In computing, buffer underrun is a state occurring when a buffer used to communicate between two devices or processes is fed with data at a lower speed than the data is being read from it. This requires the program or device reading from the buffer to pause its processing while the buffer refills. This can cause undesired and sometimes serious side effects, since the data being buffered is generally not suited to stop-start access of this kind. Originally, the word computing was synonymous with counting and calculating, and a science that deals with the original sense of computing mathematical calculations. ... Buffer can have various meanings: In chemistry, the term buffer refers to a buffer solution used to stabilize the pH (acidity) of a liquid. ... In computing, a process is a running instance of a program, including all variables and other state. ... Jump to: navigation, search DATA (Debt, AIDS, Trade, Africa) was established in 2002 by Bono (Paul Hewson) of the Rock band U2, and Bobby Shiver, along with activists from the Jubilee 2000 Drop the Debt Campaign, as an organisaton focused on Justice, not charity. ...

General causes and solutions

The term should not be confused with buffer overflow, a condition where a portion of memory being used as a buffer has a fixed size but is filled with more than that amount of data. Whereas buffer overflows are usually the result of programming errors, and thus preventable, buffer underruns are often the result of transitory issues on the "connection" which is being buffered—either a connection between two processes, with others competing for CPU time; or a physical link, with devices competing for bandwidth. In computer programming, a buffer overflow is an anomalous condition where a program somehow writes data beyond the allocated end of a buffer in memory. ... CPU can stand for: in computing: Central processing unit in journalism: Commonwealth Press Union in law enforcement: Crime prevention unit in software: Critical patch update, a type of software patch distributed by Oracle Corporation in Macleans College is often known as Ash Lim. ... Jump to: navigation, search // Analog systems For analog signals, which can be mathematically viewed as a function of time, bandwidth is the width, measured in hertz, of a frequency range in which the signals Fourier transform is nonzero. ...

The simplest guard against such problems is to increase the size of the buffer—if an incoming data stream needs to be read at 1 bit per second, a buffer of 10 bits would allow the connection to be blocked for up to 10 seconds before failing, whereas one of 60 bits would allow a blockage of up to a minute. However, this requires more memory to be available to the process or device, which can be expensive. It also assumes that the buffer starts full—requiring a potentially significant pause before the reading process begins—and that it will always be full unless the connection is currently blocked. This latter caveat means that if the data does not, on average, arrive significantly faster than it is needed, any "blockages" on the connection will be cumulative—so that "dropping" one bit every minute on our hypothetical connection would lead to the 60-bit buffer underrunning if the connection remained active for an hour. In telecommunications, a data stream is a sequence of digitally encoded signals used to represent information in transmission. ...

CD and DVD recording issues

Buffer underruns can cause serious problems during CD/DVD burning, because once the laser is on, it cannot stop and resume flawlessly; thus the pause necessitated by the underrun can cause the data on the disc to become invalid, and thus unusable. Since the buffer is generally being filled from a relatively slow source, such as a hard disk or another CD/DVD, a heavy CPU or memory load from other concurrent tasks can easily exhaust the capacity of a small buffer. Therefore, a technique called buffer underrun protection was implemented by various individual CD/DVD writer vendors, under various trademarks, such as Plextor BurnProof and Yamaha SafeBurn. CD may stand for: Compact Disc Canadian Forces Decoration Cash Dispenser (at least used in Japan) CD LPMud Driver Centrum-Demokraterne (Centre Democrats of Denmark) Certificate of Deposit České Dráhy (Czech Railways) Chad (NATO country code) Chalmers Datorförening (computer club of the Chalmers University of Technology) a 1960s... Jump to: navigation, search DVD is an optical disc storage media format that can be used for data storage, including movies with high video and sound quality. ... Typical hard drives of the mid-1990s. ... A trademark (Commonwealth English: trade mark)[1] is a distinctive sign of some kind which is used by a business to identify itself and its products and services to consumers, and to set the business and its products or services apart from those of other businesses. ... The brand Plextor is best known for its CD and DVD writers. ... The Yamaha Corporation (ヤマハ株式会社) (TYO: 7951) is a Japanese company with a large number of product areas. ...

Another way to protect against the problem, when using rewritable media (CD-RW, DVD-RW, DVD-RAM), is to use the UDF file system, which organizes data in smaller "packets", referenced by a single, updated address table, which can therefore be written in shorter bursts. Jump to: navigation, search Compact Disc ReWritable (CD-RW) is a rewritable optical disc format. ... The title given to this article is incorrect due to technical limitations. ... You can recognize a DVD-RAM immediately because visually there are lots of little rectangles distributed on the surface of the data carrier. ... Jump to: navigation, search The Universal Disk Format (UDF) is a format specification of a file system for storing files on recordable media. ... A packet is the fundamental unit of information carriage in all modern computer networks. ...