1 Tracing Skia Execution 2 ====================== 3 4 Introduction 5 ------------ 6 7 Skia is instrumented to provide execution traces in several ways. Within Chrome, Skia is traced 8 with the standard [tracing interface](chrome://tracing), along with the rest of Chromium. In 9 the Android framework, Skia's tracing is integrated into 10 [atrace](https://source.android.com/devices/tech/debug/ftrace). 11 12 For standalone builds, Skia's tools (DM, nanobench, and Viewer) are capable of tracing execution 13 in three ways, controlled by the `--trace` command line argument. 14 15 Android ATrace 16 -------------- 17 18 Running any tool with `--trace atrace` on an Android device will cause the application to forward 19 tracing information to [atrace](https://source.android.com/devices/tech/debug/ftrace). On other 20 platforms, this has no effect. 21 22 If you run `systrace` from the host command line, you will need to supply `-a <app_name>`, 23 and the `<app_name>` argument will need to exactly match the command line used on the target 24 device. For example, if you use `adb shell "cd /data/local/tmp; ./nanobench --trace atrace ..."` 25 you must pass `-a ./nanobench` or systrace will ignore events from the application. 26 27 Console Logging 28 --------------- 29 30 For simple situations, all tracing events can be directed to the console with `--trace debugf`: 31 32 <!--?prettify lang=sh?--> 33 34 # Run DM on a single GM with SkDebugf tracing 35 out/Release/dm --config gl --match ^gamma$ --trace debugf 36 37 ~~~ 38 [ 0] <skia.gpu> GrDrawingManager::internalFlush id=1 #0 { 39 [ 0] } GrDrawingManager::internalFlush 40 [ 0] <skia.gpu> GrGpu::createTexture id=1 #1 { 41 [ 0] } GrGpu::createTexture 42 [ 0] <skia.gpu> GrRenderTargetContext::discard id=1 #2 { 43 [ 0] } GrRenderTargetContext::discard 44 [ 0] <skia.gpu> SkGpuDevice::clearAll id=1 #3 { 45 [ 1] <skia.gpu> GrRenderTargetContext::clear id=1 #4 { 46 [ 1] } GrRenderTargetContext::clear 47 [ 0] } SkGpuDevice::clearAll 48 [ 0] <skia> SkCanvas::drawRect() #5 { 49 [ 1] <skia.gpu> SkGpuDevice::drawRect id=1 #6 { 50 [ 2] <skia.gpu> GrRenderTargetContext::drawRect id=1 #7 { 51 [ 3] <skia.gpu> GrRenderTargetContext::addDrawOp id=1 #8 { 52 [ 3] } GrRenderTargetContext::addDrawOp 53 [ 2] } GrRenderTargetContext::drawRect 54 [ 1] } SkGpuDevice::drawRect 55 [ 0] } SkCanvas::drawRect() 56 ... 57 ~~~ 58 59 Chrome Tracing 60 -------------- 61 62 Any other argument to `--trace` will be interpreted as a filename, and trace events will be written 63 to that file in JSON format, suitable for viewing with [chrome://tracing](chrome://tracing). 64 65 <!--?prettify lang=sh?--> 66 67 # Run DM on several GMs to get tracing data 68 out/Release/dm --config gl --match bleed --trace gl_bleed_gms.json 69 70 This creates a file `gl_bleed_gms.json` in the current directory. Go to 71 [chrome://tracing](chrome://tracing), click Load: 72 73  74 75 ... then select the JSON file. The data will be loaded and can be navigated/inspected using the 76 tracing tools. Tip: press '?' for a help screen explaining the available keyboard and mouse 77 controls. 78 79  80
