load time : Java Glossary


load time
java.exe takes quite a long time to start up. It loads DLL (Dynamic Link Library) s, then it loads your classes one by one in class file format and compiles and optimises them to machine code. What can be done to speed this up?
  1. The most dramatic savings is by using Jet, particularly the new beta which doubles the speed yet again, which does static native compilation. It does the preparation of the highly optimised machine code well in advance and only loads the minimum number of classes you need.
  2. Use java.exe -client rather than java.exe -server. -client favours fast start up over fast execution.
  3. If you are using an old Java, upgrade to Java version 1.6 which is faster at loading.
  4. Sun is not much interested in fast load. They are mostly concerned with server side where a program loads then runs for weeks or months at a time. They make their money selling premium server hardware. Even if it took 10 minutes for a server program to fire up, it would not matter. You need to put pressure on Sun to take an interest in speeding up program load for desktop utilities.
  5. I have proposed two projects to speed load, but both require modifying the JVM (Java Virtual Machine). See Gespenster fast program load and Hibernation (Suspended Animation) Fast Program Load. You might try implementing them as a prototype and convincing Sun to incorporate your proven idea. Java is open source.
  6. Use psychological techniques. Keep your user entertained with an interesting, varying display while the program loads. If the program looks frantically busy, the user is much less likely to be frustrated by the delay. You might write a little kicker program in C that launches your Java program then sets about in parallel displaying flash screens, perhaps enhanced with variable web content, to keep the user amused.

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