datadog.trace.bootstrap

Class AgentBootstrap

java.lang.Object

datadog.trace.bootstrap.AgentBootstrap

public class AgentBootstrap
extends Object

Entry point for initializing the agent.

The bootstrap process of the agent is somewhat complicated and care has to be taken to make sure things do not get broken by accident.

JVM loads this class onto app's classloader, afterwards agent needs to inject its classes onto bootstrap classpath. This leads to this class being visible on bootstrap. This in turn means that this class may be loaded again on bootstrap by accident if we ever reference it after bootstrap has been setup.

In order to avoid this we need to make sure we do a few things:

• Do as little as possible here
• Never reference this class after we have setup bootstrap and jumped over to 'real' agent code
• Do not store any static data in this class
• Do dot touch any logging facilities here so we can configure them later

Constructor Summary

Constructors

Constructor and Description
AgentBootstrap()

Method Summary

Modifier and Type	Method and Description
static void	agentmain(String agentArgs, Instrumentation inst)
static String	getAgentVersion() Read version file out of the agent jar.
static void	main(String... args) Main entry point.
static void	premain(String agentArgs, Instrumentation inst)

Methods inherited from class java.lang.Object

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

Constructor Detail

AgentBootstrap

public AgentBootstrap()

Method Detail

premain

public static void premain(String agentArgs,
                           Instrumentation inst)

agentmain

public static void agentmain(String agentArgs,
                             Instrumentation inst)

main

public static void main(String... args)

Main entry point.

Parameters:

args - command line agruments

getAgentVersion

public static String getAgentVersion()
                              throws IOException

Read version file out of the agent jar.

Returns:

Agent version

Throws:

IOException