Java Reference
In-Depth Information
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Figure 13-7. VisualGC plug-in
The VisualGC plug-in, shown in
Figure 13-7
, is one of the simplest and best initial
GC debugging tools available. As mentioned in
Chapter 6
, for serious analysis, GC
logs are to be preferred to the JMX-based view that VisualGC provides. Having said
that, VisualGC can be a good way to start to understand the GC behavior of an
application, and to inform deeper investigations. It provides a near real-time view of
the memory pools inside HotSpot, and allows the developer to see how GC causes
objects to flow from space to space over the course of GC cycles.
Java 8 Proiles
The original roadmap for Java 8 included Project Jigsaw, a full-featured modularity
solution that included a modularization of the platform itself and a move away from
a single, monolithic
rt.jar
.
However, the constraints of the Java 8 release cycle meant that this work could not
be completed in time for the intended launch date. Rather than delay the release of
Java 8, the project team opted to put off the modularization of the platform until
Java 9.
Motivation
Instead of full modularity, Java 8 was updated to include Profiles. These are reduced
versions of Java SE, which must satisfy these requirements:
• They must completely implement the JVM specification.
