[tsan] race_on_write test

llvm-svn: 174599

compiler-rt/lib/tsan/lit_tests/race_on_write.cc

@@ -0,0 +1,39 @@
+// RUN: %clangxx_tsan -O1 %s -o %t && %t 2>&1 | FileCheck %s
+#include <pthread.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+int fd;
+char buf;
+
+void *Thread1(void *x) {
+  buf = 1;
+  sleep(1);
+  return NULL;
+}
+
+void *Thread2(void *x) {
+  write(fd, &buf, 1);
+  return NULL;
+}
+
+int main() {
+  fd = open("/dev/null", O_WRONLY);
+  if (fd < 0) return 1;
+  pthread_t t[2];
+  pthread_create(&t[0], NULL, Thread1, NULL);
+  sleep(1);
+  pthread_create(&t[1], NULL, Thread2, NULL);
+  pthread_join(t[0], NULL);
+  pthread_join(t[1], NULL);
+  close(fd);
+}
+
+// CHECK: WARNING: ThreadSanitizer: data race
+// CHECK:   Read of size 1
+// CHECK:     #0 write
+// CHECK:   Previous write of size 1
+// CHECK:     #0 Thread1