1 // RUN: %clang_tsan -O1 %s -o %t && %deflake %run %t | FileCheck %s
2 #include <pthread.h>
3 #include <stdio.h>
4 #include <unistd.h>
5 
6 int Global;
7 
8 void __attribute__((noinline)) foo1() {
9   Global = 42;
10 }
11 
12 void __attribute__((noinline)) bar1() {
13   volatile int tmp = 42; (void)tmp;
14   foo1();
15 }
16 
17 void __attribute__((noinline)) foo2() {
18   volatile int v = Global; (void)v;
19 }
20 
21 void __attribute__((noinline)) bar2() {
22   volatile int tmp = 42; (void)tmp;
23   foo2();
24 }
25 
26 void *Thread1(void *x) {
27   sleep(1);
28   bar1();
29   return NULL;
30 }
31 
32 void *Thread2(void *x) {
33   bar2();
34   return NULL;
35 }
36 
37 void StartThread(pthread_t *t, void *(*f)(void*)) {
38   pthread_create(t, NULL, f, NULL);
39 }
40 
41 int main() {
42   pthread_t t[2];
43   StartThread(&t[0], Thread1);
44   StartThread(&t[1], Thread2);
45   pthread_join(t[0], NULL);
46   pthread_join(t[1], NULL);
47   return 0;
48 }
49 
50 // CHECK:      WARNING: ThreadSanitizer: data race
51 // CHECK-NEXT:   Write of size 4 at {{.*}} by thread T1:
52 // CHECK-NEXT:     #0 foo1{{.*}} {{.*}}simple_stack.c:9{{(:3)?}} ({{.*}})
53 // CHECK-NEXT:     #1 bar1{{.*}} {{.*}}simple_stack.c:14{{(:3)?}} ({{.*}})
54 // CHECK-NEXT:     #2 Thread1{{.*}} {{.*}}simple_stack.c:28{{(:3)?}} ({{.*}})
55 // CHECK:        Previous read of size 4 at {{.*}} by thread T2:
56 // CHECK-NEXT:     #0 foo2{{.*}} {{.*}}simple_stack.c:18{{(:26)?}} ({{.*}})
57 // CHECK-NEXT:     #1 bar2{{.*}} {{.*}}simple_stack.c:23{{(:3)?}} ({{.*}})
58 // CHECK-NEXT:     #2 Thread2{{.*}} {{.*}}simple_stack.c:33{{(:3)?}} ({{.*}})
59 // CHECK:        Thread T1 (tid={{.*}}, running) created by main thread at:
60 // CHECK-NEXT:     #0 pthread_create {{.*}} ({{.*}})
61 // CHECK-NEXT:     #1 StartThread{{.*}} {{.*}}simple_stack.c:38{{(:3)?}} ({{.*}})
62 // CHECK-NEXT:     #2 main{{.*}} {{.*}}simple_stack.c:43{{(:3)?}} ({{.*}})
63 // CHECK:        Thread T2 ({{.*}}) created by main thread at:
64 // CHECK-NEXT:     #0 pthread_create {{.*}} ({{.*}})
65 // CHECK-NEXT:     #1 StartThread{{.*}} {{.*}}simple_stack.c:38{{(:3)?}} ({{.*}})
66 // CHECK-NEXT:     #2 main{{.*}} {{.*}}simple_stack.c:44{{(:3)?}} ({{.*}})
67