HP-UX Programmer's Guide for Java 2
Table Of Contents
- Table of Contents
- 1 Introduction
- 2 HotSpot Technology Tools and Commands
- 3 Configuration for Java™ Support
- 4 Performance and Tuning
- 5 Measuring System Performance
- 6 Using Threads
- 7 Using Signals
- 8 Using Java™ 2 JNI on HP-UX
- 9 Expanding Memory
- Determine your requirements
- Memory layout under HP-UX 11.0 (PA-RISC only)
- Additional memory available under HP-UX 11i (PA-RISC only)
- Allocating physical memory and swap in the Java™ heap
- Useful key command-line options for allocating memory
- Application-dependent considerations using large heap size HP-UX 11i PA-RISC
- Expanding heap size in native applications on PA-RISC HP-UX 11.11 and later releases
- Expanding heap size in native applications on Integrity HP-UX 11.23 and later releases
- Expanding heap size in HP-UX PA-RISC
- Expanding heap size in HP-UX Integrity
- 10 Diagnosing Memory Leaks
- A JDK/JRE 6.0.n and 7.0.n Usage Notes
- Using Java 2 JNI on HP-UX
- Garbage collection
- Asian TrueType fonts and Asian locales
- Date/Time methods defaults
- Profiling
- Compatibility with previous releases
- Java Cryptography Extension (JCE) policy files
- Configuring the Java Runtime Plug-In
- CLASSPATH environment variable
- Java Web Start technology usage
- Upgrading from a previous Java Web Start version
- IPv6 support
- Allocation Site Statistics and Zero Preparation -Xverbosegc
- JDK 6.0.04 flags
- GC log-rotation support
- NUMA collector enhancements
- ThreadDumpPath support
- Garbage-First garbage collector (-XX:+UseG1GC)
- jmap, jinfo, and jstack tools included in JDK 6.0.03
- Additional Java Web Start documentation
- B JDK/JRE 5.0.n Usage Notes
- Using Java 2 JNI on HP-UX
- Garbage collectors: Parallel and Concurrent Mark Sweep
- Allocating physical memory and swap in the Java heap
- Asian TrueType fonts and Asian locales
- Date/Time methods defaults
- Profiling
- Closing a socket (PA-RISC only)
- Compatibility with previous releases
- Java Cryptography Extension (JCE) policy files
- Allocation Site Statistics and Zero Preparation -Xverbosegc
- IPv6 support on Java 5.0
- GC log-rotation support in 5.0
- ThreadDumpPath support in 5.0
- Dynamically loaded libraries in 5.0
- Performance improvement for String.intern()
- Configuring the Java Runtime Plug-In
- CLASSPATH environment variable
- Java Web Start technology usage
- C SDK/RTE 1.4.2.n Usage Notes
- Removing support for unwanted architectures in the JRE
- Support for dynamic thread local storage (TLS)
- Signal Chaining functionality
- Using Java 2 JNI on HP-UX
- HotSpot JVM options
- Garbage collectors: Parallel and Concurrent mark sweep
- Allocating physical memory and swap in the Java heap
- Asian TrueType fonts and Asian locales
- Date/Time methods defaults
- Profiling
- Closing a socket when accept or read is pending (PA-RISC) - new patch information!
- Compatibility with previous releases
- Runtime Plug-In usage and configuration
- GC log-rotation support
- ThreadDumpPath support
- D Additional Resources
- Index
For more details on why this occurs and for examples of using key command line
options, see “Allocating physical memory and swap in the Java™ heap” (page 64).
Asian TrueType fonts and Asian locales
Asian locales are supported by HP's JDK 1.4 with TrueType fonts. For more details,
see HP-UX Fonts and the Java™ Runtime Environment at:
http://www.hp.com/go/hpux-java-docs
Date/Time methods defaults
The HotSpot JVM uses the gettimeofday() system call to obtain date and time
information. For performance reasons a new mechanism that uses the number of CPU
ticks since the application started is used to calculate the current time. As a result,
changes to the system date or time using the date command, the adjtime() function,
or time synchronization utilities such as ntp will not be reflected in the date and time
that the Java program returns until the process is restarted.
If your application requires that system time changes are immediately reflected, you
can use the -XX:+UseGetTimeOfDay option to tell the JVM to use the gettimeofday
call instead of the new, lightweight mechanism. However you may notice a drop in
performance.
Profiling
In the SDK Version 1.4, a SIGPROF handler to support future profiling capability is
installed automatically. This may cause incompatibilities with other native code or
profiling tools which use SIGPROF.
You can turn off the SIGPROF handler by using the following option:
-XX:+ReduceSignalUsage
However, be aware that using this option also turns off the SIGQUIT handler, and you
therefore will not be able to get a Java stack trace.
Closing a socket when accept or read is pending (PA-RISC) - new patch
information!
Because of changes to the mechanism by which a socket is closed in the VM, for all
supported HP-UX PA-RISC systems, you no longer need to use the
-XdoCloseWithReadPending option we recommended in earlier releases. However for
HP-UX 11.11 the following patches (or their superseded patches) are required:
PHKL_32457
PHKL_25840
PHKL_25842
PHNE_25644
PHNE_25084
For more detailed information, see Closing a socket when accept or read is pending
(PA-RISC).
Asian TrueType fonts and Asian locales 91