|  | // RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s | 
|  | #include <pthread.h> | 
|  | #include <stdlib.h> | 
|  | #include <stdio.h> | 
|  |  | 
|  | struct Cache { | 
|  | int x; | 
|  | explicit Cache(int x) | 
|  | : x(x) { | 
|  | } | 
|  | }; | 
|  |  | 
|  | void foo(Cache *my) { | 
|  | static Cache *c = my ? my : new Cache(rand()); | 
|  | if (c->x >= RAND_MAX) | 
|  | exit(1); | 
|  | } | 
|  |  | 
|  | void *Thread(void *x) { | 
|  | foo(new Cache(rand())); | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | int main() { | 
|  | pthread_t t[2]; | 
|  | pthread_create(&t[0], 0, Thread, 0); | 
|  | pthread_create(&t[1], 0, Thread, 0); | 
|  | pthread_join(t[0], 0); | 
|  | pthread_join(t[1], 0); | 
|  | fprintf(stderr, "PASS\n"); | 
|  | } | 
|  |  | 
|  | // CHECK-NOT: WARNING: ThreadSanitizer: data race |