"Javolution creator Jean-Marie Dautelle discusses different methods to reduce the worst-case execution time of Java applications by leveraging the extra processing power of multicore systems. The methods described here do not require specialized real-time virtual machines and are suitable for many types of applications for which unexpected delays in the tens or hundreds of milliseconds are not acceptable."
"Contributions from JEOPARD will be to be made to the RTSJ (Real-Time Specification for Java), which focuses on development of portable software in the multicore embedded space, The Open Group said. Also, JEOPARD will feature development of a platform-independent software development interface for real-time multicore systems based on RTSJ and Safety-Critical Java. RTSJ is the subject of Java Specification Requests 001 and 282 in the Java Community Process, while Safety-Critical Java is covered in JSR 302."
"I've worked in investment banking for several years and my experience suggests that most problems in financial software arise from the lack of real-time support. Many large financial IT systems use a Java platform, and even an unplanned two-second stop for full garbage collection in an application can cause a loss of tens of thousands of dollars. The situation is worsened by the fact that garbage collections usually occur during a high-application activity, when the app is especially sensitive to any breaks in execution. The same situation occurs in other high-tech and production industries, which is why they are taking a careful look at real-time Java specification and its implementations."
"The KnowNow LiveData platform includes both server and connector software components. KnowNow LiveServer provides topic and content-based information routing over the Web to a variety of desktop applications and devices. The KnowNow Application Connectors for Web browsers, Excel spreadsheets, corporate databases and PDAs are small software libraries that enable commercial applications to receive real-time information updates from KnowNow LiveServers."
"There is an ETL-EAI convergence underway, according to Stephen Aikins, product manger for DT/Studio at Embarcadero Technologies. The trend, which blends ETL capabilities with EAI middleware traits, may have been slow to develop in recent years, but could gain momentum in months to come. Yet bumps in the road still exist."
"Embedded developers have long looked at the Java language from across a great divide. For years the language was not able to run on many of the diverse, narrowly-focused 8- or 16-bit systems that were commonly used in embedded development. In addition, the Java language wasn't predictable enough to deal with real-time, real-world events."
"Software developers working on producing safe, real-time Java solutions for the airlines and military now have a new tool available from DDC-I called Scorpion. This plug-in for the Eclipse environment promises the creation of lower latency Java applications than other such tools, according to an announcement issued by DDC-I."
"Key to that success was the establishment at the very beginning of a project management office that included members from "every area we could possibly think of in the company," said Aiello. Not only did the project management office include all the business departments such as sales and marketing, it also included reps from IT areas not directly involved in the E-Way application."
"Part 1 of this series looked at the Real-Time Specification for Java (RTSJ), JSR 1, and examined the topics of thread priorities, memory management, and advanced communication between threads. Part 2 will examine the topic of garbage collection and introduce the Sun Java Real-Time System (Java RTS), Sun's commercial implementation of the RTSJ."
"It's conventional wisdom that real-time programming is challenging. But this has changed under the leadership of Sun Microsystems Distinguished Engineer, Greg Bollella. Real-Time Specification for Java (RTSJ) has taken a highly-engineered and optimized system platform, the HotSpot JVM, and modified it so that it not only retains its value for non-real-time programs, but can engage in real-time programming of physical systems with relative ease."
"The Real-Time Specification for Java (RTSJ), or JSR 1, specifies how Java systems should behave in a real-time context and was developed over several years by experts from both the Java and real-time domains."
"The recent Mars mission gave Java technology some well-deserved recognition, with Java language pioneer James Gosling calling the ground-side control system that sent signals to the Mars Rover "the coolest Java app ever". While impressive, the uses of Java technology on the mission represent the tip of the iceberg as more and more physical systems requiring precise control rely on software for their implementation. Greg Bollella, a Distinguished Engineer at Sun Microsystems Laboratories (Sun Labs), has worked in recent years to explore the uses of Real-Time Specification for Java (RTSJ) in controlling physical systems -- from rockets to power plants to automobiles. He is part of a project, "Golden Gate," in which Sun Labs, NASA's Jet Propulsion Labs, and Carnegie Mellon University have joined together to create a software implementation using Java applications and RTSJ, called the Mission Data System, that would allow for greater commonality between the flight and ground systems in future Mars missions."
"We will publish this interview in two parts. The first part establishes the case for real-time requirements in the enterprise, and helps decide whether real-time Java may be applicable to the type of applications you're working on. In tomorrow's installment, Bollella and Hofert explain two special threading techniques used by the garbage collector in the real-time JVM."
"Garbage-collection pauses are not acceptable in applications with real-time requirements, and in this installment of Artima's JavaOne 2007 interview with Greg Bollella, Sun's lead engineer of Real-Time Java, and Dave Hofert, the company's Real-Time Java marketing manager, the two focus on a new feature of Sun's real-time JVM implementation: the real-time garbage collector, RT GC."
"The Real-time Specification for Java (RTSJ) provides various solutions to the problem of GC pauses. It acknowledges the importance to Java programmers of automatic memory management, but it also introduces new memory areas for avoiding GC effects that require the programmers to retake control of memory. As shown in the section on NoHeapRealtimeThreads, this raises the bar in several challenging ways for writing reliable Java applications. An alternative approach, suitable for many RT applications that can tolerate very short pauses, is to use an RT garbage collector such as Metronome in WebSphere Real Time."
"Simply bringing the advantages of using the Java language to the process of creating RT systems is a tremendous benefit to developers. But there's always room for improvement, and we are constantly evaluating new features that could simplify RT programming even further. You can go to our IBM alphaWorks site to try out our expedited real-time threads research technology that lets developers manage extremely high-frequency events with very little tolerance for variance or delay (see Resources). The tooling achieves highly deterministic behaviour by preloading, preinitializing, and precompiling the code to handle events and then running the code independently of the garbage collector with fewer and less onerous restrictions than the NHRTs in the RTSJ. You'll also find tooling called TuningFork, which traces paths from the operating system through the JVM and into applications, making it easier to perform detailed performance analysis."
"The Real-time Specification for Java (RTSJ) provides extensions to facilitate the development of real-time (RT) applications using the Java language. One such extension is a mechanism for applications to manage areas of memory outside of the heap and avoid delays that are caused by garbage collection (GC). These memory areas are referred to as scoped and immortal memory. To ensure the integrity of the heap and the immortal memory area, the RTSJ defines rules for using scoped memory. These rules control both the relationships allowed between scopes and the allowed references from an object in a scope to objects in other memory areas. The rules enable scopes to be used in a wide range of design patterns and applications, but such flexibility comes at the cost of complexity. As a result, some developers find using scopes difficult and vulnerable to mistakes. This article introduces a technique that you can use to simplify scoped memory usage."
"Nature stubbornly refuses to go digital. The typical member of the animal kingdom just doesn't appreciate the value of digital signal processing and is not likely to get a personal computer or cell phone. If the real world won't go digital, computers have to accommodate analog input. To make computers relate to the real world, we need sensors and analog-to-digital conversion. An exercise bicycle is a great example of how to interface a computer and an Informix or DB2 database to sensor data. Creating a row in a table for every revolution of a bicycle pedal also can motivate an interesting discussion about what information is worth capturing, what data is valuable and worth saving, and when data should be aggregated and archived."
"Threading and synchronization are core features of the Java programming language, described in the Java Language Specification (JLS). The RTSJ extends the core capabilities of the JLS in a number of ways. (See Resources for links to the JLS and RTSJ.) For example, the RTSJ introduces new real-time (RT) thread types that must follow a stricter scheduling policy than a regular Java thread. Another example is priority inheritance, a locking policy that defines how lock synchronization is managed when a lock is contested."
"This article looks at some of the issues involved in compiling the Java language both statically and dynamically, with a focus on implications for real-time (RT) systems. It briefly describes how Java language interpreters operate and then describes the advantages and drawbacks of native code compilation performed by modern JIT compilers. It introduces the AOT compilation technology IBM® has released in WebSphere® Real Time and covers some of its advantages and disadvantages. It then compares and contrasts the two compilation strategies and points out several application areas as well as execution environments where AOT compilation is probably the better approach. The main point is that these two compilation technologies are not mutually exclusive: both have advantages and drawbacks that impact the kinds of applications for which each technology is most effective."
"Ben Biron has been working on the J9 Virtual Machine team since May 2006, when he received his B.Eng. in Computer Systems from Carleton University. His primary focus is on Metronome and real-time garbage collection. Outside of work, Ben enjoys volleyball, hockey, golf, and open source software development."
"Some features of the Java language specification, particularly the non-deterministic runtime garbage collections and threading, have hindered the adoption of Java in industries for Real-Time Systems and software applications. Both industry representatives and academics understand this limitation of the application of Java in Real-Time so a workshop at the National Institute of Standards and Technology (NIST) was organized to discuss and propose a draft for Real-Time Specification for Java (RTSJ). This requirement lead to the formation of an expert group in the Java Community Process (JCP) to draft a specification for Java in Real-Time."
