OpenMP in Small Bites/Scoping

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HPC.NRW
HPC.NRW
Other HPC Courses
1. Gprof Tutorial
2. Introduction to Linux in HPC
OpenMP in Small Bites
1. Overview
2. Worksharing
3. Data Scoping
4. Non-Uniform Memory Access







Video


Quiz

1. What is the default data scoping of variable in a parallel region when this variable is declared before a parallel region?

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2. What is the data scoping of the variables a, b, c and d in the following code snippet in the parallel region? What is printed when executing the code?
int a = 0;
int b = 23;
int c = -3;
# pragma omp parallel num_threads(2) private(a) reduction(+:c)
{
int d = omp_get_thread_num();
a = 42 + d;
# pragma omp critical
b = 1;
c += a + b;
}
c = c / 2;
printf("a=%d, b=%d, c=%d\n", a, b, c)

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3. The following code snippet is wrong due to a missing data sharing attribute. How can you fix it?

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