Security: Tighten DynamicLinker*, NativeLibrary and DynamicLibraryBundle access (2)

- Completes 23341a2df2d2ea36784a16fa1db8bc7385351a12

- Replace 'DynamicLinker' interface w/ well documented one

- All DynamicLinker methods are now considered secure, i.e.:
  - open/lookup and close utilize reference counting on handle via a hash map.

  - lookupSymbol(..) and close(..) impl. validate the passed library handle
    whether it's retrieved via open*.
    This is the fast path, not that expensive.

  - lookupSymbolGlobal(..) performs
    Check acccess of 'new RuntimePermission("loadLibrary.*")' if SecurityManager is installed.
    This is the slow path.

- DynamicLibraryBundleInfo now reflects the security requirements,
  i.e. whether priviledged access is needed.

9 files changed, 190 insertions, 108 deletions

diff --git a/src/java/com/jogamp/common/os/DynamicLibraryBundle.java b/src/java/com/jogamp/common/os/DynamicLibraryBundle.java
index fc36908..31ca372 100644
--- a/src/java/com/jogamp/common/os/DynamicLibraryBundle.java
+++ b/src/java/com/jogamp/common/os/DynamicLibraryBundle.java
@@ -324,7 +324,7 @@ public class DynamicLibraryBundle implements DynamicLookupHelper {
         long addr = 0;
         NativeLibrary lib = null;
 
-        if(info.shallLookupGlobal()) {
+        if( info.shallLookupGlobal() ) {
             // Try a global symbol lookup first ..
             addr = NativeLibrary.dynamicLookupFunctionGlobal(funcName);
         }
diff --git a/src/java/com/jogamp/common/os/DynamicLibraryBundleInfo.java b/src/java/com/jogamp/common/os/DynamicLibraryBundleInfo.java
index dc90eab..ef44298 100644
--- a/src/java/com/jogamp/common/os/DynamicLibraryBundleInfo.java
+++ b/src/java/com/jogamp/common/os/DynamicLibraryBundleInfo.java
@@ -28,14 +28,19 @@
  
 package com.jogamp.common.os;
 
-import java.util.*;
+import java.util.List;
 
 import com.jogamp.common.util.RunnableExecutor;
 
+
 public interface DynamicLibraryBundleInfo {
     public static final boolean DEBUG = DynamicLibraryBundle.DEBUG;
 
-    /** @return a list of Tool library names or alternative library name lists.<br>
+    /** 
+     * If a {@link SecurityManager} is installed, user needs link permissions
+     * for the named libraries.
+     *  
+     * @return a list of Tool library names or alternative library name lists.<br>
      * <ul>
      * <li>GL/GLU example Unix:   [ [ "libGL.so.1", "libGL.so", "GL" ], [ "libGLU.so", "GLU" ] ] </li>
      * <li>GL/GLU example Windows: [ "OpenGL32", "GLU32" ] </li>
@@ -44,7 +49,11 @@ public interface DynamicLibraryBundleInfo {
      */
     public List<List<String>> getToolLibNames();
 
-    /** @return a list of Glue library names.<br>
+    /** 
+     * If a {@link SecurityManager} is installed, user needs link permissions
+     * for the named libraries.
+     *  
+     * @return a list of Glue library names.<br>
      * <ul>
      * <li>GL:   [ "nativewindow_x11", "jogl_gl2es12", "jogl_desktop" ] </li>
      * <li>NEWT: [ "nativewindow_x11", "newt" ] </li>
@@ -55,23 +64,21 @@ public interface DynamicLibraryBundleInfo {
      */
     public List<String> getGlueLibNames();
 
-    /** May return the native libraries <pre>GetProcAddressFunc</pre> names, the first found function is being used.<br>
+    /** 
+     * May return the native libraries <pre>GetProcAddressFunc</pre> names, the first found function is being used.<br>
      * This could be eg: <pre> glXGetProcAddressARB, glXGetProcAddressARB </pre>.<br>
      * If your Tool does not has this facility, just return null.
      * @see #toolGetProcAddress(long, String)
      */
     public List<String> getToolGetProcAddressFuncNameList() ; 
 
-    /** May implement the lookup function using the Tools facility.<br>
+    /** 
+     * May implement the lookup function using the Tools facility.<br>
      * The actual function pointer is provided to allow proper bootstrapping of the ProcAddressTable,
      * using one of the provided function names by {@link #getToolGetProcAddressFuncNameList()}.<br>
      */
     public long toolGetProcAddress(long toolGetProcAddressHandle, String funcName);
 
-    /** May implement the lookup function using the Tools facility.<br>
-     * The actual function pointer is provided to allow proper bootstrapping of the ProcAddressTable.<br>
-     */
-    
     /**
      * @param funcName
      * @return true if {@link #toolGetProcAddress(long, String)} shall be tried before 
@@ -83,7 +90,13 @@ public interface DynamicLibraryBundleInfo {
     /** @return true if the native library symbols shall be made available for symbol resolution of subsequently loaded libraries. */
     public boolean shallLinkGlobal();
 
-    /** @return true if the dynamic symbol lookup shall happen system wide, over all loaded libraries. Otherwise only the loaded native libraries are used for lookup, which shall be the default. */
+    /** 
+     * If method returns <code>true</code> <i>and</i> if a {@link SecurityManager} is installed, user needs link permissions
+     * for <b>all</b> libraries, i.e. for <code>new RuntimePermission("loadLibrary.*");</code>!
+     *  
+     * @return true if the dynamic symbol lookup shall happen system wide, over all loaded libraries. 
+     * Otherwise only the loaded native libraries are used for lookup, which shall be the default. 
+     */
     public boolean shallLookupGlobal();
     
     /**
diff --git a/src/java/com/jogamp/common/os/DynamicLinker.java b/src/java/com/jogamp/common/os/DynamicLinker.java
index b1671b9..ed52413 100644
--- a/src/java/com/jogamp/common/os/DynamicLinker.java
+++ b/src/java/com/jogamp/common/os/DynamicLinker.java
@@ -1,55 +1,102 @@
-/*
- * Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
- * 
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met:
- * 
- * - Redistribution of source code must retain the above copyright
- *   notice, this list of conditions and the following disclaimer.
- * 
- * - Redistribution in binary form must reproduce the above copyright
- *   notice, this list of conditions and the following disclaimer in the
- *   documentation and/or other materials provided with the distribution.
- * 
- * Neither the name of Sun Microsystems, Inc. or the names of
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- * 
- * This software is provided "AS IS," without a warranty of any kind. ALL
- * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES,
- * INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
- * PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN
- * MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR
- * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
- * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR
- * ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR
- * DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE
- * DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY,
- * ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF
- * SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
- * 
- * You acknowledge that this software is not designed or intended for use
- * in the design, construction, operation or maintenance of any nuclear
- * facility.
- * 
- * Sun gratefully acknowledges that this software was originally authored
- * and developed by Kenneth Bradley Russell and Christopher John Kline.
+/**
+ * Copyright 2013 JogAmp Community. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are
+ * permitted provided that the following conditions are met:
+ *
+ *    1. Redistributions of source code must retain the above copyright notice, this list of
+ *       conditions and the following disclaimer.
+ *
+ *    2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *       of conditions and the following disclaimer in the documentation and/or other materials
+ *       provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * The views and conclusions contained in the software and documentation are those of the
+ * authors and should not be interpreted as representing official policies, either expressed
+ * or implied, of JogAmp Community.
  */
 
 package com.jogamp.common.os;
 
-/** Provides an abstract interface to the OS's low-level dynamic
-    linking functionality. */
-
+/** Low level secure dynamic linker access. */
 public interface DynamicLinker {
   public static final boolean DEBUG = NativeLibrary.DEBUG;
   public static final boolean DEBUG_LOOKUP = NativeLibrary.DEBUG_LOOKUP;
-        
+
+  /**
+   * If a {@link SecurityManager} is installed, user needs link permissions
+   * for the named library.
+   * <p>
+   * Opens the named library, allowing system wide access for other <i>users</i>.
+   * </p>
+   * 
+   * @param pathname the full pathname for the library to open
+   * @param debug set to true to enable debugging
+   * @return the library handle, maybe 0 if not found. 
+   * @throws SecurityException if user is not granted access for the named library.
+   */
   public long openLibraryGlobal(String pathname, boolean debug) throws SecurityException;
+
+  /**
+   * If a {@link SecurityManager} is installed, user needs link permissions
+   * for the named library.
+   * <p>
+   * Opens the named library, restricting access to this process.
+   * </p>
+   * 
+   * @param pathname the full pathname for the library to open
+   * @param debug set to true to enable debugging
+   * @return the library handle, maybe 0 if not found. 
+   * @throws SecurityException if user is not granted access for the named library.
+   */
   public long openLibraryLocal(String pathname, boolean debug) throws SecurityException;
-  public long lookupSymbol(long libraryHandle, String symbolName);
-  public long lookupSymbolGlobal(String symbolName);
-  public void closeLibrary(long libraryHandle);
+  
+  /**
+   * If a {@link SecurityManager} is installed, user needs link permissions
+   * for <b>all</b> libraries, i.e. for <code>new RuntimePermission("loadLibrary.*");</code>!
+   * 
+   * @param symbolName global symbol name to lookup up system wide.
+   * @return the library handle, maybe 0 if not found. 
+   * @throws SecurityException if user is not granted access for all libraries.
+   */
+  public long lookupSymbolGlobal(String symbolName) throws SecurityException;
+  
+  /**
+   * Security checks are implicit by previous call of 
+   * {@link #openLibraryLocal(String, boolean)} or {@link #openLibraryGlobal(String, boolean)}
+   * retrieving the <code>librarHandle</code>.
+   * 
+   * @param libraryHandle a library handle previously retrieved via {@link #openLibraryLocal(String, boolean)} or {@link #openLibraryGlobal(String, boolean)}.
+   * @param symbolName global symbol name to lookup up system wide.
+   * @return the library handle, maybe 0 if not found. 
+   * @throws IllegalArgumentException in case case <code>libraryHandle</code> is unknown.
+   */
+  public long lookupSymbol(long libraryHandle, String symbolName) throws IllegalArgumentException;
+  
+  /**
+   * Security checks are implicit by previous call of 
+   * {@link #openLibraryLocal(String, boolean)} or {@link #openLibraryGlobal(String, boolean)}
+   * retrieving the <code>librarHandle</code>.
+   * 
+   * @param libraryHandle a library handle previously retrieved via {@link #openLibraryLocal(String, boolean)} or {@link #openLibraryGlobal(String, boolean)}.
+   * @throws IllegalArgumentException in case case <code>libraryHandle</code> is unknown.
+   */
+  public void closeLibrary(long libraryHandle) throws IllegalArgumentException;
+  
+  /**
+   * Returns a string containing the last error. 
+   * Maybe called for debuging purposed if any method fails. 
+   * @return error string, maybe null. A null or non-null value has no semantics. 
+   */
   public String getLastError();
 }
diff --git a/src/java/com/jogamp/common/os/NativeLibrary.java b/src/java/com/jogamp/common/os/NativeLibrary.java
index 9a86209..3d81479 100644
--- a/src/java/com/jogamp/common/os/NativeLibrary.java
+++ b/src/java/com/jogamp/common/os/NativeLibrary.java
@@ -76,10 +76,6 @@ public final class NativeLibrary implements DynamicLookupHelper {
   private static final DynamicLinker dynLink;
   private static final String[] prefixes;
   private static final String[] suffixes;
-  /** TODO: Hide all lookup methods - Then make protected method accessible ..
-  private static final Method dynLinkLookupLocal;
-  private static final Method dynLinkLookupGlobal;
-  */
 
   static {
     // Instantiate dynamic linker implementation
@@ -114,23 +110,6 @@ public final class NativeLibrary implements DynamicLookupHelper {
         suffixes = new String[] { ".so" };
         break;
     }
-    
-    /** TODO: Hide all lookup methods - Then make protected method accessible ..
-        // public long lookupSymbol(long libraryHandle, String symbolName);
-        // public long lookupSymbolGlobal(String symbolName);    
-        final Method[] dlLookups = AccessController.doPrivileged(new PrivilegedAction<Method[]>() {
-            public Method[] run() {
-                final Method[] ms = new Method[2];
-                ms[0] = ReflectionUtil.getMethod(dynLink.getClass(), "lookupSymbol", Long.class, String.class);
-                ms[0].setAccessible(true);
-                ms[1] = ReflectionUtil.getMethod(dynLink.getClass(), "lookupSymbolGlobal", String.class);
-                ms[0].setAccessible(true);
-                return ms;
-            }
-        } );
-        dynLinkLookupLocal = dlLookups[0];
-        dynLinkLookupGlobal = dlLookups[1];
-      */
   }
 
   // Platform-specific representation for the handle to the open
@@ -258,7 +237,6 @@ public final class NativeLibrary implements DynamicLookupHelper {
       throw new RuntimeException("Library is not open");
     }
     return dynLink.lookupSymbol(libraryHandle, funcName);
-    // TODO: return ( (Long) ReflectionUtil.callMethod(dynLink, dynLinkLookupLocal, Long.valueOf(libraryHandle), funcName) ).longValue();
   }
 
   @Override
@@ -267,19 +245,16 @@ public final class NativeLibrary implements DynamicLookupHelper {
       throw new RuntimeException("Library is not open");
     }
     return 0 != dynLink.lookupSymbol(libraryHandle, funcName);
-    // TODO return 0 != ( (Long) ReflectionUtil.callMethod(dynLink, dynLinkLookupLocal, Long.valueOf(libraryHandle), funcName) ).longValue();
   }
 
   /** Looks up the given function name in all loaded libraries. */
   public static final long dynamicLookupFunctionGlobal(String funcName) {
     return dynLink.lookupSymbolGlobal(funcName);
-    // TODO return ( (Long) ReflectionUtil.callMethod(dynLink, dynLinkLookupGlobal, funcName) ).longValue();
   }
 
   /** Looks up the given function name in all loaded libraries. */
   public static final boolean isFunctionAvailableGlobal(String funcName) {
     return 0 != dynLink.lookupSymbolGlobal(funcName);
-    // TODO return 0 != ( (Long) ReflectionUtil.callMethod(dynLink, dynLinkLookupGlobal, funcName) ).longValue();
   }
 
   /** Retrieves the low-level library handle from this NativeLibrary
@@ -300,7 +275,7 @@ public final class NativeLibrary implements DynamicLookupHelper {
     if (DEBUG) {
       System.err.println("NativeLibrary.close(): closing " + this);
     }
-    if (libraryHandle == 0) {
+    if ( 0 == libraryHandle ) {
       throw new RuntimeException("Library already closed");
     }
     long handle = libraryHandle;
diff --git a/src/java/com/jogamp/common/util/SecurityUtil.java b/src/java/com/jogamp/common/util/SecurityUtil.java
index 4d7aa5d..6b35c9c 100644
--- a/src/java/com/jogamp/common/util/SecurityUtil.java
+++ b/src/java/com/jogamp/common/util/SecurityUtil.java
@@ -142,6 +142,17 @@ public class SecurityUtil {
     }
     
     /**
+     * Throws an {@link SecurityException} if an installed {@link SecurityManager}
+     * does not permit to dynamically link to all libraries.
+     */
+    public static final void checkAllLinkPermission() throws SecurityException {
+        if( null != securityManager ) {
+            securityManager.checkPermission(allLinkPermission);
+        }
+    }
+    private static final RuntimePermission allLinkPermission = new RuntimePermission("loadLibrary.*");
+    
+    /**
      * @param clz
      * @return
      * @throws SecurityException if the caller has no permission to access the ProtectedDomain of the given class.
diff --git a/src/java/jogamp/common/os/BionicDynamicLinkerImpl.java b/src/java/jogamp/common/os/BionicDynamicLinkerImpl.java
index b4ae70e..15d884f 100644
--- a/src/java/jogamp/common/os/BionicDynamicLinkerImpl.java
+++ b/src/java/jogamp/common/os/BionicDynamicLinkerImpl.java
@@ -55,7 +55,13 @@ public final class BionicDynamicLinkerImpl extends UnixDynamicLinkerImpl {
     // having to dlsym all entry points. System.loadLibrary() uses
     // RTLD_LOCAL visibility so can't be used for this purpose.
     SecurityUtil.checkLinkPermission(pathname);
-    return dlopen(pathname, RTLD_LAZY | RTLD_LOCAL);
+    final long handle = dlopen(pathname, RTLD_LAZY | RTLD_LOCAL);
+    if( 0 != handle ) {
+        incrLibRefCount(handle, pathname);
+    } else if ( DEBUG || debug ) {
+        System.err.println("dlopen \""+pathname+"\" local failed, error: "+dlerror());
+    }
+    return handle;
   }
 
   @Override
@@ -68,11 +74,18 @@ public final class BionicDynamicLinkerImpl extends UnixDynamicLinkerImpl {
     // having to dlsym all entry points. System.loadLibrary() uses
     // RTLD_LOCAL visibility so can't be used for this purpose.
     SecurityUtil.checkLinkPermission(pathname);
-    return dlopen(pathname, RTLD_LAZY | RTLD_GLOBAL);
+    final long handle = dlopen(pathname, RTLD_LAZY | RTLD_GLOBAL);
+    if( 0 != handle ) {
+        incrLibRefCount(handle, pathname);
+    } else if ( DEBUG || debug ) {
+        System.err.println("dlopen \""+pathname+"\" global failed, error: "+dlerror());
+    }
+    return handle;
   }
   
   @Override
-  public final long lookupSymbolGlobal(String symbolName) {
+  public final long lookupSymbolGlobal(String symbolName) throws SecurityException {
+    SecurityUtil.checkAllLinkPermission();
     final long addr = dlsym(RTLD_DEFAULT, symbolName);
     if(DEBUG_LOOKUP) {
         System.err.println("DynamicLinkerImpl.lookupSymbolGlobal("+symbolName+") -> 0x"+Long.toHexString(addr));
diff --git a/src/java/jogamp/common/os/MacOSXDynamicLinkerImpl.java b/src/java/jogamp/common/os/MacOSXDynamicLinkerImpl.java
index b0b77ce..beab5d5 100644
--- a/src/java/jogamp/common/os/MacOSXDynamicLinkerImpl.java
+++ b/src/java/jogamp/common/os/MacOSXDynamicLinkerImpl.java
@@ -53,7 +53,13 @@ public final class MacOSXDynamicLinkerImpl extends UnixDynamicLinkerImpl {
     // having to dlsym all entry points. System.loadLibrary() uses
     // RTLD_LOCAL visibility so can't be used for this purpose.
     SecurityUtil.checkLinkPermission(pathname);
-    return dlopen(pathname, RTLD_LAZY | RTLD_LOCAL);
+    final long handle = dlopen(pathname, RTLD_LAZY | RTLD_LOCAL);
+    if( 0 != handle ) {
+        incrLibRefCount(handle, pathname);
+    } else if ( DEBUG || debug ) {
+        System.err.println("dlopen \""+pathname+"\" local failed, error: "+dlerror());
+    }
+    return handle;
   }
   
   @Override
@@ -66,11 +72,18 @@ public final class MacOSXDynamicLinkerImpl extends UnixDynamicLinkerImpl {
     // having to dlsym all entry points. System.loadLibrary() uses
     // RTLD_LOCAL visibility so can't be used for this purpose.
     SecurityUtil.checkLinkPermission(pathname);
-    return dlopen(pathname, RTLD_LAZY | RTLD_GLOBAL);
+    final long handle = dlopen(pathname, RTLD_LAZY | RTLD_GLOBAL);
+    if( 0 != handle ) {
+        incrLibRefCount(handle, pathname);
+    } else if ( DEBUG || debug ) {
+        System.err.println("dlopen \""+pathname+"\" global failed, error: "+dlerror());
+    }
+    return handle;
   }
   
   @Override
-  public final long lookupSymbolGlobal(String symbolName) {
+  public final long lookupSymbolGlobal(String symbolName) throws SecurityException {
+    SecurityUtil.checkAllLinkPermission();
     final long addr = dlsym(RTLD_DEFAULT, symbolName);
     if(DEBUG_LOOKUP) {
         System.err.println("DynamicLinkerImpl.lookupSymbolGlobal("+symbolName+") -> 0x"+Long.toHexString(addr));
diff --git a/src/java/jogamp/common/os/UnixDynamicLinkerImpl.java b/src/java/jogamp/common/os/UnixDynamicLinkerImpl.java
index 1942477..25f4072 100644
--- a/src/java/jogamp/common/os/UnixDynamicLinkerImpl.java
+++ b/src/java/jogamp/common/os/UnixDynamicLinkerImpl.java
@@ -27,9 +27,7 @@
  */
 package jogamp.common.os;
 
-import com.jogamp.common.os.DynamicLinker;
-
-/* pp */ abstract class UnixDynamicLinkerImpl implements DynamicLinker {
+/* pp */ abstract class UnixDynamicLinkerImpl extends DynamicLinkerImpl {
 
   //
   // Package private scope of class w/ protected native code access
@@ -49,9 +47,11 @@ import com.jogamp.common.os.DynamicLinker;
   /** Interface to C language function: <br> <code> void *  dlsym(void * , const char * ); </code>    */
   protected static native long dlsym(long arg0, java.lang.String arg1);
 
-
   @Override
-  public final long lookupSymbol(long libraryHandle, String symbolName) {
+  public final long lookupSymbol(long libraryHandle, String symbolName) throws IllegalArgumentException {
+    if( null == getLibRef( libraryHandle ) ) {
+        throw new IllegalArgumentException("Library handle 0x"+Long.toHexString(libraryHandle)+" unknown.");
+    }
     final long addr = dlsym(libraryHandle, symbolName);
     if(DEBUG_LOOKUP) {
         System.err.println("DynamicLinkerImpl.lookupSymbol(0x"+Long.toHexString(libraryHandle)+", "+symbolName+") -> 0x"+Long.toHexString(addr));
@@ -60,7 +60,10 @@ import com.jogamp.common.os.DynamicLinker;
   }
 
   @Override
-  public final void closeLibrary(long libraryHandle) {
+  public final void closeLibrary(long libraryHandle) throws IllegalArgumentException {
+    if( null == decrLibRefCount( libraryHandle ) ) {
+        throw new IllegalArgumentException("Library handle 0x"+Long.toHexString(libraryHandle)+" unknown.");
+    }
     dlclose(libraryHandle);
   }
   
diff --git a/src/java/jogamp/common/os/WindowsDynamicLinkerImpl.java b/src/java/jogamp/common/os/WindowsDynamicLinkerImpl.java
index b95f204..adb2492 100644
--- a/src/java/jogamp/common/os/WindowsDynamicLinkerImpl.java
+++ b/src/java/jogamp/common/os/WindowsDynamicLinkerImpl.java
@@ -27,10 +27,9 @@
  */
 package jogamp.common.os;
 
-import com.jogamp.common.os.DynamicLinker;
 import com.jogamp.common.util.SecurityUtil;
 
-public final class WindowsDynamicLinkerImpl implements DynamicLinker {
+public final class WindowsDynamicLinkerImpl extends DynamicLinkerImpl {
 
   /** Interface to C language function: <br> <code> BOOL FreeLibrary(HANDLE hLibModule); </code>    */
   private static native int FreeLibrary(long hLibModule);
@@ -44,7 +43,6 @@ public final class WindowsDynamicLinkerImpl implements DynamicLinker {
   /** Interface to C language function: <br> <code> HANDLE LoadLibraryW(LPCWSTR lpLibFileName); </code>    */
   private static native long LoadLibraryW(java.lang.String lpLibFileName);
 
-
   @Override
   public final long openLibraryLocal(String libraryName, boolean debug) throws SecurityException {
     // How does that work under Windows ?
@@ -55,8 +53,10 @@ public final class WindowsDynamicLinkerImpl implements DynamicLinker {
   @Override
   public final long openLibraryGlobal(String libraryName, boolean debug) throws SecurityException {
     SecurityUtil.checkLinkPermission(libraryName);
-    long handle = LoadLibraryW(libraryName);
-    if(0==handle && debug) {
+    final long handle = LoadLibraryW(libraryName);
+    if( 0 != handle ) {
+        incrLibRefCount(handle, libraryName);
+    } else if ( DEBUG || debug ) {
         int err = GetLastError();
         System.err.println("LoadLibraryW \""+libraryName+"\" failed, error code: 0x"+Integer.toHexString(err)+", "+err);
     }
@@ -64,7 +64,20 @@ public final class WindowsDynamicLinkerImpl implements DynamicLinker {
   }
   
   @Override
-  public final long lookupSymbol(long libraryHandle, String symbolName) {
+  public final long lookupSymbolGlobal(String symbolName) throws SecurityException {
+    SecurityUtil.checkAllLinkPermission();
+    if(DEBUG_LOOKUP) {
+        System.err.println("lookupSymbolGlobal: Not supported on Windows");
+    }
+    // allow DynamicLibraryBundle to continue w/ local libs
+    return 0;
+  }
+
+  @Override
+  public final long lookupSymbol(long libraryHandle, String symbolName) throws IllegalArgumentException {
+    if( null == getLibRef( libraryHandle ) ) {
+        throw new IllegalArgumentException("Library handle 0x"+Long.toHexString(libraryHandle)+" unknown.");
+    }
     String _symbolName = symbolName;
     long addr = GetProcAddressA(libraryHandle, _symbolName);
     if(0==addr) {
@@ -84,16 +97,10 @@ public final class WindowsDynamicLinkerImpl implements DynamicLinker {
   }
   
   @Override
-  public final long lookupSymbolGlobal(String symbolName) {
-    if(DEBUG_LOOKUP) {
-        System.err.println("lookupSymbolGlobal: Not supported on Windows");
+  public final void closeLibrary(long libraryHandle) throws IllegalArgumentException {
+    if( null == decrLibRefCount( libraryHandle ) ) {
+        throw new IllegalArgumentException("Library handle 0x"+Long.toHexString(libraryHandle)+" unknown.");
     }
-    // allow DynamicLibraryBundle to continue w/ local libs
-    return 0;
-  }
-
-  @Override
-  public final void closeLibrary(long libraryHandle) {
     FreeLibrary(libraryHandle);
   }