Copyright (c) 2019 IBM Corporation and others.
All rights reserved. This program and the accompanying materials
are made available under the terms of the Eclipse Public License v1.0
which accompanies this distribution, and is available at
http://www.eclipse.org/legal/epl-v10.html
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2019 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.osgi.framework.util;

import java.lang.management.LockInfo;
import java.lang.management.ManagementFactory;
import java.lang.management.MonitorInfo;
import java.lang.management.ThreadInfo;
import java.lang.management.ThreadMXBean;

public class ThreadInfoReport extends RuntimeException {
	private static final long serialVersionUID = 1L;

	public ThreadInfoReport(String failedMonitor) {
		super(getThreadDump(failedMonitor));
	}

	public static String getThreadDump(String failedMonitor) {
		long currentId = Thread.currentThread().getId();
		ThreadMXBean threadMXBean = ManagementFactory.getThreadMXBean();
		StringBuilder dump = new StringBuilder("Thread dump"); //$NON-NLS-1$
		ThreadInfo[] infos = threadMXBean.dumpAllThreads(threadMXBean.isObjectMonitorUsageSupported(), threadMXBean.isSynchronizerUsageSupported());
		for (ThreadInfo info : infos) {
			dumpThreadIDNameState(info, dump);
			dumpLockInfo(currentId, failedMonitor, info, dump);
			dumpStackTrace(info, dump);
		}
		return dump.toString();
	}

	private static void dumpThreadIDNameState(ThreadInfo info, StringBuilder dump) {
		dump.append('\n').append('\n');
		dump.append("ThreadId: ").append(info.getThreadId()); //$NON-NLS-1$
		dump.append(" ThreadName: ").append(info.getThreadName()); //$NON-NLS-1$
		dump.append(" ThreadState: ").append(info.getThreadState()); //$NON-NLS-1$
	}

	private static void dumpLockInfo(long currentId, String failedMonitor, ThreadInfo info, StringBuilder dump) {
		dump.append('\n');
		dump.append("  Blocked On: "); //$NON-NLS-1$
		LockInfo blockedOn = info.getLockInfo();
		if (blockedOn == null) {
			if (currentId == info.getThreadId() && failedMonitor != null) {
				dump.append(failedMonitor);
			} else {
				dump.append("none"); //$NON-NLS-1$
			}
		} else {
			dump.append(blockedOn.toString());
			dump.append(" LockOwnerId: ").append(info.getLockOwnerId()); //$NON-NLS-1$
			dump.append(" LockOwnerName: ").append(info.getLockOwnerName()); //$NON-NLS-1$
		}
		dump.append('\n');

		dump.append("  Synchronizers Locked: "); //$NON-NLS-1$
		LockInfo[] synchronizers = info.getLockedSynchronizers();
		if (synchronizers.length == 0) {
			dump.append("none"); //$NON-NLS-1$
		} else {
			for (LockInfo sync : synchronizers) {
				dump.append('\n');
				dump.append("    ").append(sync.toString()); //$NON-NLS-1$
			}
		}
		dump.append('\n');

		dump.append("  Monitors Locked: "); //$NON-NLS-1$
		MonitorInfo[] monitors = info.getLockedMonitors();
		if (monitors.length == 0) {
			dump.append("none"); //$NON-NLS-1$
		}
		for (MonitorInfo monitor : monitors) {
			dump.append('\n');
			dump.append("    ").append(monitor.toString()); //$NON-NLS-1$
		}
		dump.append('\n');
	}

	private static void dumpStackTrace(ThreadInfo info, StringBuilder dump) {
		dump.append("  Stack Trace: "); //$NON-NLS-1$
		for (StackTraceElement e : info.getStackTrace()) {
			dump.append('\n').append("    ").append(e); //$NON-NLS-1$
		}
	}
}