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Debuggers
A debugger is a computer program used to software testing, test and debugging, debug other programs (the "target" programs). Common features of debuggers include the ability to run or halt the target program using breakpoints, stepping (debugging), step through code line by line, and display or modify the contents of memory, CPU registers, and stack frames. The code to be examined might alternatively be running on an ''instruction set simulator'' (ISS), a technique that allows great power in its ability to halt when specific conditions are encountered, but which will typically be somewhat slower than executing the code directly on the appropriate (or the same) processor. Some debuggers offer two modes of operation, full or partial simulation, to limit this impact. An exception occurs when the program cannot normally continue because of a software bug, programming bug or invalid data. For example, the program might have tried to use an instruction not available on the current ver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time Travel Debugging
Time travel debugging or time traveling debugging is the process of stepping back in time through source code to understand what is happening during execution of a computer program. Typically, debugging and debuggers, tools that assist a user with the process of debugging, allow users to pause the execution of running software and inspect the current state of the program. Users can then step forward in time, stepping into or over statements and proceeding in a forward direction. Interactive debuggers include the ability to modify code and step forward based on updated information. Reverse debugging tools allow users to step backwards in time through the steps that resulted in reaching a particular point in the program. Time traveling debuggers provide these features and also allow users to interact with the program, changing the history if desired, and watch how the program responds. Characteristics supporting bi-directional travel There are several characteristics that support t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instruction Set Simulator
An instruction set simulator (ISS) is a simulation model (abstract), model, usually coded in a high-level programming language, which mimics the behavior of a mainframe or microprocessor by "reading" instructions and maintaining internal variables which represent the processor's Processor register, registers. Instruction simulation is a methodology employed for one of several possible reasons: * To simulate the instruction set architecture (ISA) of a future processor to allow software development and test to proceed without waiting for the development and production of the hardware to finish. This is often known as "shift-left" or "pre-silicon support" in the hardware development field. A full system simulator or virtual platform for the future hardware typically includes one or more instruction set simulators. * To simulate the machine code of another hardware device or entire computer for upward Compatibility mode (software), compatibility. :: For example, the IBM 1401 was simu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Debugging
In engineering, debugging is the process of finding the Root cause analysis, root cause, workarounds, and possible fixes for bug (engineering), bugs. For software, debugging tactics can involve interactive debugging, control flow analysis, Logfile, log file analysis, monitoring at the application monitoring, application or system monitoring, system level, memory dumps, and profiling (computer programming), profiling. Many Programming language, programming languages and Programming tool, software development tools also offer programs to aid in debugging, known as debuggers. Etymology The term ''bug'', in the sense of defect, dates back at least to 1878 when Thomas Edison wrote "little faults and difficulties" in his inventions as "Bugs". A popular story from the 1940s is from Admiral Grace Hopper. While she was working on a Harvard Mark II, Mark II computer at Harvard University, her associates discovered a moth stuck in a relay that impeded operation and wrote in a log book ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Record And Replay Debugging
Record and replay debugging is the process of recording the execution of a software program so that it may be played back within a debugger to help diagnose and resolve defects. The concept is analogous to the use of a flight data recorder to diagnose the cause of an airplane flight malfunction. Recording and replaying Record and replay debuggers record application state at every step of the program's process and thread execution, including memory interactions, deterministic and non-deterministic inputs, system resource status, and store it to disk in a log. The recording allows the program to be replayed again and again, and debugged exactly as it happened. Usage Recordings can be made in one location and replayed in another, which makes it useful for remote debugging. Record and replay debugging is particularly useful for debugging intermittent and non-deterministic defects, which can be difficult to reproduce. Record and replay debugging technology is often fundamental to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dbx (debugger)
dbx is a source-level debugger found primarily on Solaris, AIX, IRIX, Tru64 UNIX, Linux and BSD operating systems. It provides symbolic debugging for programs written in C, C++, Fortran, Pascal and Java. Useful features include stepping through programs one source line or machine instruction at a time. In addition to simply viewing operation of the program, variables can be manipulated and a wide range of expressions can be evaluated and displayed. History dbx was originally developed at University of California, Berkeley, by Mark Linton during the years 1981–1984 and subsequently made its way to various vendors who had licensed BSD. Availability dbx is provided with AIX, and was also provided with IRIX and Tru64 UNIX. It is included as part of the Oracle Solaris Studio product from Oracle Corporation, and is supported on both Solaris and Linux. It supports programs compiled with the Oracle Solaris Studio compilers and GCC. It is also available on IB ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Profiling (computer Programming)
In software engineering, profiling (program profiling, software profiling) is a form of dynamic program analysis that measures, for example, the space (memory) or time complexity of a program, the usage of particular instructions, or the frequency and duration of function calls. Most commonly, profiling information serves to aid program optimization, and more specifically, performance engineering. Profiling is achieved by instrumenting either the program source code or its binary executable form using a tool called a ''profiler'' (or ''code profiler''). Profilers may use a number of different techniques, such as event-based, statistical, instrumented, and simulation methods. Gathering program events Profilers use a wide variety of techniques to collect data, including hardware interrupts, code instrumentation, instruction set simulation, operating system hooks, and performance counters. Use of profilers The output of a profiler may be: * A statistical ''summary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Storage Violation
In computing a storage violation is a hardware or software fault that occurs when a task attempts to access an area of computer storage which it is not permitted to access. Types of storage violation Storage violation can, for instance, consist of reading from, writing to, or freeing storage not owned by the task. A common type of storage violation is known as a stack buffer overflow where a program attempts to exceed the limits set for its call stack. It can also refer to attempted modification of memory "owned" by another thread where there is incomplete (or no) memory protection. Avoidance of storage violations Storage violations can occur in transaction systems such as CICS in circumstances where it is possible to write to storage not owned by the transaction; such violations can be reduced by enabling features such as storage protection and transaction isolation. Detection of storage violations Storage violations can be difficult to detect as a program can often run for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PL/1
PL/I (Programming Language One, pronounced and sometimes written PL/1) is a procedural, imperative computer programming language initially developed by IBM. It is designed for scientific, engineering, business and system programming. It has been in continuous use by academic, commercial and industrial organizations since it was introduced in the 1960s. A PL/I American National Standards Institute (ANSI) technical standard, X3.53-1976, was published in 1976. PL/I's main domains are data processing, numerical computation, scientific computing, and system programming. It supports recursion, structured programming, linked data structure handling, fixed-point, floating-point, complex, character string handling, and bit string handling. The language syntax is English-like and suited for describing complex data formats with a wide set of functions available to verify and manipulate them. Early history In the 1950s and early 1960s, business and scientific users programmed for dif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Assembly Language
In computing, assembly language (alternatively assembler language or symbolic machine code), often referred to simply as assembly and commonly abbreviated as ASM or asm, is any low-level programming language with a very strong correspondence between the instructions in the language and the architecture's machine code instructions. Assembly language usually has one statement per machine instruction (1:1), but constants, comments, assembler directives, symbolic labels of, e.g., memory locations, registers, and macros are generally also supported. The first assembly code in which a language is used to represent machine code instructions is found in Kathleen and Andrew Donald Booth's 1947 work, ''Coding for A.R.C.''. Assembly code is converted into executable machine code by a utility program referred to as an '' assembler''. The term "assembler" is generally attributed to Wilkes, Wheeler and Gill in their 1951 book '' The Preparation of Programs for an Electronic Dig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
COBOL
COBOL (; an acronym for "common business-oriented language") is a compiled English-like computer programming language designed for business use. It is an imperative, procedural, and, since 2002, object-oriented language. COBOL is primarily used in business, finance, and administrative systems for companies and governments. COBOL is still widely used in applications deployed on mainframe computers, such as large-scale batch and transaction processing jobs. Many large financial institutions were developing new systems in the language as late as 2006, but most programming in COBOL today is purely to maintain existing applications. Programs are being moved to new platforms, rewritten in modern languages, or replaced with other software. COBOL was designed in 1959 by CODASYL and was partly based on the programming language FLOW-MATIC, designed by Grace Hopper. It was created as part of a U.S. Department of Defense effort to create a portable programming language for data pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
