1 // RUN: %clang_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s 2 // CHECK-NOT: ThreadSanitizer: data race 3 // CHECK: DONE 4 5 #include <stdio.h> 6 #include <stdlib.h> 7 #include <pthread.h> 8 #include <unistd.h> 9 10 const int kSize = 4; 11 volatile int kIter = 10; // prevent unwinding 12 int data[2][kSize]; 13 pthread_barrier_t barrier; 14 thr(void * p)15void *thr(void *p) { 16 int idx = (int)(long)p; 17 for (int i = 0; i < kIter; i++) { 18 int *prev = data[i % 2]; 19 int *curr = data[(i + 1) % 2]; 20 int left = idx - 1 >= 0 ? prev[idx - 1] : 0; 21 int right = idx + 1 < kSize ? prev[idx + 1] : 0; 22 curr[idx] = (left + right) / 2; 23 pthread_barrier_wait(&barrier); 24 } 25 return 0; 26 } 27 main()28int main() { 29 pthread_barrier_init(&barrier, 0, kSize); 30 pthread_t th[kSize]; 31 for (int i = 0; i < kSize; i++) 32 pthread_create(&th[i], 0, thr, (void*)(long)i); 33 for (int i = 0; i < kSize; i++) 34 pthread_join(th[i], 0); 35 pthread_barrier_destroy(&barrier); 36 fprintf(stderr, "DONE\n"); 37 } 38