X Means Y
- 1. Samsung Developer Office Hours NYC X Means Y: Interpreting the Development Tools Copyright 息 2012CommonsWare, LLC
- 2. 01-03 01:32:11.986: E/AndroidRuntime(17991): Caused by: android.os.NetworkOnMainThreadException Copyright 息 2012CommonsWare, LLC
- 3. StrictMode Reports obvious long-running stuff on main application thread Network I/O automatically reported on Android 3.0+ Do not disable the error fix the problem! Opt-in for Android 2.3 Can also configure to report disk I/O on main thread, failure to close files/databases/cursors, etc. Copyright 息 2012CommonsWare, LLC
- 4. Copyright 息 2012CommonsWare, LLC
- 5. 06-29 23:11:17.796: I/Choreographer(691): Skipped 18 frames! The application may be doing too much work on its main thread. Copyright 息 2012CommonsWare, LLC
- 6. Choreographer Information Message in LogCat Skipped N frames * 16ms = amount of time you took on main application thread The more frames skipped, the more likely it is the user will notice UI frozen and not responsive Animation/scrolling hiccups Android 4.1+ Copyright 息 2012CommonsWare, LLC
- 7. Project Butter UI Updates @ 60 frames/second Objective: smoother UI updates Especially animations Transparent to developers No code changes to opt into Butter effects Google I/O 2012: For Butter or Worse Copyright 息 2012CommonsWare, LLC
- 8. Project Butter Ramifications Only ~16ms Per Frame Your code on the main application thread Framework code Other interruptions (e.g., background process) Net: Get Off the Main Application Thread! Anything taking more than a few milliseconds needs to move to background thread or be executed incrementally Copyright 息 2012CommonsWare, LLC
- 9. 12-12 08:56:20.746: E/AndroidRuntime(1570): java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare() Copyright 息 2012CommonsWare, LLC
- 10. Looper and Handler Queuing mechanism Used by main application thread Error results from trying to do wrong thing on background thread setContentView() requestLocationUpdates() HandlerThread Copyright 息 2012CommonsWare, LLC
- 11. java.lang.StackOverflowError at android.widget.TextView.onDraw(TextView.java:4329) at android.view.View.draw(View.java:6993) at android.view.ViewGroup.drawChild(ViewGroup.java:1732) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1459) at android.view.View.draw(View.java:6996) at android.view.ViewGroup.drawChild(ViewGroup.java:1732) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1459) at android.view.View.draw(View.java:6996) at android.view.ViewGroup.drawChild(ViewGroup.java:1732) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1459) at android.view.View.draw(View.java:6996) at android.view.ViewGroup.drawChild(ViewGroup.java:1732) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1459) at android.view.View.draw(View.java:6996) at android.view.ViewGroup.drawChild(ViewGroup.java:1732) at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1459) . . . Copyright 息 2012CommonsWare, LLC
- 12. StackOverflowError Your code? Too-deep recursion View/ViewGroup code? Too-complex UI: nested containers 8KB stack space on main application thread Copyright 息 2012CommonsWare, LLC
- 13. StackOverflowError Diagnostics Open UI in emulator Or device if you embed ViewServer in it Run Hierarchy View Eclipse perspective or via monitor Count depth Find stuff safe to eliminate Containers with only one child Copyright 息 2012CommonsWare, LLC
- 14. 07-13 10:42:23.820: E/AndroidRuntime(2065): java.lang.OutOfMemoryError Copyright 息 2012CommonsWare, LLC
- 15. OutOfMemoryError Limited heap sizes 16-64MB, depending on OS version and device capabilities Non-compacting garbage collector Cannot allocate a block big enough for your request Primary culprit: bitmaps 1080p image = ~8MB Copyright 息 2012CommonsWare, LLC
- 16. OutOfMemoryError Diagnostics MAT Dump heap (HPROF) using Debug or DDMS Load into MAT (Eclipse plug-in or standalone) Hunt for culprits adb shell dumpsys meminfo Lots of low-level information Difficult to accurately interpret Copyright 息 2012CommonsWare, LLC
- 17. OutOfMemoryError BitmapFactory.Options inSampleSize: downsample for less heap use inPurgeable/inInputShareable: for sharing backing data for mutations of common ancestor bitmap inBitmap: for reusing existing Bitmap buffer Must be of the same dimensions and bit depth Maintain your own object pools versus fragmenting your heap Copyright 息 2012CommonsWare, LLC
- 18. I/DEBUG (18110): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** I/DEBUG (18110): Build fingerprint: 'MOTO_O2DE/umts_sholes/umts_sholes/sholes:2.1-... I/DEBUG (18110): pid: 23912, tid: 23913 >>> com.example.test <<< I/DEBUG (18110): signal 11 (SIGSEGV), fault addr 0000000c I/DEBUG (18110): r0 00140120 r1 00000048 r2 00000000 r3 00140168 I/DEBUG (18110): r4 afe3ae08 r5 00000006 r6 00140158 r7 0000a000 I/DEBUG (18110): r8 100ffcf8 r9 4185eef8 10 4185eee0 fp 001243b0 I/DEBUG (18110): ip 00000000 sp 100ffc50 lr afe0f130 pc afe0aeec cpsr 80000070 I/DEBUG (18110): #00 pc 0000aeec /system/lib/libc.so I/DEBUG (18110): #01 pc 000008e6 /system/lib/libstdc++.so I/DEBUG (18110): #02 pc 00014124 /system/lib/libutils.so I/DEBUG (18110): #03 pc 0001423c /system/lib/libutils.so I/DEBUG (18110): #04 pc 0001af28 /system/lib/libbinder.so I/DEBUG (18110): #05 pc 0001ba20 /system/lib/libbinder.so I/DEBUG (18110): #06 pc 0001bcd6 /system/lib/libbinder.so I/DEBUG (18110): #07 pc 00014236 /system/lib/libutils.so I/DEBUG (18110): #08 pc 000293a6 /system/lib/libandroid_runtime.so I/DEBUG (18110): #09 pc 000313ca /system/lib/libandroid_runtime.so I/DEBUG (18110): #10 pc 0000ecb4 /system/lib/libdvm.so I/DEBUG (18110): #11 pc 00038838 /system/lib/libdvm.so I/DEBUG (18110): #12 pc 000139b8 /system/lib/libdvm.so I/DEBUG (18110): #13 pc 00019338 /system/lib/libdvm.so I/DEBUG (18110): #14 pc 00018804 /system/lib/libdvm.so . . . Copyright 息 2012CommonsWare, LLC
- 19. SIGSEGV Doing NDK development? Might be core dump from your code Repeatable across devices, or on Nexus? Probably a bug in Android Only happens on certain ROM? Probably a bug in the ROM mod Copyright 息 2012CommonsWare, LLC
- 20. Getting Help StackOverflow android tag Google Hangouts by Android Developer Support QR code for YouTube archives www.andglobe.com Q&A sites, organized by language Copyright 息 2012CommonsWare, LLC
- 21. Speaker Contact Information Copyright 息 2012CommonsWare, LLC