Meditation in JVM

I’ve noticed something many times: after a busy programming day at work, my mind feels cloudy, full, and overloaded. I take some time to sit right after work. After a meditation session, the mind feels clean and fresh again. Java Garbage Collectors work for my applications; meditation works for my mind. I couldn’t help but notice the parallel: meditation is to the mind what a garbage collector is to the JVM.

Meditation means many things in many different ways. But here I want to look at it specifically through the lens of how I understand a GC.

The JVM and its cleaner

The JVM is the platform where Java and many other languages can run. Among many other things, one of its strengths is having a garbage collector. It takes away the responsibility from programmers, in a way liberating them.

The JVM abstracts away memory management. It allocates memory and releases it automatically, and the garbage collector is the magical component doing this work.

I’m not an expert in JVM memory management, so here is the simple version: objects are created in memory by all kinds of operations as Java programs run. Memory is always limited (think of RAM/space), and not all objects are always needed. Some trash accumulates (how restarting a phone or PC can suddenly make it feel faster again). Restarting a JVM process is still an option, but ideally, we rely on the capabilities of the GC so our programs don’t slow down because of garbage (memory that is occupied but no longer used).

A GC scans the memory managed by the JVM and discovers which objects are in use and which are not. Unused ones are released (like deleting unused apps on your phone), freeing space for new objects. Some objects are “favorites”; they might be moved to a special place and treated differently (the old generation). Different objects have different life cycles. Some are short-lived (local objects in a method — the surface of the mind) and some are long-lived (the conditioned parts of the mind). Because of these differences, the JVM has many GC algorithms, each suited for different requirements.

That is enough for JVM and its awesomeness.

What does this have to do with meditation?

retreat as garbage collection

A retreat is the stop-the-world garbage collector.

In the retreat format I know, one is disconnected from the world and from other people completely. Daily ways of being pause. The person turns inward; there are no external interactions. This is the famous stop-the-world GC. It stops our Java program and does some cleaning. And because it stops the world, it cannot run for too long. It is short.

A 10-day retreat is brief compared to a lifetime, but incredibly intense. We can scan more, and that helps release more. In stop-the-world mode, we’re also lucky: fewer “new objects” are created, so the cleaning feels even more refreshing.

daily sits are shorter

Outside retreats, one might practice daily sits. These might still feel like stop-the-world operations but only for a short time. Your users (partner, friends, family) may not even notice your brief absence. Here the dynamic is different: you may be producing more objects (more contact) than you can clean in those sessions.

Daily sits are helpful for day-to-day functioning, it is surface cleaning. Retreats are deep cleaning. Intense practice lets us reach and discover objects that occupy our being but are no longer needed.

responsive and reactive

Reference checking happens as things come up and other parts of the system react. A GC decides whether an object is still in use by discovering relationships. Are other objects referencing this one? If so, it stays.

Similarly, when something arises in the mind and we react, that reaction is like a reference — clinging or aversion. As long as the references remain, the object will not be cleaned.

Equanimity is like leaving the object alone, allowing it to be garbage-collected, to be released.

Just as a JVM running too long can slow down if the GC can’t clean fast enough, the mind also becomes sluggish when overloaded. At times it becomes unresponsive (no memory left), at times reactive (queued-up operations running all at once). That is how a busy, scattered mind behaves.

garbage collection

Java released us from the responsibility of managing memory but that does not mean that we are completely unhook from that space. If a program creates too many objects in a short time, that will create lots of work for a GC. This would be simple to observe nowadays by every one after an intense or mindless interaction. Anyone can observe this today after intense or mindless interaction. So we might be able to collect more garbage than a cleaner can handle. Every contact with the senses is like calling new in Java.

different techniques

There are different meditation techniques, just as there are different GCs. They operate at different levels, with different parameters, for different needs. Each makes a different promise for the same fundamental task.

As experience grows, different solutions become appropriate at different times. One can use:

How lucky we are to have these options available. I’m thankful to the people who designed these systems.

We can draw many other parallels between these two distinct but surprisingly similar practices.

Is it a bird or a plane?

Can we run a JVM without a garbage collector?

GC and Vipassana

In Anapana, one simply observes the natural breath. In Vipassana, one scans the body in different ways. Isn’t it mind-tickling that some GCs follow Vipassana instructions almost to the letter? Memory is the body, the sense-doors provide inputs, and their contacts create objects. Aggregations are sub-programs.

A GC scans memory and objects — does it care what the object means? An object may be crucial to the application, but for the GC it is simply something occupying memory. All objects are neutral. They have properties but not the meaning the application gives them. For the GC, they are impersonal and impermanent.

GC is just another object in the memory.
It will also be cleaned and released.

JVM is just another object in the memory.
It will also be cleaned and released.