Add Java GC Logs

[MatthewKhouzam]

This feature is taken from the Eclipse JIFA project, the code was slightly tweaked, removing certain dependencies such as Lombok and SL4J, but it works well, is well tested and brings in several new views that are of interest:

• Java Memory VS Time, in the counters views, one can see the memory status by pool
• GC latency analysis: Shows the amount of time spent in the GC.

The code that will be kept if JIFA makes a jar for GC parsing would be GCTrace.java as it is the adapter between the GCModel and Trace Compass. Special attention in the reivew should be put there.

Known Issues:

• The GC log is entirely read to ram in the init phase. this can freeze the UI thread.
• The GC parser doesn't always read GC events as it changes from one JVM to another.

[MatthewKhouzam]

how to log in GC. I will add to wiki since it's out of scope of the project. (tracer vs trace viewer)

Java 8: Use -Xloggc: -XX:+PrintGCDetails -XX:+PrintGCDateStamps. Java 9+: Use -Xlog:gc*:file= or more specific logging options.

[MatthewKhouzam]

Thanks!