diff --git a/api.debugger.jpda/apichanges.xml b/api.debugger.jpda/apichanges.xml
--- a/api.debugger.jpda/apichanges.xml
+++ b/api.debugger.jpda/apichanges.xml
@@ -689,6 +689,27 @@
         <issue number="136099"/>
     </change>
 
+    <change>
+        <api name="JPDADebuggerAPI"/>
+        <summary>Improve threading model.</summary>
+        <version major="2" minor="18"/>
+        <date day="13" month="1" year="2009"/>
+        <author login="mentlicher"/>
+        <compatibility addition="yes" source="compatible" binary="compatible"/>
+        <description>
+            ReadWriteLock is introduced to synchronize the access to JPDAThread.
+            ReadLock of that read/write pair is publicly available through the
+            new method JPDAThread.getReadAccessLock(). Clients can use this lock
+            to assure that the thread is not resumed in the mean time.
+            <p>
+                Added methods:<br/>
+                <code>JPDAThread.getReadAccessLock()</code>,
+            </p>
+        </description>
+        <class package="org.netbeans.api.debugger.jpda" name="JPDAThread" />
+        <issue number="156368"/>
+    </change>
+
 
 </changes>
 
diff --git a/api.debugger.jpda/manifest.mf b/api.debugger.jpda/manifest.mf
--- a/api.debugger.jpda/manifest.mf
+++ b/api.debugger.jpda/manifest.mf
@@ -1,6 +1,6 @@
 Manifest-Version: 1.0
 OpenIDE-Module: org.netbeans.api.debugger.jpda/2
 OpenIDE-Module-Localizing-Bundle: org/netbeans/api/debugger/jpda/Bundle.properties
-OpenIDE-Module-Specification-Version: 2.17
+OpenIDE-Module-Specification-Version: 2.18
 OpenIDE-Module-Package-Dependencies: com.sun.jdi[VirtualMachineManager]
 
diff --git a/api.debugger.jpda/src/org/netbeans/api/debugger/jpda/JPDAThread.java b/api.debugger.jpda/src/org/netbeans/api/debugger/jpda/JPDAThread.java
--- a/api.debugger.jpda/src/org/netbeans/api/debugger/jpda/JPDAThread.java
+++ b/api.debugger.jpda/src/org/netbeans/api/debugger/jpda/JPDAThread.java
@@ -45,6 +45,7 @@
 import com.sun.jdi.ThreadReference;
 import java.beans.PropertyChangeListener;
 import java.util.List;
+import java.util.concurrent.locks.Lock;
 import org.netbeans.spi.debugger.jpda.EditorContext;
 import org.netbeans.spi.debugger.jpda.EditorContext.Operation;
 
@@ -89,7 +90,20 @@
      * @since 2.16     */
     public static final String PROP_BREAKPOINT = "currentBreakpoint";
 
-    
+
+    /**
+     * Getter for the "read" lock under which it's guaranteed that the thread
+     * does not change it's suspended state.
+     *
+     * Multiple threads can acquire this "read" lock at the same time. But the
+     * thread state can be changed only under an internal "write" lock.
+     * Clients can use this lock while retrieving data to assure that the thread
+     * is not resumed in the mean time.
+     *
+     * @return The read access lock.
+     * @since 2.18
+     */
+    public Lock getReadAccessLock();
     
     /**
      * Getter for the name of thread property.