llvm-project/compiler-rt/test/tsan/barrier.cc

38 lines
949 B
C++

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