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Testing High-performance Computing Applications
High performance computing applications run on massively parallel supercomputers consist of concurrent programs designed using multi-threaded, multi-process models. The applications may consist of various constructs ( threads, local processes, distributed processes, etc.) with varying degree of parallelism. Although high performance concurrent programs use similar design patterns, models and principles as that of sequential programs, unlike sequential programs, they typically demonstrate non-deterministic behavior. The probability of bugs increases with the number of interactions between the various parallel constructs. Race conditions, data races, deadlocks, missed signals and live lock are common error types. Challenges Parallel programs can be divided into two general categories: explicitly and implicitly parallel. Using parallel language constructs defined for process creation, communication and synchronization make an application explicitly parallel. Using a tool or paralle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Performance Computing
High-performance computing (HPC) uses supercomputers and computer clusters to solve advanced computation problems. Overview HPC integrates systems administration (including network and security knowledge) and parallel programming into a multidisciplinary field that combines digital electronics, computer architecture, system software, programming languages, algorithms and computational techniques. HPC technologies are the tools and systems used to implement and create high performance computing systems. Recently, HPC systems have shifted from supercomputing to computing clusters and grids. Because of the need of networking in clusters and grids, High Performance Computing Technologies are being promoted by the use of a collapsed network backbone, because the collapsed backbone architecture is simple to troubleshoot and upgrades can be applied to a single router as opposed to multiple ones. The term is most commonly associated with computing used for scientific research or com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Functional Testing
Functional testing is a quality assurance (QA) processPrasad, Dr. K.V.K.K. (2008) ''ISTQB Certification Study Guide'', Wiley, , p. vi and a type of black-box testing that bases its test cases on the specifications of the software component under test. Functions are tested by feeding them input and examining the output, and internal program structure is rarely considered (unlike white-box testing).Kaner, Falk, Nguyen. ''Testing Computer Software''. Wiley Computer Publishing, 1999, p. 42. . Functional testing is conducted to evaluate the compliance of a system or component with specified functional requirements. Functional testing usually describes ''what'' the system does. Since functional testing is a type of black-box testing, the software's functionality can be tested without knowing the internal workings of the software. This means that testers do not need to know programming languages or how the software has been implemented. This, in turn, could lead to reduced developer bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parallel Parametric Test
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] |
Page Fault
In computing, a page fault (sometimes called PF or hard fault) is an exception that the memory management unit (MMU) raises when a process accesses a memory page without proper preparations. Accessing the page requires a mapping to be added to the process's virtual address space. Besides, the actual page contents may need to be loaded from a backing store, such as a disk. The MMU detects the page fault, but the operating system's kernel handles the exception by making the required page accessible in the physical memory or denying an illegal memory access. Valid page faults are common and necessary to increase the amount of memory available to programs in any operating system that uses virtual memory, such as Windows, macOS, and the Linux kernel. Types Minor If the page is loaded in memory at the time the fault is generated, but is not marked in the memory management unit as being loaded in memory, then it is called a minor or soft page fault. The page fault handler in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synchronous Rendezvous
In parallel computing, a barrier is a type of synchronization method. A barrier for a group of threads or processes in the source code means any thread/process must stop at this point and cannot proceed until all other threads/processes reach this barrier. Many collective routines and directive-based parallel languages impose implicit barriers. For example, a parallel ''do'' loop in Fortran with OpenMP will not be allowed to continue on any thread until the last iteration is completed. This is in case the program relies on the result of the loop immediately after its completion. In message passing, any global communication (such as reduction or scatter) may imply a barrier. In concurrent computing, a barrier may be in a ''raised'' or ''lowered state''. The term latch is sometimes used to refer to a barrier that starts in the raised state and cannot be re-raised once it is in the lowered state. The term count-down latch is sometimes used to refer to a latch that is automatically lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deadlock
In concurrent computing, deadlock is any situation in which no member of some group of entities can proceed because each waits for another member, including itself, to take action, such as sending a message or, more commonly, releasing a lock. Deadlocks are a common problem in multiprocessing systems, parallel computing, and distributed systems, because in these contexts systems often use software or hardware locks to arbitrate shared resources and implement process synchronization. In an operating system, a deadlock occurs when a process or thread enters a waiting state because a requested system resource is held by another waiting process, which in turn is waiting for another resource held by another waiting process. If a process remains indefinitely unable to change its state because resources requested by it are being used by another process that itself is waiting, then the system is said to be in a deadlock. In a communications system, deadlocks occur mainly due t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Static Slicing
In computer programming, program slicing is the computation of the set of program statements, the program slice, that may affect the values at some point of interest, referred to as a slicing criterion. Program slicing can be used in debugging to locate source of errors more easily. Other applications of slicing include software maintenance, optimization, program analysis, and information flow control. Slicing techniques have been seeing a rapid development since the original definition by Mark Weiser. At first, slicing was only static, i.e., applied on the source code with no other information than the source code. Bogdan Korel and Janusz Laski introduced ''dynamic slicing'', which works on a specific execution of the program (for a given execution trace). Other forms of slicing exist, for instance path slicing. Static slicing Based on the original definition of Weiser, informally, a static program slice S consists of all statements in program P that may affect the valu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Escape Analysis
In compiler optimization, escape analysis is a method for determining the dynamic scope of pointers where in the program a pointer can be accessed. It is related to pointer analysis and shape analysis. When a variable (or an object) is allocated in a subroutine, a pointer to the variable can ''escape'' to other threads of execution, or to calling subroutines. If an implementation uses tail call optimization (usually required for functional languages), objects may also be seen as escaping to ''called'' subroutines. If a language supports first-class continuations (as do Scheme and Standard ML of New Jersey), portions of the call stack may also escape. If a subroutine allocates an object and returns a pointer to it, the object can be accessed from undetermined places in the program the pointer has "escaped". Pointers can also escape if they are stored in global variables or other data structures that, in turn, escape the current procedure. Escape analysis determines all the pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclomatic Complexity
Cyclomatic complexity is a software metric used to indicate the complexity of a program. It is a quantitative measure of the number of linearly independent paths through a program's source code. It was developed by Thomas J. McCabe, Sr. in 1976. Cyclomatic complexity is computed using the control-flow graph of the program: the nodes of the graph correspond to indivisible groups of commands of a program, and a directed edge connects two nodes if the second command might be executed immediately after the first command. Cyclomatic complexity may also be applied to individual functions, modules, methods or classes within a program. One testing strategy, called basis path testing by McCabe who first proposed it, is to test each linearly independent path through the program; in this case, the number of test cases will equal the cyclomatic complexity of the program. Description Definition The cyclomatic complexity of a section of source code is the number of linearly independen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control Flow Analysis
In computer science, control-flow analysis (CFA) is a static-code-analysis technique for determining the control flow of a program. The control flow is expressed as a control-flow graph (CFG). For both functional programming languages and object-oriented programming languages, the term CFA, and elaborations such as ''k''-CFA, refer to specific algorithms that compute control flow. For many imperative programming languages, the control flow of a program is explicit in a program's source code. As a result, interprocedural control-flow analysis implicitly usually refers to a static analysis technique for determining the receiver(s) of function or method calls in computer programs written in a higher-order programming language. For example, in a programming language with higher-order functions like Scheme, the target of a function call may not be explicit: in the isolated expression (lambda (f) (f x)) it is unclear to which procedure f may refer. A control-flow analysis must co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Flow Analysis
In the pursuit of knowledge, data (; ) is a collection of discrete values that convey information, describing quantity, quality, fact, statistics, other basic units of meaning, or simply sequences of symbols that may be further interpreted. A datum is an individual value in a collection of data. Data is usually organized into structures such as tables that provide additional context and meaning, and which may themselves be used as data in larger structures. Data may be used as variables in a computational process. Data may represent abstract ideas or concrete measurements. Data is commonly used in scientific research, economics, and in virtually every other form of human organizational activity. Examples of data sets include price indices (such as consumer price index), unemployment rates, literacy rates, and census data. In this context, data represents the raw facts and figures which can be used in such a manner in order to capture the useful information out of it. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Static Program Analysis
In computer science, static program analysis (or static analysis) is the analysis of computer programs performed without executing them, in contrast with dynamic program analysis, which is performed on programs during their execution. The term is usually applied to analysis performed by an automated tool, with human analysis typically being called "program understanding", program comprehension, or code review. In the last of these, software inspection and software walkthroughs are also used. In most cases the analysis is performed on some version of a program's source code, and, in other cases, on some form of its object code. Rationale The sophistication of the analysis performed by tools varies from those that only consider the behaviour of individual statements and declarations, to those that include the complete source code of a program in their analysis. The uses of the information obtained from the analysis vary from highlighting possible coding errors (e.g., the lint t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
