org.opencms.search.solr.TestThreadUtils Maven / Gradle / Ivy
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package org.opencms.search.solr;
import java.lang.management.ManagementFactory;
import java.lang.management.MonitorInfo;
import java.lang.management.ThreadInfo;
import java.lang.management.ThreadMXBean;
/**
* Utility class for thread analyzing.
*/
public final class TestThreadUtils {
/**
* Hide default constructor.
*/
private TestThreadUtils() {
// noop
}
/**
* Returns all thread infos.
*
* @return all thread infos
*/
public static ThreadInfo[] getAllThreadInfos() {
final ThreadMXBean thbean = ManagementFactory.getThreadMXBean();
final long[] ids = thbean.getAllThreadIds();
ThreadInfo[] infos;
if (!thbean.isObjectMonitorUsageSupported() || !thbean.isSynchronizerUsageSupported()) {
infos = thbean.getThreadInfo(ids);
} else {
infos = thbean.getThreadInfo(ids, true, true);
}
final ThreadInfo[] notNulls = new ThreadInfo[infos.length];
int nNotNulls = 0;
for (ThreadInfo info : infos) {
if (info != null) {
notNulls[nNotNulls++] = info;
}
}
if (nNotNulls == infos.length) {
return infos;
}
return java.util.Arrays.copyOf(notNulls, nNotNulls);
}
/**
* Returns all threads.
*
* @return all threads
*/
public static Thread[] getAllThreads() {
final ThreadGroup root = getRootThreadGroup();
final ThreadMXBean thbean = ManagementFactory.getThreadMXBean();
int nAlloc = thbean.getThreadCount();
int n = 0;
Thread[] threads;
do {
nAlloc *= 2;
threads = new Thread[nAlloc];
n = root.enumerate(threads, true);
} while (n == nAlloc);
return java.util.Arrays.copyOf(threads, n);
}
/**
* Returns the thread that is blocking the given one.
*
* @param thread the thread to get the blocking thread for
*
* @return the thread that is blocking the given one
*/
public static Thread getBlockingThread(final Thread thread) {
final ThreadInfo info = getThreadInfo(thread);
if (info == null) {
return null;
}
final long id = info.getLockOwnerId();
if (id == -1) {
return null;
}
return getThread(id);
}
/**
* Returns a list of all threads belonging to one thread group.
*
* @param group the group to get the threads for
*
* @return an array of threads for the given group
*/
public static Thread[] getGroupThreads(final ThreadGroup group) {
if (group == null) {
throw new NullPointerException("Null thread group");
}
int nAlloc = group.activeCount();
int n = 0;
Thread[] threads;
do {
nAlloc *= 2;
threads = new Thread[nAlloc];
n = group.enumerate(threads);
} while (n == nAlloc);
return java.util.Arrays.copyOf(threads, n);
}
/**
* Returns the thread that is locking the thread identified by the given id.
*
* @param identity the thread id to get the locking thread for
*
* @return the locaking thread or null if the thread for the given id is not locked
*/
public static Thread getLockingThread(long identity) {
final Thread[] allThreads = getAllThreads();
ThreadInfo info = null;
MonitorInfo[] monitors = null;
for (Thread thread : allThreads) {
info = getThreadInfo(thread.getId());
if (info == null) {
continue;
}
monitors = info.getLockedMonitors();
for (MonitorInfo monitor : monitors) {
if (identity == monitor.getIdentityHashCode()) {
return thread;
}
}
}
return null;
}
/**
* Returns the locking thread for the given object.
*
* @param object the object that is potentially locked
*
* @return the locking thread for the given object or null if not locked
*/
public static Thread getLockingThread(final Object object) {
if (object == null) {
throw new NullPointerException("Null object");
}
final long identity = System.identityHashCode(object);
final Thread[] allThreads = getAllThreads();
ThreadInfo info = null;
MonitorInfo[] monitors = null;
for (Thread thread : allThreads) {
info = getThreadInfo(thread.getId());
if (info == null) {
continue;
}
monitors = info.getLockedMonitors();
for (MonitorInfo monitor : monitors) {
if (identity == monitor.getIdentityHashCode()) {
return thread;
}
}
}
return null;
}
/**
* Returns the thread group of the current thread.
*
* @return the thread group
*/
public static ThreadGroup getRootThreadGroup() {
ThreadGroup tg = Thread.currentThread().getThreadGroup();
ThreadGroup ptg;
while ((ptg = tg.getParent()) != null) {
tg = ptg;
}
return tg;
}
/**
* Returns the thread for the given id.
*
* @param id of a thread
*
* @return the thread or null if not existent
*/
public static Thread getThread(final long id) {
final Thread[] threads = getAllThreads();
for (Thread thread : threads) {
if (thread.getId() == id) {
return thread;
}
}
return null;
}
/**
* Returns the thread for the given name.
*
* @param name the name of the thread to get
*
* @return the thread for the given name or null if not existent
*/
public static Thread getThread(final String name) {
if (name == null) {
throw new NullPointerException("Null name");
}
final Thread[] threads = getAllThreads();
for (Thread thread : threads) {
if (thread.getName().equals(name)) {
return thread;
}
}
return null;
}
/**
* Returns the thread info for the thread identified by the given id.
*
* @param id the id og the thread to get the info for
*
* @return the thread info for the thread identified by the given id or null if not existent
*/
public static ThreadInfo getThreadInfo(final long id) {
final ThreadMXBean thbean = ManagementFactory.getThreadMXBean();
if (!thbean.isObjectMonitorUsageSupported() || !thbean.isSynchronizerUsageSupported()) {
return thbean.getThreadInfo(id);
}
final ThreadInfo[] infos = thbean.getThreadInfo(new long[] {id}, true, true);
if (infos.length == 0) {
return null;
}
return infos[0];
}
/**
* Returns the thread info for the thread identified by the given name.
*
* @param name the name of the thread to get the info for
*
* @return the thread info for the thread identified by the given name or null if not existent
*/
public static ThreadInfo getThreadInfo(final String name) {
if (name == null) {
throw new NullPointerException("Null name");
}
final Thread[] threads = getAllThreads();
for (Thread thread : threads) {
if (thread.getName().equals(name)) {
return getThreadInfo(thread.getId());
}
}
return null;
}
/**
* Returns the thread info of the given thread.
*
* @param thread the thread to get the info for
*
* @return the thread info of the given thread or null if not existent
*/
public static ThreadInfo getThreadInfo(final Thread thread) {
if (thread == null) {
throw new NullPointerException("Null thread");
}
return getThreadInfo(thread.getId());
}
}