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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] |
Debugger
A debugger or debugging tool is a computer program used to test and debug other programs (the "target" program). The main use of a debugger is to run the target program under controlled conditions that permit the programmer to track its execution and monitor changes in computer resources that may indicate malfunctioning code. Typical debugging facilities include the ability to run or halt the target program at specific points, display the contents of memory, CPU registers or storage devices (such as disk drives), and modify memory or register contents in order to enter selected test data that might be a cause of faulty program execution. 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 m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flight Data Recorder
A flight recorder is an electronic recording device placed in an aircraft for the purpose of facilitating the investigation of aviation accidents and incidents. The device may often be referred to as a "black box", an outdated name which has become a misnomer—they are now required to be painted bright orange, to aid in their recovery after accidents. There are two types of flight recording devices: the flight data recorder (FDR) preserves the recent history of the flight through the recording of dozens of parameters collected several times per second; the cockpit voice recorder (CVR) preserves the recent history of the sounds in the cockpit, including the conversation of the pilots. The two devices may be combined into a single unit. Together, the FDR and CVR objectively document the aircraft's flight history, which may assist in any later investigation. The two flight recorders are required by international regulation, overseen by the International Civil Aviation Organiza ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Application State
In information technology and computer science, a system is described as stateful if it is designed to remember preceding events or user interactions; the remembered information is called the state of the system. The set of states a system can occupy is known as its state space. In a discrete system, the state space is countable and often finite. The system's internal behaviour or interaction with its environment consists of separately occurring individual actions or events, such as accepting input or producing output, that may or may not cause the system to change its state. Examples of such systems are digital logic circuits and components, automata and formal language, computer programs, and computers. The output of a digital circuit or deterministic computer program at any time is completely determined by its current inputs and its state. Digital logic circuit state Digital logic circuits can be divided into two types: combinational logic, whose output signals are depend ... [...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] |
GNU Debugger
The GNU Debugger (GDB) is a portable debugger that runs on many Unix-like systems and works for many programming languages, including Ada, C, C++, Objective-C, Free Pascal, Fortran, Go, and partially others. History GDB was first written by Richard Stallman in 1986 as part of his GNU system, after his GNU Emacs was "reasonably stable". GDB is free software released under the GNU General Public License (GPL). It was modeled after the DBX debugger, which came with Berkeley Unix distributions. From 1990 to 1993 it was maintained by John Gilmore. Now it is maintained by the GDB Steering Committee which is appointed by the Free Software Foundation. Technical details Features GDB offers extensive facilities for tracing and altering the execution of computer programs. The user can monitor and modify the values of programs' internal variables, and even call functions independently of the program's normal behavior. GDB target processors (as of 2003) include: Alpha, ARM, AVR ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Undo (company)
Undo is a software debugging company based in Cambridge, UK. The company was founded in 2005 by Greg Law and Julian Smith. Undo’s technology is used by software engineering teams to debug software programs. History Undo was initially bootstrapped in 2005 by Greg Law and Julian Smith out of Law’s garden shed in Cambridge. Law and Smith developed the core technology that would eventually become UndoDB, a reversible debugger for Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, w ... software. LiveRecorder was then developed based on UndoDB to enable development teams to record and replay the execution of software programs. In 2012, Undo secured its initial seed funding. It closed a $3.3 million Series A funding round in 2016, and a $14 million Series B in 2018. References {{re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rr (debugging)
In computing, rr is a debugging tool for Linux designed to record and replay program execution. During the replay phase, rr provides an enhanced gdb debugging experience that supports reverse execution. rr was originally developed by Mozilla to debug Mozilla Firefox on commodity hardware and software. rr is now widely used outside Mozilla and capable of debugging software such as Google Chrome, QEMU, and LibreOffice. rr is free software. Design During the recording phase, rr records all inputs to a Linux process group from the kernel, as well as nondeterministic CPU effects (such as rdtsc). These inputs are logged to disk and become the "trace". Once the trace is recorded, it can be replayed as many times as desired and all state will be reproduced exactly. During replay rr will act as a gdbserver providing a gdb experience capable of reverse-execution. Because a bug can be replayed over and over again, rr enables new methods of debugging issues that are very difficult to so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Python (Programming Language)
Python is a high-level, general-purpose programming language. Its design philosophy emphasizes code readability with the use of significant indentation. Python is dynamically-typed and garbage-collected. It supports multiple programming paradigms, including structured (particularly procedural), object-oriented and functional programming. It is often described as a "batteries included" language due to its comprehensive standard library. Guido van Rossum began working on Python in the late 1980s as a successor to the ABC programming language and first released it in 1991 as Python 0.9.0. Python 2.0 was released in 2000 and introduced new features such as list comprehensions, cycle-detecting garbage collection, reference counting, and Unicode support. Python 3.0, released in 2008, was a major revision that is not completely backward-compatible with earlier versions. Python 2 was discontinued with version 2.7.18 in 2020. Python consistently r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
