base/synchronization/lock_unittest.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/synchronization/lock.h"
   6
   7 #include <stdlib.h>
   8
   9 #include "base/compiler_specific.h"
  10 #include "base/threading/platform_thread.h"
  11 #include "testing/gtest/include/gtest/gtest.h"
  12
  13 namespace base {
  14
  15 // Basic test to make sure that Acquire()/Release()/Try() don't crash ----------
  16
  17 class BasicLockTestThread : public PlatformThread::Delegate {
  18  public:
  19   explicit BasicLockTestThread(Lock* lock) : lock_(lock), acquired_(0) {}
  20
  21   void ThreadMain() override {
  22     for (int i = 0; i < 10; i++) {
  23       lock_->Acquire();
  24       acquired_++;
  25       lock_->Release();
  26     }
  27     for (int i = 0; i < 10; i++) {
  28       lock_->Acquire();
  29       acquired_++;
  30       PlatformThread::Sleep(TimeDelta::FromMilliseconds(rand() % 20));
  31       lock_->Release();
  32     }
  33     for (int i = 0; i < 10; i++) {
  34       if (lock_->Try()) {
  35         acquired_++;
  36         PlatformThread::Sleep(TimeDelta::FromMilliseconds(rand() % 20));
  37         lock_->Release();
  38       }
  39     }
  40   }
  41
  42   int acquired() const { return acquired_; }
  43
  44  private:
  45   Lock* lock_;
  46   int acquired_;
  47
  48   DISALLOW_COPY_AND_ASSIGN(BasicLockTestThread);
  49 };
  50
  51 TEST(LockTest, Basic) {
  52   Lock lock;
  53   BasicLockTestThread thread(&lock);
  54   PlatformThreadHandle handle;
  55
  56   ASSERT_TRUE(PlatformThread::Create(0, &thread, &handle));
  57
  58   int acquired = 0;
  59   for (int i = 0; i < 5; i++) {
  60     lock.Acquire();
  61     acquired++;
  62     lock.Release();
  63   }
  64   for (int i = 0; i < 10; i++) {
  65     lock.Acquire();
  66     acquired++;
  67     PlatformThread::Sleep(TimeDelta::FromMilliseconds(rand() % 20));
  68     lock.Release();
  69   }
  70   for (int i = 0; i < 10; i++) {
  71     if (lock.Try()) {
  72       acquired++;
  73       PlatformThread::Sleep(TimeDelta::FromMilliseconds(rand() % 20));
  74       lock.Release();
  75     }
  76   }
  77   for (int i = 0; i < 5; i++) {
  78     lock.Acquire();
  79     acquired++;
  80     PlatformThread::Sleep(TimeDelta::FromMilliseconds(rand() % 20));
  81     lock.Release();
  82   }
  83
  84   PlatformThread::Join(handle);
  85
  86   EXPECT_GE(acquired, 20);
  87   EXPECT_GE(thread.acquired(), 20);
  88 }
  89
  90 // Test that Try() works as expected -------------------------------------------
  91
  92 class TryLockTestThread : public PlatformThread::Delegate {
  93  public:
  94   explicit TryLockTestThread(Lock* lock) : lock_(lock), got_lock_(false) {}
  95
  96   void ThreadMain() override {
  97     got_lock_ = lock_->Try();
  98     if (got_lock_)
  99       lock_->Release();
 100   }
 101
 102   bool got_lock() const { return got_lock_; }
 103
 104  private:
 105   Lock* lock_;
 106   bool got_lock_;
 107
 108   DISALLOW_COPY_AND_ASSIGN(TryLockTestThread);
 109 };
 110
 111 TEST(LockTest, TryLock) {
 112   Lock lock;
 113
 114   ASSERT_TRUE(lock.Try());
 115   // We now have the lock....
 116
 117   // This thread will not be able to get the lock.
 118   {
 119     TryLockTestThread thread(&lock);
 120     PlatformThreadHandle handle;
 121
 122     ASSERT_TRUE(PlatformThread::Create(0, &thread, &handle));
 123
 124     PlatformThread::Join(handle);
 125
 126     ASSERT_FALSE(thread.got_lock());
 127   }
 128
 129   lock.Release();
 130
 131   // This thread will....
 132   {
 133     TryLockTestThread thread(&lock);
 134     PlatformThreadHandle handle;
 135
 136     ASSERT_TRUE(PlatformThread::Create(0, &thread, &handle));
 137
 138     PlatformThread::Join(handle);
 139
 140     ASSERT_TRUE(thread.got_lock());
 141     // But it released it....
 142     ASSERT_TRUE(lock.Try());
 143   }
 144
 145   lock.Release();
 146 }
 147
 148 // Tests that locks actually exclude -------------------------------------------
 149
 150 class MutexLockTestThread : public PlatformThread::Delegate {
 151  public:
 152   MutexLockTestThread(Lock* lock, int* value) : lock_(lock), value_(value) {}
 153
 154   // Static helper which can also be called from the main thread.
 155   static void DoStuff(Lock* lock, int* value) {
 156     for (int i = 0; i < 40; i++) {
 157       lock->Acquire();
 158       int v = *value;
 159       PlatformThread::Sleep(TimeDelta::FromMilliseconds(rand() % 10));
 160       *value = v + 1;
 161       lock->Release();
 162     }
 163   }
 164
 165   void ThreadMain() override { DoStuff(lock_, value_); }
 166
 167  private:
 168   Lock* lock_;
 169   int* value_;
 170
 171   DISALLOW_COPY_AND_ASSIGN(MutexLockTestThread);
 172 };
 173
 174 TEST(LockTest, MutexTwoThreads) {
 175   Lock lock;
 176   int value = 0;
 177
 178   MutexLockTestThread thread(&lock, &value);
 179   PlatformThreadHandle handle;
 180
 181   ASSERT_TRUE(PlatformThread::Create(0, &thread, &handle));
 182
 183   MutexLockTestThread::DoStuff(&lock, &value);
 184
 185   PlatformThread::Join(handle);
 186
 187   EXPECT_EQ(2 * 40, value);
 188 }
 189
 190 TEST(LockTest, MutexFourThreads) {
 191   Lock lock;
 192   int value = 0;
 193
 194   MutexLockTestThread thread1(&lock, &value);
 195   MutexLockTestThread thread2(&lock, &value);
 196   MutexLockTestThread thread3(&lock, &value);
 197   PlatformThreadHandle handle1;
 198   PlatformThreadHandle handle2;
 199   PlatformThreadHandle handle3;
 200
 201   ASSERT_TRUE(PlatformThread::Create(0, &thread1, &handle1));
 202   ASSERT_TRUE(PlatformThread::Create(0, &thread2, &handle2));
 203   ASSERT_TRUE(PlatformThread::Create(0, &thread3, &handle3));
 204
 205   MutexLockTestThread::DoStuff(&lock, &value);
 206
 207   PlatformThread::Join(handle1);
 208   PlatformThread::Join(handle2);
 209   PlatformThread::Join(handle3);
 210
 211   EXPECT_EQ(4 * 40, value);
 212 }
 213
 214 }  // namespace base