--- /dev/null
+// RUN: %clangxx_tsan -O1 %s -o %t && %deflake %run %t | FileCheck %s
+#include <pthread.h>
+#include <stdio.h>
+#include <unistd.h>
+
+char s[] = "abracadabra";
+
+void *Thread0(void *p) {
+ puts(s);
+ return 0;
+}
+
+void *Thread1(void *p) {
+ s[3] = 'z';
+ return 0;
+}
+
+int main() {
+ pthread_t th[2];
+ pthread_create(&th[0], 0, Thread0, 0);
+ pthread_create(&th[1], 0, Thread1, 0);
+ pthread_join(th[0], 0);
+ pthread_join(th[1], 0);
+ fprintf(stderr, "DONE");
+}
+
+// CHECK: WARNING: ThreadSanitizer: data race
+// CHECK: DONE
+