1 files changed, 34 insertions, 0 deletions
diff --git a/test/tsan/aligned_vs_unaligned_race.cc b/test/tsan/aligned_vs_unaligned_race.cc
new file mode 100644
index 000000000000..f82542ed2b85
--- /dev/null
+++ b/test/tsan/aligned_vs_unaligned_race.cc
@@ -0,0 +1,34 @@
+// RUN: %clangxx_tsan -O1 %s -o %t && %run %t 2>&1 | FileCheck %s
+// Race between an aligned access and an unaligned access, which
+// touches the same memory region.
+// This is a real race which is not detected by tsan.
+// https://code.google.com/p/thread-sanitizer/issues/detail?id=17
+#include <pthread.h>
+#include <stdio.h>
+#include <stdint.h>
+
+uint64_t Global[2];
+
+void *Thread1(void *x) {
+  Global[1]++;
+  return NULL;
+}
+
+void *Thread2(void *x) {
+  char *p1 = reinterpret_cast<char *>(&Global[0]);
+  uint64_t *p4 = reinterpret_cast<uint64_t *>(p1 + 1);
+  (*p4)++;
+  return NULL;
+}
+
+int main() {
+  pthread_t t[2];
+  pthread_create(&t[0], NULL, Thread1, NULL);
+  pthread_create(&t[1], NULL, Thread2, NULL);
+  pthread_join(t[0], NULL);
+  pthread_join(t[1], NULL);
+  printf("Pass\n");
+  // CHECK-NOT: ThreadSanitizer: data race
+  // CHECK: Pass
+  return 0;
+}