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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 __thread int local_var = 100;
22 int shared_var = 200;
23 
reset_vars()24 static void reset_vars() {
25   local_var = 1000;
26   shared_var = 2000;
27   // local_var should be reset by threads
28 }
29 
30 typedef void* (*MyThread)(void*);
31 
inc_shared_var(void * p)32 static void* inc_shared_var(void* p) {
33   int *data = reinterpret_cast<int*>(p);
34   shared_var++;
35   *data = shared_var;
36   return nullptr;
37 }
38 
inc_local_var(void * p)39 static void* inc_local_var(void* p) {
40   int *data = reinterpret_cast<int*>(p);
41   local_var++;
42   *data = local_var;
43   return nullptr;
44 }
45 
run_one_thread(MyThread foo)46 static int run_one_thread(MyThread foo) {
47   pthread_t t;
48   int data;
49   int error = pthread_create(&t, nullptr, foo, &data);
50   if (!error)
51       error = pthread_join(t, nullptr);
52   return error ? error : data;
53 }
54 
TEST(thread_local_storage,shared)55 TEST(thread_local_storage, shared) {
56   reset_vars();
57   ASSERT_EQ(local_var, 1000);
58   ASSERT_EQ(shared_var, 2000);
59 
60   // Update shared_var, local_var remains 1000.
61   ASSERT_EQ(run_one_thread(inc_shared_var), 2001);
62   ASSERT_EQ(local_var, 1000);
63   ASSERT_EQ(shared_var, 2001);
64 
65   ASSERT_EQ(run_one_thread(inc_shared_var), 2002);
66   ASSERT_EQ(local_var, 1000);
67   ASSERT_EQ(shared_var, 2002);
68 
69   ASSERT_EQ(run_one_thread(inc_shared_var), 2003);
70   ASSERT_EQ(local_var, 1000);
71   ASSERT_EQ(shared_var, 2003);
72 }
73 
TEST(thread_local_storage,local)74 TEST(thread_local_storage, local) {
75   reset_vars();
76   ASSERT_EQ(local_var, 1000);
77   ASSERT_EQ(shared_var, 2000);
78 
79   // When a child thread updates its own TLS variable,
80   // this thread's local_var and shared_var are not changed.
81   // TLS local_var is initialized to 100 in a thread.
82   ASSERT_EQ(run_one_thread(inc_local_var), 101);
83   ASSERT_EQ(local_var, 1000);
84   ASSERT_EQ(shared_var, 2000);
85 
86   ASSERT_EQ(run_one_thread(inc_local_var), 101);
87   ASSERT_EQ(local_var, 1000);
88   ASSERT_EQ(shared_var, 2000);
89 
90   ASSERT_EQ(run_one_thread(inc_local_var), 101);
91   ASSERT_EQ(local_var, 1000);
92   ASSERT_EQ(shared_var, 2000);
93 }
94 
95 // Test TLS initialization of more complicated type, array of struct.
96 struct Point {
97   int x, y;
98 };
99 
100 typedef Point Triangle[3];
101 
102 __thread Triangle local_triangle = {{10,10}, {20,20}, {30,30}};
103 Triangle shared_triangle = {{1,1}, {2,2}, {3,3}};
104 
reset_triangle()105 static void reset_triangle() {
106   static const Triangle t1 = {{3,3}, {4,4}, {5,5}};
107   static const Triangle t2 = {{2,2}, {3,3}, {4,4}};
108   memcpy(local_triangle, t1, sizeof(local_triangle));
109   memcpy(shared_triangle, t2, sizeof(shared_triangle));
110 }
111 
move_shared_triangle(void * p)112 static void* move_shared_triangle(void* p) {
113   int *data = reinterpret_cast<int*>(p);
114   shared_triangle[1].y++;
115   *data = shared_triangle[1].y;
116   return nullptr;
117 }
118 
move_local_triangle(void * p)119 static void* move_local_triangle(void* p) {
120   int *data = reinterpret_cast<int*>(p);
121   local_triangle[1].y++;
122   *data = local_triangle[1].y;
123   return nullptr;
124 }
125 
TEST(thread_local_storage,shared_triangle)126 TEST(thread_local_storage, shared_triangle) {
127   reset_triangle();
128   ASSERT_EQ(local_triangle[1].y, 4);
129   ASSERT_EQ(shared_triangle[1].y, 3);
130 
131   // Update shared_triangle, local_triangle remains 1000.
132   ASSERT_EQ(run_one_thread(move_shared_triangle), 4);
133   ASSERT_EQ(local_triangle[1].y, 4);
134   ASSERT_EQ(shared_triangle[1].y, 4);
135 
136   ASSERT_EQ(run_one_thread(move_shared_triangle), 5);
137   ASSERT_EQ(local_triangle[1].y, 4);
138   ASSERT_EQ(shared_triangle[1].y, 5);
139 
140   ASSERT_EQ(run_one_thread(move_shared_triangle), 6);
141   ASSERT_EQ(local_triangle[1].y, 4);
142   ASSERT_EQ(shared_triangle[1].y, 6);
143 }
144 
TEST(thread_local_storage,local_triangle)145 TEST(thread_local_storage, local_triangle) {
146   reset_triangle();
147   ASSERT_EQ(local_triangle[1].y, 4);
148   ASSERT_EQ(shared_triangle[1].y, 3);
149 
150   // Update local_triangle, parent thread's
151   // shared_triangle and local_triangle are unchanged.
152   ASSERT_EQ(run_one_thread(move_local_triangle), 21);
153   ASSERT_EQ(local_triangle[1].y, 4);
154   ASSERT_EQ(shared_triangle[1].y, 3);
155 
156   ASSERT_EQ(run_one_thread(move_local_triangle), 21);
157   ASSERT_EQ(local_triangle[1].y, 4);
158   ASSERT_EQ(shared_triangle[1].y, 3);
159 
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 
165 // Test emutls runtime data structures and __emutls_get_address function.
166 typedef unsigned int gcc_word __attribute__((mode(word)));
167 typedef unsigned int gcc_pointer __attribute__((mode(pointer)));
168 struct gcc_emutls_object {  // for libgcc
169   gcc_word size;
170   gcc_word align;
171   union {
172     gcc_pointer offset;
173     void* ptr;
174   } loc;
175   void* templ;
176 };
177 
178 typedef struct __emutls_control {  // for clang/llvm
179   size_t size;
180   size_t align;
181   union {
182     uintptr_t index;
183     void* address;
184   } object;
185   void* value;
186 } __emutls_control;
187 
TEST(thread_local_storage,type_size)188 TEST(thread_local_storage, type_size) {
189   static_assert(sizeof(size_t) == sizeof(gcc_word),
190                 "size_t != gcc_word");
191   static_assert(sizeof(uintptr_t) == sizeof(gcc_pointer),
192                 "uintptr_t != gcc_pointer");
193   static_assert(sizeof(uintptr_t) == sizeof(void*),
194                 "sizoeof(uintptr_t) != sizeof(void*)");
195   static_assert(sizeof(__emutls_control) == sizeof(struct gcc_emutls_object),
196                 "sizeof(__emutls_control) != sizeof(struct gcc_emutls_object)");
197 }
198 
199 extern "C" void* __emutls_get_address(__emutls_control*);
200 
TEST(thread_local_storage,init_value)201 TEST(thread_local_storage, init_value) {
202   char tls_value1[] = "123456789";
203   char tls_value2[] = "abcdefghi";
204   constexpr size_t num_saved_values = 10;
205   __emutls_control tls_var[num_saved_values];
206   size_t prev_index = 0;
207   void* saved_gap[num_saved_values];
208   void* saved_p[num_saved_values];
209   ASSERT_TRUE(strlen(tls_value2) <= strlen(tls_value1));
210   __emutls_control c =
211       {strlen(tls_value1) + 1, 1, {0}, tls_value1};
212   for (size_t n = 0; n < num_saved_values; n++) {
213     memcpy(&tls_var[n], &c, sizeof(c));
214     tls_var[n].align = (1 << n);
215   }
216   for (size_t n = 0; n < num_saved_values; n++) {
217     // Try to mess up malloc space so that the next malloc will not have the
218     // required alignment, but __emutls_get_address should still return an
219     // aligned address.
220     saved_gap[n] = malloc(1);
221     void* p = __emutls_get_address(&tls_var[n]);
222     saved_p[n] = p;
223     ASSERT_TRUE(p != nullptr);
224     ASSERT_TRUE(tls_var[n].object.index != 0);
225     // check if p is a new object.
226     if (n > 0) {
227       // In single-thread environment, object.address == p.
228       // In multi-threads environment, object.index is increased.
229       ASSERT_TRUE(prev_index + 1 == tls_var[n].object.index ||
230                   p == tls_var[n].object.address);
231       ASSERT_TRUE(p != saved_p[n - 1]);
232     }
233     prev_index = tls_var[n].object.index;
234     // check if p is aligned
235     uintptr_t align = (1 << n);
236     uintptr_t address= reinterpret_cast<uintptr_t>(p);
237     ASSERT_EQ((address & ~(align - 1)), address);
238     // check if *p is initialized
239     ASSERT_STREQ(tls_value1, static_cast<char*>(p));
240     // change value in *p
241     memcpy(p, tls_value2, strlen(tls_value2) + 1);
242   }
243   for (size_t n = 0; n < num_saved_values; n++) {
244     free(saved_gap[n]);
245   }
246   for (size_t n = 0; n < num_saved_values; n++) {
247     void* p = __emutls_get_address(&tls_var[n]);
248     ASSERT_EQ(p, saved_p[n]);
249     // check if *p has the new value
250     ASSERT_STREQ(tls_value2, static_cast<char*>(p));
251   }
252 }
253