Computer programming is the process of performing particular computations, usually by designing and building executable computer programs. Programming involves tasks such as analysis, generating algorithms, profiling algorithms' accuracy and resource consumption, and the implementation of algorithms. The source code of a program is written in one or more languages that are intelligible to programmers, rather than machine code, which is directly executed by the central processing unit. To produce machine code, the source code must either be compiled or transpiled. Compiling takes the source code from a low-level programming language and converts it into machine code. Transpiling on the other hand, takes the source-code from a high-level programming language and converts it into bytecode. This is interpreted into machine code. The purpose of programming is to find a sequence of instructions that will automate the performance of a task on a computer, often for solving a given problem. Proficient programming thus usually requires expertise in several different subjects, including knowledge of the application domain, specialized algorithms, and formal logic.
Mach is a kernel developed at Carnegie Mellon University by Richard Rashid and Avie Tevanian to support operating system research, primarily distributed and parallel computing. Mach is often considered one of the earliest examples of a microkernel. However, not all versions of Mach are microkernels. Mach's derivatives are the basis of the operating system kernel in GNU Hurd and of Apple's XNU kernel used in macOS, iOS, iPadOS, tvOS, and watchOS.
A software bug is an error, flaw or fault in the design, development, or operation of computer software that causes it to produce an incorrect or unexpected result, or to behave in unintended ways. The process of finding and correcting bugs is termed "debugging" and often uses formal techniques or tools to pinpoint bugs. Since the 1950s, some computer systems have been designed to deter, detect or auto-correct various computer bugs during operations.
In computer programming, specifically when using the imperative programming paradigm, an assertion is a predicate connected to a point in the program, that always should evaluate to true at that point in code execution. Assertions can help a programmer read the code, help a compiler compile it, or help the program detect its own defects.
In computer science, a lock or mutex is a synchronization primitive: a mechanism that enforces limits on access to a resource when there are many threads of execution. A lock is designed to enforce a mutual exclusion concurrency control policy, and with a variety of possible methods there exists multiple unique implementations for different applications.
In computing, a crash, or system crash, occurs when a computer program such as a software application or an operating system stops functioning properly and exits. On some operating systems or individual applications, a crash reporting service will report the crash and any details relating to it, usually to the developer(s) of the application. If the program is a critical part of the operating system, the entire system may crash or hang, often resulting in a kernel panic or fatal system error.
A programming tool or software development tool is a computer program that software developers use to create, debug, maintain, or otherwise support other programs and applications. The term usually refers to relatively simple programs, that can be combined to accomplish a task, much as one might use multiple hands to fix a physical object. The most basic tools are a source code editor and a compiler or interpreter, which are used ubiquitously and continuously. Other tools are used more or less depending on the language, development methodology, and individual engineer, often used for a discrete task, like a debugger or profiler. Tools may be discrete programs, executed separately – often from the command line – or may be parts of a single large program, called an integrated development environment (IDE). In many cases, particularly for simpler use, simple ad hoc techniques are used instead of a tool, such as print debugging instead of using a debugger, manual timing instead of a profiler, or tracking bugs in a text file or spreadsheet instead of a bug tracking system.
A patch is a set of changes to a computer program or its supporting data designed to update, fix, or improve it. This includes fixing security vulnerabilities and other bugs, with such patches usually being called bugfixes or bug fixes. Patches are often written to improve the functionality, usability, or performance of a program. The majority of patches are provided by software vendors for operating system and application updates.
A race condition or race hazard is the condition of an electronics, software, or other system where the system's substantive behavior is dependent on the sequence or timing of other uncontrollable events. It becomes a bug when one or more of the possible behaviors is undesirable.
Apache Log4j is a Java-based logging utility originally written by Ceki Gülcü. It is part of the Apache Logging Services, a project of the Apache Software Foundation. Log4j is one of several Java logging frameworks.
In computer programming jargon, a heisenbug is a software bug that seems to disappear or alter its behavior when one attempts to study it. The term is a pun on the name of Werner Heisenberg, the physicist who first asserted the observer effect of quantum mechanics, which states that the act of observing a system inevitably alters its state. In electronics, the traditional term is probe effect, where attaching a test probe to a device changes its behavior.
Dynamic program analysis is analysis of computer software that involves executing the program in question. Dynamic program analysis includes familiar techniques from software engineering such as unit testing, debugging, and measuring code coverage, but also includes lesser-known techniques like program slicing and invariant inference. Dynamic program analysis is widely applied in security in the form of runtime memory error detection, fuzzing, dynamic symbolic execution, and taint tracking.
Windows Error Reporting (WER) is a crash reporting technology introduced by Microsoft with Windows XP and included in later Windows versions and Windows Mobile 5.0 and 6.0. Not to be confused with the Dr. Watson debugging tool which left the memory dump on the user's local machine, Windows Error Reporting collects and offers to send post-error debug information using the Internet to Microsoft when an application crashes or stops responding on a user's desktop. No data is sent without the user's consent. When a crash dump reaches the Microsoft server, it is analyzed, and information about a solution is sent back to the user if available. Solutions are served using Windows Error Reporting Responses. Windows Error Reporting runs as a Windows service. Kinshuman is the original architect of WER. WER was also included in the ACM hall of fame for its impact on the computing industry.
Orchestra Control Engine is a suite of software components used for the planning, development and deployment of real-time control applications for industrial machines and robots.
Shotgun surgery is an antipattern in software development and occurs where a developer adds features to an application codebase which span a multiplicity of implementors or implementations in a single change. This is common practice in many programming scenarios, as a great amount of programming effort is usually expended on adding new features to increase the value of programming assets. As a consequence, these new features may require adding code in several places simultaneously where the code itself looks very similar and may only have slight variations. Owing to the fast-paced nature of commercial software development, there may not be sufficient time to remodel a system to support the new features trivially. As a consequence, the practice of copy-and-paste programming is prevalent; the code is written in a single place then simply copied to all other places where that implementation is required.
The Blue Screen of Death (BSoD), Blue screen error, Blue Screen, fatal error, or bugcheck, and officially known as a Stop error, is a critical error screen displayed by the Microsoft Windows and ReactOS operating systems in the event of a fatal system error.
In computer programming and software development, debugging is the process of finding and resolving bugs within computer programs, software, or systems.
The LLDB Debugger (LLDB) is the debugger component of the LLVM project. It is built as a set of reusable components which extensively use existing libraries from LLVM, such as the Clang expression parser and LLVM disassembler. LLDB is free and open-source software under the University of Illinois/NCSA Open Source License, a BSD-style permissive software license. Since v9.0.0, it was relicensed to the Apache License 2.0 with LLVM Exceptions.
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 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.
