--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/hotspot/jtreg/vmTestbase/nsk/share/jdi/ThreadState.java	Mon Apr 30 18:10:24 2018 -0700
@@ -0,0 +1,105 @@
+/*
+ * Copyright (c) 2014, 2018, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package nsk.share.jdi;
+
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.TimeUnit;
+
+import nsk.share.Failure;
+
+/**
+ * Functions to set and wait for states in threads.
+ * Used to sync main thread and debuggee thread.
+ */
+public class ThreadState {
+    private final Lock lock = new ReentrantLock();
+    private final Condition cond = lock.newCondition();
+    private volatile String currentState;
+    private long timeoutMs;
+
+    public ThreadState(String startState, long timeoutMs) {
+        currentState = startState;
+        this.timeoutMs = timeoutMs;
+    }
+
+    /**
+     * Set new state.
+     */
+    public void setState(String newState) {
+        lock.lock();
+        try {
+            log(MSG_SET_STATE, newState);
+            currentState = newState;
+            cond.signalAll();
+        } finally {
+            lock.unlock();
+        }
+    }
+
+    /**
+     * Wait for the specified state.
+     * Throws Failure if timeout.
+     */
+    public void waitForState(String waitState) {
+        lock.lock();
+        try {
+            log(MSG_WAIT_STATE, waitState);
+            while (!currentState.equals(waitState)) {
+                if (!cond.await(timeoutMs, TimeUnit.MILLISECONDS)) {
+                    throw new Failure(format(MSG_TIMEOUT, waitState));
+                }
+            }
+            log(MSG_GOT_STATE, waitState);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+            throw new Failure(e);
+        } finally {
+            lock.unlock();
+        }
+    }
+
+    /**
+     * Simple helper that sets a new state and then wait for another state.
+     */
+    public void setAndWait(String newState, String waitState) {
+        setState(newState);
+        waitForState(waitState);
+    }
+
+    private static final String MSG_TIMEOUT = "ThreadState(thread='%s', state='%s') timeout waiting for %s";
+    private static final String MSG_SET_STATE = "ThreadState(thread='%s', state='%s') set state to %s";
+    private static final String MSG_WAIT_STATE = "ThreadState(thread='%s', state='%s') waiting for state %s";
+    private static final String MSG_GOT_STATE = "ThreadState(thread='%s', state='%s') got state %s";
+
+    private String format(String pattern, String state) {
+        final String threadName = Thread.currentThread().getName();
+        return String.format(pattern, threadName, currentState, state);
+    }
+
+    private void log(String pattern, String state) {
+        System.out.println(format(pattern, state));
+    }
+}