41 lines
1.0 KiB
C++
41 lines
1.0 KiB
C++
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// RUN: %clang_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
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// CHECK-NOT: ThreadSanitizer: data race
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// CHECK: DONE
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// pthread barriers are not available on OS X
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// UNSUPPORTED: darwin
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#include <stdio.h>
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#include <stdlib.h>
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#include <pthread.h>
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#include <unistd.h>
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const int kSize = 4;
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volatile int kIter = 10; // prevent unwinding
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int data[2][kSize];
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pthread_barrier_t barrier;
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void *thr(void *p) {
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int idx = (int)(long)p;
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for (int i = 0; i < kIter; i++) {
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int *prev = data[i % 2];
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int *curr = data[(i + 1) % 2];
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int left = idx - 1 >= 0 ? prev[idx - 1] : 0;
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int right = idx + 1 < kSize ? prev[idx + 1] : 0;
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curr[idx] = (left + right) / 2;
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pthread_barrier_wait(&barrier);
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}
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return 0;
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}
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int main() {
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pthread_barrier_init(&barrier, 0, kSize);
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pthread_t th[kSize];
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for (int i = 0; i < kSize; i++)
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pthread_create(&th[i], 0, thr, (void*)(long)i);
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for (int i = 0; i < kSize; i++)
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pthread_join(th[i], 0);
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pthread_barrier_destroy(&barrier);
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fprintf(stderr, "DONE\n");
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}
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