Shared queues in Java

Print DataMatrix in Java Shared queues
Shared queues
Encode ECC200 In Java
Using Barcode encoder for Java Control to generate, create Data Matrix image in Java applications.
The shared queue is a commonly used ADT and an excellent example of the Shared Data pattern The Shared Queue pattern discusses concurrency control protocols and the techniques used to achieve highly efficient shared queue programs
Barcode Printer In Java
Using Barcode encoder for Java Control to generate, create barcode image in Java applications.
Genetic algorithm for nonlinear optimization
Recognizing Bar Code In Java
Using Barcode scanner for Java Control to read, scan read, scan image in Java applications.
Consider the GAFORT program from the SPEC OMP2001 benchmark suite [ADE 01 + ] GAFORT is a small Fortran program (around 1,500 lines) that implements a genetic algorithm for nonlinear optimization The calculations are predominantly integer arithmetic, and the program's performance is dominated by the cost of moving large arrays of data through the memory subsystem The details of the genetic algorithm are not important for this discussion We are going to focus on a single loop within GAFORT Pseudocode for the sequential version of this loop, based on the discussion of GAFORT in [EM], is shown in Fig 534 This loop shuffles the population of chromosomes and consumes on the order of 36 percent of the runtime in a typical GAFORT job [AE03]
ECC200 Creator In Visual C#.NET
Using Barcode drawer for .NET framework Control to generate, create ECC200 image in Visual Studio .NET applications.
Figure 534 Pseudocode for the population shuffle loop from the genetic algorithm program GAFORT Int const NPOP // number of chromosomes ("40000) Int const NCHROME // length of each chromosome Real :: tempScalar Array of Real :: temp(NCHROME) Array of Int :: iparent(NCHROME, NPOP) Array of Int :: fitness(NPOP) Int :: j, iother loop [j] over NPOP iother = rand(j) // returns random value greater // than or equal to zero but not // equal to j and less than NPOP // Swap Chromosomes temp(1:NCHROME) = iparent(1:NCHROME, iother) iparent(1:NCHROME, iother) = iparent(1:NCHROME, j)
ECC200 Creation In Visual Studio .NET
Using Barcode maker for ASP.NET Control to generate, create Data Matrix image in ASP.NET applications.
iparent(1:NCHROME, j) = temp(1:NCHROME) // Swap fitness metrics tempScalar = fitness(iother) fitness(iother) = fitness(j) fitness(j) = tempScalar end loop [j]
DataMatrix Maker In .NET
Using Barcode generation for .NET framework Control to generate, create ECC200 image in VS .NET applications.
A parallel version of this program will be created by parallelizing the loop, using the Loop Parallelism pattern In this example, the shared data consists of the iparent and fitness arrays Within the body of the loop, calculations involving these arrays consist of swapping two elements of iparent and then swapping the corresponding elements of fitness Examination of these operations shows that two swap operations interfere when at least one of the locations being swapped is the same in both operations Thinking about the shared data as an ADT helps us to identify and analyze the actions taken on the shared data This does not mean, however, that the implementation itself always needs to reflect this structure In some cases, especially when the data structure is simple and the programming language does not support ADTs well, it can be more effective to forgo the encapsulation implied in an ADT and work with the data directly This example illustrates this As mentioned earlier, the chromosomes being swapped might interfere with each other; thus the loop over j cannot safely execute in parallel The most straightforward approach is to enforce a "one at a time" protocol using a critical section, as shown in Fig 535 It is also necessary to modify the random number generator so it produces a consistent set of pseudorandom numbers when called in parallel by many threads The algorithms to accomplish this are well understood [Mas97], but will not be discussed here
Data Matrix 2d Barcode Maker In Visual Basic .NET
Using Barcode encoder for Visual Studio .NET Control to generate, create Data Matrix ECC200 image in .NET framework applications.
Figure 535 Pseudocode for an ineffective approach to parallelizing the population shuffle in the genetic algorithm program GAFORT
Data Matrix ECC200 Maker In Java
Using Barcode generator for Java Control to generate, create Data Matrix 2d barcode image in Java applications.
Code View: Scroll / Show All
Creating Barcode In Java
Using Barcode generation for Java Control to generate, create barcode image in Java applications.
#include <omph> Int const NPOP // number of chromosomes ("40000) Int const NCHROME // length of each chromosome Real :: tempScalar Array of Real :: temp(NCHROME) Array of Int :: iparent(NCHROME, NPOP) Array of Int :: fitness(NPOP) Int :: j, iother #pragma omp parallel for loop [j] over NPOP iother = par_rand(j) // returns random value greater // than or equal to zero but not // equal to j and less than NPOP #pragma omp critical { // Swap Chromosomes
Drawing Universal Product Code Version A In Java
Using Barcode encoder for Java Control to generate, create UPCA image in Java applications.
temp(1:NCHROME) = iparent(1:NCHROME, iother) iparent(1:NCHROME, iother) = iparent(1:NCHROME, j) iparent(1:NCHROME, j) = temp(1:NCHROME) // Swap fitness metrics tempScalar = fitness(iother) fitness(iother) = fitness(j) fitness(j) = tempScalar } end loop [j]
EAN 13 Creation In Java
Using Barcode encoder for Java Control to generate, create EAN 13 image in Java applications.
The program in Fig 535 can safely execute with multiple threads, but it will not run any faster as more threads are added In fact, this program will slow down as more threads are added because the threads will waste system resources as they wait for their turn to execute the critical section In essence, the concurrency control protocol eliminates all of the available concurrency The solution to this problem is to take advantage of the fact that the swap operations on the shared data only interfere when at least one of the locations being swapped is the same in both operations Hence, the right concurrency control protocol uses pairwise synchronization with nested locks, thereby adding only modest overhead when loop iterations do not interfere The approach used in
GTIN - 128 Generation In Java
Using Barcode drawer for Java Control to generate, create EAN / UCC - 13 image in Java applications.
[ADE 01 + ] is to create an OpenMP lock for each chromosome Pseudocode for this solution is shown in Fig 536 In the resulting program, most of the loop iterations do not actually interfere with each other The total number of chromosomes, NPOP (40,000 in the SPEC OMP2001 benchmark), is much larger than the number of UEs, so there is only a slight chance that loop iterations will happen to interfere with another loop iteration OpenMP locks are described in the OpenMP appendix, Appendix A The locks themselves use an opaque type, omp_lock_t, defined in the omph header file The lock array is defined and later initialized in a separate parallel loop Once inside the chromosome swapping loop, the locks are set for the pair of swapping chromosomes, the swap is carried out, and the locks are unset Nested locks are being used, so the possibility of deadlock must be considered The solution here is to order the locks using the value of the indices of the array element associated with the lock Always acquiring locks in this order will prevent deadlock when a pair of loop iterations happen to be swapping the same two elements at the same time After the more efficient concurrency control protocol is implemented, the program runs well in parallel
Planet Maker In Java
Using Barcode drawer for Java Control to generate, create USPS PLANET Barcode image in Java applications.
Barcode Generator In .NET
Using Barcode generation for ASP.NET Control to generate, create barcode image in ASP.NET applications.
Encoding Data Matrix ECC200 In C#
Using Barcode encoder for .NET framework Control to generate, create Data Matrix ECC200 image in .NET applications.
Drawing Bar Code In Visual Basic .NET
Using Barcode encoder for .NET framework Control to generate, create barcode image in Visual Studio .NET applications.
Drawing Code 39 In C#
Using Barcode generator for .NET framework Control to generate, create Code 39 Extended image in VS .NET applications.