one.profiler

Class AsyncProfiler

java.lang.Object

one.profiler.AsyncProfiler

All Implemented Interfaces:

AsyncProfilerMXBean

public class AsyncProfiler
extends java.lang.Object
implements AsyncProfilerMXBean

Java API for in-process profiling. Serves as a wrapper around async-profiler native library. This class is a singleton. The first call to getInstance() initiates loading of libasyncProfiler.so.

Method Summary

Modifier and Type	Method and Description
void	addThread(java.lang.Thread thread) Add the given thread to the set of profiled threads.
java.lang.String	dumpCollapsed(Counter counter) Dump profile in 'collapsed stacktraces' format
java.lang.String	dumpFlat(int maxMethods) Dump flat profile, i.e. the histogram of the hottest methods
java.lang.String	dumpTraces(int maxTraces) Dump collected stack traces
java.lang.String	execute(java.lang.String command) Execute an agent-compatible profiling command - the comma-separated list of arguments described in arguments.cpp
static AsyncProfiler	getInstance()
static AsyncProfiler	getInstance(java.lang.String libPath)
long	getSamples() Get the number of samples collected during the profiling session
java.lang.String	getVersion() Get profiler agent version, e.g. "1.0"
void	removeThread(java.lang.Thread thread) Remove the given thread from the set of profiled threads.
void	resume(java.lang.String event, long interval) Start or resume profiling without resetting collected data.
void	start(java.lang.String event, long interval) Start profiling
void	stop() Stop profiling (without dumping results)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

getInstance

public static AsyncProfiler getInstance()

getInstance

public static AsyncProfiler getInstance(java.lang.String libPath)

start

public void start(java.lang.String event,
                  long interval)
           throws java.lang.IllegalStateException

Start profiling

Specified by:

start in interface AsyncProfilerMXBean

Parameters:

event - Profiling event, see Events

interval - Sampling interval, e.g. nanoseconds for Events.CPU

Throws:

java.lang.IllegalStateException - If profiler is already running

resume

public void resume(java.lang.String event,
                   long interval)
            throws java.lang.IllegalStateException

Start or resume profiling without resetting collected data. Note that event and interval may change since the previous profiling session.

Specified by:

resume in interface AsyncProfilerMXBean

Parameters:

event - Profiling event, see Events

interval - Sampling interval, e.g. nanoseconds for Events.CPU

Throws:

java.lang.IllegalStateException - If profiler is already running

stop

public void stop()
          throws java.lang.IllegalStateException

Stop profiling (without dumping results)

Specified by:

stop in interface AsyncProfilerMXBean

Throws:

java.lang.IllegalStateException - If profiler is not running

getSamples

public long getSamples()

Get the number of samples collected during the profiling session

Specified by:

getSamples in interface AsyncProfilerMXBean

Returns:

Number of samples

getVersion

public java.lang.String getVersion()

Get profiler agent version, e.g. "1.0"

Specified by:

getVersion in interface AsyncProfilerMXBean

Returns:

Version string

execute

public java.lang.String execute(java.lang.String command)
                         throws java.lang.IllegalArgumentException,
                                java.io.IOException

Execute an agent-compatible profiling command - the comma-separated list of arguments described in arguments.cpp

Specified by:

execute in interface AsyncProfilerMXBean

Parameters:

command - Profiling command

Returns:

The command result

Throws:

java.lang.IllegalArgumentException - If failed to parse the command

java.io.IOException - If failed to create output file

dumpCollapsed

public java.lang.String dumpCollapsed(Counter counter)

Dump profile in 'collapsed stacktraces' format

Specified by:

dumpCollapsed in interface AsyncProfilerMXBean

Parameters:

counter - Which counter to display in the output

Returns:

Textual representation of the profile

dumpTraces

public java.lang.String dumpTraces(int maxTraces)

Dump collected stack traces

Specified by:

dumpTraces in interface AsyncProfilerMXBean

Parameters:

maxTraces - Maximum number of stack traces to dump. 0 means no limit

Returns:

Textual representation of the profile

dumpFlat

public java.lang.String dumpFlat(int maxMethods)

Dump flat profile, i.e. the histogram of the hottest methods

Specified by:

dumpFlat in interface AsyncProfilerMXBean

Parameters:

maxMethods - Maximum number of methods to dump. 0 means no limit

Returns:

Textual representation of the profile

addThread

public void addThread(java.lang.Thread thread)

Add the given thread to the set of profiled threads. 'filter' option must be enabled to use this method.

Parameters:

thread - Thread to include in profiling

removeThread

public void removeThread(java.lang.Thread thread)

Remove the given thread from the set of profiled threads. 'filter' option must be enabled to use this method.

Parameters:

thread - Thread to exclude from profiling