2 files changed, 24 insertions, 0 deletions
diff --git a/src/nativewindow/classes/com/jogamp/nativewindow/NativeSurface.java b/src/nativewindow/classes/com/jogamp/nativewindow/NativeSurface.java
index ce0699c56..5433ea6c0 100644
--- a/src/nativewindow/classes/com/jogamp/nativewindow/NativeSurface.java
+++ b/src/nativewindow/classes/com/jogamp/nativewindow/NativeSurface.java
@@ -28,6 +28,8 @@
 
 package com.jogamp.nativewindow;
 
+import com.jogamp.common.util.locks.RecursiveLock;
+
 /**
  * Provides low-level information required for
  * hardware-accelerated rendering using a surface in a platform-independent manner.
@@ -55,6 +57,23 @@ public interface NativeSurface extends SurfaceUpdatedListener {
   /** Returned by {@link #lockSurface()} if the surface is locked, and is unchanged, {@value}. */
   public static final int LOCK_SUCCESS = 3;
 
+
+  /**
+   * Returns the implementation's {@link RecursiveLock} synchronizing multithreaded access
+   * if used. Otherwise {@code null} is being returned.
+   * <p>
+   * {@link NativeSurface}'s {@link RecursiveLock} is only exposed to resolve special
+   * situations within the implementation and its usage is not advised if not absolutely necessary.
+   * </p>
+   * <p>
+   * Note that certain {@link NativeSurface} implementations only use the {@link RecursiveLock}
+   * as an upfront re-entrance lock vehicle, but actually acquire and release
+   * the underlying windowing toolkit's lock facility on the first or last re-entrance lock,
+   * respectively.
+   * </p>
+   */
+  public RecursiveLock getLock();
+
   /**
    * Lock the surface of this native window.
    * <p>
diff --git a/src/nativewindow/classes/jogamp/nativewindow/ProxySurfaceImpl.java b/src/nativewindow/classes/jogamp/nativewindow/ProxySurfaceImpl.java
index 9f650f760..98fb6aa3b 100644
--- a/src/nativewindow/classes/jogamp/nativewindow/ProxySurfaceImpl.java
+++ b/src/nativewindow/classes/jogamp/nativewindow/ProxySurfaceImpl.java
@@ -191,6 +191,11 @@ public abstract class ProxySurfaceImpl implements ProxySurface {
     }
 
     @Override
+    public RecursiveLock getLock() {
+        return surfaceLock;
+    }
+
+    @Override
     public int lockSurface() throws NativeWindowException, RuntimeException  {
         surfaceLock.lock();
         int res = surfaceLock.getHoldCount() == 1 ? LOCK_SURFACE_NOT_READY : LOCK_SUCCESS; // new lock ?