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Encyclopedia > Crash (computing)

A crash in computing is a condition where a program (either an application or part of the operating system) stops performing its expected function and also stops responding to other parts of the system. Often the offending program may simply appear to freeze. If this program is a critical part of the operating system kernel the entire computer may crash (a system crash). Originally, the word computing was synonymous with counting and calculating, and a science that deals with the original sense of computing mathematical calculations. ... Application software is a loosely defined subclass of computer software that employs the capabilities of a computer directly to a task that the user wishes to perform. ... An operating system (OS) is a software program that manages the hardware and software resources of a computer. ... See Hang. ... In computer science, the kernel is the core piece of most operating systems. ...


Many crashes are the result of the execution of a single machine instruction, but the causes of this are manifold. Typical causes are when the program counter loses track of the correct execution path or a buffer overflow overwrites a portion of program code, due to an earlier bug. In either case it is quite common for the processor to attempt to execute data or random memory values. Since all data are possible, but only some of these are valid instructions, this very often results in an illegal instruction exception. One might say that the original bug that upset the program counter "caused" the crash, but the actual fault was an illegal instruction, possibly some time later. The art of debugging such crashes is connecting the actual cause of the crash (easily determined) with the code that set off the chain of events. This is often very far from obvious—the original bug may in fact be perfectly valid code from the processor's perspective. In computer science, an instruction typically refers to a single operation of a processor within a computer architecture. ... The program counter (also called the instruction pointer in some computers) is a register in a computer processor which indicates where the computer is in its instruction sequence. ... In computer security and programming, a buffer overflow, or buffer overrun, is an anomalous condition where a process attempts to store data beyond the boundaries of a buffer. ... A computer bug is an error, flaw, mistake, failure, or fault in a computer program that prevents it from working as intended, or produces an incorrect result. ... CPU redirects here. ... Debugging is a methodical process of finding and reducing the number of bugs, or defects, in a computer program or a piece of electronic hardware thus making it behave as expected. ...


On earlier personal computers, it was actually possible to cause hardware damage through trying to write to hardware addresses outside of the system's main memory. Occasionally, execution of arbitrary data on a system will result in a breakup of screen display. This is widely considered a severe system crash.


Another cause of crashes is a race condition in communication between processes. One process may send a signal to a second process then stop execution until it receives a response. If the second process is busy the signal will be forced to wait until the process can get to it. However, if the second process was busy sending a signal to the first process then both processes would wait forever for the other to respond to signals and never see the other’s signal. If the processes are uninterruptable they will hang and have to be shut down. If at least one of the processes is a critical kernel process the whole system may crash and have to be restarted. To meet Wikipedias quality standards, this article or section may require cleanup. ... In computing, a process is, roughly speaking, a task being run by a computer, often simultaneously with many other tasks. ... A signal is an asynchronous event transmitted between one process and another. ... In computing, either a single computer program or the whole system may hang. ... In computer science, the kernel is the core piece of most operating systems. ...

Contents


Etymology

The term "crash" may originate in the phrase "head crash" which would occur when the read/write heads in a hard disk would physically come into contact with (i.e. crash into) the disk surface. The result of this would usually be that the computer would freeze up. A head crash occurs when the read-write head of a hard disk drive touches its rotating platter. ... Microphotograph of a hard disk head. ... Typical hard drives of the mid-1990s. ...


Application crashes

An application typically crashes when it performs an operation which is not allowed by the operating system. The operating system then shuts down the application. Application software is a loosely defined subclass of computer software that employs the capabilities of a computer directly to a task that the user wishes to perform. ...


Typical errors that result in application crashes include:

  • attempting to read or write memory that is not allocated for reading or writing by that application (general protection fault)
  • attempting to execute privileged or invalid instructions
  • unforeseen circumstances or poor code writing that results in the program executing an endless loop
  • attempting to perform I/O operations on hardware devices to which it does not have permission to access
  • passing invalid arguments to system calls
  • attempting to access other system resources to which the application does not have permission to access (bus error)

A general protection fault in the Intel x86 architecture is a fault indicating that a currently executing program has in some way violated the rules of the hardware on which it is running. ... Hardware is the general term that is used to describe physical artifacts of a technology. ... In computing, a bus error is generally an attempt to access memory that the computer cannot address. ...

Website crashes

When a website crashes, it cannot be accessed. The only way it can be seen is with a cached page. For example, when Wikipedia crashed on January 3, 2006, its homepage could be seen on a cache such as Google Cache. This page as shown in the AOL 9. ... Wikipedia (IPA: , or ) is an international Web-based free-content encyclopedia. ... Google Inc. ...


Operating system crashes

An operating system crash often happens when a hardware exception occurs which cannot be handled, such as a hardware exception occurring within the operating system itself.


Operating system crashes can also occur when internal sanity-checking logic within the operating system detects that the operating system has lost its internal self-consistency.


In an ideal world, well-written operating systems should not be able to be crashed by application-level activity. However, until 1993, with the release of Windows NT 3.1, this wasn't the case for the average PC. Industrial strength systems have enjoyed this sort of stability for much longer. 1993 (MCMXCIII) was a common year starting on Friday of the Gregorian calendar and marked the Beginning of the International Decade to Combat Racism and Racial Discrimination (1993-2003). ... Windows NT 3. ...


UNIX based operating systems tend to crash less often than those that are derived from other sources. Some examples of UNIX based systems include Mac OS X, Linux, BSD, and NEXTSTEP. Mac OS X is a proprietary operating system developed and sold by Apple Computer, Inc. ... Linux (also known as GNU/Linux) is a computer operating system. ... BSD redirects here; for other uses see BSD (disambiguation). ... NeXTSTEP is the original object-oriented, multitasking operating system that NeXT Computer, Inc. ...


Recent versions of Microsoft Windows are far more stable. Windows XP (Home, Professional, Media Center) is a 32-bit operating system, that has versions for both home and business users. Previously the only avaiable Windows operating systems designed for home use were hybrid 16-bit and 32-bit, like Windows 95, Windows 98/98SE and Windows ME, which didn't have the stability of a true 32-bit operating system. Some home users would however run Windows 2000 Professional, but it was primarily targeted at the business market. Since the introduction of Windows XP Home, home users have enjoyed a much more stable operating system. ‹ The template below has been proposed for deletion. ... Windows XP is the name of a line of operating systems developed by Microsoft for use on general-purpose computer systems, including home and business desktops, notebook computers, and media centers. ... A boxed copy of Windows 95 Upgrade. ... Windows 98 (codename Memphis) is a graphical operating system released on June 25, 1998 by Microsoft. ... Windows 98 (codename Memphis) is a graphical operating system released on June 25, 1998 by Microsoft. ... Windows Me (originally codenamed Millennium), also known as Windows Millennium Edition, is a 16-bit/32-bit graphical operating system released on September 14, 2000 by Microsoft. ... Windows 2000 (also referred to as Win2K or W2K) is a preemptible and interruptible, graphical, business-oriented operating system that was designed to work with either uniprocessor or symmetric multi-processor (SMP) 32-bit Intel x86 computers. ...


See also

The black screen of death (BSoD), is either of two things: a failure mode of Microsoft Windows 3. ... A public payphone that has failed and is displaying the Blue Screen of Death. ... A Crash to Desktop (or CTD) is a computer program crash which is said to occur when a full screen program (usually a game) in a Graphical User Interface environment unexpectedly quits, abruptly taking the user back to the desktop. ... Safe Mode is a special diagnostic mode used by certain computer operating systems (Windows, Mac OS X) and other complex electronic devices. ... Debugging is a methodical process of finding and reducing the number of bugs, or defects, in a computer program or a piece of electronic hardware thus making it behave as expected. ... The Mac OS X kernel panic alert Kernel panic on a Linux 2. ... ReBoot poster. ... Recovery is the first e-book and seventh installment of The New Jedi Order series set in the Star Wars galaxy. ... Crash Reporter is the standard crash reporter in Mac OS X, fount at /System/Library/CoreServices/Crash Reporter. ... A crash in computing is a condition where a program (either an application or part of the operating system) stops performing its expected function and also stops responding to other parts of the system. ...

External links

  • Microrecovery & Microreboot / Crash-Only Software
  • Citations from CiteSeer
  • Flickr photo album of public computer crashes

  Results from FactBites:
 
Crash (computing) - Wikipedia, the free encyclopedia (842 words)
A crash in computing is a condition where a program (either an application or part of the operating system) stops performing its expected function and also stops responding to other parts of the system.
Many crashes are the result of the execution of a single machine instruction, but the causes of this are manifold.
The art of debugging such crashes is connecting the actual cause of the crash (easily determined) with the code that set off the chain of events.
Crash (disambiguation) - Wikipedia, the free encyclopedia (420 words)
Crash (computing), a common term for a computer fault
Crash cymbal, a type of cymbal that is commonly found in drum kits, often used for a cartoon "crash" sound-effect
Crash (Schedule duration), the effort to reduce the overall duration of a schedule
  More results at FactBites »

 
 

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