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Jupiter JVM
Jupiter JVM is an open-source software, 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: *Memory locality - Objects are allocated on the heap with little or no consideration for locality. While this approach may be appropriate for uniprocessors or small-scale SMPs, it is unlikely to work well on a cluster of workstations where remote memory access is one or two orders of magnitude slower than local memory access. *Parallel garbage collection - Garbage collection can consume a considerable amount of application time. Typically, JVMs employ "stop-the-world" garbage collectors, where program threads are halted during garbage collection. This approach will not work for large numbers of processors, for two reasons. First, the cost of "stopping the world" is considerably higher when the numb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java Virtual Machine
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. The JVM reference implementation is developed by the OpenJDK project as open source code and includes a JIT compiler called HotSpot. The commercially supported Java releases available from Oracle are based on the OpenJDK runtime. Eclipse OpenJ9 is another open source JVM for OpenJDK. JVM specification The Java virtual machine is an abstract (virtual) computer defined by a specification. It is a part of java runtime environment. The garbage-collection algorithm u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open-source Software
Open-source software (OSS) is computer software that is released under a license in which the copyright holder grants users the rights to use, study, change, and distribute the software and its source code to anyone and for any purpose. Open-source software may be developed in a collaborative public manner. Open-source software is a prominent example of open collaboration, meaning any capable user is able to participate online in development, making the number of possible contributors indefinite. The ability to examine the code facilitates public trust in the software. Open-source software development can bring in diverse perspectives beyond those of a single company. A 2008 report by the Standish Group stated that adoption of open-source software models has resulted in savings of about $60 billion per year for consumers. Open source code can be used for studying and allows capable end users to adapt software to their personal needs in a similar way user scripts an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Java Virtual Machine
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. The JVM reference implementation is developed by the OpenJDK project as open source code and includes a JIT compiler called HotSpot. The commercially supported Java releases available from Oracle are based on the OpenJDK runtime. Eclipse OpenJ9 is another open source JVM for OpenJDK. JVM specification The Java virtual machine is an abstract (virtual) computer defined by a specification. It is a part of java runtime environment. The garbage-collection algorithm u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boehm Garbage Collector
The Boehm–Demers–Weiser garbage collector, often simply known as Boehm GC, is a Tracing_garbage_collection#Precise_vs._conservative_and_internal_pointers, conservative Garbage collection (computer science), garbage collector for C (programming language), C and C++ developed by Hans Boehm, Alan Demers, and Mark Weiser.Hans BoehmA garbage collector for C and C++/ref>Andrew W. Appel (1998), Modern Compiler Implementation in C' -Boehm Conservative Garbage Collector, Boehm GC is free software distributed under a permissive free software licence similar to the X11 license. The first paper introducing this collector appeared in 1992. Design Hans Boehm describes the operation of the collector as follows: Boehm GC can also run in Memory leak, leak detection mode in which memory management is still done manually, but the Boehm GC can check if it is done properly. In this way a programmer can find memory leaks and double deallocations. Boehm GC is also distributed with a C strin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Classpath
GNU Classpath is a free software implementation of the standard class library for the Java programming language. Most classes from J2SE 1.4 and 5.0 are implemented. Classpath can thus be used to run Java-based applications. GNU Classpath is a part of the GNU Project. It was originally developed in parallel with libgcj due to license incompatibilities, but later the two projects merged. GNU Classpath was deemed a high priority project by the Free Software Foundation. When the Classpath project began, the license for the official Java implementation from Sun Microsystems did not allow distribution of any alterations. Since the inception of the Classpath project, the OpenJDK was released under the GPL and now serves as the official reference implementation for the Java platform. License GNU Classpath is licensed under the GNU General Public License with a linking exception. This is a free software license. All code is formally owned by the Free Software Foundation, and this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory Locality
In computer science, locality of reference, also known as the principle of locality, is the tendency of a processor to access the same set of memory locations repetitively over a short period of time. There are two basic types of reference locality temporal and spatial locality. Temporal locality refers to the reuse of specific data and/or resources within a relatively small time duration. Spatial locality (also termed ''data locality''"NIST Big Data Interoperability Framework: Volume 1"urn:doi:10.6028/NIST.SP.1500-1r2) refers to the use of data elements within relatively close storage locations. Sequential locality, a special case of spatial locality, occurs when data elements are arranged and accessed linearly, such as traversing the elements in a one-dimensional Array data structure, array. Locality is a type of predictability, predictable behavior that occurs in computer systems. Systems that exhibit strong ''locality of reference'' are great candidates for performance optimiza ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parallel Garbage Collection
Parallel is a geometric term of location which may refer to: Computing * Parallel algorithm * Parallel computing * Parallel metaheuristic * Parallel (software), a UNIX utility for running programs in parallel * Parallel Sysplex, a cluster of IBM mainframes * Parallel communication * Parallel port * Parallel ATA * Parallel Computers, Inc., an American computer manufacturer of the 1980s Mathematics and science * Parallel circuits, as opposed to series * Parallel (geometry) *Parallel (operator), mathematical function used in electrical engineering * Parallel postulate * Parallel evolution * Parallel transport *Parallel manipulator Navigation * Parallel (latitude), an imaginary east–west line circling a globe * Parallel of declination, used in astronomy Music and entertainment * ''Parallel'' (manga) * ''Parallel'' (2018 film), a Canadian science fiction thriller film * Parallel (2023 film) an upcoming American science fiction thriller film * Parallel key, the minor (or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Memory Consistency Model
In computer science, a consistency model specifies a contract between the programmer and a system, wherein the system guarantees that if the programmer follows the rules for operations on memory, memory will be consistent and the results of reading, writing, or updating memory will be predictable. Consistency models are used in distributed systems like distributed shared memory systems or distributed data stores (such as filesystems, databases, optimistic replication systems or web caching). Consistency is different from coherence, which occurs in systems that are cached or cache-less, and is consistency of data with respect to all processors. Coherence deals with maintaining a global order in which writes to a single location or single variable are seen by all processors. Consistency deals with the ordering of operations to multiple locations with respect to all processors. High level languages, such as C++ and Java, maintain the consistency contract by translating memory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thread (computer Science)
In computer science, a thread of execution is the smallest sequence of programmed instructions that can be managed independently by a scheduler, which is typically a part of the operating system. The implementation of threads and processes differs between operating systems. In Modern Operating Systems, Tanenbaum shows that many distinct models of process organization are possible.TANENBAUM, Andrew S. Modern Operating Systems. 1992. Prentice-Hall International Editions, ISBN 0-13-595752-4. In many cases, a thread is a component of a process. The multiple threads of a given process may be executed concurrently (via multithreading capabilities), sharing resources such as memory, while different processes do not share these resources. In particular, the threads of a process share its executable code and the values of its dynamically allocated variables and non- thread-local global variables at any given time. History Threads made an early appearance under the name of "tasks ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synchronization
Synchronization is the coordination of events to operate a system in unison. For example, the conductor of an orchestra keeps the orchestra synchronized or ''in time''. Systems that operate with all parts in synchrony are said to be synchronous or ''in sync''—and those that are not are '' asynchronous''. Today, time synchronization can occur between systems around the world through satellite navigation signals and other time and frequency transfer techniques. Navigation and railways Time-keeping and synchronization of clocks is a critical problem in long-distance ocean navigation. Before radio navigation and satellite-based navigation, navigators required accurate time in conjunction with astronomical observations to determine how far east or west their vessel traveled. The invention of an accurate marine chronometer revolutionized marine navigation. By the end of the 19th century, important ports provided time signals in the form of a signal gun, flag, or dropping time ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Java Virtual Machines
This article provides non-exhaustive lists of Java SE Java virtual machines (JVMs). It does not include every Java ME vendor. Note that Java EE runs on the standard Java SE JVM but that some vendors specialize in providing a modified JVM optimized for Java EE applications. Much Java development work takes place on Windows, Solaris, Linux, and FreeBSD, primarily with the Oracle JVMs. Note the further complication of different 32-bit/64-bit varieties. The primary reference Java VM implementation is HotSpot, produced by Oracle Corporation and many other big and medium-sized companies (e.g. IBM, Redhat, Microsoft, Azul, SAP). Free and open source implementations Active * Codename One – uses the open source ParparVM * Eclipse OpenJ9 – open-source from IBM J9, for AIX, Linux (x86, Power, and Z), macOS, Windows, MVS, OS/400, Pocket PC, z/OS. * GraalVM – is based on HotSpot/OpenJDK, it has a polyglot feature, to transparently mix and match supported languages. * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
