Working With VM Arguments as a Co-op Student

Stereotypically, interns are known to receive the short end of the stick. Whether it’s cleaning up scrappy (and usually unimportant) parts of a project, or doing boring brain-dead tasks that the full-time members are too busy to do, the work that we interns tend to receive is usually viewed as miscellaneous housework. Two weeks into…

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OpenJ9 Internship: Auto detection and Web Projects

This post describes my winter 2019 internship in the Eclipse OpenJ9 team. At the time of writing, I am a second-year computer science student at the University of Waterloo. This was my first co-op term, so I was excited to utilize the knowledge learned from university in a real-world programming project. The first part of…

Cgroup Metrics – now available in Javacore

  Eclipse OpenJ9 can now provide Linux cgroup information as part of a Java dump file, commonly known as a javacore. This can be very handy to debug clearly by having the information about the environment in which JVM is running and if JVM is aware of the limits imposed by the environment etc. In…

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New DDR Extensions and ValueTypes

This blog is intended to serve as a technical overview of current Direct Dump Reader (DDR) implementation and an instruction to add new DDR extensions. It is the responsibility of Eclipse OpenJ9 developers to modify DDR whenever there are some changes in J9VM. Additionally, I briefly introduce memory layouts of ValueTypes in J9VM and a…

Adaptive Spinning

This is blog 5 in the OpenJ9 locking/synchronization series (blog 1). This blog covers OpenJ9’s adaptive spinning strategy which dynamically enables/disables lock spinning using heuristics in order to avoid the negative impact of lock spinning. Before reading this blog, one needs to know about the system-monitors (blog 2), object-monitors (blog 3) and three-tier spinning (blog…

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