Unified Parallel C (UPC) is an extension of the
C programming language
''The C Programming Language'' (sometimes termed ''K&R'', after its authors' initials) is a computer programming book written by Brian Kernighan and Dennis Ritchie, the latter of whom originally designed and implemented the language, as well a ...
designed for
high-performance computing
High-performance computing (HPC) uses supercomputers and computer clusters to solve advanced computation problems.
Overview
HPC integrates systems administration (including network and security knowledge) and parallel programming into a mult ...
on large-scale
parallel machines, including those with a common global
address space
In computing, an address space defines a range of discrete addresses, each of which may correspond to a network host, peripheral device, disk sector, a memory cell or other logical or physical entity.
For software programs to save and retrieve s ...
(
SMP and
NUMA
Nuclear mitotic apparatus protein 1 is a protein that in humans is encoded by the ''NUMA1'' gene.
Interactions
Nuclear mitotic apparatus protein 1 has been shown to interact with PIM1, Band 4.1, GPSM2
G-protein-signaling modulator 2, also ca ...
) and those with
distributed memory
In computer science, distributed memory refers to a multiprocessor computer system in which each processor has its own private memory. Computational tasks can only operate on local data, and if remote data are required, the computational task mu ...
(e. g.
clusters). The
programmer
A computer programmer, sometimes referred to as a software developer, a software engineer, a programmer or a coder, is a person who creates computer programs — often for larger computer software.
A programmer is someone who writes/creates ...
is presented with a single
partitioned global address space
In computer science, partitioned global address space (PGAS) is a parallel programming model paradigm. PGAS is typified by communication operations involving a global memory address space abstraction that is logically partitioned, where a portio ...
; where shared variables may be directly read and written by any
processor
Processor may refer to:
Computing Hardware
* Processor (computing)
**Central processing unit (CPU), the hardware within a computer that executes a program
*** Microprocessor, a central processing unit contained on a single integrated circuit (I ...
, but each variable is physically associated with a single processor. UPC uses a ''single program, multiple data'' (
SPMD
In computing, single program, multiple data (SPMD) is a technique employed to achieve parallelism; it is a subcategory of MIMD. Tasks are split up and run simultaneously on multiple processors with different input in order to obtain results fast ...
) model of computation in which the amount of parallelism is fixed at program startup time, typically with a single
thread of execution per processor.
In order to express parallelism, UPC extends
ISO C 99 with the following constructs:
* An explicitly parallel execution model
* A shared address space ( storage qualifier) with thread-local parts (normal variables)
* Synchronization primitives and a memory consistency model
* Explicit communication primitives, e. g. upc_memput
*
Memory management
Memory management is a form of resource management applied to computer memory. The essential requirement of memory management is to provide ways to dynamically allocate portions of memory to programs at their request, and free it for reuse when ...
primitives
The UPC language evolved from experiences with three other earlier languages that proposed parallel extensions to ISO C 99: AC,
Split-C, and Parallel C preprocessor (PCP). UPC is not a
superset
In mathematics, set ''A'' is a subset of a set ''B'' if all elements of ''A'' are also elements of ''B''; ''B'' is then a superset of ''A''. It is possible for ''A'' and ''B'' to be equal; if they are unequal, then ''A'' is a proper subset of ...
of these three languages, but rather an attempt to distill the best characteristics of each. UPC combines the programmability advantages of the shared memory programming paradigm and the control over data layout and performance of the
message passing
In computer science, message passing is a technique for invoking behavior (i.e., running a program) on a computer. The invoking program sends a message to a process (which may be an actor or object) and relies on that process and its supporting ...
programming paradigm
Programming paradigms are a way to classify programming languages based on their features. Languages can be classified into multiple paradigms.
Some paradigms are concerned mainly with implications for the execution model of the language, suc ...
.
See also
*
Cilk
*
Coarray Fortran
*
Chapel
A chapel is a Christian place of prayer and worship that is usually relatively small. The term has several meanings. Firstly, smaller spaces inside a church that have their own altar are often called chapels; the Lady chapel is a common type ...
*
X10
*
High Performance Fortran
*
OpenMP
OpenMP (Open Multi-Processing) is an application programming interface (API) that supports multi-platform shared-memory multiprocessing programming in C, C++, and Fortran, on many platforms, instruction-set architectures and operating syst ...
*
Partitioned global address space
In computer science, partitioned global address space (PGAS) is a parallel programming model paradigm. PGAS is typified by communication operations involving a global memory address space abstraction that is logically partitioned, where a portio ...
*
Parallel programming model
In computing, a parallel programming model is an abstraction of parallel computer architecture, with which it is convenient to express algorithms and their composition in programs. The value of a programming model can be judged on its ''generality ...
*
Software transactional memory
External links
*
UPC at LBNLUPC at GWUGNU UPCUPC Tutorial(2003)
{{Authority control
Concurrent programming languages
Parallel computing
C programming language family