net.openhft.chronicle.core.threads

Class ThreadDump

java.lang.Object

net.openhft.chronicle.core.threads.ThreadDump

public class ThreadDump
extends Object

Utility class for monitoring and managing threads.

Intended for unit and integration test assertions to detect stray threads and should not be used on hot paths as the checks are relatively expensive.

Provides functionality for collecting stack traces of threads and detecting unexpected thread creation, which can be useful in testing and debugging scenarios.

Field Summary

Fields

Modifier and Type	Field and Description
static String	IGNORE_THREAD_IF_IN_NAME

Constructor Summary

Constructors

Constructor and Description
ThreadDump() Constructs a ThreadDump instance, initializing the set of threads at the time of creation.

Method Summary

Modifier and Type	Method and Description
static void	add(Thread t, StackTrace stackTrace) Adds a thread with its stack trace to the map of monitored threads.
void	assertNoNewThreads() Fail if any new threads still exist after an adaptive wait.
void	assertNoNewThreads(int delay, @NotNull TimeUnit delayUnit) Fail if any new threads remain after a supplied delay.
static StackTrace	createdHereFor(Thread thread) Retrieves the stack trace for a given thread.
void	ignore(String threadName) Marks a thread to be ignored by the assertNoNewThreads() check.

Methods inherited from class java.lang.Object

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

Field Detail

IGNORE_THREAD_IF_IN_NAME

public static final String IGNORE_THREAD_IF_IN_NAME

See Also:

Constant Field Values

Constructor Detail

ThreadDump

public ThreadDump()

Constructs a ThreadDump instance, initializing the set of threads at the time of creation.

Method Detail

add

public static void add(Thread t,
                       StackTrace stackTrace)

Adds a thread with its stack trace to the map of monitored threads.

Parameters:

t - the thread to be monitored

stackTrace - the stack trace of the thread

createdHereFor

public static StackTrace createdHereFor(Thread thread)

Retrieves the stack trace for a given thread.

Parameters:

thread - the thread whose stack trace is to be retrieved

Returns:

the stack trace for the given thread

ignore

public void ignore(String threadName)

Marks a thread to be ignored by the assertNoNewThreads() check.

Parameters:

threadName - the name of the thread to be ignored

assertNoNewThreads

public void assertNoNewThreads()

Fail if any new threads still exist after an adaptive wait.

The initial set of threads is captured when this object is constructed. The method waits in a loop with exponentially increasing pauses to give short-lived threads time to finish.

assertNoNewThreads

public void assertNoNewThreads(int delay,
                               @NotNull
                               @NotNull TimeUnit delayUnit)

Fail if any new threads remain after a supplied delay.

The wait is adaptive: up to fourteen iterations (eighteen on ARM) are performed, each pausing for delay divided across the loop plus an exponential back-off of 1L << (i/2) milliseconds. Longer delays on ARM compensate for slower context switching.

Parameters:

delay - total extra time to wait across all iterations

delayUnit - unit of delay