+++ /dev/null
-Tracing Dalvik VM (Java) applications on Android
-================================================
-
-Android's Java machine, DalvikVM, runs as a system service (started at bootup
-by `init`) and Java applications are run by forks of the initial resident
-process. Thus, injecting apitrace's tracing library is different from other
-operating systems.
-
-The following discussion assumes that tracing library is copied to '/data':
-
- adb push /path/to/apitrace/build/wrappers/egltrace.so /data
-
-Tracing on Android 4.0 and newer
---------------------------------
-
-Starting from Android 4.0 (Ice Cream Sandwich) release, Dalvik supports
-running designated processes with wrappers, in which case a new Java VM is
-started with 'system()' library call for that process.
-
-Obtain the process name of the application to be traced (the one reported in
-`ps` output, such as `com.android.settings`), and set two system properties:
-
- PROCNAME=com.android.settings
- adb shell setprop wrap.$PROCNAME LD_PRELOAD=/data/egltrace.so
- adb shell setprop debug.apitrace.procname $PROCNAME
-
-(the former is read by Dalvik and specifies wrapping prefix, the latter is
-read by apitrace itself and used in case apitrace is preloaded into Java VM
-globally to specify which process should be traced).
-
-Make sure the process is not loaded before starting to trace it, for example
-use `-S` flag to `am start`:
-
- adb shell am start -S $PROCNAME
-
-Use `adb logcat \*:S apitrace` to examine apitrace debug output. Trace files
-are saved into '/data/' directory by default:
-
- adb pull /data/$PROCNAME.trace
- adb shell rm /data/$PROCNAME.trace
-
-(you need to `chmod 0777 /data` beforehand).
-
-
-Injecting tracing library globally
-----------------------------------
-
-If `LD_PRELOAD` is supported (Android 2.3 "Gingerbread" and newer), it is
-possible to inject `egltrace.so` into the resident Java VM, in which case
-`debug.apitrace.procname` system propery is used to control for which process
-tracing will be active.
-
-Restarting 'zygote' (Java VM) service is not straightforward, since '/init.rc'
-is read only once at system bootup, and restored from the recovery image on
-reboots. Thus, you either need to augment '/init.rc' in the recovery image
-with `setenv LD_PRELOAD /data/egltrace.so` in `service zygote` section, or you
-can use a tool such as
-[adjust-child-env](https://github.com/amonakov/adjust-child-env) to restart
-the service with modified environment.
-
-Put `adjust-child-env` and a script with the following contents into `/data`:
-
- stop zygote
- /data/adjust-child-env 1 /system/bin/app_process LD_PRELOAD=/data/egltrace.so &
- sleep 1
- start zygote
-
-The scripts restarts the Java VM ('zygote') with modified environment.
-
-Invoke the script with `adb shell` to prepare for tracing, and then follow the
-Android 4.0 directions.
projects / apitrace / blobdiff