Android启动器停止运行的调试

 一.开机时出现问题：很抱歉，”启动器“已停止运行，源码级调试如下：


日志中Java调用栈如下：
8044 03-27 15:37:40.747  3023  3039 E AndroidRuntime: FATAL EXCEPTION: setWallpaperDimension
8045 03-27 15:37:40.747  3023  3039 E AndroidRuntime: Process: com.android.launcher, PID: 3023
8046 03-27 15:37:40.747  3023  3039 E AndroidRuntime: java.lang.IllegalArgumentException: width and height must be > 0
8047 03-27 15:37:40.747  3023  3039 E AndroidRuntime:        at android.os.Parcel.readException(Parcel.java:1544)
8048 03-27 15:37:40.747  3023  3039 E AndroidRuntime:        at android.os.Parcel.readException(Parcel.java:1493)
8049 03-27 15:37:40.747  3023  3039 E AndroidRuntime:        at android.app.IWallpaperManager$Stub$Proxy.setDimensionHints(IWallpaperManager.java     :361)
8050 03-27 15:37:40.747  3023  3039 E AndroidRuntime:        at android.app.WallpaperManager.suggestDesiredDimensions(WallpaperManager.java:947)
8051 03-27 15:37:40.747  3023  3039 E AndroidRuntime:        at com.android.launcher2.Workspace$2.run(Workspace.java:864)


在源码中添加打印信息，修改如下：
    private float wallpaperTravelToScreenWidthRatio(int width, int height) {
//        float aspectRatio = width / (float) height;
        float h = (float) height;
        float aspectRatio = width / h;
        Log.d(TAG, "float height:" + h + "  aspectRatio:" + aspectRatio);


        final float ASPECT_RATIO_LANDSCAPE = 16/10f;
        final float ASPECT_RATIO_PORTRAIT = 10/16f;
        Log.d(TAG, "SCAPE:" + ASPECT_RATIO_LANDSCAPE + "  TRAIT:" + ASPECT_RATIO_PORTRAIT );


        final float WALLPAPER_WIDTH_TO_SCREEN_RATIO_LANDSCAPE = 1.5f;
        final float WALLPAPER_WIDTH_TO_SCREEN_RATIO_PORTRAIT = 1.2f;
//        final float x =
//            (WALLPAPER_WIDTH_TO_SCREEN_RATIO_LANDSCAPE - WALLPAPER_WIDTH_TO_SCREEN_RATIO_PORTRAIT) /
//            (ASPECT_RATIO_LANDSCAPE - ASPECT_RATIO_PORTRAIT);
//        final float y = WALLPAPER_WIDTH_TO_SCREEN_RATIO_PORTRAIT - x * ASPECT_RATIO_PORTRAIT;
//        Log.d(TAG, "x:" + x + "  y:" + y + "  aspectRatio:" + aspectRatio);
//        return x * aspectRatio + y;


       float lp = WALLPAPER_WIDTH_TO_SCREEN_RATIO_LANDSCAPE - WALLPAPER_WIDTH_TO_SCREEN_RATIO_PORTRAIT;
       float st = ASPECT_RATIO_LANDSCAPE - ASPECT_RATIO_PORTRAIT;
       final float x = lp / st;
       Log.d(TAG, "LANDSCAPE - PORTRAIT:"  + lp + "  SCAPE - TRAIT:" + st + "  x:" + x);


       float t = x * ASPECT_RATIO_PORTRAIT;
       final float y = WALLPAPER_WIDTH_TO_SCREEN_RATIO_PORTRAIT - t;
       float xt = x * aspectRatio;
       Log.d(TAG, "t:" + t + "  y:" + y + "  xt:" + xt);
       return xt + y;
    }


   protected void setWallpaperDimension() {
        Point minDims = new Point();
        Point maxDims = new Point();
        mLauncher.getWindowManager().getDefaultDisplay().getCurrentSizeRange(minDims, maxDims);


        final int maxDim = Math.max(maxDims.x, maxDims.y);
        final int minDim = Math.min(minDims.x, minDims.y);
        Log.d(TAG, "minDim:" + minDim + "  maxDim:" + maxDim);


        if (LauncherApplication.isScreenLarge()) {
//            mWallpaperWidth = (int) (maxDim * wallpaperTravelToScreenWidthRatio(maxDim, minDim));
              mWallpaperHeight = maxDim;


              float a = wallpaperTravelToScreenWidthRatio(maxDim, minDim);
              float b = maxDim * a;
              mWallpaperWidth = (int) (b);
              Log.d(TAG, "WallpaperTravel:" + a);
              Log.d(TAG, "WallpaperTravel * maxDim:" + b);
        } else {
            mWallpaperWidth = Math.max((int) (minDim * WALLPAPER_SCREENS_SPAN), maxDim);
            mWallpaperHeight = maxDim;
        }
        Log.d(TAG, "mWallpaperWidth:" + mWallpaperWidth + "  mWallpaperHeight:" + mWallpaperHeight);


        new Thread("setWallpaperDimension") {
            public void run() {
                mWallpaperManager.suggestDesiredDimensions(mWallpaperWidth, mWallpaperHeight);
            }
        }.start();
}


打印的日志如下：
03-28 08:47:39.573  2395  2395 D Launcher.Workspace: float height:7.70372E-34  aspectRatio:1.0
03-28 08:47:39.573  2395  2395 D Launcher.Workspace: SCAPE:1.6  TRAIT:0.625
03-28 08:47:39.574  2395  2395 D Launcher.Workspace: LANDSCAPE - PORTRAIT:0.29999995  SCAPE - TRAIT:0.975  x:1.0
03-28 08:47:39.575  2395  2395 D Launcher.Workspace: t:1.0  y:0.0  xt:1.0
03-28 08:47:40.176  2395  2395 D Launcher.Workspace: minDim:951  maxDim:1280
03-28 08:47:40.177  2395  2395 D Launcher.Workspace: float height:7.70372E-34  aspectRatio:1.0
03-28 08:47:40.177  2395  2395 D Launcher.Workspace: SCAPE:1.6  TRAIT:0.625
03-28 08:47:40.178  2395  2395 D Launcher.Workspace: LANDSCAPE - PORTRAIT:0.29999995  SCAPE - TRAIT:0.975  x:1.0
03-28 08:47:40.178  2395  2395 D Launcher.Workspace: t:1.0  y:0.0  xt:1.0
03-28 08:47:40.179  2395  2395 D Launcher.Workspace: WallpaperTravel:2.0
03-28 08:47:40.179  2395  2395 D Launcher.Workspace: WallpaperTravel * maxDim:1.733337E-33
03-28 08:47:40.180  2395  2395 D Launcher.Workspace: mWallpaperWidth:0  mWallpaperHeight:1280


二. 写了一个实现上述运算的TestFloatTC.apk,在interpret-only模式下运行


public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
verify();
}


private static final String TAG = "Launcher.Workspace";
//main
public static void verify() {
        final int maxDim = 1280;
        final int minDim = 951;        
        float a = wallpaperTravelToScreenWidthRatio(maxDim, minDim);
        float b = maxDim * a;
        int mWallpaperWidth = (int) (b);   
        
        Log.d(TAG, "WallpaperTravel:" + a);
        Log.d(TAG, "WallpaperTravel * maxDim:" + b);
        Log.d(TAG, "mWallpaperWidth:" + mWallpaperWidth);
    }

static float wallpaperTravelToScreenWidthRatio(int width, int height) {
        float h = (float) height;       
float aspectRatio = width / h;
        Log.d(TAG, "float height:" + h + "  aspectRatio:" + aspectRatio);
        
        final float SCAPE = 16/10f;
        final float TRAIT = 10/16f;
        Log.d(TAG, "SCAPE:" + SCAPE + "  TRAIT:" + TRAIT );
        
        final float LANDSCAPE = 1.5f;
        final float PORTRAIT = 1.2f;
        float lp = LANDSCAPE - PORTRAIT;
        float st = SCAPE - TRAIT;
        final float x = lp / st;
        Log.d(TAG, "LANDSCAPE - PORTRAIT:"  + lp + "  SCAPE - TRAIT:" + st + "  x:" + x);
        
        float t = x * TRAIT;
        final float y = PORTRAIT - t;
        float xt = x * aspectRatio;
        Log.d(TAG, "t:" + t + "  y:" + y + "  xt:" + xt);
        return xt + y;
    }
}


TestFloatTC.apk 在 interpret-only 模式下测得的结果如下：
6076 03-27 21:25:13.810  2427  2427 D Launcher.Workspace: float height:951.0  aspectRatio:1.3459517
6077 03-27 21:25:13.810  2427  2427 D Launcher.Workspace: SCAPE:1.6  TRAIT:0.625
6078 03-27 21:25:13.813  2427  2427 D Launcher.Workspace: LANDSCAPE - PORTRAIT:0.29999995  SCAPE - TRAIT:0.975  x:0.30769226
6079 03-27 21:25:13.814  2427  2427 D Launcher.Workspace: t:0.19230767  y:1.0076923  xt:0.4141389
6080 03-27 21:25:13.814  2427  2427 D Launcher.Workspace: float height:951.0  aspectRatio:1.3459517
6081 03-27 21:25:13.815  2427  2427 D Launcher.Workspace: SCAPE:1.6  TRAIT:0.625
6082 03-27 21:25:13.816  2427  2427 D Launcher.Workspace: LANDSCAPE - PORTRAIT:0.29999995  SCAPE - TRAIT:0.975  x:0.30769226
6083 03-27 21:25:13.818  2427  2427 D Launcher.Workspace: t:0.19230767  y:1.0076923  xt:0.4141389
6084 03-27 21:25:13.818  2427  2427 D Launcher.Workspace: WallpaperTravel:1.4218313
6085 03-27 21:25:13.819  2427  2427 D Launcher.Workspace: WallpaperTravel * maxDim:1819.944
6086 03-27 21:25:13.820  2427  2427 D Launcher.Workspace: mWallpaperWidth:1819

由此判断，硬件上没有出现问题，是speed模式下整型数据转浮点数据时出现了问题。

三.启动器停止运行的汇编级调试


问题对应的函数的java源代码的简化版：
   private float wallpaperTravelToScreenWidthRatio(int width, int height) {
//        float aspectRatio = width / (float) height;


//        Log.d(TAG, "enter height:" + height);
        float h = (float) height;
        Log.d(TAG, "after height:" + h);
        float t = 951.0f;
        Log.d(TAG, "after t:" + t);
        return 0.0f;
    }


对应的oatdump反汇编的dalvik字节码：
  50: float com.android.launcher2.Workspace.wallpaperTravelToScreenWidthRatio(int, int) (dex_method_idx=5418)
    DEX CODE:
      0x0000: 8270                              | int-to-float v0, v7
      0x0001: 1a02 d404                         | const-string v2, "Launcher.Workspace" // string@1236
      0x0003: 2203 1f03                         | new-instance v3, java.lang.StringBuilder // type@799
      0x0005: 7010 a715 0300                | invoke-direct {v3}, void java.lang.StringBuilder.() // method@5543
      0x0008: 1a04 a009                         | const-string v4, "after height:" // string@2464
      0x000a: 6e20 b015 4300                | invoke-virtual {v3, v4}, java.lang.StringBuilder java.lang.StringBuilder.append(java.lang.String) // method@5552
      0x000d: 0c03                              | move-result-object v3
      0x000e: 6e20 ab15 0300                | invoke-virtual {v3, v0}, java.lang.StringBuilder java.lang.StringBuilder.append(float) // method@5547
      0x0011: 0c03                              | move-result-object v3
      0x0012: 6e10 b515 0300                | invoke-virtual {v3}, java.lang.String java.lang.StringBuilder.toString() // method@5557
      0x0015: 0c03                              | move-result-object v3
      0x0016: 7120 3707 3200                | invoke-static {v2, v3}, int android.util.Log.d(java.lang.String, java.lang.String) // method@1847
      0x0019: 1401 00c0 6d44                | const v1, #+1148043264
      0x001c: 1a02 d404                         | const-string v2, "Launcher.Workspace" // string@1236
      0x001e: 2203 1f03                         | new-instance v3, java.lang.StringBuilder // type@799
      0x0020: 7010 a715 0300                | invoke-direct {v3}, void java.lang.StringBuilder.() // method@5543
      0x0023: 1a04 a109                         | const-string v4, "after t:" // string@2465
      0x0025: 6e20 b015 4300                | invoke-virtual {v3, v4}, java.lang.StringBuilder java.lang.StringBuilder.append(java.lang.String) // method@5552
      0x0028: 0c03                              | move-result-object v3
      0x0029: 6e20 ab15 1300                | invoke-virtual {v3, v1}, java.lang.StringBuilder java.lang.StringBuilder.append(float) // method@5547
      0x002c: 0c03                              | move-result-object v3
      0x002d: 6e10 b515 0300                | invoke-virtual {v3}, java.lang.String java.lang.StringBuilder.toString() // method@5557
      0x0030: 0c03                              | move-result-object v3
      0x0031: 7120 3707 3200                | invoke-static {v2, v3}, int android.util.Log.d(java.lang.String, java.lang.String) // method@1847
      0x0034: 1202                              | const/4 v2, #+0
      0x0035: 0f02                              | return v2


对应的oatdump反汇编mips代码：
    CODE: (code_offset=0x00307f9c size_offset=0x00307f98 size=920)...
//    build stack & check overflow
      0x00307f9c: 8e220080  lw      r2, +128(r17)  ; stack_end
      0x00307fa0: 27bdfffc  addiu   r29, r29, -4
      0x00307fa4: afbf0000  sw      r31, +0(r29)
      0x00307fa8: 27a3ffd4  addiu   r3, r29, -44
      0x00307fac: 0062402b  sltu    r8, r3, r2
      0x00307fb0: 150000a2  bne     r8, r0, 0x0030823c  ; +652
      0x00307fb4: 00000000  nop


      0x00307fb8: 0060e825  or      r29, r3, r0  // <-- SP(r29)


      0x00307fbc: afa40000  sw      r4, +0(r29)
      0x00307fc0: afa50034  sw      r5, +52(r29)
      0x00307fc4: afa60038  sw      r6, +56(r29)
      0x00307fc8: afa7003c  sw      r7, +60(r29)


print r7
      0x00307fcc: c7a0003c  lwc1    f0, +60(r29)
      0x00307fd0: 46800060  cvt.s.w f1, f0
print f1


      0x00307fd4: e7a10014  swc1    f1, +20(r29)
      0x00307fd8: 8fa60000  lw      r6, +0(r29)
      0x00307fdc: 8cc40008  lw      r4, +8(r6)
      0x00307fe0: 8c840014  lw      r4, +20(r4)
      0x00307fe4: 8c82135c  lw      r2, +4956(r4)
      0x00307fe8: 10400099  beq     r2, r0, 0x00308250  ; +616
      0x00307fec: 00000000  nop
      0x00307ff0: afa2001c  sw      r2, +28(r29)
      0x00307ff4: 8e390114  lw      r25, +276(r17)  ; pAllocObject
      0x00307ff8: 8fa50000  lw      r5, +0(r29)
      0x00307ffc: 3404031f  ori     r4, r0, 799
      0x00308000: 0320f809  jalr    r25
      0x00308004: 00000000  nop

问题比较复杂，等待高人解决。