mixare的measureText方法在频繁调用时抛出“referencetable overflow max 1024”的解决方案

这几天在搞基于位置的AR应用，采用了github上两款开源项目：

mixare

android-argument-reality-framework

这两个项目实现机制大致相同，我选取的是android-argument-reality-framework，原因是我认为他的代码结构要清晰很多（纯属个人意见）。这两个项目的demo在运行时都会crash，通过查看控制台，可以看到如下信息：

07-31 14:35:38.685: W/dalvikvm(13686): ReferenceTable overflow (max=1024)07-31 14:35:38.685: W/dalvikvm(13686): JNI pinned array reference table (0x5fc810) dump:07-31 14:35:38.685: W/dalvikvm(13686):   Last 10 entries (of 1024):07-31 14:35:38.685: W/dalvikvm(13686):      1023: 0x4130ada8 char[] (29 elements)07-31 14:35:38.685: W/dalvikvm(13686):      1022: 0x4130a768 char[] (29 elements)07-31 14:35:38.685: W/dalvikvm(13686):      1021: 0x413ad8d0 char[] (29 elements)07-31 14:35:38.685: W/dalvikvm(13686):      1020: 0x413aa990 char[] (36 elements)07-31 14:35:38.685: W/dalvikvm(13686):      1019: 0x40ea2eb0 char[] (5 elements)07-31 14:35:38.685: W/dalvikvm(13686):      1018: 0x40e262d8 char[] (5 elements)07-31 14:35:38.685: W/dalvikvm(13686):      1017: 0x40ee8000 char[] (4 elements)07-31 14:35:38.685: W/dalvikvm(13686):      1016: 0x40e97418 char[] (4 elements)07-31 14:35:38.685: W/dalvikvm(13686):      1015: 0x413a9e38 char[] (22 elements)07-31 14:35:38.685: W/dalvikvm(13686):      1014: 0x413a9858 char[] (33 elements)07-31 14:35:38.685: W/dalvikvm(13686):   Summary:07-31 14:35:38.685: W/dalvikvm(13686):         1 of byte[] (128 elements)07-31 14:35:38.685: W/dalvikvm(13686):        50 of char[] (4 elements) (2 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        50 of char[] (5 elements) (2 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        25 of char[] (22 elements) (25 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        24 of char[] (23 elements) (24 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        24 of char[] (24 elements) (24 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        24 of char[] (25 elements) (24 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        24 of char[] (27 elements) (24 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        24 of char[] (28 elements) (24 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):       508 of char[] (29 elements) (508 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        24 of char[] (31 elements) (24 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        49 of char[] (33 elements) (49 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        25 of char[] (34 elements) (25 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        50 of char[] (36 elements) (50 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        25 of char[] (37 elements) (25 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        49 of char[] (39 elements) (49 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        24 of char[] (44 elements) (24 unique instances)07-31 14:35:38.685: W/dalvikvm(13686):        24 of char[] (63 elements) (24 unique instances)07-31 14:35:38.685: E/dalvikvm(13686): Failed adding to JNI pinned array ref table (1024 entries)07-31 14:35:38.685: I/dalvikvm(13686): "main" prio=5 tid=1 RUNNABLE07-31 14:35:38.685: I/dalvikvm(13686):   | group="main" sCount=0 dsCount=0 obj=0x40a59460 self=0x34383007-31 14:35:38.685: I/dalvikvm(13686):   | sysTid=13686 nice=0 sched=0/0 cgrp=default handle=107451738407-31 14:35:38.685: I/dalvikvm(13686):   | schedstat=( 23316582697 3886607959 27513 ) utm=2194 stm=137 core=007-31 14:35:38.685: I/dalvikvm(13686):   at android.graphics.Paint.native_measureText(Native Method)07-31 14:35:38.685: I/dalvikvm(13686):   at android.graphics.Paint.measureText(Paint.java:1288)07-31 14:35:38.685: I/dalvikvm(13686):   at org.mixare.lib.gui.PaintScreen.getTextWidth(PaintScreen.java:153)07-31 14:35:38.685: I/dalvikvm(13686):   at org.mixare.lib.gui.TextObj.prepTxt(TextObj.java:107)07-31 14:35:38.685: I/dalvikvm(13686):   at org.mixare.lib.gui.TextObj.<init>(TextObj.java:65)07-31 14:35:38.685: I/dalvikvm(13686):   at org.mixare.lib.gui.TextObj.<init>(TextObj.java:50)07-31 14:35:38.685: I/dalvikvm(13686):   at org.mixare.marker.ImageMarker.drawTitle(ImageMarker.java:135)07-31 14:35:38.685: I/dalvikvm(13686):   at org.mixare.marker.ImageMarker.draw(ImageMarker.java:120)07-31 14:35:38.685: I/dalvikvm(13686):   at org.mixare.DataView.draw(DataView.java:252)07-31 14:35:38.685: I/dalvikvm(13686):   at org.mixare.AugmentedView.onDraw(MixView.java:1411)07-31 14:35:38.685: I/dalvikvm(13686):   at android.view.View.draw(View.java:10978)07-31 14:35:38.685: I/dalvikvm(13686):   at android.view.ViewGroup.drawChild(ViewGroup.java:2887)07-31 14:35:38.685: I/dalvikvm(13686):   at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)07-31 14:35:38.685: I/dalvikvm(13686):   at android.view.ViewGroup.drawChild(ViewGroup.java:2885)07-31 14:35:38.685: I/dalvikvm(13686):   at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)07-31 14:35:38.685: I/dalvikvm(13686):   at android.view.ViewGroup.drawChild(ViewGroup.java:2885)07-31 14:35:38.685: I/dalvikvm(13686):   at android.view.ViewGroup.dispatchDraw(ViewGroup.java:2489)07-31 14:35:38.685: I/dalvikvm(13686):   at android.view.View.draw(View.java:10981)07-31 14:35:38.685: I/dalvikvm(13686):   at android.widget.FrameLayout.draw(FrameLayout.java:450)07-31 14:35:38.685: I/dalvikvm(13686):   at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:2126)07-31 14:35:38.690: I/dalvikvm(13686):   at android.view.ViewRootImpl.draw(ViewRootImpl.java:2026)07-31 14:35:38.690: I/dalvikvm(13686):   at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1634)07-31 14:35:38.690: I/dalvikvm(13686):   at android.view.ViewRootImpl.handleMessage(ViewRootImpl.java:2442)07-31 14:35:38.690: I/dalvikvm(13686):   at android.os.Handler.dispatchMessage(Handler.java:99)07-31 14:35:38.690: I/dalvikvm(13686):   at android.os.Looper.loop(Looper.java:137)07-31 14:35:38.690: I/dalvikvm(13686):   at android.app.ActivityThread.main(ActivityThread.java:4575)07-31 14:35:38.690: I/dalvikvm(13686):   at java.lang.reflect.Method.invokeNative(Native Method)07-31 14:35:38.690: I/dalvikvm(13686):   at java.lang.reflect.Method.invoke(Method.java:511)07-31 14:35:38.690: I/dalvikvm(13686):   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)07-31 14:35:38.690: I/dalvikvm(13686):   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)07-31 14:35:38.690: I/dalvikvm(13686):   at dalvik.system.NativeStart.main(Native Method)07-31 14:35:38.690: E/dalvikvm(13686): VM aborting

通过https://code.google.com/p/mixare/issues/detail?id=145和https://code.google.com/p/android/issues/detail?id=36908大致了解到了原因就是在频繁调用native_measureText可能出现了内存泄露，但是始终没有好的解决方案。

最后经过一番折腾，终于在https://code.google.com/p/android-augment-reality-framework/issues/detail?id=22里找到的解决的，给出的解决方案如下：

http://stackoverflow.com/questions/16813706/android-apps-activity-force-back。

修改android-augment-reality-framework项目的src/com/jwetherell/augmented_reality/ui/objects/PaintableObject.java中的getTextWidth方法为如下代码即可：

/** * Get the width of the text String. *  * @param txt *            CharSequence to get the width of. * @param start *            Start of the text. * @param end *            End of the text. * @return float width of the text String. * @throws NullPointerException *             if the String param is NULL. */public float getTextWidth(CharSequence text) {if (text == null)throw new NullPointerException();TextPaint textPaint = new TextPaint(paint);int widthWrap = 1000; // you may have to change thisStaticLayout layout = measure(textPaint, text, widthWrap);return getMaxLineWidth(layout);}private float getMaxLineWidth(StaticLayout layout) {float maxLine = 0.0f;int lineCount = layout.getLineCount();for (int i = 0; i < lineCount; i++) {if (layout.getLineWidth(0) > maxLine) {maxLine = layout.getLineWidth(0);}}return maxLine;}private StaticLayout measure(TextPaint textPaint, CharSequence text,Integer wrapWidth) {int boundedWidth = Integer.MAX_VALUE;if (wrapWidth != null && wrapWidth > 0) {boundedWidth = wrapWidth;}StaticLayout layout = new StaticLayout(text, textPaint, boundedWidth,Alignment.ALIGN_NORMAL, 1.0f, 0.0f, false);return layout;}