NonStop Server for Java 7.0 Programmer's Reference

4 Implementation specifics
This section explains the various topics pertaining to the implementation specifics of NonStop
Server for Java:
• “Headless support” (page 34)
• “Additional files” (page 35)
• “Additional environment variable” (page 35)
• “Java native interface (JNI)” (page 35)
• “Floating-point implementation” (page 39)
• “Multi-threaded programming” (page 40)
• “Java print service” (page 44)
• “Using the Guardian printer” (page 45)
• “Java authentication and authorization service” (page 46)
• “JavaBeans” (page 47)
• “Debugging Java programs” (page 47)
• “Deviations in JVM specification options” (page 50)
• “Garbage collection (GC)” (page 51)
• “Java garbage collector tuning for application performance” (page 57)
• “GC profiling” (page 59)
• “ZapInitialHeap option” (page 62)
• “64–bit process support” (page 63)
• “32–bit process support” (page 64)
• “Version command-line option” (page 65)
• “Posting signals to GC process” (page 65)
• “Unhandled exception” (page 67)
• “Error file” (page 67)
• “System property” (page 69)
• “LogVMOutput option” (page 69)
• “UseCompressedOops” (page 69)
• “SecureRandom startup enhancement” (page 69)
• “VirtualMachine.list() support” (page 70)
See also, “Application tuning and profiling” (page 86).
Headless support
Since NonStop operating system does not provide support for GUI operations, NSJ7 is a headless
JVM that conforms to the Oracle's headless support standards regarding Java Abstract Window
Toolkit (AWT) classes and methods. For similar reasons, NSJ7 does not support the AppletViewer
tool.
Class data sharing (CDS) is a feature intended to reduce application startup time and footprint,
which is available only with a Java HotSpot client VM. Hence this is not supported in NSJ.
34 Implementation specifics