// RUN: %clangxx_tsan -O1 %s -o %t && %deflake %run %t 2>&1 | FileCheck %s #include "test.h" long long Data; long long Sync; void *Thread1(void *x) { Data++; __atomic_store_n(&Sync, 1, __ATOMIC_RELEASE); barrier_wait(&barrier); barrier_wait(&barrier); return NULL; } void *Thread2(void *x) { barrier_wait(&barrier); if (__atomic_load_n(&Sync, __ATOMIC_RELAXED) != 1) exit(0); // This store must terminate release sequence of the store in Thread1, // thus tsan must detect race between Thread1 and main on Data. __atomic_store_n(&Sync, 2, __ATOMIC_RELEASE); barrier_wait(&barrier); return NULL; } int main() { barrier_init(&barrier, 3); pthread_t t[2]; pthread_create(&t[0], NULL, Thread1, NULL); pthread_create(&t[1], NULL, Thread2, NULL); barrier_wait(&barrier); barrier_wait(&barrier); if (__atomic_load_n(&Sync, __ATOMIC_ACQUIRE) != 2) exit(0); if (Data != 1) exit(0); pthread_join(t[0], NULL); pthread_join(t[1], NULL); fprintf(stderr, "DONE\n"); return 0; } // CHECK: WARNING: ThreadSanitizer: data race // CHECK: Read // CHECK: #0 main // CHECK: Previous write // CHECK: #0 Thread1 // CHECK: Location is global 'Data' // CHECK: DONE