aboutsummaryrefslogtreecommitdiffstats
path: root/src/jogl/classes/com/jogamp/opengl/util/AnimatorBase.java
blob: c2da68cd95366d69e9170751d973de4a455bb177 (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
644
645
646
647
648
649
650
651
652
653
/**
 * Copyright 2010 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.opengl.util;

import jogamp.opengl.Debug;
import jogamp.opengl.FPSCounterImpl;

import java.io.PrintStream;
import java.util.ArrayList;
import java.util.Locale;

import com.jogamp.opengl.GLAnimatorControl;
import com.jogamp.opengl.GLAutoDrawable;
import com.jogamp.opengl.GLException;
import com.jogamp.opengl.GLProfile;

import com.jogamp.common.ExceptionUtils;
import com.jogamp.common.util.InterruptedRuntimeException;

/**
 * Base implementation of GLAnimatorControl<br>
 * <p>
 * The change synchronization is done via synchronized blocks on the AnimatorBase instance.<br>
 * Status get / set activity is synced with a RecursiveLock, used as a memory barrier.<br>
 * This is suitable, since all change requests are allowed to be expensive
 * as they are not expected to be called at every frame.
 * </p>
 */
public abstract class AnimatorBase implements GLAnimatorControl {
    protected static final boolean DEBUG = Debug.debug("Animator");

    /** A 1s timeout while waiting for a native action response, limiting {@link #finishLifecycleAction(Condition, long)} */
    protected static final long TO_WAIT_FOR_FINISH_LIFECYCLE_ACTION = 1000;

    protected static final long POLLP_WAIT_FOR_FINISH_LIFECYCLE_ACTION = 32; // 2 frames @ 60Hz

    /**
     * If present in <code>modeBits</code> field and
     * {@link GLProfile#isAWTAvailable() AWT is available},
     * implementation is aware of the AWT EDT, otherwise not.
     * <p>
     * This is the <i>default</i>.
     * </p>
     * @see #setModeBits(boolean, int)
     */
    public static final int MODE_EXPECT_AWT_RENDERING_THREAD = 1 << 0;


    @SuppressWarnings("serial")
    public static class UncaughtAnimatorException extends RuntimeException {
        final GLAutoDrawable drawable;
        public UncaughtAnimatorException(final GLAutoDrawable drawable, final Throwable cause) {
            super(cause);
            this.drawable = drawable;
        }
        public final GLAutoDrawable getGLAutoDrawable() { return drawable; }
    }

    public static interface AnimatorImpl {
        /**
         * @param drawables
         * @param ignoreExceptions
         * @param printExceptions
         * @throws UncaughtAnimatorException as caused by {@link GLAutoDrawable#display()}
         */
        void display(final ArrayList<GLAutoDrawable> drawables, final boolean ignoreExceptions, final boolean printExceptions) throws UncaughtAnimatorException;
        boolean blockUntilDone(final Thread thread);
    }

    private static int seqInstanceNumber = 0;

    protected int modeBits;
    protected AnimatorImpl impl;
    protected String baseName;

    protected ArrayList<GLAutoDrawable> drawables = new ArrayList<GLAutoDrawable>();
    protected boolean drawablesEmpty;
    protected Thread animThread;
    protected boolean ignoreExceptions;
    protected boolean printExceptions;
    protected boolean exclusiveContext;
    protected Thread userExclusiveContextThread;
    protected UncaughtExceptionHandler uncaughtExceptionHandler;
    protected FPSCounterImpl fpsCounter = new FPSCounterImpl();

    private final static Class<?> awtAnimatorImplClazz;
    static {
        GLProfile.initSingleton();
        if( GLProfile.isAWTAvailable() ) {
            Class<?> clazz;
            try {
                clazz = Class.forName("com.jogamp.opengl.util.AWTAnimatorImpl");
            } catch (final Exception e) {
                clazz = null;
            }
            awtAnimatorImplClazz =  clazz;
        } else {
            awtAnimatorImplClazz = null;
        }
    }

    /**
     * Creates a new, empty Animator instance
     * while expecting an AWT rendering thread if AWT is available.
     *
     * @see GLProfile#isAWTAvailable()
     */
    public AnimatorBase() {
        modeBits = MODE_EXPECT_AWT_RENDERING_THREAD; // default!
        drawablesEmpty = true;
    }

    private static final boolean useAWTAnimatorImpl(final int modeBits) {
        return 0 != ( MODE_EXPECT_AWT_RENDERING_THREAD & modeBits ) && null != awtAnimatorImplClazz;
    }

    /**
     * Initializes implementation details post setup,
     * invoked at {@link #add(GLAutoDrawable)}, {@link #start()}, ..
     * <p>
     * Operation is a NOP if <code>force</code> is <code>false</code>
     * and this instance is already initialized.
     * </p>
     *
     * @throws GLException if Animator is {@link #isStarted()}
     */
    protected final synchronized void initImpl(final boolean force) {
        if( force || null == impl ) {
            final String seqSuffix = String.format((Locale)null, "#%02d", seqInstanceNumber++);
            if( useAWTAnimatorImpl( modeBits ) ) {
                try {
                    impl = (AnimatorImpl) awtAnimatorImplClazz.newInstance();
                    baseName = getBaseName("AWT")+seqSuffix;
                } catch (final Exception e) { e.printStackTrace(); }
            }
            if( null == impl ) {
                impl = new DefaultAnimatorImpl();
                baseName = getBaseName("")+seqSuffix;
            }
            if(DEBUG) {
                System.err.println("Animator.initImpl: baseName "+baseName+", implClazz "+impl.getClass().getName()+" - "+toString()+" - "+getThreadName());
            }
        }
    }
    protected abstract String getBaseName(String prefix);

    /**
     * Enables or disables the given <code>bitValues</code>
     * in this Animators <code>modeBits</code>.
     * @param enable
     * @param bitValues
     *
     * @throws GLException if Animator is {@link #isStarted()} and {@link #MODE_EXPECT_AWT_RENDERING_THREAD} about to change
     * @see AnimatorBase#MODE_EXPECT_AWT_RENDERING_THREAD
     */
    public final synchronized void setModeBits(final boolean enable, final int bitValues) throws GLException {
        final int _oldModeBits = modeBits;
        if(enable) {
            modeBits |=  bitValues;
        } else {
            modeBits &= ~bitValues;
        }
        if( useAWTAnimatorImpl( _oldModeBits ) != useAWTAnimatorImpl( modeBits ) ) {
            if( isStarted() ) {
                throw new GLException("Animator already started");
            }
            initImpl(true);
        }
    }
    public synchronized int getModeBits() { return modeBits; }


    @Override
    public final synchronized void add(final GLAutoDrawable drawable) {
        if(DEBUG) {
            System.err.println("Animator add: 0x"+Integer.toHexString(drawable.hashCode())+" - "+toString()+" - "+getThreadName());
        }
        if( drawables.contains(drawable) ) {
            throw new IllegalArgumentException("Drawable already added to animator: "+this+", "+drawable);
        }
        initImpl(false);
        pause();
        if( isStarted() ) {
            drawable.setExclusiveContextThread( exclusiveContext ? getExclusiveContextThread() : null ); // if already running ..
        }
        drawables.add(drawable);
        drawablesEmpty = drawables.size() == 0;
        drawable.setAnimator(this);
        if( isPaused() ) { // either paused by pause() above, or if previously drawablesEmpty==true
            resume();
        }
        final Condition waitForAnimatingAndECTCondition = new Condition() {
            @Override
            public boolean eval() {
                final Thread dect = drawable.getExclusiveContextThread();
                return isStarted() && !isPaused() && !isAnimating() && ( exclusiveContext && null == dect || !exclusiveContext && null != dect );
            } };
        final boolean res = finishLifecycleAction(waitForAnimatingAndECTCondition, 0);
        if(DEBUG) {
            System.err.println("Animator add: Wait for Animating/ECT OK: "+res+", "+toString()+", dect "+drawable.getExclusiveContextThread());
        }
        notifyAll();
    }

    @Override
    public final synchronized void remove(final GLAutoDrawable drawable) {
        if(DEBUG) {
            System.err.println("Animator remove: 0x"+Integer.toHexString(drawable.hashCode())+" - "+toString()+" - "+getThreadName());
        }
        if( !drawables.contains(drawable) ) {
            throw new IllegalArgumentException("Drawable not added to animator: "+this+", "+drawable);
        }

        if( exclusiveContext && isAnimating() ) {
            drawable.setExclusiveContextThread( null );
            final Condition waitForNullECTCondition = new Condition() {
                @Override
                public boolean eval() {
                    return null != drawable.getExclusiveContextThread();
                } };
            final boolean res = finishLifecycleAction(waitForNullECTCondition, POLLP_WAIT_FOR_FINISH_LIFECYCLE_ACTION);
            if(DEBUG) {
                System.err.println("Animator remove: Wait for Null-ECT OK: "+res+", "+toString()+", dect "+drawable.getExclusiveContextThread());
            }
        }

        final boolean paused = pause();
        drawables.remove(drawable);
        drawablesEmpty = drawables.size() == 0;
        drawable.setAnimator(null);
        if(paused) {
            resume();
        }
        final boolean res = finishLifecycleAction(waitForNotAnimatingIfEmptyCondition, 0);
        if(DEBUG) {
            System.err.println("Animator remove: Wait for !Animating-if-empty OK: "+res+", "+toString());
        }
        notifyAll();
    }
    private final Condition waitForNotAnimatingIfEmptyCondition = new Condition() {
        @Override
        public boolean eval() {
            return isStarted() && drawablesEmpty && isAnimating();
        } };


    /**
     * Dedicate all {@link GLAutoDrawable}'s context to the given exclusive context thread.
     * <p>
     * The given thread will be exclusive to all {@link GLAutoDrawable}'s context while {@link #isAnimating()}.
     * </p>
     * <p>
     * If already started and disabling, method waits
     * until change is propagated to all {@link GLAutoDrawable} if not
     * called from the animator thread or {@link #getExclusiveContextThread() exclusive context thread}.
     * </p>
     * <p>
     * Note: Utilizing this feature w/ AWT could lead to an AWT-EDT deadlock, depending on the AWT implementation.
     * Hence it is advised not to use it with native AWT GLAutoDrawable like GLCanvas.
     * </p>
     *
     * @param enable
     * @return previous value
     * @see #setExclusiveContext(boolean)
     * @see #getExclusiveContextThread()
     * @see #isExclusiveContextEnabled()
     */
    // @Override
    public final synchronized Thread setExclusiveContext(final Thread t) {
        final boolean enable = null != t;
        final Thread old = userExclusiveContextThread;
        if( enable && t != animThread ) { // disable: will be cleared at end after propagation && filter out own animThread usae
            userExclusiveContextThread=t;
        }
        setExclusiveContext(enable);
        return old;
    }

    /**
     * Dedicate all {@link GLAutoDrawable}'s context to this animator thread.
     * <p>
     * The given thread will be exclusive to all {@link GLAutoDrawable}'s context while {@link #isAnimating()}.
     * </p>
     * <p>
     * If already started and disabling, method waits
     * until change is propagated to all {@link GLAutoDrawable} if not
     * called from the animator thread or {@link #getExclusiveContextThread() exclusive context thread}.
     * </p>
     * <p>
     * Note: Utilizing this feature w/ AWT could lead to an AWT-EDT deadlock, depending on the AWT implementation.
     * Hence it is advised not to use it with native AWT GLAutoDrawable like GLCanvas.
     * </p>
     *
     * @param enable
     * @return previous value
     * @see #setExclusiveContext(Thread)
     * @see #getExclusiveContextThread()
     * @see #isExclusiveContextEnabled()
     */
    // @Override
    public final boolean setExclusiveContext(final boolean enable) {
        final boolean propagateState;
        final boolean oldExclusiveContext;
        final Thread _exclusiveContextThread;
        synchronized (AnimatorBase.this) {
            propagateState = isStarted() && !drawablesEmpty;
            _exclusiveContextThread = userExclusiveContextThread;
            oldExclusiveContext = exclusiveContext;
            exclusiveContext = enable;
            if(DEBUG) {
                System.err.println("AnimatorBase.setExclusiveContextThread: "+oldExclusiveContext+" -> "+exclusiveContext+", propagateState "+propagateState+", "+this);
            }
        }
        final Thread dECT = enable ? ( null != _exclusiveContextThread ? _exclusiveContextThread : animThread ) : null ;
        UncaughtAnimatorException displayCaught = null;
        if( propagateState ) {
            setDrawablesExclCtxState(enable);
            if( !enable ) {
                if( Thread.currentThread() == getThread() || Thread.currentThread() == _exclusiveContextThread ) {
                    try {
                        display(); // propagate exclusive context -> off!
                    } catch (final UncaughtAnimatorException dre) {
                        displayCaught = dre;
                    }
                } else {
                    final boolean resumed = isAnimating() ? false : resume();
                    int counter = 10;
                    while( 0<counter && isAnimating() && !validateDrawablesExclCtxState(dECT) ) {
                        try {
                            Thread.sleep(20);
                        } catch (final InterruptedException e) { }
                        counter--;
                    }
                    if(resumed) {
                        pause();
                    }
                }
                synchronized(AnimatorBase.this) {
                    userExclusiveContextThread=null;
                }
            }
        }
        if(DEBUG) {
            System.err.println("AnimatorBase.setExclusiveContextThread: all-GLAD Ok: "+validateDrawablesExclCtxState(dECT)+", "+this);
            if( null != displayCaught ) {
                System.err.println("AnimatorBase.setExclusiveContextThread: caught: "+displayCaught.getMessage());
                displayCaught.printStackTrace();
            }
        }
        if( null != displayCaught ) {
            throw displayCaught;
        }
        return oldExclusiveContext;
    }

    /**
     * Returns <code>true</code>, if the exclusive context thread is enabled, otherwise <code>false</code>.
     *
     * @see #setExclusiveContext(boolean)
     * @see #setExclusiveContext(Thread)
     */
    // @Override
    public final synchronized boolean isExclusiveContextEnabled() {
        return exclusiveContext;
    }

    /**
     * Returns the exclusive context thread if {@link #isExclusiveContextEnabled()} and {@link #isStarted()}, otherwise <code>null</code>.
     * <p>
     * If exclusive context is enabled via {@link #setExclusiveContext(boolean)}
     * the {@link #getThread() animator thread} is returned if above conditions are met.
     * </p>
     * <p>
     * If exclusive context is enabled via {@link #setExclusiveContext(Thread)}
     * the user passed thread is returned if above conditions are met.
     * </p>
     * @see #setExclusiveContext(boolean)
     * @see #setExclusiveContext(Thread)
     */
    // @Override
    public final synchronized Thread getExclusiveContextThread() {
        return ( isStarted() && exclusiveContext ) ? ( null != userExclusiveContextThread ? userExclusiveContextThread : animThread ) : null ;
    }

    /**
     * Should be called at {@link #start()} and {@link #stop()}
     * from within the animator thread.
     * <p>
     * At {@link #stop()} an additional {@link #display()} call shall be issued
     * to allow propagation of releasing the exclusive thread.
     * </p>
     */
    protected final synchronized void setDrawablesExclCtxState(final boolean enable) {
        if(DEBUG) {
            System.err.println("AnimatorBase.setExclusiveContextImpl exlusive "+exclusiveContext+": Enable "+enable+" for "+this+" - "+Thread.currentThread());
            // Thread.dumpStack();
        }
        final Thread ect = getExclusiveContextThread();
        for (int i=0; i<drawables.size(); i++) {
            try {
                drawables.get(i).setExclusiveContextThread( enable ? ect : null );
            } catch (final RuntimeException e) {
                e.printStackTrace();
            }
        }
    }
    protected final boolean validateDrawablesExclCtxState(final Thread expected) {
        for (int i=0; i<drawables.size(); i++) {
            if( expected != drawables.get(i).getExclusiveContextThread() ) {
                return false;
            }
        }
        return true;
    }

    @Override
    public final synchronized Thread getThread() {
        return animThread;
    }

    /** Called every frame to cause redrawing of all of the
        GLAutoDrawables this Animator manages. Subclasses should call
        this to get the most optimized painting behavior for the set of
        components this Animator manages, in particular when multiple
        lightweight widgets are continually being redrawn. */
    protected final void display() throws UncaughtAnimatorException {
        impl.display(drawables, ignoreExceptions, printExceptions);
        fpsCounter.tickFPS();
    }

    @Override
    public final void setUpdateFPSFrames(final int frames, final PrintStream out) {
        fpsCounter.setUpdateFPSFrames(frames, out);
    }

    @Override
    public final void resetFPSCounter() {
        fpsCounter.resetFPSCounter();
    }

    @Override
    public final int getUpdateFPSFrames() {
        return fpsCounter.getUpdateFPSFrames();
    }

    @Override
    public final long getFPSStartTime()   {
        return fpsCounter.getFPSStartTime();
    }

    @Override
    public final long getLastFPSUpdateTime() {
        return fpsCounter.getLastFPSUpdateTime();
    }

    @Override
    public final long getLastFPSPeriod() {
        return fpsCounter.getLastFPSPeriod();
    }

    @Override
    public final float getLastFPS() {
        return fpsCounter.getLastFPS();
    }

    @Override
    public final int getTotalFPSFrames() {
        return fpsCounter.getTotalFPSFrames();
    }

    @Override
    public final long getTotalFPSDuration() {
        return fpsCounter.getTotalFPSDuration();
    }

    @Override
    public final float getTotalFPS() {
        return fpsCounter.getTotalFPS();
    }

    /** Sets a flag causing this Animator to ignore exceptions produced
    while redrawing the drawables. By default this flag is set to
    false, causing any exception thrown to halt the Animator. */
    public final void setIgnoreExceptions(final boolean ignoreExceptions) {
        this.ignoreExceptions = ignoreExceptions;
    }

    /** Sets a flag indicating that when exceptions are being ignored by
    this Animator (see {@link #setIgnoreExceptions}), to print the
    exceptions' stack traces for diagnostic information. Defaults to
    false. */
    public final void setPrintExceptions(final boolean printExceptions) {
        this.printExceptions = printExceptions;
    }

    @Override
    public final UncaughtExceptionHandler getUncaughtExceptionHandler() {
        return uncaughtExceptionHandler;
    }

    @Override
    public final void setUncaughtExceptionHandler(final UncaughtExceptionHandler handler) {
        uncaughtExceptionHandler = handler;
    }

    /**
     * Should be called in case of an uncaught exception
     * from within the animator thread, throws given exception if no handler has been installed.
     * @return {@code true} if handled, otherwise {@code false}. In case of {@code false},
     *         caller needs to propagate the exception.
     */
    protected final synchronized boolean handleUncaughtException(final UncaughtAnimatorException ue) {
        if( null != uncaughtExceptionHandler ) {
            try {
                uncaughtExceptionHandler.uncaughtException(this, ue.getGLAutoDrawable(), ue.getCause());
            } catch (final Throwable t) { /* ignore intentionally */ }
            return true;
        } else {
            return false;
        }
    }

    /**
     * Should be called in case of an uncaught exception
     * from within the animator thread to flush all animator.
     * <p>
     * The animator instance shall not be locked when calling this method!
     * </p>
     */
    protected final void flushGLRunnables() {
        for (int i=0; i<drawables.size(); i++) {
            drawables.get(i).flushGLRunnables();
        }
    }

    protected static interface Condition {
        /**
         * @return true if branching (continue waiting, action), otherwise false
         */
        boolean eval();
    }

    /**
     * @param waitCondition method will wait until TO is reached or {@link Condition#eval() waitCondition.eval()} returns <code>false</code>.
     * @param pollPeriod if <code>0</code>, method will wait until TO is reached or being notified.
     *                   if &gt; <code>0</code>, method will wait for the given <code>pollPeriod</code> in milliseconds.
     * @return <code>true</code> if {@link Condition#eval() waitCondition.eval()} returned <code>false</code>
     *         or if {@link AnimatorImpl#blockUntilDone(Thread) non-blocking}. Otherwise returns <code>false</code>.
     */
    protected final synchronized boolean finishLifecycleAction(final Condition waitCondition, long pollPeriod) {
        /**
         * It's hard to tell whether the thread which changes the lifecycle has
         * dependencies on the Animator's internal thread. Currently we
         * use a couple of heuristics to determine whether we should do
         * the blocking wait().
         */
        initImpl(false);
        final boolean blocking;
        long remaining;
        boolean nok;

        if( impl.blockUntilDone(animThread) ) {
            blocking = true;
            remaining = TO_WAIT_FOR_FINISH_LIFECYCLE_ACTION;
            if( 0 >= pollPeriod ) {
                pollPeriod = remaining;
            }
            nok = waitCondition.eval();
            while ( nok && remaining>0 ) {
                final long t1 = System.currentTimeMillis();
                if( pollPeriod > remaining ) { pollPeriod = remaining; }
                notifyAll();
                try {
                    wait(pollPeriod);
                } catch (final InterruptedException ie) {
                    throw new InterruptedRuntimeException(ie);
                }
                remaining -= System.currentTimeMillis() - t1 ;
                nok = waitCondition.eval();
            }
        } else {
            /**
             * Even though we are not able to block until operation is completed at this point,
             * best effort shall be made to preserve functionality.
             * Here: Issue notifyAll() if waitCondition still holds and test again.
             *
             * Non blocking reason could be utilizing AWT Animator while operation is performed on AWT-EDT.
             */
            blocking = false;
            remaining = 0;
            nok = waitCondition.eval();
            if( nok ) {
                notifyAll();
                nok = waitCondition.eval();
            }
        }
        final boolean res = !nok || !blocking;
        if(DEBUG || blocking && nok) { // Info only if DEBUG or ( blocking && not-ok ) ; !blocking possible if AWT
            if( blocking && remaining<=0 && nok ) {
                System.err.println("finishLifecycleAction(" + waitCondition.getClass().getName() + "): ++++++ timeout reached ++++++ " + getThreadName());
            }
            System.err.println("finishLifecycleAction(" + waitCondition.getClass().getName() + "): OK "+(!nok)+
                    "- pollPeriod "+pollPeriod+", blocking "+blocking+" -> res "+res+
                    ", waited " + (blocking ? ( TO_WAIT_FOR_FINISH_LIFECYCLE_ACTION - remaining ) : 0 ) + "/" + TO_WAIT_FOR_FINISH_LIFECYCLE_ACTION +
                    " - " + getThreadName());
            System.err.println(" - "+toString());
            if(nok) {
                ExceptionUtils.dumpStack(System.err);
            }
        }
        return res;
    }

    @Override
    public synchronized boolean isStarted() {
        return animThread != null ;
    }

    protected static String getThreadName() { return Thread.currentThread().getName(); }

    @Override
    public String toString() {
        return getClass().getName()+"[started "+isStarted()+", animating "+isAnimating()+", paused "+isPaused()+", drawable "+drawables.size()+
               ", totals[dt "+getTotalFPSDuration()+", frames "+getTotalFPSFrames()+", fps "+getTotalFPS()+
               "], modeBits "+modeBits+", init'ed "+(null!=impl)+", animThread "+getThread()+", exclCtxThread "+exclusiveContext+"("+getExclusiveContextThread()+")]";
    }
}