| Final release | 1.0.0 beta / July 15, 2002 |
|---|---|
| Type | Java Virtual Machine |
| License | GPL |
| Website | www |
Jupiter JVM is an open-source Java virtual machine, which has been developed as a master thesis with modularity and extensibility in mind. It uses Boehm garbage collector and GNU Classpath. The Jupiter Virtual Machine main aspects of its design can be simplified as:
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In computer science, garbage collection (GC) is a form of automatic memory management. The garbage collector, or just collector, attempts to reclaim garbage, or memory occupied by objects that are no longer in use by the program. Garbage collection was invented by John McCarthy around 1959 to simplify manual memory management in Lisp.
Java is a general-purpose programming language that is class-based, object-oriented, and designed to have as few implementation dependencies as possible. It is intended to let application developers write once, run anywhere (WORA), meaning that compiled Java code can run on all platforms that support Java without the need for recompilation. Java applications are typically compiled to bytecode that can run on any Java virtual machine (JVM) regardless of the underlying computer architecture. The syntax of Java is similar to C and C++, but it has fewer low-level facilities than either of them. As of 2019, Java was one of the most popular programming languages in use according to GitHub, particularly for client-server web applications, with a reported 9 million developers.
A Java virtual machine (JVM) is a virtual machine that enables a computer to run Java programs as well as programs written in other languages that are also compiled to Java bytecode. The JVM is detailed by a specification that formally describes what is required in a JVM implementation. Having a specification ensures interoperability of Java programs across different implementations so that program authors using the Java Development Kit (JDK) need not worry about idiosyncrasies of the underlying hardware platform.
This is a comparison of Java and C++, two prominent object-oriented programming languages.
The Java Native Interface (JNI) is a foreign function interface programming framework that enables Java code running in a Java virtual machine (JVM) to call and be called by native applications and libraries written in other languages such as C, C++ and assembly.
In computer programming, tracing garbage collection is a form of automatic memory management that consists of determining which objects should be deallocated by tracing which objects are reachable by a chain of references from certain "root" objects, and considering the rest as "garbage" and collecting them. Tracing garbage collection is the most common type of garbage collection – so much so that "garbage collection" often refers to tracing garbage collection, rather than other methods such as reference counting – and there are a large number of algorithms used in implementation.
In computer science, asynchronous I/O is a form of input/output processing that permits other processing to continue before the transmission has finished.
Jikes Research Virtual Machine is a mature virtual machine that runs programs written for the Java platform. Unlike most other Java virtual machines (JVMs), it is written in the programming language Java, in a style of implementation termed meta-circular. It is free and open source software released under an Eclipse Public License.
In computer programming, a runtime system, also called run-time system, runtime environment or run-time environment, primarily implements portions of an execution model. This is not to be confused with the runtime lifecycle phase of a program, during which the runtime system is in operation. Most languages have some form of runtime system that provides an environment in which programs run. This environment may address a number of issues including the layout of application memory, how the program accesses variables, mechanisms for passing parameters between procedures, interfacing with the operating system, and otherwise. The compiler makes assumptions depending on the specific runtime system to generate correct code. Typically the runtime system will have some responsibility for setting up and managing the stack and heap, and may include features such as garbage collection, threads or other dynamic features built into the language.
In computer science, manual memory management refers to the usage of manual instructions by the programmer to identify and deallocate unused objects, or garbage. Up until the mid-1990s, the majority of programming languages used in industry supported manual memory management, though garbage collection has existed since 1959, when it was introduced with Lisp. Today, however, languages with garbage collection such as Java are increasingly popular and the languages Objective-C and Swift provide similar functionality through Automatic Reference Counting. The main manually managed languages still in widespread use today are C and C++ – see C dynamic memory allocation.
Application virtualization software refers to both application virtual machines and software responsible for implementing them. Application virtual machines are typically used to allow application bytecode to run portably on many different computer architectures and operating systems. The application is usually run on the computer using an interpreter or just-in-time compilation (JIT). There are often several implementations of a given virtual machine, each covering a different set of functions.
In software engineering, the initialization-on-demand holder idiom is a lazy-loaded singleton. In all versions of Java, the idiom enables a safe, highly concurrent lazy initialization of static fields with good performance.
In computer programming, green threads are threads that are scheduled by a runtime library or virtual machine (VM) instead of natively by the underlying operating system (OS). Green threads emulate multithreaded environments without relying on any native OS abilities, and they are managed in user space instead of kernel space, enabling them to work in environments that do not have native thread support.
The Java programming language and the Java virtual machine (JVM) have been designed to support concurrent programming, and all execution takes place in the context of threads. Objects and resources can be accessed by many separate threads; each thread has its own path of execution but can potentially access any object in the program. The programmer must ensure read and write access to objects is properly coordinated between threads. Thread synchronization ensures that objects are modified by only one thread at a time and that threads are prevented from accessing partially updated objects during modification by another thread. The Java language has built-in constructs to support this coordination.
In software development, the programming language Java was historically considered slower than the fastest 3rd generation typed languages such as C and C++. The main reason being a different language design, where after compiling, Java programs run on a Java virtual machine (JVM) rather than directly on the computer's processor as native code, as do C and C++ programs. Performance was a matter of concern because much business software has been written in Java after the language quickly became popular in the late 1990s and early 2000s.
Eclipse OpenJ9 is a high performance, scalable, Java virtual machine (JVM) implementation that is fully compliant with the Java Virtual Machine Specification.
Azul Systems, Inc., a privately held company, develops runtime platforms for executing Java-based applications. Founded in March 2002, Azul Systems is headquartered in Sunnyvale, California, with offices in London, United Kingdom; Saint Petersburg and Novosibirsk, Russia and Bangalore, India.
Software is said to exhibit scalable parallelism if it can make use of additional processors to solve larger problems, i.e. this term refers to software for which Gustafson's law holds. Consider a program whose execution time is dominated by one or more loops, each of that updates every element of an array --- for example, the following finite difference heat equation stencil calculation:
for t := 0 to T dofor i := 1 to N-1 do new(i) := * .25 // explicit forward-difference with R = 0.25 endfor i := 1 to N-1 do A(i) := new(i) endend
The Garbage-First Collector (G1) is a garbage collection algorithm introduced in the Oracle HotSpot Java virtual machine (JVM) 6 and supported from 7 Update 4. It was planned to replace Concurrent mark sweep collector (CMS) in JVM 7.
Language interoperability is the capability of two different programming languages to natively interact as part of the same system. Interoperability is advantageous, because different programming language are optimized for specific tasks, and allowing them to communicate can create better systems.
