Java memory disk map update#
Java memory disk map portable#
Java memory disk map free#

The segmented storage region is not necessarily made up of contiguous chunks. The idea is that a storage container (say 1 gigabyte) can be made up of a selection of chunks (say 1 megabyte each). Segmented storage is based on a pool but allows allocation of larger storage containers than a single pool chunk. In this post I am going to discuss pool backed segmented storage. However, pools are very fast indeed to manage. This requires more memory than a pure heap if the pool is not fully used or if the elements being mapped into pool chunks are smaller than the chunks themselves. Rather than a memory system which mixes everything together in one great glorious heap, we have pools of same sized objects. This is thrown into sharp focus when working with memory pools.Īs latency or throughput performance become more critical than memory use there comes a point where one has to break out memory pools.

The issues with the JVM’s management of large memory systems are because of its bounds checking and object model. Years of experience with both Java and C++ has taught me that neither collected nor explicit heap management is efficient or easy to get right. Let me be very clear indeed, I am not talking about garbage collection. The first one to get our heads around is just how inefficient normal memory management of large memory systems is in Java. I admit there are a lot of concepts here. In so doing I will explain how we can remove the overhead of traditional Java memory access techniques and then expand the ideas for a more general approach to sharing and persisting large memory systems in JVM programming. Last year I gave a high level overview of the method this year I am deep diving to implementation of performance details. I suspect I am getting near the limit at which Java is no longer at a performance disadvantage to C++. Here I turn Java into a memory power house by implementing the same system but very much more efficiently. Memory intensive operations like mixing were a bottle neck in this system.

Whilst this was a breakthrough, it was also inefficient. For example, this recent piece took over 50 gigabytes of memory to create: I got this to work late last year and discussed it (briefly) in the Java Advent Calendar ( ) overview of Sonic Field. Disk based memory allows Sonic Field to process audio systems which require huge amounts of memory on my humble 16 gigabyte laptop. So, I wanted to develop a system for Sonic Field (my pet audio processing/synthesis project) which gave the same powerful disk based memory approach but in pure Java. This is a common approach for such issues where we store a huge amount of information and want random access to it.

Java memory disk map free#

Audacity, an amazing free audio processor, manages this using a file backed storage system. Audio processing requires huge amounts of memory. The left panel of the program shows the folder and file sizes in a familiar File Explorer-like display, while the right side displays a pie chart for visualizing each folder's disk usage.ĭisktective is relatively user-friendly, but it's hindered by a few key limitations: the export-to-HTML feature doesn't produce a very easy-to-read file, you can't delete or open folders or files from within the program, and the size units are static, meaning they're all either in bytes, kilobytes, or megabytes (whatever you choose).All this started with the realisation that I could not afford a big enough computer. You can choose any folder on any hard drive that's plugged in, including removable ones, as well as the entire hard drives.

Java memory disk map portable#

This one is portable and takes up less than 1 MB of disk space, so you can carry it with you on a flash drive.Įach time Disktective opens, it asks what directory you want to scan.

Java memory disk map update#

Unable to delete files directly from the program.Īn update hasn't been released since 2010.ĭisktective is another free disk space analyzer for Windows.