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Java Performance
In software development, the programming language Java was historically considered slower than the fastest third-generation typed languages such as C and C++. In contrast to those languages, Java compiles by default to a Java Virtual Machine (JVM) with operations distinct from those of the actual computer hardware. Early JVM implementations were interpreters; they simulated the virtual operations one-by-one rather than translating them into machine code for direct hardware execution. Since the late 1990s, the execution speed of Java programs improved significantly via introduction of just-in-time compilation (JIT) (in 1997 for Java 1.1), the addition of language features supporting better code analysis, and optimizations in the JVM (such as HotSpot becoming the default for Sun's JVM in 2000). Sophisticated garbage collection strategies were also an area of improvement. Hardware execution of Java bytecode, such as that offered by ARM's Jazelle, was explored but not depl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Development
Software development is the process of designing and Implementation, implementing a software solution to Computer user satisfaction, satisfy a User (computing), user. The process is more encompassing than Computer programming, programming, writing source code, code, in that it includes conceiving the goal, evaluating feasibility, analyzing software requirements, requirements, software design, design, software testing, testing and software release life cycle, release. The process is part of software engineering which also includes management, organizational management, Software project management, project management, configuration management and other aspects. Software development involves many skills and job specializations including software programmer, programming, software test, testing, Technical writing, documentation, graphic design, user support, marketing, and fundraising. Software development involves many software tools, tools including: compiler, integrated develo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Hardware
Computer hardware includes the physical parts of a computer, such as the central processing unit (CPU), random-access memory (RAM), motherboard, computer data storage, graphics card, sound card, and computer case. It includes external devices such as a Computer monitor, monitor, Computer mouse, mouse, Computer keyboard, keyboard, and Computer speakers, speakers. By contrast, software is a set of written instructions that can be stored and run by hardware. Hardware derived its name from the fact it is ''Hardness, hard'' or rigid with respect to changes, whereas software is ''soft'' because it is easy to change. Hardware is typically directed by the software to execute any command or Instruction (computing), instruction. A combination of hardware and software forms a usable computing system, although Digital electronics, other systems exist with only hardware. History Early computing devices were more complicated than the ancient abacus date to the seventeenth century. French ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quake II
''Quake II'' is a 1997 first-person shooter, first-person shooter game developed by id Software and published by Activision. It is the second installment of the Quake (series), ''Quake'' series, following ''Quake (video game), Quake''. Developed over the course of a year, ''Quake II'' was released on December 9, 1997. In contrast to the first game, which featured a combination of science fiction and fantasy elements, ''Quake II'' entirely drops the latter elements and is set during humankind's war against a rogue alien race known as the Strogg, half-mutant half-machine creatures whose homeplanet, Stroggos, is the target of the humans' invasion force. The player takes the role of a space marine (referred to as Bitterman) as he crash-lands on the planet and, being the last survivor of his squad, is tasked with completing a series of missions to cripple the Strogg and end their plans to conquer Earth. The game's storyline is continued in its expansions, including one tying in ''Quak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Garbage Collection (computer Science)
In computer science, garbage collection (GC) is a form of automatic memory management. The ''garbage collector'' attempts to reclaim memory that was allocated by the program, but is no longer referenced; such memory is called ''garbage (computer science), garbage''. Garbage collection was invented by American computer scientist John McCarthy (computer scientist), John McCarthy around 1959 to simplify manual memory management in Lisp (programming language), Lisp. Garbage collection relieves the programmer from doing manual memory management, where the programmer specifies what objects to de-allocate and return to the memory system and when to do so. Other, similar techniques include stack-based memory allocation, stack allocation, region inference, and memory ownership, and combinations thereof. Garbage collection may take a significant proportion of a program's total processing time, and affect computer performance, performance as a result. Resources other than memory, such a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynamic Memory Allocation
Memory management (also dynamic memory management, dynamic storage allocation, or dynamic memory allocation) is a form of resource management applied to computer memory. The essential requirement of memory management is to provide ways to dynamically allocate portions of memory to programs at their request, and free it for reuse when no longer needed. This is critical to any advanced computer system where more than a single process might be underway at any time. Several methods have been devised that increase the effectiveness of memory management. Virtual memory systems separate the memory addresses used by a process from actual physical addresses, allowing separation of processes and increasing the size of the virtual address space beyond the available amount of RAM using paging or swapping to secondary storage. The quality of the virtual memory manager can have an extensive effect on overall system performance. The system allows a computer to appear as if it may have more ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tracing Garbage Collection
In computer programming, tracing garbage collection is a form of automatic memory management that consists of determining which objects should be deallocated ("garbage collected") 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 is the most common type of garbage collection – so much so that "garbage collection" often refers to the tracing method, rather than others such as reference counting – and there are a large number of algorithms used in implementation. Reachability of an object Informally, an object is reachable if it is referenced by at least one variable in the program, either directly or through references from other reachable objects. More precisely, objects can be reachable in only two ways: # A distinguished set of roots: objects that are assumed to be reachable. Typically, these include all the objects referenced from anywhere in the call stac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deoptimization
Adaptive optimization is a technique in computer science that performs dynamic recompilation of portions of a program based on the current execution profile. With a simple implementation, an adaptive optimizer may simply make a trade-off between just-in-time compilation and interpreting instructions. At another level, adaptive optimization may take advantage of local data conditions to optimize away branches and to use inline expansion to decrease the cost of procedure calls. Consider a hypothetical banking application that handles transactions one after another. These transactions may be checks, deposits, and a large number of more obscure transactions. When the program executes, the actual data may consist of clearing tens of thousands of checks without processing a single deposit and without processing a single check with a fraudulent account number. An adaptive optimizer would compile assembly code to optimize for this common case. If the system then started processing tens o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynamic Recompilation
In computer science, dynamic recompilation is a feature of some emulators and virtual machines, where the system may recompile some part of a program during execution. By compiling during execution, the system can tailor the generated code to reflect the program's run-time environment, and potentially produce more efficient code by exploiting information that is not available to a traditional static compiler. Uses Most dynamic recompilers are used to convert machine code between architectures at runtime. This is a task often needed in the emulation of legacy gaming platforms. In other cases, a system may employ dynamic recompilation as part of an adaptive optimization strategy to execute a portable program representation such as Java or .NET Common Language Runtime bytecodes. Full-speed debuggers also utilize dynamic recompilation to reduce the space overhead incurred in most deoptimization techniques, and other features such as dynamic thread migration. Tasks The main task ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intel Corporation
Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, and incorporated in Delaware. Intel designs, manufactures, and sells computer components such as central processing units (CPUs) and related products for business and consumer markets. It is one of the world's largest semiconductor chip manufacturers by revenue, and ranked in the ''Fortune'' 500 list of the largest United States corporations by revenue for nearly a decade, from 2007 to 2016 fiscal years, until it was removed from the ranking in 2018. In 2020, it was reinstated and ranked 45th, being the 7th-largest technology company in the ranking. It was one of the first companies listed on Nasdaq. Intel supplies microprocessors for most manufacturers of computer systems, and is one of the developers of the x86 series of instruction sets found in most personal computers (PCs). It also manufactures chipsets, network interface controllers, fl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overhead (computing)
Overhead in computer systems consists of shared functions that benefit all users or processes but are not directly attributable to any specific task. It is thus similar to overhead in organizations. Computer system overhead shows up as slower processing, less memory, less storage capacity, less network bandwidth, or bigger latency than would be expected from reading the system specifications. It is a special case of engineering overhead. Overhead can be a deciding factor in software design, with regard to structure, error correction, and feature inclusion. Examples of computing overhead may be found in object-oriented programming (OOP), functional programming, data transfer, data structures, and file systems on data storage devices. Software design Choice of implementation A programmer/software engineer may have a choice of several algorithms, encodings, data types or data structures, each of which have known characteristics. When choosing among them, their respective overhead ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optimization (computer Science)
In computer science, program optimization, code optimization, or software optimization is the process of modifying a software system to make some aspect of it work more algorithmic efficiency, efficiently or use fewer resources. In general, a computer program may be optimized so that it executes more rapidly, or to make it capable of operating with less Computer data storage, memory storage or other resources, or draw less power. Overview Although the term "optimization" is derived from "optimum", achieving a truly optimal system is rare in practice, which is referred to as superoptimization. Optimization typically focuses on improving a system with respect to a specific quality metric rather than making it universally optimal. This often leads to trade-offs, where enhancing one metric may come at the expense of another. One popular example is space-time tradeoff, reducing a program’s execution time by increasing its memory consumption. Conversely, in scenarios where memory is l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virtual Machine
In computing, a virtual machine (VM) is the virtualization or emulator, emulation of a computer system. Virtual machines are based on computer architectures and provide the functionality of a physical computer. Their implementations may involve specialized hardware, software, or a combination of the two. Virtual machines differ and are organized by their function, shown here: * ''System virtual machines'' (also called full virtualization VMs, or SysVMs) provide a substitute for a real machine. They provide the functionality needed to execute entire operating systems. A hypervisor uses native code, native execution to share and manage hardware, allowing for multiple environments that are isolated from one another yet exist on the same physical machine. Modern hypervisors use hardware-assisted virtualization, with virtualization-specific hardware features on the host CPUs providing assistance to hypervisors. * ''Process virtual machines'' are designed to execute computer programs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
