summaryrefslogtreecommitdiffstats
path: root/src/java/com/jogamp/common/jvm/JNILibLoaderBase.java
blob: 4e62d54d8244907bea5eb57063686b571fe9ac51 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
/*
 * Copyright (c) 2003 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.
 */

package com.jogamp.common.jvm;

import java.io.IOException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.URISyntaxException;
import java.net.URL;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;

import com.jogamp.common.net.Uri;
import com.jogamp.common.os.NativeLibrary;
import com.jogamp.common.util.JarUtil;
import com.jogamp.common.util.PropertyAccess;
import com.jogamp.common.util.cache.TempJarCache;

import jogamp.common.Debug;
import jogamp.common.os.PlatformPropsImpl;

public class JNILibLoaderBase {
  public static final boolean DEBUG;
  protected static final boolean PERF;

  static {
      Debug.initSingleton();
      DEBUG = Debug.debug("JNILibLoader");
      PERF = DEBUG || PropertyAccess.isPropertyDefined("jogamp.debug.JNILibLoader.Perf", true);
  }

  private static final Object perfSync = new Object();
  private static long perfTotal = 0;
  private static long perfCount = 0;

  public interface LoaderAction {
    /**
     * Loads the library specified by libname.<br>
     * The implementation should ignore, if the library has been loaded already.<br>
     * @param libname the library to load
     * @param ignoreError if true, errors during loading the library should be ignored
     * @param cl optional ClassLoader, used to locate the library
     * @return true if library loaded successful
     */
    boolean loadLibrary(String libname, boolean ignoreError, ClassLoader cl);

    /**
     * Loads the library specified by libname.<br>
     * Optionally preloads the libraries specified by preload.<br>
     * The implementation should ignore, if any library has been loaded already.<br>
     * @param libname the library to load
     * @param preload the libraries to load before loading the main library if not null
     * @param preloadIgnoreError if true, errors during loading the preload-libraries should be ignored
     * @param cl optional ClassLoader, used to locate the library
     */
    void loadLibrary(String libname, String[] preload, boolean preloadIgnoreError, ClassLoader cl);
  }

  private static class DefaultAction implements LoaderAction {
    @Override
    public boolean loadLibrary(final String libname, final boolean ignoreError, final ClassLoader cl) {
      boolean res = true;
      if(!isLoaded(libname)) {
          try {
            loadLibraryInternal(libname, cl);
            addLoaded(libname);
            if(DEBUG) {
                System.err.println("JNILibLoaderBase: loaded "+libname);
            }
          } catch (final UnsatisfiedLinkError e) {
            res = false;
            if(DEBUG) {
                e.printStackTrace();
            }
            if (!ignoreError && e.getMessage().indexOf("already loaded") < 0) {
              throw e;
            }
          }
      }
      return res;
    }

    @Override
    public void loadLibrary(final String libname, final String[] preload, final boolean preloadIgnoreError, final ClassLoader cl) {
      if(!isLoaded(libname)) {
          if (null!=preload) {
            for (int i=0; i<preload.length; i++) {
              loadLibrary(preload[i], preloadIgnoreError, cl);
            }
          }
          loadLibrary(libname, false, cl);
      }
    }
  }

  private static final HashSet<String> loaded = new HashSet<String>();
  private static LoaderAction loaderAction = new DefaultAction();

  public static boolean isLoaded(final String libName) {
    return loaded.contains(libName);
  }

  public static void addLoaded(final String libName) {
    loaded.add(libName);
    if(DEBUG) {
        System.err.println("JNILibLoaderBase: Loaded Native Library: "+libName);
    }
  }

  public static void disableLoading() {
    setLoadingAction(null);
  }

  public static void enableLoading() {
    setLoadingAction(new DefaultAction());
  }

  public static synchronized void setLoadingAction(final LoaderAction action) {
    loaderAction = action;
  }

  private static final String nativeJarTagPackage = "jogamp.nativetag"; // TODO: sync with gluegen-cpptasks-base.xml

  /**
   *
   * @param classFromJavaJar
   * @param classJarUri
   * @param jarBasename jar basename w/ suffix
   * @param nativeJarBasename native jar basename w/ suffix
   * @return
   * @throws IOException
   * @throws SecurityException
   * @throws URISyntaxException
   */
  private static final boolean addNativeJarLibsImpl(final Class<?> classFromJavaJar, final Uri classJarUri,
                                                    final Uri.Encoded jarBasename, final Uri.Encoded nativeJarBasename)
    throws IOException, SecurityException, URISyntaxException
  {
    if (DEBUG) {
        final StringBuilder msg = new StringBuilder();
        msg.append("JNILibLoaderBase: addNativeJarLibsImpl(").append(PlatformPropsImpl.NEWLINE);
        msg.append("  classFromJavaJar  = ").append(classFromJavaJar).append(PlatformPropsImpl.NEWLINE);
        msg.append("  classJarURI       = ").append(classJarUri).append(PlatformPropsImpl.NEWLINE);
        msg.append("  jarBasename       = ").append(jarBasename).append(PlatformPropsImpl.NEWLINE);
        msg.append("  os.and.arch       = ").append(PlatformPropsImpl.os_and_arch).append(PlatformPropsImpl.NEWLINE);
        msg.append("  nativeJarBasename = ").append(nativeJarBasename).append(PlatformPropsImpl.NEWLINE);
        msg.append(")");
        System.err.println(msg.toString());
    }
    final long t0 = PERF ? System.currentTimeMillis() : 0; // 'Platform.currentTimeMillis()' not yet available!

    boolean ok = false;

    final Uri jarSubURI = classJarUri.getContainedUri();
    if (null == jarSubURI) {
        throw new IllegalArgumentException("JarSubURI is null of: "+classJarUri);
    }

    final Uri jarSubUriRoot = jarSubURI.getDirectory();

    if (DEBUG) {
        System.err.printf("JNILibLoaderBase: addNativeJarLibsImpl: initial: %s -> %s%n", jarSubURI, jarSubUriRoot);
    }

    final String nativeLibraryPath = String.format((Locale)null, "natives/%s/", PlatformPropsImpl.os_and_arch);
    if (DEBUG) {
        System.err.printf("JNILibLoaderBase: addNativeJarLibsImpl: nativeLibraryPath: %s%n", nativeLibraryPath);
    }
    {
        // Attempt-1 a 'one slim native jar file' per 'os.and.arch' layout
        // with native platform libraries under 'natives/os.and.arch'!
        final Uri nativeJarURI = JarUtil.getJarFileUri( jarSubUriRoot.getEncoded().concat(nativeJarBasename) );

        if (DEBUG) {
            System.err.printf("JNILibLoaderBase: addNativeJarLibsImpl: module: %s -> %s%n", nativeJarBasename, nativeJarURI);
        }

        try {
            ok = TempJarCache.addNativeLibs(classFromJavaJar, nativeJarURI, nativeLibraryPath);
        } catch(final Exception e) {
            if(DEBUG) {
                System.err.printf("JNILibLoaderBase: addNativeJarLibsImpl: Caught %s%n", e.getMessage());
                e.printStackTrace();
            }
        }
    }
    if (!ok) {
        final ClassLoader cl = classFromJavaJar.getClassLoader();
        {
            // Attempt-2 a 'one big-fat jar file' layout, containing java classes
            // and all native platform libraries under 'natives/os.and.arch' per platform!
            final URL nativeLibraryURI = cl.getResource(nativeLibraryPath);
            if (null != nativeLibraryURI) {
                final Uri nativeJarURI = JarUtil.getJarFileUri( jarSubUriRoot.getEncoded().concat(jarBasename) );
                try {
                    if( TempJarCache.addNativeLibs(classFromJavaJar, nativeJarURI, nativeLibraryPath) ) {
                        ok = true;
                        if (DEBUG) {
                            System.err.printf("JNILibLoaderBase: addNativeJarLibsImpl: fat: %s -> %s%n", jarBasename, nativeJarURI);
                        }
                    }
                } catch(final Exception e) {
                    if(DEBUG) {
                        System.err.printf("JNILibLoaderBase: addNativeJarLibsImpl: Caught %s%n", e.getMessage());
                        e.printStackTrace();
                    }
                }
            }
        }
        if (!ok) {
            // Attempt-3 to find via ClassLoader and Native-Jar-Tag,
            // assuming one slim native jar file per 'os.and.arch'
            // and native platform libraries under 'natives/os.and.arch'!
            final String moduleName;
            {
                final String packageName = classFromJavaJar.getPackage().getName();
                final int idx = packageName.lastIndexOf('.');
                if( 0 <= idx ) {
                    moduleName = packageName.substring(idx+1);
                } else {
                    moduleName = packageName;
                }
            }
            final String os_and_arch_dot = PlatformPropsImpl.os_and_arch.replace('-', '.');
            final String nativeJarTagClassName = nativeJarTagPackage + "." + moduleName + "." + os_and_arch_dot + ".TAG"; // TODO: sync with gluegen-cpptasks-base.xml
            try {
                if(DEBUG) {
                    System.err.printf("JNILibLoaderBase: addNativeJarLibsImpl: ClassLoader/TAG: Locating module %s, os.and.arch %s: %s%n",
                            moduleName, os_and_arch_dot, nativeJarTagClassName);
                }
                final Uri nativeJarTagClassJarURI = JarUtil.getJarUri(nativeJarTagClassName, cl);
                if (DEBUG) {
                    System.err.printf("JNILibLoaderBase: addNativeJarLibsImpl: ClassLoader/TAG: %s -> %s%n", nativeJarTagClassName, nativeJarTagClassJarURI);
                }
                ok = TempJarCache.addNativeLibs(classFromJavaJar, nativeJarTagClassJarURI, nativeLibraryPath);
            } catch (final Exception e ) {
                if(DEBUG) {
                    System.err.printf("JNILibLoaderBase: addNativeJarLibsImpl: Caught %s%n", e.getMessage());
                    e.printStackTrace();
                }
            }
        }
    }

    if (DEBUG || PERF) {
        final long tNow = System.currentTimeMillis() - t0;
        final long tTotal, tCount;
        synchronized(perfSync) {
            tCount = perfCount+1;
            tTotal = perfTotal + tNow;
            perfTotal = tTotal;
            perfCount = tCount;
        }
        final double tAvrg = tTotal / (double)tCount;
        System.err.printf("JNILibLoaderBase: addNativeJarLibsImpl.X: %s / %s -> ok: %b; duration: now %d ms, total %d ms (count %d, avrg %.3f ms)%n",
                          jarBasename, nativeJarBasename, ok, tNow, tTotal, tCount, tAvrg);
    }
    return ok;
  }

  /**
   * Loads and adds a JAR file's native library to the TempJarCache,
   * calling {@link JNILibLoaderBase#addNativeJarLibs(Class[], String)}
   * with default JOGL deployment configuration:
   * <pre>
        return JNILibLoaderBase.addNativeJarLibs(classesFromJavaJars, "-all");
   * </pre>
   * If <code>Class1.class</code> is contained in a JAR file which name includes <code>singleJarMarker</code> <i>-all</i>,
   * implementation will attempt to resolve the native JAR file as follows:
   * <ul>
   *   <li><i>ClassJar-all</i>.jar to <i>ClassJar-all</i>-natives-<i>os.and.arch</i>.jar</li>
   * </ul>
   * Otherwise the native JAR files will be resolved for each class's JAR file:
   * <ul>
   *   <li><i>ClassJar1</i>.jar to <i>ClassJar1</i>-natives-<i>os.and.arch</i>.jar</li>
   *   <li><i>ClassJar2</i>.jar to <i>ClassJar2</i>-natives-<i>os.and.arch</i>.jar</li>
   *   <li>..</li>
   * </ul>
   */

  public static final boolean addNativeJarLibsJoglCfg(final Class<?>[] classesFromJavaJars) {
      return addNativeJarLibs(classesFromJavaJars, "-all");
  }

  /**
   * Loads and adds a JAR file's native library to the TempJarCache.<br>
   * The native library JAR file's URI is derived as follows:
   * <ul>
   *   <li> [1] <code>GLProfile.class</code> -> </li>
   *   <li> [2] <code>http://lala/gluegen-rt.jar</code> -> </li>
   *   <li> [3] <code>http://lala/gluegen-rt</code> -> </li>
   *   <li> [4] <code>http://lala/gluegen-rt-natives-'os.and.arch'.jar</code> </li>
   * </ul>
   * Where:
   * <ul>
   *   <li> [1] is one of <code>classesFromJavaJars</code></li>
   *   <li> [2] is it's complete URI</li>
   *   <li> [3] is it's <i>base URI</i></li>
   *   <li> [4] is the derived native JAR filename</li>
   * </ul>
   * <p>
   * Generic description:
   * <pre>
       final Class<?>[] classesFromJavaJars = new Class<?>[] { Class1.class, Class2.class };
       JNILibLoaderBase.addNativeJarLibs(classesFromJavaJars, "-all");
   * </pre>
   * If <code>Class1.class</code> is contained in a JAR file which name includes <code>singleJarMarker</code>, here <i>-all</i>,
   * implementation will attempt to resolve the native JAR file as follows:
   * <ul>
   *   <li><i>ClassJar-all</i>.jar to <i>ClassJar-all</i>-natives-<i>os.and.arch</i>.jar</li>
   * </ul>
   * Otherwise the native JAR files will be resolved for each class's JAR file:
   * <ul>
   *   <li><i>Class1Jar</i>.jar to <i>Class1Jar</i>-natives-<i>os.and.arch</i>.jar</li>
   *   <li><i>Class2Jar</i>.jar to <i>Class2Jar</i>-natives-<i>os.and.arch</i>.jar</li>
   * </ul>
   * </p>
   * <p>
   * Examples:
   * </p>
   * <p>
   * JOCL:
   * <pre>
        // only: jocl.jar -> jocl-natives-<i>os.and.arch</i>.jar
        addNativeJarLibs(new Class<?>[] { JOCLJNILibLoader.class }, null, null );
   * </pre>
   * </p>
   * <p>
   * JOGL:
   * <pre>
       final ClassLoader cl = GLProfile.class.getClassLoader();
       // jogl-all.jar         -> jogl-all-natives-<i>os.and.arch</i>.jar
       // jogl-all-noawt.jar   -> jogl-all-noawt-natives-<i>os.and.arch</i>.jar
       // jogl-all-mobile.jar  -> jogl-all-mobile-natives-<i>os.and.arch</i>.jar
       // jogl-all-android.jar -> jogl-all-android-natives-<i>os.and.arch</i>.jar
       // nativewindow.jar     -> nativewindow-natives-<i>os.and.arch</i>.jar
       // jogl.jar             -> jogl-natives-<i>os.and.arch</i>.jar
       // newt.jar             -> newt-natives-<i>os.and.arch</i>.jar (if available)
       final String newtFactoryClassName = "com.jogamp.newt.NewtFactory";
       final Class<?>[] classesFromJavaJars = new Class<?>[] { NWJNILibLoader.class, GLProfile.class, null };
       if( ReflectionUtil.isClassAvailable(newtFactoryClassName, cl) ) {
           classesFromJavaJars[2] = ReflectionUtil.getClass(newtFactoryClassName, false, cl);
       }
       JNILibLoaderBase.addNativeJarLibs(classesFromJavaJars, "-all");
   * </pre>
   * </p>
   *
   * @param classesFromJavaJars For each given Class, load the native library JAR.
   * @param singleJarMarker Optional string marker like "-all" to identify the single 'all-in-one' JAR file
   *                        after which processing of the class array shall stop.
   *
   * @return true if either the 'all-in-one' native JAR or all native JARs loaded successful or were loaded already,
   *         false in case of an error
   */
  public static boolean addNativeJarLibs(final Class<?>[] classesFromJavaJars, final String singleJarMarker) {
    if(DEBUG) {
        final StringBuilder msg = new StringBuilder();
        msg.append("JNILibLoaderBase: addNativeJarLibs(").append(PlatformPropsImpl.NEWLINE);
        msg.append("  classesFromJavaJars   = ").append(Arrays.asList(classesFromJavaJars)).append(PlatformPropsImpl.NEWLINE);
        msg.append("  singleJarMarker       = ").append(singleJarMarker).append(PlatformPropsImpl.NEWLINE);
        msg.append(")");
        System.err.println(msg.toString());
    }

    boolean ok = false;
    if (TempJarCache.isInitialized()) {
        ok = addNativeJarLibsWithTempJarCache(classesFromJavaJars, singleJarMarker);
    } else if(DEBUG) {
        System.err.println("JNILibLoaderBase: addNativeJarLibs0: disabled due to uninitialized TempJarCache");
    }
    return ok;
  }

  private static boolean addNativeJarLibsWithTempJarCache(final Class<?>[] classesFromJavaJars, final String singleJarMarker) {
      boolean ok;
      int count = 0;
      try {
          boolean done = false;
          ok = true;

          for (int i = 0; i < classesFromJavaJars.length; ++i) {
              final Class<?> c = classesFromJavaJars[i];
              if (c == null) {
                  continue;
              }

              final ClassLoader cl = c.getClassLoader();
              final Uri classJarURI = JarUtil.getJarUri(c.getName(), cl);
              final Uri.Encoded jarName = JarUtil.getJarBasename(classJarURI);

              if (jarName == null) {
                  continue;
              }

              final Uri.Encoded jarBasename = jarName.substring(0, jarName.indexOf(".jar"));

              if(DEBUG) {
                  System.err.printf("JNILibLoaderBase: jarBasename: %s%n", jarBasename);
              }

              /**
               * If a jar marker was specified, and the basename contains the
               * marker, we're done.
               */

              if (singleJarMarker != null) {
                  if (jarBasename.indexOf(singleJarMarker) >= 0) {
                      done = true;
                  }
              }

              final Uri.Encoded nativeJarBasename =
                      Uri.Encoded.cast( String.format((Locale)null, "%s-natives-%s.jar", jarBasename.get(), PlatformPropsImpl.os_and_arch) );

              ok = JNILibLoaderBase.addNativeJarLibsImpl(c, classJarURI, jarName, nativeJarBasename);
              if (ok) {
                  count++;
              }
              if (DEBUG && done) {
                  System.err.printf("JNILibLoaderBase: addNativeJarLibs0: done: %s%n", jarBasename);
              }
          }
      } catch (final Exception x) {
          System.err.printf("JNILibLoaderBase: Caught %s: %s%n", x.getClass().getSimpleName(), x.getMessage());
          if(DEBUG) {
              x.printStackTrace();
          }
          ok = false;
      }
      if(DEBUG) {
          System.err.printf("JNILibLoaderBase: addNativeJarLibsWhenInitialized: count %d, ok %b%n", count, ok);
      }
      return ok;
  }

  /**
   * Loads the library specified by libname, using the {@link LoaderAction} set by {@link #setLoadingAction(LoaderAction)}.<br>
   * The implementation should ignore, if the library has been loaded already.<br>
   * @param libname the library to load
   * @param ignoreError if true, errors during loading the library should be ignored
   * @param cl optional ClassLoader, used to locate the library
   * @return true if library loaded successful
   */
  protected static synchronized boolean loadLibrary(final String libname, final boolean ignoreError, final ClassLoader cl) {
      if (loaderAction != null) {
          return loaderAction.loadLibrary(libname, ignoreError, cl);
      }
      return false;
  }

  /**
   * Loads the library specified by libname, using the {@link LoaderAction} set by {@link #setLoadingAction(LoaderAction)}.<br>
   * Optionally preloads the libraries specified by preload.<br>
   * The implementation should ignore, if any library has been loaded already.<br>
   * @param libname the library to load
   * @param preload the libraries to load before loading the main library if not null
   * @param preloadIgnoreError if true, errors during loading the preload-libraries should be ignored
   * @param cl optional ClassLoader, used to locate the library
   */
  protected static synchronized void loadLibrary(final String libname, final String[] preload, final boolean preloadIgnoreError, final ClassLoader cl) {
      if (loaderAction != null) {
          loaderAction.loadLibrary(libname, preload, preloadIgnoreError, cl);
      }
  }

  // private static final Class<?> customLauncherClass; // FIXME: remove
  private static final Method customLoadLibraryMethod;

  static {
    final String sunAppletLauncherProperty = "sun.jnlp.applet.launcher";
    final String sunAppletLauncherClassName = "org.jdesktop.applet.util.JNLPAppletLauncher";

    final Method loadLibraryMethod = AccessController.doPrivileged(new PrivilegedAction<Method>() {
        @Override
        public Method run() {
            // FIXME: remove
            final boolean usingJNLPAppletLauncher = PropertyAccess.getBooleanProperty(sunAppletLauncherProperty, true);

            Class<?> launcherClass = null;
            Method loadLibraryMethod = null;

            if (usingJNLPAppletLauncher) {
                try {
                  launcherClass = Class.forName(sunAppletLauncherClassName);
                } catch (final ClassNotFoundException cnfe) {
                  // oops .. look like JNLPAppletLauncher doesn't exist, despite property
                  // this may happen if a previous applet was using JNLPAppletLauncher in the same JVM
                  System.err.println("JNILibLoaderBase: <"+sunAppletLauncherClassName+"> not found, despite enabled property <"+sunAppletLauncherProperty+">, JNLPAppletLauncher was probably used before");
                  System.setProperty(sunAppletLauncherProperty, Boolean.FALSE.toString());
                } catch (final LinkageError le) {
                    throw le;
                }
                if(null != launcherClass) {
                   try {
                      loadLibraryMethod = launcherClass.getDeclaredMethod("loadLibrary", new Class[] { String.class });
                   } catch (final NoSuchMethodException ex) {
                        if(DEBUG) {
                            ex.printStackTrace();
                        }
                        launcherClass = null;
                   }
                }
            }
            if(null==launcherClass) {
                final String launcherClassName = PropertyAccess.getProperty("jnlp.launcher.class", false);
                if(null!=launcherClassName) {
                    try {
                        launcherClass = Class.forName(launcherClassName);
                        loadLibraryMethod = launcherClass.getDeclaredMethod("loadLibrary", new Class[] { String.class });
                    } catch (final ClassNotFoundException ex) {
                        if(DEBUG) {
                            ex.printStackTrace();
                        }
                    } catch (final NoSuchMethodException ex) {
                        if(DEBUG) {
                            ex.printStackTrace();
                        }
                        launcherClass = null;
                    }
                }
            }
            return loadLibraryMethod;
        } } );
    customLoadLibraryMethod = loadLibraryMethod;
  }

  private static void loadLibraryInternal(final String libraryName, final ClassLoader cl) {
      // Note: special-casing JAWT which is built in to the JDK
      int mode = 0; // 1 - custom, 2 - System.load( TempJarCache ), 3 - System.loadLibrary( name ), 4 - System.load( enumLibNames )
      if (null!=customLoadLibraryMethod && !libraryName.equals("jawt")) {
          // FIXME: remove
          if(DEBUG) {
              System.err.println("JNILibLoaderBase: customLoad("+libraryName+") - mode 1");
          }
          try {
              customLoadLibraryMethod.invoke(null, new Object[] { libraryName });
              mode = 1;
          } catch (final Exception e) {
              Throwable t = e;
              if (t instanceof InvocationTargetException) {
                  t = ((InvocationTargetException) t).getTargetException();
              }
              if (t instanceof Error) {
                  throw (Error) t;
              }
              if (t instanceof RuntimeException) {
                  throw (RuntimeException) t;
              }
              // Throw UnsatisfiedLinkError for best compatibility with System.loadLibrary()
              throw (UnsatisfiedLinkError) new UnsatisfiedLinkError("can not load library "+libraryName).initCause(e);
          }
      } else {
          // System.err.println("sun.boot.library.path=" + Debug.getProperty("sun.boot.library.path", false));
          final String libraryPath = NativeLibrary.findLibrary(libraryName, cl); // implicit TempJarCache usage if used/initialized
          if(DEBUG) {
              System.err.println("JNILibLoaderBase: loadLibraryInternal("+libraryName+"), TempJarCache: "+libraryPath);
          }
          if(null != libraryPath) {
              if(DEBUG) {
                  System.err.println("JNILibLoaderBase: System.load("+libraryPath+") - mode 2");
              }
              System.load(libraryPath);
              mode = 2;
          } else {
              if(DEBUG) {
                  System.err.println("JNILibLoaderBase: System.loadLibrary("+libraryName+") - mode 3");
              }
              try {
                  System.loadLibrary(libraryName);
                  mode = 3;
              } catch (final UnsatisfiedLinkError ex1) {
                  if(DEBUG) {
                      System.err.println("ERROR (retry w/ enumLibPath) - "+ex1.getMessage());
                  }
                  final List<String> possiblePaths = NativeLibrary.enumerateLibraryPaths(libraryName, libraryName, libraryName, cl);
                  // Iterate down these and see which one if any we can actually find.
                  for (final Iterator<String> iter = possiblePaths.iterator(); 0 == mode && iter.hasNext(); ) {
                      final String path = iter.next();
                      if (DEBUG) {
                          System.err.println("JNILibLoaderBase: System.load("+path+") - mode 4");
                      }
                      try {
                          System.load(path);
                          mode = 4;
                      } catch (final UnsatisfiedLinkError ex2) {
                          if(DEBUG) {
                              System.err.println("n/a - "+ex2.getMessage());
                          }
                          if(!iter.hasNext()) {
                              throw ex2;
                          }
                      }
                  }
              }
          }
      }
      if(DEBUG) {
          System.err.println("JNILibLoaderBase: loadLibraryInternal("+libraryName+"): OK - mode "+mode);
      }
  }
}