Skip to main content

Next Generation Automatic Memory Management


Modern object-oriented programming languages such as Java, JavaScript, Ruby, and C# are becoming ubiquitous. A primary reason for this trend is that these languages provide automatic memory management (garbage collection), which relieves programmers of the burden of explicitly freeing memory that is no longer needed. Professor Kathryn McKinley at the University of Texas at Austin has led an NSF-funded research project, in collaboration with Steve Blackburn at the Australian National University, that is exploring how to build the software infrastructure that executes managed programs, i.e., programs in languages that provide automatic memory management. Garbage collection provides a number of software engineering benefits such as preventing common programmer memory errors that are among the most difficult to diagnose and fix. However, in the past, programs in garbage collected languages tended to be slower. The garbage collector makes a classic time-space tradeoff that seeks to provide space efficiency, fast reclamation of objects no longer in use, and fast run-time performance by packing contemporaneously-allocated objects together in space. The three canonical tracing garbage collectors: semi-space, mark-sweep, and mark-compact each sacrifice one of these objectives.
The PIs also introduced opportunistic defragmentation, which mixes copying and marking in a single pass. Combining both, we implement immix a novel high performance garbage collector that achieves all three performance objectives. The key insight is to allocate and reclaim memory hierarchically at a coarse block grain when possible and otherwise divide blocks in to finer grain lines, similar to pages and cache lines in hardware memory systems. It is shown that immix outperforms existing canonical algorithms, improving total application performance by 7 to 25% on average across 20 benchmarks. As the mature space in a generational collector, immix matches or beats a highly tuned generational collector, e.g., it improves SPECjbb200 by 5%. These innovations and the identification of a new family of collectors open new opportunities for garbage collector design.
Anurag

Comments

Post a Comment

Popular posts from this blog

Standard and Formatted Input / Output in C++

The C++ standard libraries provide an extensive set of input/output capabilities which we will see in subsequent chapters. This chapter will discuss very basic and most common I/O operations required for C++ programming. C++ I/O occurs in streams, which are sequences of bytes. If bytes flow from a device like a keyboard, a disk drive, or a network connection etc. to main memory, this is called   input operation   and if bytes flow from main memory to a device like a display screen, a printer, a disk drive, or a network connection, etc., this is called   output operation . Standard Input and Output in C++ is done through the use of  streams . Streams are generic places to send or receive data. In C++, I/O is done through classes and objects defined in the header file  <iostream> .  iostream  stands for standard input-output stream. This header file contains definitions to objects like  cin ,  cout , etc. /O Library Header Files There are...
Post a Comment
Read more

Genetic Algorithm: Population, Fitness Function, Parent Selection, Cross over, Mutation

Genetic Algo Population Population is a subset of solutions in the current generation. It can also be defined as a set of chromosomes. There are several things to be kept in mind when dealing with GA population − The diversity of the population should be maintained otherwise it might lead to premature convergence. The population size should not be kept very large as it can cause a GA to slow down, while a smaller population might not be enough for a good mating pool. Therefore, an optimal population size needs to be decided by trial and error. The population is usually defined as a two dimensional array of –  size population, size x, chromosome size . Population Initialization There are two primary methods to initialize a population in a GA. They are − Random Initialization  − Populate the initial population with completely random solutions. Heuristic initialization  − Populate the initial population using a known heuristic for the problem. It has been observed that the e...
Post a Comment
Read more

Difference between net platform and dot net framework...

Difference between net platform and dot net framework... .net platform supports programming languages that are .net compatible. It is the platform using which we can build and develop the applications. .net framework is the engine inside the .net platform which actually compiles and produces the executable code. .net framework contains CLR(Common Language Runtime) and FCL(Framework Class Library) using which it produces the platform independent codes. What is the .NET Framework? The Microsoft .NET Framework is a platform for building, deploying, and running Web Services and applications. It provides a highly productive, standards-based, multi-language environment for integrating existing investments with next-generation applications and services as well as the agility to solve the challenges of deployment and operation of Internet-scale applications. The .NET Framework consists of three main parts: the common language runtime, a hierarchical set of unified class librari...
3 comments
Read more