Detail

of

static ProcessChecker of(java.lang.String ppid)

Creates the appropriate ProcessChecker implementation for the given parent PID.

On Java 9+, uses ProcessHandleChecker which leverages the ProcessHandle API. On Java 8, falls back to PpidChecker which uses native commands.

Parameters:

ppid - the parent process ID as a string, or null

Returns:

a new checker instance, or null if ppid is null

isProcessHandleSupported

static boolean isProcessHandleSupported()

Returns whether the ProcessHandle API is available in the current JVM.

Returns:

true if running on Java 9+ with ProcessHandle available

canUse

@Deprecated
boolean canUse()

Deprecated.

with using ProcessHandleChecker on Java 9+, this method will always return true and can be removed in a future release.

Checks whether this checker can be used to monitor the process.

This method must return true before isProcessAlive() can be called.

Returns:

true if the checker is operational and can monitor the process

isProcessAlive

boolean isProcessAlive()

Checks if the process is still alive.

This method can only be called after canUse() has returned true.

Returns:

true if the process is still running; false if it has terminated or if the PID has been reused by a different process

Throws:

java.lang.IllegalStateException - if canUse() returns false or if the checker has been stopped

stop

void stop()

Stops the checker and releases any resources.

After calling this method, canUse() will return false.

destroyActiveCommands

void destroyActiveCommands()

Destroys any active commands or subprocesses used by this checker.

This is called during shutdown to ensure clean termination.

isStopped

boolean isStopped()

Checks if the checker has been stopped.

Returns:

true if stop() or destroyActiveCommands() has been called

processInfo

org.apache.maven.surefire.booter.ProcessInfo processInfo()

Returns information about the process being checked.

Returns:

the process information, or null if not yet initialized