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In his article about the util.concurrent package, Brian Goetz points out that "Most of us would never think of writing our own XML parser, text indexing and search engine, regular expression compiler, ...". We use existing standard packages. The open source community does sometimes recreate standard tools for a very good reason: to make them open source. But it gets a bit ridiculous when we end up with four versions of slightly different open source tools. This seems to the situation with Java profilers. We now have at least four open source versions, (jcoverage, EJP, jProf, simpleprofiler) all seemingly in alpha release. They are of varying ages, going back to 1999. As each one successively became unsupported by its author, it seems like the next one started being developed by someone else. Why?
The quality of articles being written is still impressive this month. My own article on nulling and GC was well received; Brian Goetz's article on util.concurrent, the first of a series, is excellent as usual with Brian. If garbage collection (GC) is of interest to you, Nagarajayya and Mayer have updated their GC tuning article to cover 1.4.1. The article is well worth reading in detail: 1.4.1 includes five (yes 5!) garbage collection algorithms, and the article explains their aims and interactions.
I don't normally list research articles that don't have concrete performance tips. But I've made an exception for Vivek Haldar's research paper on verifying compile time assists for JITs (actually entitled "Verifying Data Flow Optimizations for Just-in-Time Compilation"). Since 1.1, compile time optimizations have been gradually reduced until the -O does nothing, mainly because the JIT knows more at runtime and can apply better optimizations then. I've been waiting for techniques to appear which will reverse this process of leaving everything to runtime, after all at compile time you have far more time to do optimizations. Now Haldar's paper shows how the compiler can add optimization hints while still satisfying the Java security model, which was probably the biggest sticking point.
Otherwise, we list a number of other articles covering EJBs, servlets, JDBC, XML parsing, web services, performance monitoring and analysis, J2ME design and portability, and more.
The roundup and Javva are also here, and our interview this month is with Ed lycklama of Sitraka (now part of Quest), who gives us his interesting view of Java performance. And we also have all the new performance tips extracted from our listed articles.
Java performance tuning related news.
Back to newsletter 025 contents
