On 29/09/2016 18:50, Rafael Winterhalter wrote:
:
Therefore I want to propose adding a static method to the Instrumentation
interface:
interface Instrumentation {
static Instrumentation getInstance(boolean redefine, boolean retransform,
boolean nativePrefix) {
// security manager check
return getInstance0(redefine, retransform, nativePrefix);
}
}
The original intention, back in JSR 163, was that java.lang.instrument
be for instrumentation agents, not applications. This is why the API
deliberately does not include a method to get the Instrumentation object
along the lines you have propose. Sure, you can leak it from an agent
started on the command line or attached at runtime but that is not the
original intention. So I think introducing this method is a very
significant change that would require a lot of consideration (previous
requests to provide a way for applications to get the Instrumentation
object without an agent in the picture were resisted).
Separately, introducing this method creates a complication for runtimes
that do not have JVM TI support (the JPLIS agent is based on JVM TI). As
things stand then it's possible to create a runtime that does not have a
means to start agents from the command-line (the spec allows this) and
so there is no need to have the implementation support for this API. So
if a method like this is every introduced then it would either have to
be optional or it would require changes to the JVM TI spec to make it
non-optional (or is based on an alternative JPLIS implementation that
doesn't use JVM TI).
-Alan
