Ўзбекистон республикаси олий ва ўрта махсус таълим вазирлиги низомий номидаги тошкент давлат

Main part 
The Open MP specification on equipment of calculation and programming is 
created by some largest producers - the companies Intel, Hewlett-Packard, 
SiliconGraphics, Sun, IBM, Fujitsu, Hitachi, Siemens, Bull. They cope non-profit 
organization under the name Open MP Architecture Review Board (ARB)
Fast and easy creation carries out many streaming Open MP appendices in 
algorithmic languages of Fortran and C/C ++. The first Open MP version was 
developed in 1997 for language Fortran. And for a programming language C ++ it was 
created in 1998. In 2008 the version 3.0.Open MP was presented
After input on parallel Wednesday new streams of OMP_NUM_THREADS-1 
are created, each stream has the unique number, thus the first stream is designated by 
number 0, and it will be the main stream (master). The quantity of streams will be 
carried out in the parallel environment and remains invariable to an exit from this 
environment. After an exit from the parallel environment by means of synchronization 
all streams except the main thing are destroyed.
In certain cases the system can dynamically change quantity of the streams 
working in the parallel environment. Dynamic change of quantity of streams is carried 
out by a true value OMP_DYNAMIC broadcast. For example, in the Linux operating 
system in the form of the bush team this value can be carried out by means of the 
following team: 
export OMP_DYNAMIC = TRUE; 
In dynamically changing systems the quantity of streams, as a rule, is not 
established, and its value is equal to False. The ompin_parallel function () returns value 
1, in case of an exit from the active parallel environment. [1]] In programming 
languages C/C ++ all from listed above conditions will be published together with the 
instruction single. It is not characterized, what stream carries out a certain part of the 

---

29 
program. Provided that if NOWAIT stream is not declared, one stream carries out a 
certain part, other streams wait for completion of its work. The instruction Single is 
necessary for work with the general variables.The instruction Master establishes that a 
certain part of a code is carried out by only the main stream. Other streams pass this 
part and will continue to work with the operator located below. On this instruction 
synchronization is not carried out. 
In the With / With programming language ++ the instruction appears as 
follows:
#pragma omp master 
In a programming language C/C ++ the static variables defined in the parallel 
program, are considered as shared (general). Dynamically allocated memory also is 
considered the general, but this indicator can be and the general, and local. 
Conclusion 
This material is dedicated to in-line architectures, a well as software packages 
Open MP designed for multi-core processors. Open MP - an application program 
interface to create multi-threaded applications, primarily designed for parallel 
computing systems with shared memory. Also presents data on Open MP streams.
References 
1.  "About the OpenMP ARB and". OpenMP.org. 2013-07-11. Retrieved 2013-08-
14. 
2.  "OpenMP Compilers". OpenMP.org. 2013-04-10. Retrieved 2013-08-14. 
3. Gagne, Abraham Silberschatz, Peter Baer Galvin, Greg. Operating system 
concepts(9th ed.). Hoboken, N.J.: Wiley. pp. 181–182. ISBN 978-1-118-06333-0. 
4. OpenMP Tutorial at Supercomputing 2008 
5. Using OpenMP – Portable Shared Memory Parallel Programming – Download Book 
Examples and Discuss 

---

30