1 | /****************************************************************************** |
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2 | * FILE: omp_hello.c |
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3 | * DESCRIPTION: |
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4 | * OpenMP Example - Hello World - C/C++ Version |
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5 | * In this simple example, the master thread forks a parallel region. |
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6 | * All threads in the team obtain their unique thread number and print it. |
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7 | * The master thread only prints the total number of threads. Two OpenMP |
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8 | * library routines are used to obtain the number of threads and each |
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9 | * thread's number. |
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10 | * AUTHOR: Blaise Barney 5/99 |
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11 | * LAST REVISED: 04/06/05 |
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12 | ******************************************************************************/ |
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13 | #include <omp.h> |
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14 | #include <stdio.h> |
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15 | #include <stdlib.h> |
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16 | |
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17 | int main (int argc, char *argv[]) |
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18 | { |
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19 | int nthreads, tid; |
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20 | |
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21 | /* Fork a team of threads giving them their own copies of variables */ |
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22 | #pragma omp parallel private(nthreads, tid) |
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23 | { |
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24 | |
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25 | /* Obtain thread number */ |
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26 | tid = omp_get_thread_num(); |
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27 | printf("Hello World from thread = %d\n", tid); |
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28 | |
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29 | /* Only master thread does this */ |
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30 | if (tid == 0) |
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31 | { |
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32 | nthreads = omp_get_num_threads(); |
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33 | printf("Number of threads = %d\n", nthreads); |
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34 | } |
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35 | |
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36 | } /* All threads join master thread and disband */ |
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37 | |
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38 | } |
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