Add one simple thread local storage test.

This test should pass with gcc and fail with clang,
until clang/llvm supports emutls or Android linker supports
ELF TLS models.

BUG: 21082792
Change-Id: Id8c97da52c68ec230c7d26af703f6ed32d53a4fe

tests/Android.mk

@@ -280,6 +280,7 @@ bionic-unit-tests_src_files := \
     dlfcn_test.cpp \
     libdl_test.cpp \
     pthread_dlfcn_test.cpp \
+    thread_local_test.cpp \
 
 bionic-unit-tests_cflags := $(test_cflags)
 

tests/thread_local_test.cpp

@@ -0,0 +1,168 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <gtest/gtest.h>
+
+#ifdef __GNUC__
+// Gcc has a bug with -O -fdata-section for the arm target: http://b/22772147.
+// Until that bug is fixed, disable optimization since
+// it is not essential for this test.
+#pragma GCC optimize("-O0")
+#endif
+
+__thread int local_var = 100;
+int shared_var = 200;
+
+static void reset_vars() {
+  local_var = 1000;
+  shared_var = 2000;
+  // local_var should be reset by threads
+}
+
+typedef void* (*MyThread)(void*);
+
+static void* inc_shared_var(void* p) {
+  int *data = reinterpret_cast<int*>(p);
+  shared_var++;
+  *data = shared_var;
+  return nullptr;
+}
+
+static void* inc_local_var(void* p) {
+  int *data = reinterpret_cast<int*>(p);
+  local_var++;
+  *data = local_var;
+  return nullptr;
+}
+
+static int run_one_thread(MyThread foo) {
+  pthread_t t;
+  int data;
+  int error = pthread_create(&t, nullptr, foo, &data);
+  if (!error)
+      error = pthread_join(t, nullptr);
+  return error ? error : data;
+}
+
+TEST(thread_local_storage, shared) {
+  reset_vars();
+  ASSERT_EQ(local_var, 1000);
+  ASSERT_EQ(shared_var, 2000);
+
+  // Update shared_var, local_var remains 1000.
+  ASSERT_EQ(run_one_thread(inc_shared_var), 2001);
+  ASSERT_EQ(local_var, 1000);
+  ASSERT_EQ(shared_var, 2001);
+
+  ASSERT_EQ(run_one_thread(inc_shared_var), 2002);
+  ASSERT_EQ(local_var, 1000);
+  ASSERT_EQ(shared_var, 2002);
+
+  ASSERT_EQ(run_one_thread(inc_shared_var), 2003);
+  ASSERT_EQ(local_var, 1000);
+  ASSERT_EQ(shared_var, 2003);
+}
+
+TEST(thread_local_storage, local) {
+  reset_vars();
+  ASSERT_EQ(local_var, 1000);
+  ASSERT_EQ(shared_var, 2000);
+
+  // When a child thread updates its own TLS variable,
+  // this thread's local_var and shared_var are not changed.
+  // TLS local_var is initialized to 100 in a thread.
+  ASSERT_EQ(run_one_thread(inc_local_var), 101);
+  ASSERT_EQ(local_var, 1000);
+  ASSERT_EQ(shared_var, 2000);
+
+  ASSERT_EQ(run_one_thread(inc_local_var), 101);
+  ASSERT_EQ(local_var, 1000);
+  ASSERT_EQ(shared_var, 2000);
+
+  ASSERT_EQ(run_one_thread(inc_local_var), 101);
+  ASSERT_EQ(local_var, 1000);
+  ASSERT_EQ(shared_var, 2000);
+}
+
+// Test TLS initialization of more complicated type, array of struct.
+struct Point {
+  int x, y;
+};
+
+typedef Point Triangle[3];
+
+__thread Triangle local_triangle = {{10,10}, {20,20}, {30,30}};
+Triangle shared_triangle = {{1,1}, {2,2}, {3,3}};
+
+static void reset_triangle() {
+  static const Triangle t1 = {{3,3}, {4,4}, {5,5}};
+  static const Triangle t2 = {{2,2}, {3,3}, {4,4}};
+  memcpy(local_triangle, t1, sizeof(local_triangle));
+  memcpy(shared_triangle, t2, sizeof(shared_triangle));
+}
+
+static void* move_shared_triangle(void* p) {
+  int *data = reinterpret_cast<int*>(p);
+  shared_triangle[1].y++;
+  *data = shared_triangle[1].y;
+  return nullptr;
+}
+
+static void* move_local_triangle(void* p) {
+  int *data = reinterpret_cast<int*>(p);
+  local_triangle[1].y++;
+  *data = local_triangle[1].y;
+  return nullptr;
+}
+
+TEST(thread_local_storage, shared_triangle) {
+  reset_triangle();
+  ASSERT_EQ(local_triangle[1].y, 4);
+  ASSERT_EQ(shared_triangle[1].y, 3);
+
+  // Update shared_triangle, local_triangle remains 1000.
+  ASSERT_EQ(run_one_thread(move_shared_triangle), 4);
+  ASSERT_EQ(local_triangle[1].y, 4);
+  ASSERT_EQ(shared_triangle[1].y, 4);
+
+  ASSERT_EQ(run_one_thread(move_shared_triangle), 5);
+  ASSERT_EQ(local_triangle[1].y, 4);
+  ASSERT_EQ(shared_triangle[1].y, 5);
+
+  ASSERT_EQ(run_one_thread(move_shared_triangle), 6);
+  ASSERT_EQ(local_triangle[1].y, 4);
+  ASSERT_EQ(shared_triangle[1].y, 6);
+}
+
+TEST(thread_local_storage, local_triangle) {
+  reset_triangle();
+  ASSERT_EQ(local_triangle[1].y, 4);
+  ASSERT_EQ(shared_triangle[1].y, 3);
+
+  // Update local_triangle, parent thread's
+  // shared_triangle and local_triangle are unchanged.
+  ASSERT_EQ(run_one_thread(move_local_triangle), 21);
+  ASSERT_EQ(local_triangle[1].y, 4);
+  ASSERT_EQ(shared_triangle[1].y, 3);
+
+  ASSERT_EQ(run_one_thread(move_local_triangle), 21);
+  ASSERT_EQ(local_triangle[1].y, 4);
+  ASSERT_EQ(shared_triangle[1].y, 3);
+
+  ASSERT_EQ(run_one_thread(move_local_triangle), 21);
+  ASSERT_EQ(local_triangle[1].y, 4);
+  ASSERT_EQ(shared_triangle[1].y, 3);
+}