141 lines
2.7 KiB
C
141 lines
2.7 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#ifdef _OPENMP
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# include <omp.h>
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#endif
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#include <pthread.h>
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enum {
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Size = 10000
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};
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const int ShouldSum = (Size-1)*Size/2;
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short Verbose = 1;
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short ThreadOK[3] = {0,0,0}; // Main, Thread1, Thread2
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// Thread
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void *_thread(void* Id) {
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int i;
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int x[Size];
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#ifdef _OPENMP
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# pragma omp parallel for
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#endif
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for ( i = 0; i < Size; i++ ) {
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#ifdef _OPENMP
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if (Verbose && i%1000==0) {
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int tid = omp_get_thread_num();
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# pragma omp critical
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printf("thread %d : tid %d handles %d\n",(int)Id,tid,i);
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}
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#endif
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x[i] = i;
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}
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int Sum=0;
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for ( i = 0; i < Size; i++ ) {
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Sum += x[i];
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}
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if (Verbose) {
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#ifdef _OPENMP
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# pragma omp critical
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#endif
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printf("Id %d : %s : %d(should be %d)\n",(int)Id, __FUNCTION__, Sum,ShouldSum);
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}
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if (Sum == ShouldSum) ThreadOK[(int)Id] = 1;
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return NULL;
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}
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// MainThread
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void MainThread() {
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int i;
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#ifdef _OPENMP
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# pragma omp parallel for
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#endif
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for ( i = 0; i < 4; i++ ) {
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#ifdef _OPENMP
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int tid = omp_get_thread_num();
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# pragma omp critical
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printf("Main : tid %d\n",tid);
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_thread((void *)tid);
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#endif
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}
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return;
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}
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// Comment in/out for checking the effect of multiple threads.
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#define SPAWN_THREADS
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// main
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int main(int argc, char *argv[]) {
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if (argc>1) Verbose = 1;
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#ifdef _OPENMP
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omp_set_nested(-1);
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printf("%s%s%s\n", "Nested parallel blocks are ", omp_get_nested()?" ":"NOT ", "supported.");
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#endif
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MainThread();
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#ifdef SPAWN_THREADS
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{
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pthread_t a_thr;
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pthread_t b_thr;
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int status;
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printf("%s:%d - %s - a_thr:%p - b_thr:%p\n",
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__FILE__,__LINE__,__FUNCTION__,a_thr.p,b_thr.p);
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status = pthread_create(&a_thr, NULL, _thread, (void*) 1 );
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if ( status != 0 ) {
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printf("Failed to create thread 1\n");
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return (-1);
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}
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status = pthread_create(&b_thr, NULL, _thread, (void*) 2 );
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if ( status != 0 ) {
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printf("Failed to create thread 2\n");
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return (-1);
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}
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status = pthread_join(a_thr, NULL);
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if ( status != 0 ) {
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printf("Failed to join thread 1\n");
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return (-1);
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}
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printf("Joined thread1\n");
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status = pthread_join(b_thr, NULL);
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if ( status != 0 ) {
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printf("Failed to join thread 2\n");
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return (-1);
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}
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printf("Joined thread2\n");
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}
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#endif // SPAWN_THREADS
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short OK = 0;
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// Check that we have OpenMP before declaring things OK formally.
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#ifdef _OPENMP
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OK = 1;
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{
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short i;
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for (i=0;i<3;i++) OK &= ThreadOK[i];
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}
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if (OK) printf("OMP : All looks good\n");
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else printf("OMP : Error\n");
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#else
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printf("OpenMP seems not enabled ...\n");
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#endif
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return OK?0:1;
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}
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//g++ -fopenmp omp_test.c -o omp_test -lpthread
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