From a crash in connection with computers is when a program (drain facilities) hard to unforeseen manner terminated or canceled or not more (figuratively) in the anticipated manner of interaction of the user responds - in this case more appropriate (the )" Freezing " (or English ' Freeze ') called. If the crashing program is part of the operating system and the abortion brings the entire computer to a standstill, we speak of a computer or system crash. If, on the other hand, the crash does not lead to a system standstill and if the crashing program is, for example, an application program , this is also referred to as a program termination or crash. A crash without an error message is also known as a crash to desktop .
The cause of crashes can be programming errors , incompatibilities , exhausted system resources or hardware errors . In many cases, the terminating program issues an error message and, under certain circumstances, additional diagnostic information, as is the case, for example, with a blue screen or a kernel panic .
Variants and causes
In addition to the unforeseen termination of a program, one speaks of a crash when a program or the operating system no longer reacts. It is then also said that the system or program has “hung up” or “frozen” (analogous to “freeze”). In this case, the program is in an endless loop , i.e. it processes the same instructions repeatedly without ever meeting the end condition for exiting this program section. Diagnostic information is usually not available in this type of crash.
A program is terminated as a crash when it is recognized by the program itself or that of a higher-level entity (for example the operating system) that an operation to be carried out cannot be correct. A very common aptly such error type is the protection fault (Engl. "Protection Fault", "segmentation fault" or "segmentation violation" in some operating systems, "General Protection Fault", "General Protection Fault" called) that is triggered when a Program is trying to access memory that has not been allocated to the program. This is mostly due to the fact that an internal program pointer points to an invalid memory address . This in turn can have various causes, for example the memory can already have been released without the pointer being reset.
Actions in the event of a crash
If an error message is output when the crash occurs, any instructions in the message should be followed, provided they are understandable. Otherwise, the message should be noted or a screenshot should be created, if this is possible and a contact person is known who can help with this problem (sometimes it is sufficient to include the message or an excerpt in an Internet search). In some cases, a so-called is also used to diagnose dump ( Dump ) created that the manufacturer of the abzustürzenden software is to be forwarded. Sometimes it is also offered to forward the diagnostic information directly to the manufacturer via the Internet .
If the system or a program has stopped responding, that is, it hangs, there is little left but to cancel the program and restart or reset the computer or turn it off and on. With Unixoid systems it sometimes only helps to shut down the X server ( + + or + ). If that does not help, a number of key combinations with the system query key are recommended to avoid data loss, see Magic S-Abf key . StrgAltBackspaceS-AbfK
Crashes are often associated with data loss , as the data currently being processed is still in the main memory and can no longer be transferred to a persistent storage medium such as the hard drive . To reduce such data loss, some application programs periodically create backup copies of the processed data automatically in the background and offer (often when the application is restarted) a restoration of the most recently saved data.
Less common, but even more serious, are cases when persistent data is also destroyed during the crash. This can be caused by the fact that the crashing program was already in an unstable or inconsistent state before the crash and, for example, is still performing incorrect write operations on the hard disk during this phase . In particular, this can also damage the file system . In these cases it can also happen that the application program or even the computer cannot be restarted after the crash.
The term “crash” is obvious simply because starting and shutting down a computer is also referred to as starting up and shutting down .
Another possible interpretation is that “crash” is derived from the English term “crash”. In turn, the English term could be traced back to the term head crash when the normally floating read / write head of a hard disk comes into contact with the rotating surface, which leads to a defect in the hard disk and thus often to a failure of the entire system.
Another, rather unlikely, assumption about the origin of the common phrase “my program crashed” relates to the time when punch cards were processed . At that time, programs were placed on a small conveyor belt in the form of small wooden boxes with stacks of punch cards with the continuous commands of a program in the evening, so that the computer could use this program (along with many others), the punch card reader unit and with it overnight (or during the day) to be processed by the computer. The program was then read in, executed and the results (at this time programs were mostly complex calculations of any kind) were again output on punched cards. If there were complications in the process, be it that the punch card reader could not read in or output the stack without errors or that the program output too much data due to incorrect programming or endless loops , then it was not uncommon for the box to fall from the output conveyor belt and all the punch cards were scattered on the floor in disorder. So the program “crashed” and the next day the author had a lot of work to do to sort the punch cards again.
- لُلُصّبُلُلصّبُررً ॣ ॣ h ॣ ॣ 冗 is a special string of characters that crashed Apple iOS devices like iPhone or iMac.
- A certain file name causes Windows Vista, 7 and 8.1 to crash.
- ↑ Crash to Desktop. In: techopedia.com. Retrieved June 30, 2018 .
- ^ Hans Herbert Schulze: The Rororo Computer Lexicon. Rowohlt Taschenbuch Verlag, Reinbek near Hamburg 1984. ISBN 3-499-18105-3 , p. 394.
- ↑ Blue screen. In: elektronikpraxis.vogel.de. Retrieved June 30, 2018 .
- ↑ Kernel panic. In: elektronikpraxis.vogel.de. Retrieved June 30, 2018 .
- ↑ What does software hang mean. In: techopedia.com. Retrieved June 30, 2018 .
- ↑ General protection violation. In: pctipp.ch. November 29, 1999, accessed June 30, 2018 .
- ↑ a b Peter Winkler: Computerlexikon 2010. Page 193f, Markt + Technik, Munich 2009, ISBN 978-3-8272-4519-9
- ↑ WhatsApp message crashes. In: heise.de. Accessed June 30, 2018 (German).
- ↑ iPhone: When message crashes. In: heise.de. Accessed June 30, 2018 (German).
- ↑ File name bug causes Windows to crash. In: pcwelt.de. Retrieved June 30, 2018 .
- lexitron.de: Crash ( Memento from December 15, 2006 in the Internet Archive )