Core dump

抄点不一样的：https://wiki.archlinux.org/title/Core_dump

$ pgrep -f firefox
2071 firefox
$ gdb -p 2071
(gdb) generate-core-file
Saved corefile core.2071
(gdb) quit

In computing, a core/memory/crash/system dump consists of the recorded state of the working memory of a computer program at a specific time, generally when the program has crashed or otherwise terminated abnormally. In practice, other key pieces of program state are usually dumped at the same time, including the processor registers, which may include the program counter and stack pointer, memory management information, and other processor and operating system flags and information. A snapshot dump (or snap dump) is a memory dump requested by the computer operator or by the running program, after which the program is able to continue. Core dumps are often used to assist in diagnosing and debugging errors in computer programs.

On many operating systems, a fatal exception in a program automatically triggers a core dump. By extension, the phrase "to dump core" has come to mean in many cases, any fatal error, regardless of whether a record of the program memory exists. The term "core dump", "memory dump", or just "dump" has also become jargon to indicate any output of a large amount of raw data for further examination or other purposes.

The name comes from magnetic core memory, the principal form of random access memory from the 1950s to the 1970s. The name has remained long after magnetic core technology became obsolete.

Magnetic-core memory was the predominant form of random-access computer memory for 20 years between about 1955 and 1975. Such memory is often just called core memory, or, informally, core.

Core memory uses toroids (rings) of a hard magnetic material (usually a semi-hard ferrite) as transformer cores, where each wire threaded through the core serves as a transformer winding. Three or four wires pass through each core. Magnetic hysteresis allows each of the cores to "remember", or store a state.

Each core stores one bit of information. A core can be magnetized in either the clockwise or counter-clockwise direction. The value of the bit stored in a core is zero or one according to the direction of that core's magnetization. Electric current pulses in some of the wires through a core allow the direction of the magnetization in that core to be set in either direction, thus storing a one or a zero. Another wire through each core, the sense wire, is used to detect whether the core changed state.

Depending on how it was wired, core memory could be exceptionally reliable. Read-only core rope memory, for example, was used on the mission-critical Apollo Guidance Computer essential to NASA's successful Moon landings.

The basic concept of using the square hysteresis loop of certain magnetic materials as a storage or switching device was known from the earliest days of computer development. Much of this knowledge had developed due to an understanding of transformers, which allowed amplification and switch-like performance when built using certain materials. The stable switching behavior was well known in the electrical engineering field, and its application in computer systems was immediate. For example, J. Presper Eckert and Jeffrey Chuan Chu had done some development work on the concept in 1945 at the Moore School during the ENIAC efforts.

Frederick Viehe applied for various patents on the use of transformers for building digital logic circuits in place of relay logic beginning in 1947. A fully developed core system was patented in 1947, and later purchased by IBM in 1956. This development was little-known, however, and the mainstream development of core is normally associated with three independent teams.

Substantial work in the field was carried out by the Shanghai-born American physicists An Wang and Way-Dong Woo, who created the pulse transfer controlling device in 1949. The name referred to the way that the magnetic field of the cores could be used to control the switching of current; his patent focused on using cores to create delay-line or shift-register memory systems. Wang and Woo were working at Harvard University's Computation Laboratory at the time, and the university was not interested in promoting inventions created in their labs. Wang was able to patent the system on his own.

The MIT Project Whirlwind computer required a fast memory system for real-time aircraft tracking. At first, an array of Williams tubes—a storage system based on cathode ray tubes—was used, but proved temperamental and unreliable. Project Whirlwind core memory; A 32 x 32 core memory plane storing 1024 bits (or 128 bytes) of data.

 

 六级/考研单词: quit, compute, crash, dump, terminate, abnormal, stack, seldom, diagnose, fatal, trigger, regardless, jargon, data, farther, headmaster, random, predominant, thread, clockwise, nil, accord, pulse, thereby, detect, indispensable, loop, amplify, patent, digit, logic, relay, mainstream, norm, physics, whirl, array, ray, temperament

标签：Core,computer,dump,core,program,memory,was
来源： https://www.cnblogs.com/funwithwords/p/15907218.html