This CL is due the thread I have made on chromium-dev:...

base/thread_collision_warner_unittest.cc

Index: base/thread_collision_warner_unittest.cc
===================================================================
--- base/thread_collision_warner_unittest.cc	(revision 0)
+++ base/thread_collision_warner_unittest.cc	(revision 0)
@@ -0,0 +1,362 @@
+// Copyright (c) 2008 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/lock.h"
+#include "base/platform_thread.h"
+#include "base/simple_thread.h"
+#include "base/thread_collision_warner.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+
+namespace {
+
+// This is the asserter used with ThreadCollisionWarner instead of the default
+// DCheckAsserter. The method fail_state is used to know if a collision took
+// place.
+class AssertReporter : public base::AsserterBase {
+ public:
+  AssertReporter()
+      : failed_(false) {}
+
+  virtual void warn() {
+    failed_ = true;
+  }
+
+  virtual ~AssertReporter() {}
+
+  bool fail_state() const { return failed_; }
+  void reset() { failed_ = false; }
+
+ private:
+  bool failed_;
+};
+
+}  // namespace
+
+TEST(ThreadCollisionTest, BookCriticalSection) {
+  AssertReporter* local_reporter = new AssertReporter();
+
+  base::ThreadCollisionWarner warner(local_reporter);
+  EXPECT_FALSE(local_reporter->fail_state());
+
+  {  // Pin section.
+    D_BOOK_CRITICAL_SECTION(warner);
+    EXPECT_FALSE(local_reporter->fail_state());
+    {  // Pin section.
+      D_BOOK_CRITICAL_SECTION(warner);
+      EXPECT_FALSE(local_reporter->fail_state());
+    }
+  }
+}
+
+TEST(ThreadCollisionTest, ScopedRecursiveBookCriticalSection) {
+  AssertReporter* local_reporter = new AssertReporter();
+
+  base::ThreadCollisionWarner warner(local_reporter);
+  EXPECT_FALSE(local_reporter->fail_state());
+
+  {  // Pin section.
+    D_SCOPED_RECURSIVE_BOOK_CRITICAL_SECTION(warner);
+    EXPECT_FALSE(local_reporter->fail_state());
+    {  // Pin section again (allowed by D_SCOPED_RECURSIVE_BOOK_CRITICAL_SECTION)
+      D_SCOPED_RECURSIVE_BOOK_CRITICAL_SECTION(warner);
+      EXPECT_FALSE(local_reporter->fail_state());
+    }  // Unpin section.
+  }  // Unpin section.
+
+  // Check that section is not pinned
+  {  // Pin section.
+    D_SCOPED_BOOK_CRITICAL_SECTION(warner);
+    EXPECT_FALSE(local_reporter->fail_state());
+  }  // Unpin section.
+}
+
+TEST(ThreadCollisionTest, ScopedBookCriticalSection) {
+  AssertReporter* local_reporter = new AssertReporter();
+
+  base::ThreadCollisionWarner warner(local_reporter);
+  EXPECT_FALSE(local_reporter->fail_state());
+
+  {  // Pin section.
+    D_SCOPED_BOOK_CRITICAL_SECTION(warner);
+    EXPECT_FALSE(local_reporter->fail_state());
+  }  // Unpin section.
+
+  {  // Pin section.
+    D_SCOPED_BOOK_CRITICAL_SECTION(warner);
+    EXPECT_FALSE(local_reporter->fail_state());
+    {  // Pin section again (not allowed by D_SCOPED_BOOK_CRITICAL_SECTION)
+      D_SCOPED_BOOK_CRITICAL_SECTION(warner);
+      EXPECT_TRUE(local_reporter->fail_state());
+      // Reset the status of warner for further tests.
+      local_reporter->reset();
+    }  // Unpin section.
+  }  // Unpin section.
+
+  {  // Pin section.
+    D_SCOPED_BOOK_CRITICAL_SECTION(warner);
+    EXPECT_FALSE(local_reporter->fail_state());
+  }  // Unpin section.
+
+}
+
+TEST(ThreadCollisionTest, MTBookCriticalSectionTest) {
+  class NonThreadSafeQueue {
+   public:
+    NonThreadSafeQueue(base::AsserterBase* asserter)
+        : push_pop_(asserter) { }
+
+    void push(int) { 
+      D_BOOK_CRITICAL_SECTION(push_pop_);
+    }
+
+    int pop() {
+      D_BOOK_CRITICAL_SECTION(push_pop_);
+      return 0;
+    }
+
+   private:
+    base::ThreadCollisionWarner push_pop_;
+
+    DISALLOW_COPY_AND_ASSIGN(NonThreadSafeQueue);
+  };
+
+  class QueueUser : public base::DelegateSimpleThread::Delegate {
+  public:
+    QueueUser(NonThreadSafeQueue& queue)
+        : queue_(queue) {}
+
+    virtual void Run() { 
+      queue_.push(0);
+      queue_.pop();
+    }
+
+  private:
+    NonThreadSafeQueue& queue_;
+  };
+
+  AssertReporter* local_reporter = new AssertReporter();
+
+  NonThreadSafeQueue queue(local_reporter);
+
+  QueueUser queue_user_a(queue);
+  QueueUser queue_user_b(queue);
+
+  base::DelegateSimpleThread thread_a(&queue_user_a, "queue_user_thread_a");
+  base::DelegateSimpleThread thread_b(&queue_user_b, "queue_user_thread_b");
+
+  thread_a.Start();
+  thread_b.Start();
+
+  thread_a.Join();
+  thread_b.Join();
+
+  EXPECT_TRUE(local_reporter->fail_state());
+}
+
+TEST(ThreadCollisionTest, MTScopedBookCriticalSectionTest) {
+
+  // Queue with a 5 seconds push execution time, hopefuly the two used threads
+  // in the test will enter the push at same time.
+  class NonThreadSafeQueue {
+   public:
+    NonThreadSafeQueue(base::AsserterBase* asserter)
+        : push_pop_(asserter) { }
+
+    void push(int) { 
+      D_SCOPED_BOOK_CRITICAL_SECTION(push_pop_);
+      PlatformThread::Sleep(5000);
+    }
+
+    int pop() {
+      D_SCOPED_BOOK_CRITICAL_SECTION(push_pop_);
+      return 0;
+    }
+
+   private:
+    base::ThreadCollisionWarner push_pop_;
+
+    DISALLOW_COPY_AND_ASSIGN(NonThreadSafeQueue);
+  };
+
+  class QueueUser : public base::DelegateSimpleThread::Delegate {
+  public:
+    QueueUser(NonThreadSafeQueue& queue)
+        : queue_(queue) {}
+
+    virtual void Run() {
+      queue_.push(0);
+      queue_.pop();
+    }
+
+  private:
+    NonThreadSafeQueue& queue_;
+  };
+
+  AssertReporter* local_reporter = new AssertReporter();
+
+  NonThreadSafeQueue queue(local_reporter);
+
+  QueueUser queue_user_a(queue);
+  QueueUser queue_user_b(queue);
+
+  base::DelegateSimpleThread thread_a(&queue_user_a, "queue_user_thread_a");
+  base::DelegateSimpleThread thread_b(&queue_user_b, "queue_user_thread_b");
+
+  thread_a.Start();
+  thread_b.Start();
+
+  thread_a.Join();
+  thread_b.Join();
+
+  EXPECT_TRUE(local_reporter->fail_state());
+}
+
+TEST(ThreadCollisionTest, MTSynchedScopedBookCriticalSectionTest) {
+
+  // Queue with a 5 seconds push execution time, hopefuly the two used threads
+  // in the test will enter the push at same time.
+  class NonThreadSafeQueue {
+   public:
+    NonThreadSafeQueue(base::AsserterBase* asserter)
+        : push_pop_(asserter) { }
+
+    void push(int) { 
+      D_SCOPED_BOOK_CRITICAL_SECTION(push_pop_);
+      PlatformThread::Sleep(5000);
+    }
+
+    int pop() {
+      D_SCOPED_BOOK_CRITICAL_SECTION(push_pop_);
+      return 0;
+    }
+
+   private:
+    base::ThreadCollisionWarner push_pop_;
+
+    DISALLOW_COPY_AND_ASSIGN(NonThreadSafeQueue);
+  };
+
+  // This time the QueueUser class protects the non thread safe queue with
+  // a lock.
+  class QueueUser : public base::DelegateSimpleThread::Delegate {
+  public:
+    QueueUser(NonThreadSafeQueue& queue, Lock& lock)
+        : queue_(queue),
+          lock_(lock) {}
+
+    virtual void Run() {
+      {
+         AutoLock auto_lock(lock_);
+         queue_.push(0);
+      }
+      {
+         AutoLock auto_lock(lock_);
+         queue_.pop();
+      }
+    }
+  private:
+    NonThreadSafeQueue& queue_;
+    Lock& lock_;
+  };
+
+  AssertReporter* local_reporter = new AssertReporter();
+
+  NonThreadSafeQueue queue(local_reporter);
+
+  Lock lock;
+
+  QueueUser queue_user_a(queue, lock);
+  QueueUser queue_user_b(queue, lock);
+
+  base::DelegateSimpleThread thread_a(&queue_user_a, "queue_user_thread_a");
+  base::DelegateSimpleThread thread_b(&queue_user_b, "queue_user_thread_b");
+
+  thread_a.Start();
+  thread_b.Start();
+
+  thread_a.Join();
+  thread_b.Join();
+
+  EXPECT_FALSE(local_reporter->fail_state());
+}
+
+TEST(ThreadCollisionTest, MTSynchedScopedRecursiveBookCriticalSectionTest) {
+
+  // Queue with a 5 seconds push execution time, hopefuly the two used threads
+  // in the test will enter the push at same time.
+  class NonThreadSafeQueue {
+   public:
+    NonThreadSafeQueue(base::AsserterBase* asserter)
+        : push_pop_(asserter) { }
+
+    void push(int) { 
+      D_SCOPED_RECURSIVE_BOOK_CRITICAL_SECTION(push_pop_);
+      bar();
+      PlatformThread::Sleep(5000);
+    }
+
+    int pop() {
+      D_SCOPED_RECURSIVE_BOOK_CRITICAL_SECTION(push_pop_);
+      return 0;
+    }
+
+    void bar() {
+      D_SCOPED_RECURSIVE_BOOK_CRITICAL_SECTION(push_pop_);
+    }
+
+   private:
+    base::ThreadCollisionWarner push_pop_;
+
+    DISALLOW_COPY_AND_ASSIGN(NonThreadSafeQueue);
+  };
+
+  // This time the QueueUser class protects the non thread safe queue with
+  // a lock.
+  class QueueUser : public base::DelegateSimpleThread::Delegate {
+  public:
+    QueueUser(NonThreadSafeQueue& queue, Lock& lock)
+        : queue_(queue),
+          lock_(lock) {}
+
+    virtual void Run() {
+      {
+         AutoLock auto_lock(lock_);
+         queue_.push(0);
+      }
+      {
+         AutoLock auto_lock(lock_);
+         queue_.bar();
+      }
+      {
+         AutoLock auto_lock(lock_);
+         queue_.pop();
+      }
+    }
+  private:
+    NonThreadSafeQueue& queue_;
+    Lock& lock_;
+  };
+
+  AssertReporter* local_reporter = new AssertReporter();
+
+  NonThreadSafeQueue queue(local_reporter);
+
+  Lock lock;
+
+  QueueUser queue_user_a(queue, lock);
+  QueueUser queue_user_b(queue, lock);
+
+  base::DelegateSimpleThread thread_a(&queue_user_a, "queue_user_thread_a");
+  base::DelegateSimpleThread thread_b(&queue_user_b, "queue_user_thread_b");
+
+  thread_a.Start();
+  thread_b.Start();
+
+  thread_a.Join();
+  thread_b.Join();
+
+  EXPECT_FALSE(local_reporter->fail_state());
+}
+