1 /*
2 * Copyright 2003-2008 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Sun designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Sun in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22 * CA 95054 USA or visit www.sun.com if you need additional information or
23 * have any questions.
24 */
25
26 package sun.font;
27
28 import java.awt.GraphicsConfiguration;
29 import java.awt.GraphicsEnvironment;
30 import java.lang.ref.Reference;
31 import java.lang.ref.ReferenceQueue;
32 import java.lang.ref.SoftReference;
33 import java.lang.ref.WeakReference;
34
35 import sun.java2d.Disposer;
36 import sun.java2d.pipe.BufferedContext;
37 import sun.java2d.pipe.RenderQueue;
38 import sun.java2d.pipe.hw.AccelGraphicsConfig;
39 import sun.misc.Unsafe;
40
41 /**
42
43 A FontStrike is the keeper of scaled glyph image data which is expensive
44 to compute so needs to be cached.
45 So long as that data may be being used it cannot be invalidated.
46 Yet we also need to limit the amount of native memory and number of
47 strike objects in use.
48 For scaleability and ease of use, a key goal is multi-threaded read
49 access to a strike, so that it may be shared by multiple client objects,
50 potentially executing on different threads, with no special reference
51 counting or "check-out/check-in" requirements which would pass on the
52 burden of keeping track of strike references to the SG2D and other clients.
53
54 A cache of strikes is maintained via Reference objects.
55 This helps in two ways :
56 1. The VM will free references when memory is low or they have not been
57 used in a long time.
58 2. Reference queues provide a way to get notification of this so we can
59 free native memory resources.
60
61 */
62
63 public final class StrikeCache {
64
65 static final Unsafe unsafe = Unsafe.getUnsafe();
66
67 static ReferenceQueue refQueue = Disposer.getQueue();
68
69 /* Reference objects may have their referents cleared when GC chooses.
70 * During application client start-up there is typically at least one
71 * GC which causes the hotspot VM to clear soft (not just weak) references
72 * Thus not only is there a GC pause, but the work done do rasterise
73 * glyphs that are fairly certain to be needed again almost immediately
74 * is thrown away. So for performance reasons a simple optimisation is to
75 * keep up to 8 strong references to strikes to reduce the chance of
76 * GC'ing strikes that have been used recently. Note that this may not
77 * suffice in Solaris UTF-8 locales where a single composite strike may be
78 * composed of 15 individual strikes, plus the composite strike.
79 * And this assumes the new architecture doesn't maintain strikes for
80 * natively accessed bitmaps. It may be worth "tuning" the number of
81 * strikes kept around for the platform or locale.
82 * Since no attempt is made to ensure uniqueness or ensure synchronized
83 * access there is no guarantee that this cache will ensure that unique
84 * strikes are cached. Every time a strike is looked up it is added
85 * to the current index in this cache. All this cache has to do to be
86 * worthwhile is prevent excessive cache flushing of strikes that are
87 * referenced frequently. The logic that adds references here could be
88 * tweaked to keep only strikes that represent untransformed, screen
89 * sizes as that's the typical performance case.
90 */
91 static int MINSTRIKES = 8; // can be overridden by property
92 static int recentStrikeIndex = 0;
93 static FontStrike[] recentStrikes;
94 static boolean cacheRefTypeWeak;
95
96 /*
97 * Native sizes and offsets for glyph cache
98 * There are 10 values.
99 */
100 static int nativeAddressSize;
101 static int glyphInfoSize;
102 static int xAdvanceOffset;
103 static int yAdvanceOffset;
104 static int boundsOffset;
105 static int widthOffset;
106 static int heightOffset;
107 static int rowBytesOffset;
108 static int topLeftXOffset;
109 static int topLeftYOffset;
110 static int pixelDataOffset;
111 static long invisibleGlyphPtr;
112
113 /* Native method used to return information used for unsafe
114 * access to native data.
115 * return values as follows:-
116 * arr[0] = size of an address/pointer.
117 * arr[1] = size of a GlyphInfo
118 * arr[2] = offset of advanceX
119 * arr[3] = offset of advanceY
120 * arr[4] = offset of width
121 * arr[5] = offset of height
122 * arr[6] = offset of rowBytes
123 * arr[7] = offset of topLeftX
124 * arr[8] = offset of topLeftY
125 * arr[9] = offset of pixel data.
126 * arr[10] = address of a GlyphImageRef representing the invisible glyph
127 */
128 static native void getGlyphCacheDescription(long[] infoArray);
129
130 static {
131
132 long[] nativeInfo = new long[11];
133 getGlyphCacheDescription(nativeInfo);
134 //Can also get address size from Unsafe class :-
135 //nativeAddressSize = unsafe.addressSize();
136 nativeAddressSize = (int)nativeInfo[0];
137 glyphInfoSize = (int)nativeInfo[1];
138 xAdvanceOffset = (int)nativeInfo[2];
139 yAdvanceOffset = (int)nativeInfo[3];
140 widthOffset = (int)nativeInfo[4];
141 heightOffset = (int)nativeInfo[5];
142 rowBytesOffset = (int)nativeInfo[6];
143 topLeftXOffset = (int)nativeInfo[7];
144 topLeftYOffset = (int)nativeInfo[8];
145 pixelDataOffset = (int)nativeInfo[9];
146 invisibleGlyphPtr = nativeInfo[10];
147 if (nativeAddressSize < 4) {
148 throw new InternalError("Unexpected address size for font data: " +
149 nativeAddressSize);
150 }
151
152 java.security.AccessController.doPrivileged(
153 new java.security.PrivilegedAction() {
154 public Object run() {
155
156 /* Allow a client to override the reference type used to
157 * cache strikes. The default is "soft" which hints to keep
158 * the strikes around. This property allows the client to
159 * override this to "weak" which hint to the GC to free
160 * memory more agressively.
161 */
162 String refType =
163 System.getProperty("sun.java2d.font.reftype", "soft");
164 cacheRefTypeWeak = refType.equals("weak");
165
166 String minStrikesStr =
167 System.getProperty("sun.java2d.font.minstrikes");
168 if (minStrikesStr != null) {
169 try {
170 MINSTRIKES = Integer.parseInt(minStrikesStr);
171 if (MINSTRIKES <= 0) {
172 MINSTRIKES = 1;
173 }
174 } catch (NumberFormatException e) {
175 }
176 }
177
178 recentStrikes = new FontStrike[MINSTRIKES];
179
180 return null;
181 }
182 });
183 }
184
185
186 static void refStrike(FontStrike strike) {
187 int index = recentStrikeIndex;
188 recentStrikes[index] = strike;
189 index++;
190 if (index == MINSTRIKES) {
191 index = 0;
192 }
193 recentStrikeIndex = index;
194 }
195
196 private static final void doDispose(FontStrikeDisposer disposer) {
197 if (disposer.intGlyphImages != null) {
198 freeIntMemory(disposer.intGlyphImages,
199 disposer.pScalerContext);
200 } else if (disposer.longGlyphImages != null) {
201 freeLongMemory(disposer.longGlyphImages,
202 disposer.pScalerContext);
203 } else if (disposer.segIntGlyphImages != null) {
204 /* NB Now making multiple JNI calls in this case.
205 * But assuming that there's a reasonable amount of locality
206 * rather than sparse references then it should be OK.
207 */
208 for (int i=0; i<disposer.segIntGlyphImages.length; i++) {
209 if (disposer.segIntGlyphImages[i] != null) {
210 freeIntMemory(disposer.segIntGlyphImages[i],
211 disposer.pScalerContext);
212 /* native will only free the scaler context once */
213 disposer.pScalerContext = 0L;
214 disposer.segIntGlyphImages[i] = null;
215 }
216 }
217 /* This may appear inefficient but it should only be invoked
218 * for a strike that never was asked to rasterise a glyph.
219 */
220 if (disposer.pScalerContext != 0L) {
221 freeIntMemory(new int[0], disposer.pScalerContext);
222 }
223 } else if (disposer.segLongGlyphImages != null) {
224 for (int i=0; i<disposer.segLongGlyphImages.length; i++) {
225 if (disposer.segLongGlyphImages[i] != null) {
226 freeLongMemory(disposer.segLongGlyphImages[i],
227 disposer.pScalerContext);
228 disposer.pScalerContext = 0L;
229 disposer.segLongGlyphImages[i] = null;
230 }
231 }
232 if (disposer.pScalerContext != 0L) {
233 freeLongMemory(new long[0], disposer.pScalerContext);
234 }
235 } else if (disposer.pScalerContext != 0L) {
236 /* Rarely a strike may have been created that never cached
237 * any glyphs. In this case we still want to free the scaler
238 * context.
239 */
240 if (longAddresses()) {
241 freeLongMemory(new long[0], disposer.pScalerContext);
242 } else {
243 freeIntMemory(new int[0], disposer.pScalerContext);
244 }
245 }
246 }
247
248 private static boolean longAddresses() {
249 return nativeAddressSize == 8;
250 }
251
252 static void disposeStrike(final FontStrikeDisposer disposer) {
253 // we need to execute the strike disposal on the rendering thread
254 // because they may be accessed on that thread at the time of the
255 // disposal (for example, when the accel. cache is invalidated)
256
257 // REMIND: this look a bit heavyweight, but should be ok
258 // because strike disposal is a relatively infrequent operation,
259 // more worrisome is the necessity of getting a GC here.
260 RenderQueue rq = null;
261 GraphicsEnvironment ge =
262 GraphicsEnvironment.getLocalGraphicsEnvironment();
263 if (!ge.isHeadless()) {
264 GraphicsConfiguration gc =
265 ge.getDefaultScreenDevice().getDefaultConfiguration();
266 if (gc instanceof AccelGraphicsConfig) {
267 AccelGraphicsConfig agc = (AccelGraphicsConfig)gc;
268 BufferedContext bc = agc.getContext();
269 if (bc != null) {
270 rq = bc.getRenderQueue();
271 }
272 }
273 }
274 if (rq != null) {
275 rq.lock();
276 try {
277 rq.flushAndInvokeNow(new Runnable() {
278 public void run() {
279 doDispose(disposer);
280 }
281 });
282 } finally {
283 rq.unlock();
284 }
285 } else {
286 doDispose(disposer);
287 }
288 }
289
290 static native void freeIntPointer(int ptr);
291 static native void freeLongPointer(long ptr);
292 private static native void freeIntMemory(int[] glyphPtrs, long pContext);
293 private static native void freeLongMemory(long[] glyphPtrs, long pContext);
294
295
296 public static Reference getStrikeRef(FontStrike strike) {
297 return getStrikeRef(strike, cacheRefTypeWeak);
298 }
299
300 public static Reference getStrikeRef(FontStrike strike, boolean weak) {
301 /* Some strikes may have no disposer as there's nothing
302 * for them to free, as they allocated no native resource
303 * eg, if they did not allocate resources because of a problem,
304 * or they never hold native resources. So they create no disposer.
305 * But any strike that reaches here that has a null disposer is
306 * a potential memory leak.
307 */
308 if (strike.disposer == null) {
309 if (weak) {
310 return new WeakReference(strike);
311 } else {
312 return new SoftReference(strike);
313 }
314 }
315
316 if (weak) {
317 return new WeakDisposerRef(strike);
318 } else {
319 return new SoftDisposerRef(strike);
320 }
321 }
322
323 static interface DisposableStrike {
324 FontStrikeDisposer getDisposer();
325 }
326
327 static class SoftDisposerRef
328 extends SoftReference implements DisposableStrike {
329
330 private FontStrikeDisposer disposer;
331
332 public FontStrikeDisposer getDisposer() {
333 return disposer;
334 }
335
336 SoftDisposerRef(FontStrike strike) {
337 super(strike, StrikeCache.refQueue);
338 disposer = strike.disposer;
339 Disposer.addReference(this, disposer);
340 }
341 }
342
343 static class WeakDisposerRef
344 extends WeakReference implements DisposableStrike {
345
346 private FontStrikeDisposer disposer;
347
348 public FontStrikeDisposer getDisposer() {
349 return disposer;
350 }
351
352 WeakDisposerRef(FontStrike strike) {
353 super(strike, StrikeCache.refQueue);
354 disposer = strike.disposer;
355 Disposer.addReference(this, disposer);
356 }
357 }
358
359 }