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      1 /*
      2  * Copyright (C) 2015 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include <gtest/gtest.h>
     18 #include <stdint.h>
     19 #include <string.h>
     20 
     21 #if defined(__GNUC__) && !defined(__clang__) && \
     22     (defined(__arm__) || defined(__aarch64__))
     23 // Gcc has a bug with -O -fdata-section for the arm target: http://b/22772147.
     24 // Until that bug is fixed, disable optimization since
     25 // it is not essential for this test.
     26 #pragma GCC optimize("-O0")
     27 #endif
     28 
     29 __thread int local_var = 100;
     30 int shared_var = 200;
     31 
     32 static void reset_vars() {
     33   local_var = 1000;
     34   shared_var = 2000;
     35   // local_var should be reset by threads
     36 }
     37 
     38 typedef void* (*MyThread)(void*);
     39 
     40 static void* inc_shared_var(void* p) {
     41   int *data = reinterpret_cast<int*>(p);
     42   shared_var++;
     43   *data = shared_var;
     44   return nullptr;
     45 }
     46 
     47 static void* inc_local_var(void* p) {
     48   int *data = reinterpret_cast<int*>(p);
     49   local_var++;
     50   *data = local_var;
     51   return nullptr;
     52 }
     53 
     54 static int run_one_thread(MyThread foo) {
     55   pthread_t t;
     56   int data;
     57   int error = pthread_create(&t, nullptr, foo, &data);
     58   if (!error)
     59       error = pthread_join(t, nullptr);
     60   return error ? error : data;
     61 }
     62 
     63 TEST(thread_local_storage, shared) {
     64   reset_vars();
     65   ASSERT_EQ(local_var, 1000);
     66   ASSERT_EQ(shared_var, 2000);
     67 
     68   // Update shared_var, local_var remains 1000.
     69   ASSERT_EQ(run_one_thread(inc_shared_var), 2001);
     70   ASSERT_EQ(local_var, 1000);
     71   ASSERT_EQ(shared_var, 2001);
     72 
     73   ASSERT_EQ(run_one_thread(inc_shared_var), 2002);
     74   ASSERT_EQ(local_var, 1000);
     75   ASSERT_EQ(shared_var, 2002);
     76 
     77   ASSERT_EQ(run_one_thread(inc_shared_var), 2003);
     78   ASSERT_EQ(local_var, 1000);
     79   ASSERT_EQ(shared_var, 2003);
     80 }
     81 
     82 TEST(thread_local_storage, local) {
     83   reset_vars();
     84   ASSERT_EQ(local_var, 1000);
     85   ASSERT_EQ(shared_var, 2000);
     86 
     87   // When a child thread updates its own TLS variable,
     88   // this thread's local_var and shared_var are not changed.
     89   // TLS local_var is initialized to 100 in a thread.
     90   ASSERT_EQ(run_one_thread(inc_local_var), 101);
     91   ASSERT_EQ(local_var, 1000);
     92   ASSERT_EQ(shared_var, 2000);
     93 
     94   ASSERT_EQ(run_one_thread(inc_local_var), 101);
     95   ASSERT_EQ(local_var, 1000);
     96   ASSERT_EQ(shared_var, 2000);
     97 
     98   ASSERT_EQ(run_one_thread(inc_local_var), 101);
     99   ASSERT_EQ(local_var, 1000);
    100   ASSERT_EQ(shared_var, 2000);
    101 }
    102 
    103 // Test TLS initialization of more complicated type, array of struct.
    104 struct Point {
    105   int x, y;
    106 };
    107 
    108 typedef Point Triangle[3];
    109 
    110 __thread Triangle local_triangle = {{10,10}, {20,20}, {30,30}};
    111 Triangle shared_triangle = {{1,1}, {2,2}, {3,3}};
    112 
    113 static void reset_triangle() {
    114   static const Triangle t1 = {{3,3}, {4,4}, {5,5}};
    115   static const Triangle t2 = {{2,2}, {3,3}, {4,4}};
    116   memcpy(local_triangle, t1, sizeof(local_triangle));
    117   memcpy(shared_triangle, t2, sizeof(shared_triangle));
    118 }
    119 
    120 static void* move_shared_triangle(void* p) {
    121   int *data = reinterpret_cast<int*>(p);
    122   shared_triangle[1].y++;
    123   *data = shared_triangle[1].y;
    124   return nullptr;
    125 }
    126 
    127 static void* move_local_triangle(void* p) {
    128   int *data = reinterpret_cast<int*>(p);
    129   local_triangle[1].y++;
    130   *data = local_triangle[1].y;
    131   return nullptr;
    132 }
    133 
    134 TEST(thread_local_storage, shared_triangle) {
    135   reset_triangle();
    136   ASSERT_EQ(local_triangle[1].y, 4);
    137   ASSERT_EQ(shared_triangle[1].y, 3);
    138 
    139   // Update shared_triangle, local_triangle remains 1000.
    140   ASSERT_EQ(run_one_thread(move_shared_triangle), 4);
    141   ASSERT_EQ(local_triangle[1].y, 4);
    142   ASSERT_EQ(shared_triangle[1].y, 4);
    143 
    144   ASSERT_EQ(run_one_thread(move_shared_triangle), 5);
    145   ASSERT_EQ(local_triangle[1].y, 4);
    146   ASSERT_EQ(shared_triangle[1].y, 5);
    147 
    148   ASSERT_EQ(run_one_thread(move_shared_triangle), 6);
    149   ASSERT_EQ(local_triangle[1].y, 4);
    150   ASSERT_EQ(shared_triangle[1].y, 6);
    151 }
    152 
    153 TEST(thread_local_storage, local_triangle) {
    154   reset_triangle();
    155   ASSERT_EQ(local_triangle[1].y, 4);
    156   ASSERT_EQ(shared_triangle[1].y, 3);
    157 
    158   // Update local_triangle, parent thread's
    159   // shared_triangle and local_triangle are unchanged.
    160   ASSERT_EQ(run_one_thread(move_local_triangle), 21);
    161   ASSERT_EQ(local_triangle[1].y, 4);
    162   ASSERT_EQ(shared_triangle[1].y, 3);
    163 
    164   ASSERT_EQ(run_one_thread(move_local_triangle), 21);
    165   ASSERT_EQ(local_triangle[1].y, 4);
    166   ASSERT_EQ(shared_triangle[1].y, 3);
    167 
    168   ASSERT_EQ(run_one_thread(move_local_triangle), 21);
    169   ASSERT_EQ(local_triangle[1].y, 4);
    170   ASSERT_EQ(shared_triangle[1].y, 3);
    171 }
    172 
    173 // Test emutls runtime data structures and __emutls_get_address function.
    174 typedef unsigned int gcc_word __attribute__((mode(word)));
    175 typedef unsigned int gcc_pointer __attribute__((mode(pointer)));
    176 struct gcc_emutls_object {  // for libgcc
    177   gcc_word size;
    178   gcc_word align;
    179   union {
    180     gcc_pointer offset;
    181     void* ptr;
    182   } loc;
    183   void* templ;
    184 };
    185 
    186 typedef struct __emutls_control {  // for clang/llvm
    187   size_t size;
    188   size_t align;
    189   union {
    190     uintptr_t index;
    191     void* address;
    192   } object;
    193   void* value;
    194 } __emutls_control;
    195 
    196 TEST(thread_local_storage, type_size) {
    197   static_assert(sizeof(size_t) == sizeof(gcc_word),
    198                 "size_t != gcc_word");
    199   static_assert(sizeof(uintptr_t) == sizeof(gcc_pointer),
    200                 "uintptr_t != gcc_pointer");
    201   static_assert(sizeof(uintptr_t) == sizeof(void*),
    202                 "sizoeof(uintptr_t) != sizeof(void*)");
    203   static_assert(sizeof(__emutls_control) == sizeof(struct gcc_emutls_object),
    204                 "sizeof(__emutls_control) != sizeof(struct gcc_emutls_object)");
    205 }
    206 
    207 extern "C" void* __emutls_get_address(__emutls_control*);
    208 
    209 TEST(thread_local_storage, init_value) {
    210   char tls_value1[] = "123456789";
    211   char tls_value2[] = "abcdefghi";
    212   constexpr size_t num_saved_values = 10;
    213   __emutls_control tls_var[num_saved_values];
    214   size_t prev_index = 0;
    215   void* saved_gap[num_saved_values];
    216   void* saved_p[num_saved_values];
    217   ASSERT_TRUE(strlen(tls_value2) <= strlen(tls_value1));
    218   __emutls_control c =
    219       {strlen(tls_value1) + 1, 1, {0}, tls_value1};
    220   for (size_t n = 0; n < num_saved_values; n++) {
    221     memcpy(&tls_var[n], &c, sizeof(c));
    222     tls_var[n].align = (1 << n);
    223   }
    224   for (size_t n = 0; n < num_saved_values; n++) {
    225     // Try to mess up malloc space so that the next malloc will not have the
    226     // required alignment, but __emutls_get_address should still return an
    227     // aligned address.
    228     saved_gap[n] = malloc(1);
    229     void* p = __emutls_get_address(&tls_var[n]);
    230     saved_p[n] = p;
    231     ASSERT_TRUE(p != nullptr);
    232     ASSERT_TRUE(tls_var[n].object.index != 0);
    233     // check if p is a new object.
    234     if (n > 0) {
    235       // In single-thread environment, object.address == p.
    236       // In multi-threads environment, object.index is increased.
    237       ASSERT_TRUE(prev_index + 1 == tls_var[n].object.index ||
    238                   p == tls_var[n].object.address);
    239       ASSERT_TRUE(p != saved_p[n - 1]);
    240     }
    241     prev_index = tls_var[n].object.index;
    242     // check if p is aligned
    243     uintptr_t align = (1 << n);
    244     uintptr_t address= reinterpret_cast<uintptr_t>(p);
    245     ASSERT_EQ((address & ~(align - 1)), address);
    246     // check if *p is initialized
    247     ASSERT_STREQ(tls_value1, static_cast<char*>(p));
    248     // change value in *p
    249     memcpy(p, tls_value2, strlen(tls_value2) + 1);
    250   }
    251   for (size_t n = 0; n < num_saved_values; n++) {
    252     free(saved_gap[n]);
    253   }
    254   for (size_t n = 0; n < num_saved_values; n++) {
    255     void* p = __emutls_get_address(&tls_var[n]);
    256     ASSERT_EQ(p, saved_p[n]);
    257     // check if *p has the new value
    258     ASSERT_STREQ(tls_value2, static_cast<char*>(p));
    259   }
    260 }
    261