British computer scientist
Sir Charles Antony Richard Hoare
FRS
FREng ,
[3] also known as Tony Hoare or by his initials C. A. R. Hoare (; born 11 January 1934) is a British
computer scientist who has made foundational contributions to
programming languages ,
algorithms ,
operating systems ,
formal verification , and
concurrent computing .
[4] His work earned him the
Turing Award , usually regarded as the highest distinction in computer science, in 1980.
Hoare developed the
sorting algorithm
quicksort in 1959–1960.
[5] He developed
Hoare logic , an
axiomatic basis for verifying
program correctness . In the semantics of
concurrency , he introduced the formal language
communicating sequential processes (CSP) to specify the interactions of concurrent processes, and along with
Edsger Dijkstra , formulated the
dining philosophers problem .
[6]
[7]
[8]
[9]
[10]
[11] Since 1977, he has held positions at the
University of Oxford and
Microsoft Research in
Cambridge .
Education and early life
Tony Hoare was born in
Colombo , Ceylon (now
Sri Lanka ) to British parents; his father was a colonial
civil servant and his mother was the daughter of a tea planter. Hoare was educated in
England at the
Dragon School in
Oxford and the
King's School in
Canterbury .
[12] He then studied
Classics and Philosophy ("Greats") at
Merton College, Oxford .
[13] On graduating in 1956 he did 18 months
National Service in the
Royal Navy ,
[13] where he learned Russian.
[14] He returned to the
University of Oxford in 1958 to study for a postgraduate certificate in
statistics ,
[13] and it was here that he began
computer programming , having been taught
Autocode on the
Ferranti Mercury by
Leslie Fox .
[15] He then went to
Moscow State University as a
British Council exchange student,
[13] where he studied
machine translation under
Andrey Kolmogorov .
[14]
Research and career
In 1960, Hoare left the
Soviet Union and began working at
Elliott Brothers Ltd ,
[13] a small computer manufacturing firm located in London. There, he implemented the language
ALGOL 60 and began developing major
algorithms .
[16]
[17]
He was involved with developing
international standards in programming and informatics, as a member of the
International Federation for Information Processing (IFIP)
Working Group 2.1 on Algorithmic Languages and Calculi,
[18] which
specified , maintains, and supports the languages ALGOL 60 and
ALGOL 68 .
[19]
He became the Professor of
Computing Science at the
Queen's University of Belfast in 1968, and in 1977 returned to Oxford as the Professor of Computing to lead the
Programming Research Group in the
Oxford University Computing Laboratory (now
Department of Computer Science, University of Oxford ), following the death of
Christopher Strachey . He became the first
Christopher Strachey Professor of Computing on its establishment in 1988 until his retirement at Oxford in 2000.
[20] He is now an
Emeritus Professor there, and is also a principal researcher at
Microsoft Research in
Cambridge , England.
[21]
[22]
[23]
Hoare's most significant work has been in the following areas: his sorting and selection algorithm (
Quicksort and
Quickselect ),
Hoare logic , the formal language
communicating sequential processes (CSP) used to specify the interactions between
concurrent processes (and implemented in various programming languages such as
occam ), structuring computer
operating systems using the
monitor concept, and the
axiomatic specification of
programming languages .
[24]
[25]
Speaking at a software conference in 2009, Tony Hoare hyperbolically apologized for "inventing" the
null reference :
[26]
[27]
I call it my billion-dollar mistake. It was the invention of the null reference in 1965. At that time, I was designing the first comprehensive type system for references in an object oriented language (
ALGOL W ). My goal was to ensure that all use of references should be absolutely safe, with checking performed automatically by the compiler. But I couldn't resist the temptation to put in a null reference, simply because it was so easy to implement. This has led to innumerable errors, vulnerabilities, and system crashes, which have probably caused a billion dollars of pain and damage in the last forty years.
[28]
For many years under his leadership, Hoare's Oxford department worked on formal specification languages such as
CSP and
Z . These did not achieve the expected take-up by industry, and in 1995 Hoare was led to reflect upon the original assumptions:
[29]
Ten years ago, researchers into formal methods (and I was the most mistaken among them) predicted that the programming world would embrace with gratitude every assistance promised by formalisation to solve the problems of reliability that arise when programs get large and more safety-critical. Programs have now got very large and very critical – well beyond the scale which can be comfortably tackled by formal methods. There have been many problems and failures, but these have nearly always been attributable to inadequate analysis of requirements or inadequate management control. It has turned out that the world just does not suffer significantly from the kind of problem that our research was originally intended to solve.
Awards and honours
ACM Programming Systems and Languages Paper Award (1973)
[30] for the paper "Proof of correctness of data representations"
[31]
Distinguished Fellow of the British Computer Society (1978)
Turing Award for "fundamental contributions to the definition and design of
programming languages ". The award was presented to him at the ACM Annual Conference in
Nashville, Tennessee , on 27 October 1980, by Walter Carlson, chairman of the Awards committee. A transcript of Hoare's speech
[32] was published in
Communications of the ACM .
[16]
Harry H. Goode Memorial Award (1981)
Fellow of the Royal Society (1982)
[33]
Honorary Doctorate of Science by the
Queen's University Belfast (1987)
Honorary Doctorate of Science, from the
University of Bath (1993)
[34]
Honorary Fellow,
Kellogg College, Oxford (1998)
[35]
Knighted for services to education and
computer science (
2000 )
Kyoto Prize for
Information science (2000)
Fellow
[3] of the
Royal Academy of Engineering
[3] (2005)
Member of the
National Academy of Engineering (2006) for fundamental contributions to computer science in the areas of algorithms, operating systems, and programming languages.
Computer History Museum (CHM) in
Mountain View, California Fellow of the Museum "for development of the
Quicksort algorithm and for lifelong contributions to the theory of
programming languages " (2006)
[36]
Honorary Doctorate from
Heriot-Watt University (2007)
[37]
Honorary Doctorate of Science from the Department of Informatics of the
Athens University of Economics and Business (AUEB) (2007)
Friedrich L. Bauer-Prize,
Technical University of Munich (2007)
[38]
SIGPLAN Programming Languages Achievement Award (2011)
[39]
IEEE John von Neumann Medal (2011)
[40]
Honorary Doctorate,
University of Warsaw (2012)
[41]
Honorary Doctorate,
Complutense University of Madrid (2013)
[42]
Royal Medal of the Royal Society (2023)
[43]
Personal life
In 1962, Hoare married
Jill Pym , a member of his research team.
[44]
Books
References
^
a
b
Tony Hoare at the
Mathematics Genealogy Project
^ Sampaio, Augusto (1993).
An algebraic approach to compiler design . bodleian.ox.ac.uk (DPhil thesis). University of Oxford.
OCLC
854973008 .
EThOS
uk.bl.ethos.334903 . [
permanent dead link ]
^
a
b
c
"List of Fellows" . Archived from
the original on 8 June 2016. Retrieved 17 October 2014 .
^
Jones, Cliff B. ;
Misra, Jayadev , eds. (2021). Theories of Programming: The Life and Works of Tony Hoare . ACM Books. Vol. 39. New York, NY:
Association for Computing Machinery .
doi :
10.1145/3477355 .
ISBN
978-1-4503-8728-6 .
S2CID
238251696 .
^
"Sir Antony Hoare" . Computer History Museum. Archived from
the original on 3 April 2015. Retrieved 22 April 2015 .
^
Tony Hoare author profile page at the
ACM Digital Library
^
C. A. R. Hoare at
DBLP Bibliography Server
^
Tony Hoare publications indexed by
Microsoft Academic
^ Shustek, L. (2009). "Interview: An interview with C.A.R. Hoare".
Communications of the ACM . 52 (3): 38–41.
doi :
10.1145/1467247.1467261 .
S2CID
1868477 .
^ Hoare, C. A. R. (1974).
"Monitors: An operating system structuring concept" . Communications of the ACM . 17 (10): 549–557.
doi :
10.1145/355620.361161 .
S2CID
1005769 .
^
Bowen, Jonathan (8 September 2006).
Oral History of Sir Antony Hoare . Hoare (Sir Antony, C.A.R.) Oral History, CHM Reference number: X3698.2007 (Report).
Computer History Museum . Archived from the original on 3 July 2013. Retrieved 18 April 2014 . {{
cite report }}
: CS1 maint: bot: original URL status unknown (
link )
^ Lean, Thomas (2011).
"Professor Sir Tony Hoare" (PDF) . National Life Stories: An Oral History of British Science . UK:
British Library .
Archived (PDF) from the original on 15 September 2014. Retrieved 15 September 2014 .
^
a
b
c
d
e Levens, R.G.C., ed. (1964). Merton College Register 1900-1964 . Oxford: Basil Blackwell. p. 434.
^
a
b Hoare, Tony (Autumn 2009).
"My Early Days at Elliotts" . Resurrection (48).
ISSN
0958-7403 . Retrieved 27 May 2014 .
^
Roscoe, Bill ;
Jones, Cliff (2010).
"1 Insight, inspiration and collaboration" (PDF) . Reflections on the Work of C.A.R. Hoare .
Springer .
ISBN
978-1-84882-911-4 .
Archived (PDF) from the original on 9 October 2022.
^
a
b Hoare, C.A.R. (February 1981).
"The emperor's old clothes" .
Communications of the ACM . 24 (2): 5–83.
doi :
10.1145/358549.358561 .
ISSN
0001-0782 .
^ Hoare, C. A. R. (1981).
"The emperor's old clothes" . Communications of the ACM . 24 (2): 75–83.
doi :
10.1145/358549.358561 .
^ Jeuring, Johan;
Meertens, Lambert ; Guttmann, Walter (17 August 2016).
"Profile of IFIP Working Group 2.1" . Foswiki . Retrieved 7 October 2020 .
^ Swierstra, Doaitse;
Gibbons, Jeremy ;
Meertens, Lambert (2 March 2011).
"ScopeEtc: IFIP21: Foswiki" . Foswiki . Retrieved 7 October 2020 .
^
"Christopher Strachey Professorship of Computing" .
Department of Computer Science, University of Oxford . 5 November 2021. Retrieved 18 January 2024 .
^
Microsoft home page – short biography
^
Oral history interview with C. A. R. Hoare at
Charles Babbage Institute , University of Minnesota, Minneapolis.
^
The classic article on monitors – The original article on monitors
^
"Preface to the ACM Turing Award lecture" (PDF) . Archived from
the original (PDF) on 19 April 2012.
^
"C. Antony (Tony) R. Hoare" . Archived from
the original on 1 July 2012.
^ Hoare, Tony (25 August 2009).
"Null References: The Billion Dollar Mistake" . InfoQ.com.
^
"Null: The Billion Dollar Mistake" . hashnode.com. 3 September 2020.
^
Hoare, Tony (2009).
"Null References: The Billion Dollar Mistake" (Presentation abstract). QCon London.
Archived from the original on 28 June 2009.
^ Hoare, C. A. R. (1996). "Unification of Theories: A Challenge for Computing Science". Selected papers from the 11th Workshop on Specification of Abstract Data Types Joint with the 8th COMPASS Workshop on Recent Trends in Data Type Specification . Springer-Verlag. pp. 49–57.
ISBN
3-540-61629-2 .
^
"ACM Programming Systems and Languages Paper Award" . Association for Computing Machinery. 1973. Retrieved 7 July 2022 .
^
Hoare, C.A.R. (1972).
"Proof of correctness of data representations" .
Communications of the ACM . 1 (4): 271–281.
doi :
10.1007/BF00289507 .
S2CID
34414224 .
^ Hoare, Charles Anthony Richard (27 October 1980).
"The Emperor's Old Clothes: The 1980 ACM Turing Award Lecture" (PDF) . Association for Computing Machinery. Archived from
the original (PDF) on 19 April 2012.
^ Anon (1982).
"Anthony Hoare FRS" . royalsociety.org . London:
Royal Society .
^
"Honorary Graduates 1989 to present" . bath.ac.uk .
University of Bath . Archived from
the original on 17 July 2010. Retrieved 18 February 2012 .
^
"(Charles) Antony Richard (Tony) Hoare Biography" . Archived from
the original on 17 July 2014.
^
"Sir Antony Hoare: 2006 Fellow" . Archived from
the original on 3 April 2015. Retrieved 8 March 2020 .
"Sir Antony Hoare | Computer History Museum" . Archived from
the original on 3 April 2015. Retrieved 22 April 2015 .
^
"Annual Review 2007: Principal's Review" . www1.hw.ac.uk . Archived from
the original on 5 March 2016. Retrieved 29 March 2016 .
^
"Preisverleihung auf der Festveranstaltung "40 Jahre Informatik in München": TU München vergibt Friedrich L. Bauer-Preis an Tony Hoare" (in German).
Technical University of Munich . 26 October 2007. Archived from
the original on 10 June 2016. Retrieved 14 May 2016 .
^
"Programming Languages Achievement Award 2011" . ACM. Retrieved 28 August 2012 .
^
"IEEE John von Neumann Medal Recipients" (PDF) . IEEE.
Archived (PDF) from the original on 9 October 2022. Retrieved 26 February 2011 .
^ Krzysztof, Diks (15 November 2012).
"Profesor Hoare doktorem honoris causa Uniwersytetu Warszawskiego" (in Polish).
University of Warsaw . Archived from
the original on 26 August 2014. Retrieved 26 November 2012 .
^
"Los informáticos Tony Hoare y Mateo Valero serán investidos hoy doctores honoris causa por la Complutense" (in Spanish). 10 May 2013. Retrieved 10 May 2013 .
^
Royal Medal 2023
^
Jones, Cliff ;
Roscoe, A. W. ; Wood, Kenneth R., eds. (2010).
Reflections on the Work of C.A.R. Hoare . Springer Science. p.
3 .
Bibcode :
2010rwch.book.....R .
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text available under the
CC BY 4.0 license.
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