In computer science

Computer science

Computer science or computing science is the study of the theoretical foundations of information and computation and of practical techniques for their implementation and application in computer systems...

, a partitioned global address space (PGAS) is a parallel programming model

Parallel programming model

A parallel programming model is a concept that enables the expression of parallel programs which can be compiled and executed. The value of a programming model is usually judged on its generality: how well a range of different problems can be expressed and how well they execute on a range of...

. It assumes a global memory address space

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.- Overview :...

 that is logically partitioned and a portion of it is local to each processor. The novelty of PGAS is that the portions of the shared memory space may have an affinity for a particular thread, thereby exploiting locality of reference

Locality of reference

In computer science, locality of reference, also known as the principle of locality, is the phenomenon of the same value or related storage locations being frequently accessed. There are two basic types of reference locality. Temporal locality refers to the reuse of specific data and/or resources...

. The PGAS model is the basis of Unified Parallel C

Unified Parallel C

Unified Parallel C is an extension of the C programming language designed for high-performance computing on large-scale parallel machines, including those with a common global address space and those with distributed memory...

, Co-array Fortran

Co-array Fortran

Co-array Fortran , formerly known as F--, is an extension of Fortran 95/2003 for parallel processing created by Robert Numrich and John Reid in 1990s...

, Titanium, Fortress, Chapel and X10

X10 (programming language)

X10 is a programming language being developed by IBM at the Thomas J. Watson Research Center as part of the Productive, Easy-to-use, Reliable Computing System project funded by DARPA's High Productivity Computing Systems program...

.

See also

• Concurrency (computer science)
  Concurrency (computer science)
  In computer science, concurrency is a property of systems in which several computations are executing simultaneously, and potentially interacting with each other...
  
  
• Parallel programming model
  Parallel programming model
  A parallel programming model is a concept that enables the expression of parallel programs which can be compiled and executed. The value of a programming model is usually judged on its generality: how well a range of different problems can be expressed and how well they execute on a range of...
  
  
• Non-blocking synchronization
  Non-blocking synchronization
  In computer science, a non-blocking algorithm ensures that threads competing for a shared resource do not have their execution indefinitely postponed by mutual exclusion...
  
  
• Unified Parallel C
  Unified Parallel C
  Unified Parallel C is an extension of the C programming language designed for high-performance computing on large-scale parallel machines, including those with a common global address space and those with distributed memory...
  
  
• Fortress (programming language)
• Co-array Fortran
  Co-array Fortran
  Co-array Fortran , formerly known as F--, is an extension of Fortran 95/2003 for parallel processing created by Robert Numrich and John Reid in 1990s...
  
  
• Chapel programming language
  Chapel programming language
  Chapel is a new parallel programming language developed by Cray. It is being developed as part of the Cray Cascade project, a participant in DARPA's High Productivity Computing Systems program, which has the goal of increasing supercomputer productivity by the year 2010...
  
  
• X10 (programming language)
  X10 (programming language)
  X10 is a programming language being developed by IBM at the Thomas J. Watson Research Center as part of the Productive, Easy-to-use, Reliable Computing System project funded by DARPA's High Productivity Computing Systems program...
  
  
• Global Array (Library)

External links

• PGAS Website
• Programming in the Partitioned Global Address Space Model (2003)
• Performance and Productivity Opportunities using Global Address Space Programming Models (2006)
• GASNet Communication System - provides a software infrastructure for PGAS languages over high-performance networks
• Unified Parallel C
• Titanium
• Co-array Fortran
• Sun's project page on Fortress
• Chapel Programming Language Homepage
• X10 Website