1 // RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
2 #include "test.h"
3 
4 const int kTestCount = 4;
5 typedef long long T;
6 T atomics[kTestCount * 2];
7 
8 void Test(int test, T *p, bool main_thread) {
9   volatile T sink;
10   if (test == 0) {
11     if (main_thread)
12       __atomic_fetch_add(p, 1, __ATOMIC_RELAXED);
13     else
14       __atomic_fetch_add(p, 1, __ATOMIC_RELAXED);
15   } else if (test == 1) {
16     if (main_thread)
17       __atomic_exchange_n(p, 1, __ATOMIC_ACQ_REL);
18     else
19       __atomic_exchange_n(p, 1, __ATOMIC_ACQ_REL);
20   } else if (test == 2) {
21     if (main_thread)
22       sink = __atomic_load_n(p, __ATOMIC_SEQ_CST);
23     else
24       __atomic_store_n(p, 1, __ATOMIC_SEQ_CST);
25   } else if (test == 3) {
26     if (main_thread)
27       sink = __atomic_load_n(p, __ATOMIC_SEQ_CST);
28     else
29       sink = *p;
30   }
31 }
32 
33 void *Thread(void *p) {
34   for (int i = 0; i < kTestCount; i++) {
35     Test(i, &atomics[i], false);
36   }
37   barrier_wait(&barrier);
38   barrier_wait(&barrier);
39   for (int i = 0; i < kTestCount; i++) {
40     fprintf(stderr, "Test %d reverse\n", i);
41     Test(i, &atomics[kTestCount + i], false);
42   }
43   return 0;
44 }
45 
46 int main() {
47   barrier_init(&barrier, 2);
48   pthread_t t;
49   pthread_create(&t, 0, Thread, 0);
50   barrier_wait(&barrier);
51   for (int i = 0; i < kTestCount; i++) {
52     fprintf(stderr, "Test %d\n", i);
53     Test(i, &atomics[i], true);
54   }
55   for (int i = 0; i < kTestCount; i++) {
56     Test(i, &atomics[kTestCount + i], true);
57   }
58   barrier_wait(&barrier);
59   pthread_join(t, 0);
60 }
61 
62 // CHECK-NOT: ThreadSanitizer: data race
63