Computerized batch processing is a method of running software programs called jobs in batches automatically. While users are required to submit the jobs, no other interaction by the user is required to process the batch. Batches may automatically be run at scheduled times as well as being run contingent on the availability of computer resources.
129-498: Per Brinch Hansen (13 November 1938 – 31 July 2007) was a Danish - American computer scientist known for his work in operating systems , concurrent programming and parallel and distributed computing . Per Brinch Hansen was born in Frederiksberg , an enclave surrounded by Copenhagen , Denmark . His father, Jørgen Brinch Hansen , worked as a civil engineer, becoming a leading expert in soil mechanics , and later accepting
258-531: A COBOL compiler for the Siemens 3003 computer. Subsequently, he wrote a file system to be used during execution of the compiled COBOL programs, later observing: I now understand that it was really a small operating system, I had programmed. However, in the mid 1960s, the dividing line between language implementation and operating systems was still not clearly understood. In 1966, Brinch Hansen moved to Henning Isaksson's hardware group at Regnecentralen, by then
387-605: A Ministry of Environment and was the first country in the world to implement an environmental law in 1973. To mitigate environmental degradation and global warming the Danish Government has signed the Climate Change-Kyoto Protocol . However, the national ecological footprint is 8.26 global hectares per person, which is very high compared to a world average of 1.7 in 2010. Contributing factors to this value are an exceptional high value for cropland but also
516-459: A job queue to be run. In order to prevent deadlocks the job scheduler needs to know each job's resource requirements—memory, magnetic tapes, mountable disks , etc., so various scripting languages were developed to supply this information in a structured way. Probably the most well-known is IBM's Job Control Language (JCL). Job schedulers select jobs to run according to a variety of criteria, including priority, memory size, etc. Remote batch
645-614: A temperate climate, characterised by cool to cold winters, with mean temperatures in January of 1.5 °C (34.7 °F), and mild summers, with a mean temperature in August of 17.2 °C (63.0 °F). The most extreme temperatures recorded in Denmark, since 1874 when recordings began, was 36.4 °C (97.5 °F) in 1975 and −31.2 °C (−24.2 °F) in 1982. Denmark has an average of 179 days per year with precipitation, on average receiving
774-581: A temperate climate . Denmark exercises hegemonic influence in the Danish Realm , devolving powers to handle internal affairs. Home rule was established in the Faroe Islands in 1948. Greenland obtained home rule in 1979 and further autonomy in 2009. The unified Kingdom of Denmark emerged in the 8th century AD as a maritime power amid the struggle for control of the Baltic Sea . In 1397, it formed
903-542: A two-chamber parliament . Denmark faced war against both Prussia and the Austrian Empire in what became known as the Second Schleswig War , lasting from February to October 1864. Denmark was defeated and obliged to cede Schleswig and Holstein to Prussia . This loss came as the latest in the long series of defeats and territorial losses that had begun in the 17th century. After these events, Denmark pursued
1032-517: A batch job over a large number of processors, although there are significant programming challenges in doing so. High volume batch processing places particularly heavy demands on system and application architectures as well. Architectures that feature strong input/output performance and vertical scalability , including modern mainframe computers , tend to provide better batch performance than alternatives. Scripting languages became popular as they evolved along with batch processing. A batch window
1161-510: A company with shareholders. Together with Peter Kraft, he defined the computer architecture and instruction set for Regnecentralen's third computer, the RC 4000, using ALGOL 60 as a hardware description language to produce a formal specification . Inexperienced with multiprogramming , he used a copy of Cooperating Sequential Processes Edsger Dijkstra had sent him to understand process synchronization using semaphores , and then implemented
1290-404: A computer architect. After completing a Master of Science degree in electronic engineering in 1963, Brinch Hansen landed a job at Regnecentralen , then a research institution under The Danish Academy of Technical Sciences (Akademiet for de Tekniske Videnskaber), working in the compiler group, led by Peter Naur and Jørn Jensen . There, his first significant project was writing a parser for
1419-668: A few key trading posts in Africa and India . While Denmark's trading posts in India were of little note, it played an important role in the highly lucrative Atlantic slave trade , through its trading outposts in Fort Christiansborg in Osu , Ghana through which 1.5 million slaves were traded. While the Danish colonial empire was sustained by trade with other major powers, and plantations – ultimately
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#17330860128991548-523: A first rate department. By 1980, USC's computer science department was ranked by the National Research Council as one of the top ten in the US. While at USC, Brinch Hansen wrote his second book, The Architecture of Concurrent Programs, based on his work developing operating systems with Concurrent Pascal. Published in 1977, it was the first book on concurrent programming. In 1978, Brinch Hansen became
1677-525: A framework laid out in the Constitution of Denmark . First written in 1849, it establishes a sovereign state in the form of a constitutional monarchy , with a representative unicameral parliamentary system . The monarch officially retains executive power and presides over the Council of State ( privy council ). In practice, the duties of the monarch are strictly representative and ceremonial , such as
1806-519: A further Danevirke . In the early 11th century, Canute the Great won and united Denmark, England, and Norway for almost 30 years with a Scandinavian army. Throughout the High and Late Middle Ages , Denmark also included Skåneland (the areas of Scania, Halland , and Blekinge in present-day south Sweden) and Danish kings ruled Danish Estonia , as well as the duchies of Schleswig and Holstein . Most of
1935-399: A general-purpose RC 4000 multiprogramming system , with a goal to avoid developing a custom real-time control operating system for every RC 4000 installation, and to support batch processing and time-sharing as well. The resulting system was not a complete operating system, but a small kernel providing the mechanisms upon which operating systems for different purposes could be built. By
2064-727: A lack of resources led to its stagnation. In the Thirty Years' War , Christian tried to become the leader of the Lutheran states in Germany but suffered a crushing defeat at the Battle of Lutter . The result was that the Catholic army under Albrecht von Wallenstein was able to invade, occupy, and pillage Jutland, forcing Denmark to withdraw from the war . Denmark managed to avoid territorial concessions, but King Gustavus Adolphus ' intervention in Germany
2193-502: A language for distributed computing based on external requests consisting of procedure calls between processes. This later became known in an operating system context as the remote procedure call. Later, Brinch Hansen developed two languages extending Hoare's CSP message-passing paradigm with parallel recursion, and showed how to efficiently implement such. Denmark – in Europe (light green & dark grey) – in
2322-411: A low-cost multiprocessor architecture. Mostek began a project to implement such a multiprocessor, with Brinch Hansen working as a consultant. Brinch Hansen developed a new concurrent programming language, Edison, for the project. As with the RC 4000 project, Edison was also used as a formal specification language for the hardware. Mostek got an initial 4-node multiprocessor working and Brinch Hansen wrote
2451-535: A new language, this time leveraging the message passing paradigm of Hoare's CSP . The resulting language, Joyce , removed a major limitation of CSP by introducing parallel recursion . Brinch Hansen developed a portable implementation on an IBM PC. After finding that neither he nor his family felt at home in Denmark, Brinch Hansen decided to return to the US, but discovered that their immigration status required them to do so very quickly. Brinch Hansen contacted John Reynolds at Syracuse University and in 1987 he joined
2580-464: A policy of neutrality in Europe. Industrialisation came to Denmark in the second half of the 19th century. The nation's first railways were constructed in the 1850s, and improved communications and overseas trade allowed industry to develop in spite of Denmark's lack of natural resources. Trade unions developed, starting in the 1870s. There was a considerable migration of people from the countryside to
2709-524: A portable Edison compiler on a PDP 11/55, but shortly after, United Technologies acquired Mostek and cancelled the project. In 1982, Brinch Hansen moved the Edison system to an IBM Personal Computer (PC), and then published his third book, Programming a Personal Computer . In 1982, Brinch Hansen was named the first Henry Salvatori Professor of Computer Science at USC. In 1984, feeling homesick for Denmark after 14 years abroad, Brinch Hansen left USC and joined
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#17330860128992838-416: A professorship at Technical University of Denmark . His mother, Elsebeth Brinch Hansen (née Ring), was the daughter of Danish composer Oluf Ring and worked as a hairdresser before marrying. Brinch Hansen attended Skt. Jørgens Gymnasium and then studied electrical engineering at Technical University of Denmark where he sought an area to pursue that "was still in its pioneering phase" on the belief that "If
2967-475: A relatively high value for grazing land, which may be explained by the substantially high meat production in Denmark (115.8 kilograms (255 lb) meat annually per capita) and the large economic role of the meat and dairy industries. In December 2014, the Climate Change Performance Index for 2015 placed Denmark at the top of the table, explaining that although emissions are still quite high,
3096-493: A retrospective on the evolution of concurrent programming, The Origin of Concurrent Programming: From Semaphores to Remote Procedure Calls (2002). He self-published a 2004 memoir, A Programmer's Story: The Life of a Computer Pioneer , on his website. In 2002, Brinch Hansen was awarded the IEEE Computer Pioneer Award "For pioneering development in operating systems and concurrent programming exemplified by work on
3225-527: A single operating system image. Technologies that aid concurrent batch and online processing include Job Control Language (JCL), scripting languages such as REXX , Job Entry Subsystem ( JES2 and JES3 ), Workload Manager (WLM), Automatic Restart Manager (ARM), Resource Recovery Services (RRS), IBM Db2 data sharing, Parallel Sysplex , unique performance optimizations such as HiperDispatch , I/O channel architecture , and several others. The Unix programs cron , at , and batch (today batch
3354-425: A single input at once (not totals, for instance): start the next step for each input as it completes the previous step. In this case flow processing lowers latency for individual inputs, allowing them to be completed without waiting for the entire batch to finish. However, many applications require data from all records, notably computations such as totals. In this case the entire batch must be completed before one has
3483-652: A single unified judicial system – Denmark has one system, Greenland another, and the Faroe Islands a third. However, decisions by the highest courts in Greenland and the Faroe Islands may be appealed to the Danish High Courts. The Danish Supreme Court is the highest civil and criminal court responsible for the administration of justice in the Kingdom. The Kingdom of Denmark is a unitary state that comprises, in addition to metropolitan Denmark, two autonomous territories in
3612-447: A specialized RC 4000 real-time monitor for use in managing a fertilizer plant. Peter Kraft and Charles Simonyi , who was still a teenager, wrote a p-code interpreter and data logging task programs that were compiled to p-code. In the summer of 1967, Brinch Hansen left Regnecentralen's hardware group to become head of RC 4000 software development , where he led a team including Jørn Jensen, Peter Kraft and Søren Lauesen in defining
3741-522: A subject was being taught, it was probably already too late to make fundamental contributions." After a seven-week student internship at IBM 's Hursley Laboratory in England, he decided to dedicate his career to computers. Initially focused on computer construction, reading a book on the IBM 7030 Stretch project that described computer organization from a programmer's point of view refocused his interest toward becoming
3870-423: A time. Each user had sole control of the machine for a scheduled period of time. They would arrive at the computer with program and data, often on punched paper cards and magnetic or paper tape, and would load their program, run and debug it, and carry off their output when done. As computers became faster the setup and takedown time became a larger percentage of available computer time. Programs called monitors ,
3999-473: A top 25 classic book, ranking it 18th in the survey, and appearing on 8% of ballots. It is now available from the ACM Digital Library . Remote procedure calls used in modern operating systems trace their roots back to the RC 4000 multiprogramming system, which used a request-response communication protocol for process synchronization. In his 1978 paper on distributed processes, Brinch Hansen proposed
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4128-560: A total area of 42,943 km (16,580 sq mi), metropolitan Denmark consists of the northern part of the Jutland peninsula and an archipelago of 406 islands. Zealand is Denmark's most populated island, followed by Funen , then the North Jutlandic Island and Amager . Copenhagen, Denmark's capital and most populous city, is located on Zealand and Amager. Denmark has flat, arable land , sandy coasts, low elevations, and
4257-420: A total area of 42,943.9 square kilometres (16,581 sq mi). The area of inland water is 43 km (17 sq mi). The size of the land area cannot be stated exactly since the ocean constantly erodes and adds material to the coastline, and because of human land reclamation projects (to counter erosion). Post-glacial rebound raises the land by a bit less than 1 cm (0.4 in) per year in
4386-522: A total of 765 millimetres (30 in) per year; autumn is the wettest season and spring the driest. The position between a continent and an ocean means that the weather is often unstable. Because of Denmark's northern location, there are large seasonal variations in daylight: short days during the winter with sunrise coming around 8:45 am and sunset 3:45 pm (standard time), as well as long summer days with sunrise at 4:30 am and sunset at 10 pm ( daylight saving time ). Denmark belongs to
4515-457: A union with Norway. After Sweden permanently broke away from the personal union, Denmark tried on several occasions to reassert control over its neighbour. King Christian IV attacked Sweden in the 1611–1613 Kalmar War but failed to accomplish his main objective of forcing it to return to the union. The war led to no territorial changes, but Sweden was forced to pay a war indemnity of 1 million silver riksdaler to Denmark, an amount known as
4644-473: A usable result: partial results are not usable. Modern batch applications make use of modern batch frameworks such as Jem The Bee, Spring Batch or implementations of JSR 352 written for Java , and other frameworks for other programming languages, to provide the fault tolerance and scalability required for high-volume processing. In order to ensure high-speed processing, batch applications are often integrated with grid computing solutions to partition
4773-447: Is "a period of less-intensive online activity", when the computer system is able to run batch jobs without interference from, or with, interactive online systems. A bank's end-of-day (EOD) jobs require the concept of cutover , where transaction and data are cut off for a particular day's batch activity ("deposits after 3 PM will be processed the next day"). As requirements for online systems uptime expanded to support globalization ,
4902-457: Is a representative democracy with universal suffrage . Membership of the Folketing is based on proportional representation of political parties, with a 2% electoral threshold. Denmark elects 175 members to the Folketing, with Greenland and the Faroe Islands electing an additional two members each—179 members in total. Parliamentary elections are held at least every four years, but it is within
5031-522: Is a procedure for submitting batch jobs from remote terminals, often equipped with a punch card reader and a line printer . Sometimes asymmetric multiprocessing is used to spool batch input and output for one or more large computers using an attached smaller and less-expensive system, as in the IBM System/360 Attached Support Processor . The first general purpose time sharing system, Compatible Time-Sharing System (CTSS),
5160-489: Is divided between courts with regular civil and criminal jurisdiction and administrative courts with jurisdiction over litigation between individuals and the public administration. Articles sixty-two and sixty-four of the Constitution ensure judicial independence from government and Parliament by providing that judges shall only be guided by the law, including acts, statutes and practice. The Kingdom of Denmark does not have
5289-478: Is farther from the coast than 52 km (32 mi). On the south-west coast of Jutland, the tide is between 1 and 2 m (3.28 and 6.56 ft), and the tideline moves outward and inward on a 10 km (6.2 mi) stretch. Denmark's territorial waters total 105,000 square kilometres (40,541 square miles). Denmark's northernmost point is Skagen point (the north beach of the Skaw) at 57° 45' 7" northern latitude;
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5418-598: Is flat with little elevation, having an average height above sea level of 31 metres (102 ft). The highest natural point is Møllehøj , at 170.86 metres (560.56 ft). Although this is by far the lowest high point in the Nordic countries and also less than half of the highest point in Southern Sweden , Denmark's general elevation in its interior is generally at a safe level from rising sea levels . A sizeable portion of Denmark's terrain consists of rolling plains whilst
5547-439: Is not desired, they are not typically optimized to perform high-volume, repetitive tasks. Therefore, even new systems usually contain one or more batch applications for updating information at the end of the day, generating reports, printing documents, and other non-interactive tasks that must complete reliably within certain business deadlines. Some applications are amenable to flow processing, namely those that only need data from
5676-668: Is often known as a job , but that term is used very ambiguously. "There is no direct counterpart to z/OS batch processing in PC or UNIX systems. Batch jobs are typically executed at a scheduled time or on an as-needed basis. Perhaps the closest comparison is with processes run by an at or cron command in UNIX, although the differences are significant." Batch applications are still critical in most organizations in large part because many common business processes are amenable to batch processing. While online systems can also function when manual intervention
5805-432: Is one of the best explainers in the business. He explains things clearly and to the point. He has an eye for the general principle behind the example, but manages to avoid unnecessary abstraction. After all these years, he is still a pleasure to read. In 2005, Association for Computing Machinery (ACM) members voted Operating System Principles a top 25 classic book, in a survey to choose out-of-print classic books to add to
5934-510: Is perhaps also sometimes a human response to the tremendous pressure on university professors to get funding and recognition fast. Nevertheless, we must remember that only one thing counts in engineering: Does it work (not "might it work" or "wouldn't it be nice if it did")? The RC 4000 multiprogramming system introduced the now-standard concept of an operating system kernel and the separation of mechanism and policy in operating system design. Modern microkernel architectures trace their roots to
6063-517: Is the largest lake. The Kingdom of Denmark includes two overseas territories, both well to the west of Denmark: Greenland, the world's largest island , and the Faroe Islands in the North Atlantic Ocean. These territories are self-governing under their own parliaments (the Løgting and Inatsisartut ) and form, together with continental Denmark, part of the Danish Realm , a country. Denmark has
6192-512: Is today most often called a script , and written in scripting languages , particularly shell scripts for system tasks; in IBM PC DOS and MS-DOS this is instead known as a batch file . That includes UNIX -based computers, Microsoft Windows , macOS (whose foundation is the BSD Unix kernel), and even smartphones . A running script, particularly one executed from an interactive login session ,
6321-399: Is used in political science as a reference point for near-perfect governance and the term "getting to Denmark" is used to describe how other countries can improve their governments. The etymology of the name "Denmark", the relationship between "Danes" and "Denmark", and the emergence of Denmark as a unified kingdom are topics of continuous scholarly debate. This is centred primarily on
6450-495: The Älvsborg ransom . King Christian used this money to found several towns and fortresses, most notably Glückstadt (founded as a rival to Hamburg ) and Christiania . Inspired by the Dutch East India Company , he founded a similar Danish company and planned to claim Ceylon as a colony, but the company only managed to acquire Tranquebar on India's Coromandel Coast . Denmark's large colonial aspirations included
6579-542: The Boreal Kingdom and can be subdivided into two ecoregions : the Atlantic mixed forests and Baltic mixed forests . Almost all of Denmark's primeval temperate forests have been destroyed or fragmented, chiefly for agricultural purposes during the last millennia. The deforestation has created large swaths of heathland and devastating sand drifts . In spite of this, there are several larger second growth woodlands in
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#17330860128996708-570: The Eem interglacial period from 130,000 to 110,000 BC . Denmark has been inhabited since around 12,500 BC and agriculture has been evident since 3900 BC. The Nordic Bronze Age (1800–600 BC) in Denmark was marked by burial mounds , which left an abundance of findings including lurs and the Sun Chariot . During the Pre-Roman Iron Age (500 BC – AD 1), native groups began migrating south, and
6837-567: The European Union (light green) Denmark is a Nordic country in the south-central portion of Northern Europe with a population of nearly 6 million; 770,000 live in Copenhagen (1.9 million in the capital region). It is the metropolitan part, and most populous constituent part of, the Kingdom of Denmark , a constitutionally unitary state that includes the autonomous territories of
6966-671: The Faroe Islands and Greenland in the North Atlantic Ocean . Metropolitan Denmark is the southernmost of the Scandinavian countries, lying south-west and south of Sweden , south of Norway , and north of Germany , with which it shares a short border . As of 2013, the Kingdom of Denmark , including the Faroe Islands and Greenland , had a total of 1,419 islands greater than 100 square metres (1,100 sq ft) in area; 443 have been named and 78 are inhabited. Spanning
7095-616: The Frikorps Danmark . Iceland severed ties with Denmark and became an independent republic in 1944; Germany surrendered in May 1945. In 1948, the Faroe Islands gained home rule . In 1949, Denmark became a founding member of NATO . Denmark was a founding member of European Free Trade Association (EFTA). During the 1960s, the EFTA countries were often referred to as the Outer Seven , as opposed to
7224-650: The Inner Six of what was then the European Economic Community (EEC). In 1973, along with Britain and Ireland, Denmark joined the European Economic Community (now the European Union ) after a public referendum . The Maastricht Treaty , which involved further European integration, was rejected by the Danish people in 1992; it was only accepted after a second referendum in 1993, which provided for four opt-outs from policies. The Danes rejected
7353-673: The Internet , and other business needs, the batch window shrank and increasing emphasis was placed on techniques that would require online data to be available for a maximum amount of time. The batch size refers to the number of work units to be processed within one batch operation. Some examples are: The IBM mainframe z/OS operating system or platform has arguably the most highly refined and evolved set of batch processing facilities owing to its origins, long history, and continuing evolution. Today such systems commonly support hundreds or even thousands of concurrent online and batch tasks within
7482-670: The Jelling stones , the Danes were Christianised around 965 by Harald Bluetooth , the son of Gorm and Thyra . It is believed that Denmark became Christian for political reasons so as not to get invaded by the Holy Roman Empire . A rising Christian power in Europe, the Holy Roman Empire was an important trading partner for the Danes. As a deterrent against this threat, Harald built six fortresses around Denmark called Trelleborg and built
7611-457: The Jutland peninsula and an archipelago of 406 islands . Of these, the largest island is Zealand , on which the capital Copenhagen is situated, followed by the North Jutlandic Island , Funen , and Lolland . The island of Bornholm is located some 150 km east of the rest of the country, in the Baltic Sea . Many of the larger islands are connected by bridges; a bridge-tunnel across
7740-526: The Kalmar Union with Norway and Sweden. This union persisted until Sweden's secession in 1523. The remaining Kingdom of Denmark–Norway endured a series of wars in the 17th century that resulted in further territorial cessions . A surge of nationalist movements in the 19th century were defeated in the First Schleswig War of 1848. The adoption of the Constitution of Denmark on 5 June 1849 ended
7869-636: The North Atlantic Ocean : the Faroe Islands and Greenland . They have been integrated parts of the Danish Realm since the 18th century; however, due to their separate historical and cultural identities, these parts of the Realm have extensive political powers and have assumed legislative and administrative responsibility in a substantial number of fields. Home rule was granted to the Faroe Islands in 1948 and to Greenland in 1979, each having previously had
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#17330860128997998-610: The PDP 11/45 , written by Brinch Hansen's doctoral student, Al Hartmann, was released in January 1975. Subsequently, Brinch Hansen began writing model operating systems in Concurrent Pascal, to evaluate the language. In May 1975, he completed Solo, a single-user operating system for development of Concurrent Pascal programs. Next, he rewrote the original RC 4000 real-time scheduler in Concurrent Pascal, taking three days to write it, and three hours of machine time to systematically test it. When
8127-762: The United Kingdom and joined the League of Armed Neutrality with Russia , Sweden, and Prussia . British fears that Denmark-Norway would ally with France led to two attacks against Danish targets in Copenhagen in 1801 and 1807 . These attacks resulted in the British capturing most of the Dano-Norwegian navy and led to the outbreak of the Gunboat War . British control of the waterways between Denmark and Norway proved disastrous to
8256-401: The absolute monarchy and introduced the current parliamentary system. An industrialised exporter of agricultural produce in the second half of the 19th century, Denmark introduced social and labour-market reforms in the early 20th century, forming the basis for the present welfare state model and advanced mixed economy . Denmark remained neutral during World War I ; Danish neutrality
8385-682: The krone . Denmark is a developed country with a high standard of living , and was the first country to legally recognise same-sex partnerships . It is a founding member of NATO , the Nordic Council , the OECD , the OSCE and the United Nations , and is part of the Schengen Area . Denmark maintains close political, cultural, and linguistic ties with its Scandinavian neighbours. The Danish political system
8514-573: The Øresund connects Zealand with Sweden; the Great Belt Fixed Link connects Funen with Zealand; and the Little Belt Bridge connects Jutland with Funen. Ferries or small aircraft connect to the smaller islands. The four cities with populations over 100,000 are the capital Copenhagen on Zealand; Aarhus and Aalborg in Jutland; and Odense on Funen. The metropolitan part occupies
8643-414: The 1960s. Instead of running one batch job at a time, these systems can have multiple batch programs running at the same time in order to keep the system as busy as possible. One or more programs might be awaiting input, one actively running on the CPU, and others generating output. Instead of offline input and output, programs called spoolers read jobs from cards, disk, or remote terminals and place them in
8772-480: The 1971 Summer School in Marktoberdorf and a symposium in Belfast , Brinch Hansen, Tony Hoare and Dijkstra began to discuss ideas that evolved into the monitor concept. In the spring of 1972, after reading about the class concept invented by Ole-Johan Dahl and Kristen Nygaard for Simula 67, Brinch Hansen completed his text with a chapter on resource protection that proposed the first monitor notation, using shared classes. In 1973, Operating System Principles
8901-605: The 8th to the 10th century the wider Scandinavian region was the source of Vikings . They colonised, raided, and traded in all parts of Europe. The Danish Vikings were most active in the eastern and southern British Isles and Western Europe . They settled in parts of England (known as the Danelaw ) under King Sweyn Forkbeard in 1013, and in France where Danes and Norwegians were allowed to settle in what would become Normandy in exchange of allegiance to Robert I of France with Rollo as first ruler. Some Anglo-Saxon pence of this period have been found in Denmark. Denmark
9030-619: The ACM Digital Library. Operating System Principles ranked 15th in the survey, appearing on 8.8% of ballots. It is now available from the ACM Digital Library . Using Concurrent Pascal, Brinch Hansen demonstrated that it was feasible to fully implement operating systems in high level languages, and that doing so reduced the development effort by one to two orders of magnitude. Furthermore, entire operating systems could be published, and understood in their entirety. Brinch Hansen did precisely that in The Architecture of Concurrent Programs , leading Roy Maddux and Harlan Mills to declare: Part two of
9159-502: The Caltech computer science department shifted focus toward computer engineering and away from programming Brinch Hansen decided to leave, rather than to seek tenure there. In 1976, Brinch Hansen chose University of Southern California (USC) for his next post, so that his family could remain in their Altadena home. Joining the faculty as a tenured full professor, and first chair of a newly created computer science department, he led efforts to identify and attract top-notch faculty to build
9288-449: The Danes, one of the ethnic groups from whom modern Danes are descended. The Danevirke defence structures were built in phases from the 3rd century forward and the sheer size of the construction efforts in AD 737 are attributed to the emergence of a Danish king. A new runic alphabet was first used around the same time and Ribe , the oldest town of Denmark, was founded about AD 700. From
9417-620: The Danish government refused further co-operation and its navy scuttled most of its ships and sent many of its officers to Sweden, which was neutral. The Danish resistance performed a rescue operation that managed to evacuate several thousand Jews and their families to safety in Sweden before the Germans could send them to death camps. Some Danes supported Nazism by joining the Danish Nazi Party or volunteering to fight with Germany as part of
9546-574: The Danish throne, and Greenland becoming an integral part of Denmark. The centre-left Social Democrats led a string of coalition governments for most of the second half of the 20th century, introducing the Nordic welfare model . The Liberal Party and the Conservative People's Party have also led centre-right governments. Located in Northern Europe , Denmark consists of the northern part of
9675-540: The Faroe Islands. The Folketing is also responsible for adopting the state's budgets , approving the state's accounts, appointing and exercising control of the Government, and taking part in international co-operation. Bills may be initiated by the Government or by members of parliament . All bills passed must be presented before the Council of State to receive Royal Assent within thirty days in order to become law. Denmark
9804-588: The Nordic colonies, Denmark continued to rule over Danish India from 1620 to 1869, the Danish Gold Coast (Ghana) from 1658 to 1850, and the Danish West Indies from 1671 to 1917. A nascent Danish liberal and national movement gained momentum in the 1830s; after the European Revolutions of 1848 , Denmark peacefully became a constitutional monarchy on 5 June 1849. A new constitution established
9933-406: The RC 4000 multiprogramming system, monitors, and Concurrent Pascal." On July 31, 2007, Brinch Hansen died, shortly after being diagnosed with terminal cancer. Brinch Hansen met his wife Milena (née Hrastar) on a class trip to Yugoslavia in 1962. They married in 1965 and had two children, daughter Mette and son Thomas. In a career spanning five decades, Brinch Hansen made seminal contributions in
10062-465: The RC 4000 system it described had become outdated. In 1990, nearly two decades after its initial publication, P. J. Plauger reviewed it, saying: This book is terribly dated. It describes many of the RC4000's operating-system algorithms. The RC4000 is slow, small, and starved for peripherals by today's standards. The algorithms are presented in a subset of Pascal. Why bother? The answer is that Brinch Hansen
10191-620: The advice of the International Whaling Commission (IWC), having quota decision-making powers. Denmark is ranked 10th in Environmental Performance Index for year 2024. This Index combines various indicators around known issues around the world and measures how good they fit in among each countries on a scale. Denmark scores good in parameters like Agriculture, Climate Change Mitigation, Forests' Net Change In Tree Cover etc. Politics in Denmark operate under
10320-432: The areas of operating systems, concurrent computing and parallel and distributed computing that were influential in shaping the development of those fields and advancing them from ad hoc techniques to systematic engineering disciplines. The influence of his work was amplified by his "relentless search for simplicity," his insistence on clarity, writing and rewriting his papers many times before publishing them, becoming "one of
10449-501: The basis for a large fishing industry . Denmark stopped issuing new licences for oil and gas extraction in December 2020. Land and water pollution are two of Denmark's most significant environmental issues , although much of the country's household and industrial waste is now increasingly filtered and sometimes recycled. The country has historically taken a progressive stance on environmental preservation ; in 1971 Denmark established
10578-441: The best explainers in the business," and his commitment to testing concepts in working systems – Brinch Hansen implemented and distributed working systems for new concepts he developed, noting: It is not uncommon for a computer scientist to make a proposal without testing whether it is any good in practice. After spending 3 days writing up the monitor proposal and 3 years implementing it, I can very well understand this temptation. It
10707-527: The best of academic research in this area." Source and portable code for Concurrent Pascal and the Solo operating system were distributed to at least 75 companies and 100 universities in 21 countries, resulting in its widespread adoption, porting and adaptation in both industry and academia. Greg Andrews observed that Concurrent Pascal and monitors "greatly influenced most subsequent concurrent language proposals." Brinch Hansen's The Architecture of Concurrent Programs
10836-435: The book is indeed remarkable. Here, an entire operating system is visible, with every line of program open to scrutiny. There is no hidden mystery, and after studying such extensive examples, the reader feels that he could tackle similar jobs and that he could change the system at will. Never before have we seen an operating system shown in such detail and in a manner so amenable to modification. Brinch Hansen and Hoare developed
10965-457: The border forests in south Schleswig . The first recorded use of the word Danmark within Denmark itself is found on the two Jelling stones , which are runestones believed to have been erected by Gorm the Old ( c. 955 ) and Harald Bluetooth ( c. 965 ). The larger of the two stones is popularly cited as the "baptismal certificate" ( dåbsattest ) of Denmark, though both use
11094-555: The cities, and Danish agriculture became centred on the export of dairy and meat products. Denmark maintained its neutral stance during World War I . After the defeat of Germany, the Versailles powers offered to return the region of Schleswig-Holstein to Denmark. Fearing German irredentism , Denmark refused to consider the return of the area without a plebiscite ; the two Schleswig Plebiscites took place on 10 February and 14 March 1920, respectively. On 10 July 1920, Northern Schleswig
11223-513: The coastline is sandy, with large dunes in northern Jutland. Although once extensively forested, today Denmark largely consists of arable land . It is drained by a dozen or so rivers , and the most significant include the Gudenå , Odense , Skjern , Suså and Vidå —a river that flows along its southern border with Germany. The country has 1008 lakes, 16 have an area of more than 500 hectares (1,200 acres). Lake Arresø , located northwest of Copenhagen,
11352-469: The country and, in total, 12.9% of the land is now forested. Norway spruce is the most widespread tree (2017); an important tree in the Christmas tree production . Denmark holds a Forest Landscape Integrity Index mean score of 0.5/10, ranking it 171st globally out of 172 countries—behind only San Marino . Roe deer occupy the countryside in growing numbers, and large-antlered red deer can be found in
11481-411: The country was able to implement effective climate protection policies. In 2020, Denmark was placed first in the index again. In 2021 Denmark, with Costa Rica, launched the "Beyond Oil and Gas alliance" for stopping use fossil fuels. Denmark's territories, Greenland and the Faroe Islands , catch approximately 650 whales per year. Greenland's quotas for the catch of whales are determined according to
11610-580: The ensuing peace settlement , Denmark managed to maintain its independence and regain control of Trøndelag and Bornholm. Attaining great popularity following the war, Frederick III used this to disband the elective monarchy in favour of absolute monarchy , which lasted until 1848 in Denmark. Denmark tried but failed to regain control of Scania in the Scanian War (1675–1679). After the Great Northern War (1700–21), Denmark managed to regain control of
11739-628: The euro as the national currency in a referendum in 2000 . Greenland gained home rule in 1979 and was awarded self-determination in 2009. Neither the Faroe Islands nor Greenland are members of the European Union, the Faroese having declined membership of the EEC in 1973 and Greenland in 1986, in both cases because of fisheries policies. Constitutional change in 1953 led to a single-chamber parliament elected by proportional representation, female accession to
11868-535: The executive branch, the Cabinet is responsible for proposing bills and a budget, executing the laws, and guiding the foreign and internal policies of Denmark. The position of prime minister belongs to the person most likely to command the confidence of a majority in the Folketing; this is often the current leader of the largest political party or, more effectively, through a coalition of parties . A single party generally does not have sufficient political power in terms of
11997-434: The extensible nucleus architecture of the RC 4000. Improving microkernel performance was a major theme in operating system research for three decades after the RC 4000. Brinch Hansen's text, Operating System Principles , was the first comprehensive textbook on operating systems. Eventually published in six languages (English, Japanese, German, Czech, Polish and Serbo-Croatian), it remained in print for decades, and years after
12126-551: The faculty as a Distinguished Professor. Working with his student Rangachari Anand, Joyce was moved to an Encore Multimax 320 multiprocessor at SU's Northeast Parallel Architectures Center. Recognizing the scaling limitations of multiprocessors, however, Brinch Hansen sought a suitable multicomputer for further work. Acquiring a Meiko Computing Surface in 1989, he began experimenting with scientific applications by developing parallel programs for Householder's method (reduction) and then N -body simulation as learning exercises, and
12255-521: The faculty of the University of Copenhagen as a Professor of datalogy . In 1985, he was elected a Fellow of the Institute of Electrical and Electronics Engineers (IEEE). Later in 1985, his fourth book Brinch Hansen on Pascal Compilers , which he used for his own compiler course, was published. While designing a multicomputer operating system for Danish company GN Elmi, Brinch Hansen concluded he needed
12384-462: The finding of the Gundestrup cauldron . The tribal Danes came from the east Danish islands ( Zealand ) and Scania and spoke an early form of North Germanic . Historians believe that before their arrival, most of Jutland and the nearest islands were settled by tribal Jutes . Many Jutes migrated to Great Britain , according to legend some as mercenaries of Brythonic King Vortigern , and formed
12513-708: The first computer scientist awarded the Doctor Technices degree, the highest academic distinction within engineering and technological science in Denmark, for the work documented in The Architecture of Concurrent Programs . Later in 1978, Brinch Hansen published the Distributed Processes language concept, proposing the use of remote procedure calls to synchronize processes running across a microcomputer network. Also in 1978, L. J. Sevins and Steve Goings from Mostek visited Brinch Hansen at USC, where he outlined
12642-589: The first tribal Danes came to the country between the Pre-Roman and the Germanic Iron Age , in the Roman Iron Age (AD 1–400). The Roman provinces maintained trade routes and relations with native tribes in Denmark, and Roman coins have been found in Denmark. Evidence of strong Celtic cultural influence dates from this period in Denmark and much of North-West Europe and is among other things reflected in
12771-662: The forerunners of operating systems , were developed which could process a series, or "batch", of programs, often from magnetic tape prepared offline. The monitor would be loaded into the computer and run the first job of the batch. At the end of the job it would regain control and load and run the next until the batch was complete. Often the output of the batch would be written to magnetic tape and printed or punched offline. Examples of monitors were IBM's Fortran Monitor System , SOS (Share Operating System), and finally IBSYS for IBM's 709x systems in 1960. Third-generation computers capable of multiprogramming began to appear in
12900-536: The formal appointment and dismissal of the Prime Minister and other Government ministers. The Monarch is not answerable for his or her actions, and their person is sacrosanct . Hereditary monarch King Frederik X has been head of state since 14 January 2024. The Danish parliament is unicameral and called the Folketing ( Danish : Folketinget ). It is the legislature of the Kingdom of Denmark, passing acts that apply in Denmark and, variably, Greenland and
13029-488: The island of Bornholm . Charles X Gustav quickly regretted not having ruined Denmark and in August 1658, he launched a second attack on Denmark , conquered most of the Danish islands, and began a two-year-long siege of Copenhagen . King Frederick III actively led the defence of the city, rallying its citizens to take up arms, and repelled the Swedish attacks . The siege ended following the death of Charles X Gustav in 1660. In
13158-672: The latter being deeply involved in the Second Northern War (1655–1660), and marched on Bremen-Verden . This led to a massive Danish defeat as the armies of King Charles X Gustav of Sweden conquered Jutland and, following the Swedish March across the frozen Danish straits , occupied Funen and much of Zealand before signing the Peace of Roskilde in February 1658, which gave Sweden control of Scania, Blekinge , Bohuslän , Trøndelag , and
13287-403: The latter two now form the state of Schleswig-Holstein in northern Germany. In 1397, Denmark entered into a personal union known as the Kalmar Union with Norway and Sweden , united under Queen Margaret I . The three countries were to be treated as equals in the union. However, even from the start, Margaret may not have been so idealistic—treating Denmark as the clear "senior" partner of
13416-550: The monitor concept. Brinch Hansen published the first monitor notation, adopting the class concept of Simula 67, and invented a queueing mechanism. Hoare refined the rules of process resumption. Brinch Hansen created the first implementation of monitors, in Concurrent Pascal. More than a dozen additional monitor-based languages had been created by 1990: Simone, Modula , CSP/k, CCNPascal, PLY, Pascal Plus, Mesa, SB-Mod, Concurrent Euclid , Pascalc, Concurrent C, Emerald, Real-time Euclid, Pascal-FC, Turing Plus , Predula. Concurrent Pascal
13545-454: The morpheme "Dan" and whether it refers to the Dani or a historical person Dan and the exact meaning of the - "mark" ending. Most etymological dictionaries and handbooks derive "Dan" from a word meaning "flat land", related to German Tenne "threshing floor", English den "cave". The element mark is believed to mean woodland or borderland (see marches ), with probable references to
13674-502: The north and east, extending the coast. A circle enclosing the same area as Denmark would be 234 kilometres (145 miles) in diameter with a circumference of 736 km (457 mi) (land area only: 232.33 km (144.36 mi) and 730 km (454 mi) respectively). It shares a border of 68 kilometres (42 mi) with Germany to the south and is otherwise surrounded by 8,750 km (5,437 mi) of tidal shoreline (including small bays and inlets ). No location in Denmark
13803-469: The number of seats to form a cabinet on its own; Denmark has often been ruled by coalition governments , themselves usually minority governments dependent on non-government parties. Following the 2022 Danish general election in November 2022, incumbent prime minister and Social Democratic leader Mette Frederiksen in December 2022 formed the current Frederiksen II Cabinet , a coalition government with
13932-456: The parts of Schleswig and Holstein ruled by the house of Holstein-Gottorp in the 1720 Treaty of Frederiksborg and the 1773 Treaty of Tsarskoye Selo , respectively. Denmark prospered greatly in the last decades of the 18th century due to its neutral status allowing it to trade with both sides in the many contemporary wars. In the Napoleonic Wars , Denmark traded with both France and
14061-429: The powers of the prime minister to ask the monarch to call for an election before the term has elapsed. On a vote of no confidence , the Folketing may force a single minister or an entire government to resign. The Government of Denmark operates as a cabinet government , where executive authority is exercised—formally, on behalf of the monarch—by the prime minister and other cabinet ministers , who head ministries . As
14190-563: The south-eastern territories of Kent , the Isle of Wight and other areas, where they settled. They were later absorbed or ethnically cleansed by the invading Angles and Saxons , who formed the Anglo-Saxons . The remaining Jutish population in Jutland assimilated in with the settling Danes . A short note about the Dani in Getica by the historian Jordanes is believed to be an early mention of
14319-481: The southernmost is Gedser point (the southern tip of Falster ) at 54° 33' 35" northern latitude; the westernmost point is Blåvandshuk at 8° 4' 22" eastern longitude; and the easternmost point is Østerskær at 15° 11' 55" eastern longitude. This is in the small Ertholmene archipelago 18 kilometres (11 mi) north-east of Bornholm. The distance from east to west is 452 kilometres (281 mi), from north to south 368 kilometres (229 mi). The metropolitan part
14448-476: The sparse woodlands of Jutland. Denmark is also home to smaller mammals, such as polecats , hares and hedgehogs . Approximately 400 bird species inhabit Denmark and about 160 of those breed in the country. Large marine mammals include healthy populations of Harbour porpoise , growing numbers of pinnipeds and occasional visits of large whales, including blue whales and orcas . Cod , herring and plaice are abundant culinary fish in Danish waters and form
14577-404: The spring of 1969, a well-documented, reliable version of the RC 4000 multiprogramming system was running. In late 1970, Brinch Hansen moved to Pittsburgh , accepting an invitation from Alan Perlis to visit the department of computer science at Carnegie Mellon University as a research associate, while he wrote the first systematic textbook on operating system principles. During this time, at
14706-423: The status of counties . Batch processing The term "batch processing" originates in the traditional classification of methods of production as job production (one-off production), batch production (production of a "batch" of multiple items at once, one stage at a time), and flow production (mass production, all stages in process at once). Early computers were capable of running only one program at
14835-680: The term batch job (in early use often "batch of jobs") became common. Early use is particularly found at the University of Michigan , around the Michigan Terminal System (MTS). Although timesharing did exist, its use was not robust enough for corporate data processing; none of this was related to the earlier unit record equipment , which was human-operated. Non-interactive computation remains pervasive in computing, both for general data processing and for system "housekeeping" tasks (using system software ). A high-level program (executing multiple programs, with some additional "glue" logic)
14964-485: The union's economy and in 1813 Denmark–Norway went bankrupt. The union was dissolved by the Treaty of Kiel in 1814; the Danish monarchy "irrevocably and forever" renounced claims to the Kingdom of Norway in favour of the Swedish king. Denmark kept the possessions of Iceland (which retained the Danish monarchy until 1944), the Faroe Islands and Greenland , all of which had been governed by Norway for centuries. Apart from
15093-528: The union. Thus, much of the next 125 years of Scandinavian history revolves around this union, with Sweden breaking off and being re-conquered repeatedly. The issue was for practical purposes resolved on 17 June 1523, as Swedish King Gustav Vasa conquered the city of Stockholm . The Protestant Reformation spread to Scandinavia in the 1530s, and following the Count's Feud civil war, Denmark converted to Lutheranism in 1536. Later that year, Denmark entered into
15222-471: The until then leading opposition party Venstre and the recently founded Moderate party . Denmark has a civil law system with some references to Germanic law . Denmark resembles Norway and Sweden in never having developed a case-law like that of England and the United States nor comprehensive codes like those of France and Germany. Much of its law is customary . The judicial system of Denmark
15351-457: The word "Denmark", in the accusative ᛏᛅᚾᛘᛅᚢᚱᚴ tanmaurk ( [danmɒrk] ) on the large stone, and the genitive ᛏᛅᚾᛘᛅᚱᚴᛅᚱ "tanmarkar" (pronounced [danmarkaɽ] ) on the small stone, while the dative form tąnmarku (pronounced [danmarkʊ] ) is found on the contemporaneous Skivum stone. The inhabitants of Denmark are there called tani ( [danɪ] ), or "Danes", in the accusative. The earliest archaeological finds in Denmark date back to
15480-551: Was compatible with batch processing. This facilitated transitioning from batch processing to interactive computing . From the late 1960s onwards, interactive computing such as via text-based computer terminal interfaces (as in Unix shells or read-eval-print loops ), and later graphical user interfaces became common. Non-interactive computation, both one-off jobs such as compilation, and processing of multiple items in batches, became retrospectively referred to as batch processing , and
15609-478: Was largely consolidated by the late 8th century and its rulers are consistently referred to in Frankish sources as kings ( reges ). Under the reign of Gudfred in 804 the Danish kingdom may have included all the lands of Jutland, Scania and the Danish islands, excluding Bornholm. The extant Danish monarchy traces its roots back to Gorm the Old , who established his reign in the early 10th century. As attested by
15738-495: Was published, becoming the first comprehensive textbook on operating systems. In July 1972, Brinch Hansen joined the faculty of the California Institute of Technology (Caltech) as an Associate Professor of computer science, where he began work on defining a programming language with concurrent processes and monitors. In April 1974, he distributed a technical report on Concurrent Pascal . A Concurrent Pascal compiler for
15867-596: Was published, with programs rewritten in SuperPascal , a fully implemented publication language he created for parallel algorithms. In his later years, Brinch Hansen published a retrospective of his most important papers, The Search for Simplicity (1996), a text for a course in programming for non-majors, Programming for Everyone in Java (1999), a retrospective on the evolution of operating systems, Classic Operating Systems: From Batch Processing to Distributed Systems (2001), and
15996-456: Was recovered by Denmark, thereby adding some 163,600 inhabitants and 3,984 square kilometres (1,538 sq mi). The country's first social democratic government took office in 1924. In 1939 Denmark signed a 10-year non-aggression pact with Nazi Germany but Germany invaded Denmark on 9 April 1940 and the Danish government quickly surrendered. World War II in Denmark was characterised by economic co-operation with Germany until 1943, when
16125-558: Was seen as a sign that the military power of Sweden was on the rise while Denmark's influence in the region was declining. Swedish armies invaded Jutland in 1643 and claimed Scania in 1644. In the 1645 Treaty of Brømsebro , Denmark surrendered Halland, Gotland , the last parts of Danish Estonia, and several provinces in Norway. Seeing an opportunity to tear up the Treaty of Brømsebro, King Frederick III of Denmark , in 1657, declared war on Sweden,
16254-503: Was surprised to find that both programs had nearly identical control structures. Concluding that both fit an "all-pairs paradigm," he then focused on exploring reusable parallel algorithm structures he termed "programming paradigms" or "generic programs" (later, popularly known as " design patterns "). In 1995, Brinch Hansen's fifth book, Studies in Computational Science: Parallel Programming Paradigms
16383-556: Was the first book on concurrent programming, and was eventually published in three languages (English, Japanese, and German). More than a dozen years after its publication, P. J. Plauger observed: Sure, improvements have been made in the past dozen years. We have better synchronization algorithms and fancier (if not necessarily better) languages with concurrency control. But you won't find a better overview of concurrent programming than this book. At least I haven't found one. In 2005, ACM members voted The Architecture of Concurrent Programs
16512-452: Was the first concurrent programming language: the first language developed specifically for concurrent programming, and more importantly, the first language to demonstrate that it was possible to incorporate secure, high-level facilities for concurrency, where the system could guarantee that processes access disjoint sets of variables only and do not interfere with each other in time dependent ways. Hoare described it as "an outstanding example of
16641-540: Was violated in World War II by a rapid German invasion in April 1940. During occupation, a resistance movement emerged in 1943, while Iceland declared independence in 1944; Denmark was liberated after the end of the war in May 1945. In 1973, Denmark, together with Greenland but not the Faroe Islands , became a member of what is now the European Union , but negotiated certain opt-outs , such as retaining its own currency,
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