jianglk.darker
7ee447c011
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4 months ago | |
|---|---|---|
| .. | ||
| Android.bp | 4 months ago | |
| README.md | 4 months ago | |
| tifast.cc | 4 months ago | |
README.md
tifast
tifast is a JVMTI agent designed for profiling the performance impact listening to various JVMTI events. It is called tifast since none of the event handlers do anything meaning that it can be considered speed-of-light.
Usage
Build
m libtifast
The libraries will be built for 32-bit, 64-bit, host and target. Below examples assume you want to use the 64-bit version.
Use libtifasts if you wish to build a version without non-NDK dynamic dependencies.
Command Line
The agent is loaded using -agentpath like normal. It takes arguments in the following format:
`[log,][EventName1[,EventName2[,...]]]`
-
If 'log' is the first argument the event handlers will LOG(INFO) when they are called. This behavior is static. The no-log methods have no branches and just immediately return.
-
If 'all' is one of the arguments all events the current runtime is capable of providing will be listened for and all other arguments (excepting 'log') will be ignored.
-
The event-names are the same names as are used in the jvmtiEventCallbacks struct.
-
All required capabilities are automatically gained. No capabilities other than those needed to listen for the events are gained.
-
Only events which do not require additional function calls to cause delivery and are sent more than once are supported.
Supported events
The following events may be listened for with this agent
-
SingleStep -
MethodEntry -
MethodExit -
NativeMethodBind -
Exception -
ExceptionCatch -
ThreadStart -
ThreadEnd -
ClassLoad -
ClassPrepare -
ClassFileLoadHook -
CompiledMethodLoad -
CompiledMethodUnload -
DynamicCodeGenerated -
DataDumpRequest -
MonitorContendedEnter -
MonitorContendedEntered -
MonitorWait -
MonitorWaited -
ResourceExhausted -
VMObjectAlloc -
GarbageCollectionStart -
GarbageCollectionFinish -
VMStart -
VMInit -
VMDeath
All other events cannot be listened for by this agent. Most of these missing
events either require the use of other functions in order to be called
(FramePop, ObjectFree, etc).
ART
art -Xplugin:$ANDROID_HOST_OUT/lib64/libopenjdkjvmti.so '-agentpath:libtifast.so=MethodEntry' -cp tmp/java/helloworld.dex -Xint helloworld
-Xpluginand-agentpathneed to be used, otherwise the agent will fail during init.- If using
libartd.so, make sure to use the debug version of jvmti.
adb shell setenforce 0
adb push $ANDROID_PRODUCT_OUT/system/lib64/libtifast.so /data/local/tmp/
adb shell am start-activity --attach-agent /data/local/tmp/libtifast.so=MonitorWait,ClassPrepare some.debuggable.apps/.the.app.MainActivity
RI
java '-agentpath:libtifast.so=MethodEntry' -cp tmp/helloworld/classes helloworld