6 files changed, 666 insertions, 0 deletions
diff --git a/base/memory/ref_counted.cc b/base/memory/ref_counted.cc
new file mode 100644
index 000000000000..31ad5098cd0f
--- /dev/null
+++ b/base/memory/ref_counted.cc
@@ -0,0 +1,95 @@
+// Copyright (c) 2011 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/memory/ref_counted.h"
+
+#include "base/logging.h"
+#include "base/threading/thread_collision_warner.h"
+
+namespace base {
+
+namespace subtle {
+
+RefCountedBase::RefCountedBase()
+    : ref_count_(0)
+#ifndef NDEBUG
+    , in_dtor_(false)
+#endif
+    {
+}
+
+RefCountedBase::~RefCountedBase() {
+#ifndef NDEBUG
+  DCHECK(in_dtor_) << "RefCounted object deleted without calling Release()";
+#endif
+}
+
+void RefCountedBase::AddRef() const {
+  // TODO(maruel): Add back once it doesn't assert 500 times/sec.
+  // Current thread books the critical section "AddRelease" without release it.
+  // DFAKE_SCOPED_LOCK_THREAD_LOCKED(add_release_);
+#ifndef NDEBUG
+  DCHECK(!in_dtor_);
+#endif
+  ++ref_count_;
+}
+
+bool RefCountedBase::Release() const {
+  // TODO(maruel): Add back once it doesn't assert 500 times/sec.
+  // Current thread books the critical section "AddRelease" without release it.
+  // DFAKE_SCOPED_LOCK_THREAD_LOCKED(add_release_);
+#ifndef NDEBUG
+  DCHECK(!in_dtor_);
+#endif
+  if (--ref_count_ == 0) {
+#ifndef NDEBUG
+    in_dtor_ = true;
+#endif
+    return true;
+  }
+  return false;
+}
+
+bool RefCountedThreadSafeBase::HasOneRef() const {
+  return AtomicRefCountIsOne(
+      &const_cast<RefCountedThreadSafeBase*>(this)->ref_count_);
+}
+
+RefCountedThreadSafeBase::RefCountedThreadSafeBase() : ref_count_(0) {
+#ifndef NDEBUG
+  in_dtor_ = false;
+#endif
+}
+
+RefCountedThreadSafeBase::~RefCountedThreadSafeBase() {
+#ifndef NDEBUG
+  DCHECK(in_dtor_) << "RefCountedThreadSafe object deleted without "
+                      "calling Release()";
+#endif
+}
+
+void RefCountedThreadSafeBase::AddRef() const {
+#ifndef NDEBUG
+  DCHECK(!in_dtor_);
+#endif
+  AtomicRefCountInc(&ref_count_);
+}
+
+bool RefCountedThreadSafeBase::Release() const {
+#ifndef NDEBUG
+  DCHECK(!in_dtor_);
+  DCHECK(!AtomicRefCountIsZero(&ref_count_));
+#endif
+  if (!AtomicRefCountDec(&ref_count_)) {
+#ifndef NDEBUG
+    in_dtor_ = true;
+#endif
+    return true;
+  }
+  return false;
+}
+
+}  // namespace subtle
+
+}  // namespace base
diff --git a/base/memory/ref_counted.h b/base/memory/ref_counted.h
new file mode 100644
index 000000000000..439fda44d1ad
--- /dev/null
+++ b/base/memory/ref_counted.h
@@ -0,0 +1,299 @@
+// Copyright (c) 2011 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.
+
+#ifndef BASE_MEMORY_REF_COUNTED_H_
+#define BASE_MEMORY_REF_COUNTED_H_
+#pragma once
+
+#include "base/atomic_ref_count.h"
+#include "base/base_export.h"
+#include "base/threading/thread_collision_warner.h"
+
+namespace base {
+
+namespace subtle {
+
+class BASE_EXPORT RefCountedBase {
+ public:
+  static bool ImplementsThreadSafeReferenceCounting() { return false; }
+
+  bool HasOneRef() const { return ref_count_ == 1; }
+
+ protected:
+  RefCountedBase();
+  ~RefCountedBase();
+
+  void AddRef() const;
+
+  // Returns true if the object should self-delete.
+  bool Release() const;
+
+ private:
+  mutable int ref_count_;
+#ifndef NDEBUG
+  mutable bool in_dtor_;
+#endif
+
+  DFAKE_MUTEX(add_release_);
+
+  DISALLOW_COPY_AND_ASSIGN(RefCountedBase);
+};
+
+class BASE_EXPORT RefCountedThreadSafeBase {
+ public:
+  static bool ImplementsThreadSafeReferenceCounting() { return true; }
+
+  bool HasOneRef() const;
+
+ protected:
+  RefCountedThreadSafeBase();
+  ~RefCountedThreadSafeBase();
+
+  void AddRef() const;
+
+  // Returns true if the object should self-delete.
+  bool Release() const;
+
+ private:
+  mutable AtomicRefCount ref_count_;
+#ifndef NDEBUG
+  mutable bool in_dtor_;
+#endif
+
+  DISALLOW_COPY_AND_ASSIGN(RefCountedThreadSafeBase);
+};
+
+}  // namespace subtle
+
+//
+// A base class for reference counted classes.  Otherwise, known as a cheap
+// knock-off of WebKit's RefCounted<T> class.  To use this guy just extend your
+// class from it like so:
+//
+//   class MyFoo : public base::RefCounted<MyFoo> {
+//    ...
+//    private:
+//     friend class base::RefCounted<MyFoo>;
+//     ~MyFoo();
+//   };
+//
+// You should always make your destructor private, to avoid any code deleting
+// the object accidently while there are references to it.
+template <class T>
+class RefCounted : public subtle::RefCountedBase {
+ public:
+  RefCounted() { }
+  ~RefCounted() { }
+
+  void AddRef() const {
+    subtle::RefCountedBase::AddRef();
+  }
+
+  void Release() const {
+    if (subtle::RefCountedBase::Release()) {
+      delete static_cast<const T*>(this);
+    }
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(RefCounted<T>);
+};
+
+// Forward declaration.
+template <class T, typename Traits> class RefCountedThreadSafe;
+
+// Default traits for RefCountedThreadSafe<T>.  Deletes the object when its ref
+// count reaches 0.  Overload to delete it on a different thread etc.
+template<typename T>
+struct DefaultRefCountedThreadSafeTraits {
+  static void Destruct(const T* x) {
+    // Delete through RefCountedThreadSafe to make child classes only need to be
+    // friend with RefCountedThreadSafe instead of this struct, which is an
+    // implementation detail.
+    RefCountedThreadSafe<T,
+                         DefaultRefCountedThreadSafeTraits>::DeleteInternal(x);
+  }
+};
+
+//
+// A thread-safe variant of RefCounted<T>
+//
+//   class MyFoo : public base::RefCountedThreadSafe<MyFoo> {
+//    ...
+//   };
+//
+// If you're using the default trait, then you should add compile time
+// asserts that no one else is deleting your object.  i.e.
+//    private:
+//     friend class base::RefCountedThreadSafe<MyFoo>;
+//     ~MyFoo();
+template <class T, typename Traits = DefaultRefCountedThreadSafeTraits<T> >
+class RefCountedThreadSafe : public subtle::RefCountedThreadSafeBase {
+ public:
+  RefCountedThreadSafe() { }
+  ~RefCountedThreadSafe() { }
+
+  void AddRef() const {
+    subtle::RefCountedThreadSafeBase::AddRef();
+  }
+
+  void Release() const {
+    if (subtle::RefCountedThreadSafeBase::Release()) {
+      Traits::Destruct(static_cast<const T*>(this));
+    }
+  }
+
+ private:
+  friend struct DefaultRefCountedThreadSafeTraits<T>;
+  static void DeleteInternal(const T* x) { delete x; }
+
+  DISALLOW_COPY_AND_ASSIGN(RefCountedThreadSafe);
+};
+
+//
+// A wrapper for some piece of data so we can place other things in
+// scoped_refptrs<>.
+//
+template<typename T>
+class RefCountedData : public base::RefCounted< base::RefCountedData<T> > {
+ public:
+  RefCountedData() : data() {}
+  RefCountedData(const T& in_value) : data(in_value) {}
+
+  T data;
+};
+
+}  // namespace base
+
+//
+// A smart pointer class for reference counted objects.  Use this class instead
+// of calling AddRef and Release manually on a reference counted object to
+// avoid common memory leaks caused by forgetting to Release an object
+// reference.  Sample usage:
+//
+//   class MyFoo : public RefCounted<MyFoo> {
+//    ...
+//   };
+//
+//   void some_function() {
+//     scoped_refptr<MyFoo> foo = new MyFoo();
+//     foo->Method(param);
+//     // |foo| is released when this function returns
+//   }
+//
+//   void some_other_function() {
+//     scoped_refptr<MyFoo> foo = new MyFoo();
+//     ...
+//     foo = NULL;  // explicitly releases |foo|
+//     ...
+//     if (foo)
+//       foo->Method(param);
+//   }
+//
+// The above examples show how scoped_refptr<T> acts like a pointer to T.
+// Given two scoped_refptr<T> classes, it is also possible to exchange
+// references between the two objects, like so:
+//
+//   {
+//     scoped_refptr<MyFoo> a = new MyFoo();
+//     scoped_refptr<MyFoo> b;
+//
+//     b.swap(a);
+//     // now, |b| references the MyFoo object, and |a| references NULL.
+//   }
+//
+// To make both |a| and |b| in the above example reference the same MyFoo
+// object, simply use the assignment operator:
+//
+//   {
+//     scoped_refptr<MyFoo> a = new MyFoo();
+//     scoped_refptr<MyFoo> b;
+//
+//     b = a;
+//     // now, |a| and |b| each own a reference to the same MyFoo object.
+//   }
+//
+template <class T>
+class scoped_refptr {
+ public:
+  scoped_refptr() : ptr_(NULL) {
+  }
+
+  scoped_refptr(T* p) : ptr_(p) {
+    if (ptr_)
+      ptr_->AddRef();
+  }
+
+  scoped_refptr(const scoped_refptr<T>& r) : ptr_(r.ptr_) {
+    if (ptr_)
+      ptr_->AddRef();
+  }
+
+  template <typename U>
+  scoped_refptr(const scoped_refptr<U>& r) : ptr_(r.get()) {
+    if (ptr_)
+      ptr_->AddRef();
+  }
+
+  ~scoped_refptr() {
+    if (ptr_)
+      ptr_->Release();
+  }
+
+  T* get() const { return ptr_; }
+  operator T*() const { return ptr_; }
+  T* operator->() const { return ptr_; }
+
+  // Release a pointer.
+  // The return value is the current pointer held by this object.
+  // If this object holds a NULL pointer, the return value is NULL.
+  // After this operation, this object will hold a NULL pointer,
+  // and will not own the object any more.
+  T* release() {
+    T* retVal = ptr_;
+    ptr_ = NULL;
+    return retVal;
+  }
+
+  scoped_refptr<T>& operator=(T* p) {
+    // AddRef first so that self assignment should work
+    if (p)
+      p->AddRef();
+    if (ptr_ )
+      ptr_ ->Release();
+    ptr_ = p;
+    return *this;
+  }
+
+  scoped_refptr<T>& operator=(const scoped_refptr<T>& r) {
+    return *this = r.ptr_;
+  }
+
+  template <typename U>
+  scoped_refptr<T>& operator=(const scoped_refptr<U>& r) {
+    return *this = r.get();
+  }
+
+  void swap(T** pp) {
+    T* p = ptr_;
+    ptr_ = *pp;
+    *pp = p;
+  }
+
+  void swap(scoped_refptr<T>& r) {
+    swap(&r.ptr_);
+  }
+
+ protected:
+  T* ptr_;
+};
+
+// Handy utility for creating a scoped_refptr<T> out of a T* explicitly without
+// having to retype all the template arguments
+template <typename T>
+scoped_refptr<T> make_scoped_refptr(T* t) {
+  return scoped_refptr<T>(t);
+}
+
+#endif  // BASE_MEMORY_REF_COUNTED_H_
diff --git a/base/memory/ref_counted_memory.cc b/base/memory/ref_counted_memory.cc
new file mode 100644
index 000000000000..7e034f91af62
--- /dev/null
+++ b/base/memory/ref_counted_memory.cc
@@ -0,0 +1,72 @@
+// Copyright (c) 2011 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/memory/ref_counted_memory.h"
+
+#include "base/logging.h"
+
+RefCountedMemory::RefCountedMemory() {
+}
+
+RefCountedMemory::~RefCountedMemory() {
+}
+
+const unsigned char* RefCountedStaticMemory::front() const {
+  return data_;
+}
+
+size_t RefCountedStaticMemory::size() const {
+  return length_;
+}
+
+RefCountedBytes::RefCountedBytes() {
+}
+
+RefCountedBytes::RefCountedBytes(const std::vector<unsigned char>& initializer)
+    : data_(initializer) {
+}
+
+RefCountedBytes* RefCountedBytes::TakeVector(
+    std::vector<unsigned char>* to_destroy) {
+  RefCountedBytes* bytes = new RefCountedBytes;
+  bytes->data_.swap(*to_destroy);
+  return bytes;
+}
+
+const unsigned char* RefCountedBytes::front() const {
+  // STL will assert if we do front() on an empty vector, but calling code
+  // expects a NULL.
+  return size() ? &data_.front() : NULL;
+}
+
+size_t RefCountedBytes::size() const {
+  return data_.size();
+}
+
+RefCountedBytes::~RefCountedBytes() {
+}
+
+namespace base {
+
+RefCountedString::RefCountedString() {}
+
+RefCountedString::~RefCountedString() {}
+
+// static
+RefCountedString* RefCountedString::TakeString(std::string* to_destroy) {
+  RefCountedString* self = new RefCountedString;
+  to_destroy->swap(self->data_);
+  return self;
+}
+
+const unsigned char* RefCountedString::front() const {
+  return data_.empty() ? NULL :
+         reinterpret_cast<const unsigned char*>(data_.data());
+}
+
+size_t RefCountedString::size() const {
+  return data_.size();
+}
+
+}  //  namespace base
diff --git a/base/memory/ref_counted_memory.h b/base/memory/ref_counted_memory.h
new file mode 100644
index 000000000000..7b55d145ec20
--- /dev/null
+++ b/base/memory/ref_counted_memory.h
@@ -0,0 +1,119 @@
+// Copyright (c) 2011 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.
+
+#ifndef BASE_MEMORY_REF_COUNTED_MEMORY_H_
+#define BASE_MEMORY_REF_COUNTED_MEMORY_H_
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include "base/base_export.h"
+#include "base/compiler_specific.h"
+#include "base/memory/ref_counted.h"
+
+// TODO(erg): The contents of this file should be in a namespace. This would
+// require touching >100 files in chrome/ though.
+
+// A generic interface to memory. This object is reference counted because one
+// of its two subclasses own the data they carry, and we need to have
+// heterogeneous containers of these two types of memory.
+class BASE_EXPORT RefCountedMemory
+    : public base::RefCountedThreadSafe<RefCountedMemory> {
+ public:
+  // Retrieves a pointer to the beginning of the data we point to. If the data
+  // is empty, this will return NULL.
+  virtual const unsigned char* front() const = 0;
+
+  // Size of the memory pointed to.
+  virtual size_t size() const = 0;
+
+ protected:
+  friend class base::RefCountedThreadSafe<RefCountedMemory>;
+  RefCountedMemory();
+  virtual ~RefCountedMemory();
+};
+
+// An implementation of RefCountedMemory, where the ref counting does not
+// matter.
+class BASE_EXPORT RefCountedStaticMemory : public RefCountedMemory {
+ public:
+  RefCountedStaticMemory()
+      : data_(NULL), length_(0) {}
+  RefCountedStaticMemory(const unsigned char* data, size_t length)
+      : data_(length ? data : NULL), length_(length) {}
+
+  // Overridden from RefCountedMemory:
+  virtual const unsigned char* front() const OVERRIDE;
+  virtual size_t size() const OVERRIDE;
+
+ private:
+  const unsigned char* data_;
+  size_t length_;
+
+  DISALLOW_COPY_AND_ASSIGN(RefCountedStaticMemory);
+};
+
+// An implementation of RefCountedMemory, where we own our the data in a
+// vector.
+class BASE_EXPORT RefCountedBytes : public RefCountedMemory {
+ public:
+  RefCountedBytes();
+
+  // Constructs a RefCountedBytes object by _copying_ from |initializer|.
+  RefCountedBytes(const std::vector<unsigned char>& initializer);
+
+  // Constructs a RefCountedBytes object by performing a swap. (To non
+  // destructively build a RefCountedBytes, use the constructor that takes a
+  // vector.)
+  static RefCountedBytes* TakeVector(std::vector<unsigned char>* to_destroy);
+
+  // Overridden from RefCountedMemory:
+  virtual const unsigned char* front() const OVERRIDE;
+  virtual size_t size() const OVERRIDE;
+
+  const std::vector<unsigned char>& data() const { return data_; }
+  std::vector<unsigned char>& data() { return data_; }
+
+ private:
+  friend class base::RefCountedThreadSafe<RefCountedBytes>;
+  virtual ~RefCountedBytes();
+
+  std::vector<unsigned char> data_;
+
+  DISALLOW_COPY_AND_ASSIGN(RefCountedBytes);
+};
+
+namespace base {
+
+// An implementation of RefCountedMemory, where the bytes are stored in an STL
+// string. Use this if your data naturally arrives in that format.
+class BASE_EXPORT RefCountedString : public RefCountedMemory {
+ public:
+  RefCountedString();
+
+  // Constructs a RefCountedString object by performing a swap. (To non
+  // destructively build a RefCountedString, use the default constructor and
+  // copy into object->data()).
+  static RefCountedString* TakeString(std::string* to_destroy);
+
+  // Overridden from RefCountedMemory:
+  virtual const unsigned char* front() const OVERRIDE;
+  virtual size_t size() const OVERRIDE;
+
+  const std::string& data() const { return data_; }
+  std::string& data() { return data_; }
+
+ private:
+  friend class base::RefCountedThreadSafe<RefCountedString>;
+  virtual ~RefCountedString();
+
+  std::string data_;
+
+  DISALLOW_COPY_AND_ASSIGN(RefCountedString);
+};
+
+}  // namespace base
+
+#endif  // BASE_MEMORY_REF_COUNTED_MEMORY_H_
diff --git a/base/memory/ref_counted_memory_unittest.cc b/base/memory/ref_counted_memory_unittest.cc
new file mode 100644
index 000000000000..19360400c14a
--- /dev/null
+++ b/base/memory/ref_counted_memory_unittest.cc
@@ -0,0 +1,45 @@
+// Copyright (c) 2011 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/memory/ref_counted_memory.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+
+TEST(RefCountedMemoryUnitTest, RefCountedStaticMemory) {
+  scoped_refptr<RefCountedMemory> mem = new RefCountedStaticMemory(
+      reinterpret_cast<const uint8*>("static mem00"), 10);
+
+  EXPECT_EQ(10U, mem->size());
+  EXPECT_EQ("static mem",
+            std::string(reinterpret_cast<const char*>(mem->front()),
+                        mem->size()));
+}
+
+TEST(RefCountedMemoryUnitTest, RefCountedBytes) {
+  std::vector<uint8> data;
+  data.push_back(45);
+  data.push_back(99);
+  scoped_refptr<RefCountedMemory> mem = RefCountedBytes::TakeVector(&data);
+
+  EXPECT_EQ(0U, data.size());
+
+  EXPECT_EQ(2U, mem->size());
+  EXPECT_EQ(45U, mem->front()[0]);
+  EXPECT_EQ(99U, mem->front()[1]);
+}
+
+TEST(RefCountedMemoryUnitTest, RefCountedString) {
+  std::string s("destroy me");
+  scoped_refptr<RefCountedMemory> mem = RefCountedString::TakeString(&s);
+
+  EXPECT_EQ(0U, s.size());
+
+  EXPECT_EQ(10U, mem->size());
+  EXPECT_EQ('d', mem->front()[0]);
+  EXPECT_EQ('e', mem->front()[1]);
+}
+
+}  //  namespace base
diff --git a/base/memory/ref_counted_unittest.cc b/base/memory/ref_counted_unittest.cc
new file mode 100644
index 000000000000..dcc292f00ddf
--- /dev/null
+++ b/base/memory/ref_counted_unittest.cc
@@ -0,0 +1,36 @@
+// Copyright (c) 2011 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/memory/ref_counted.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+class SelfAssign : public base::RefCounted<SelfAssign> {
+  friend class base::RefCounted<SelfAssign>;
+
+  ~SelfAssign() {}
+};
+
+class CheckDerivedMemberAccess : public scoped_refptr<SelfAssign> {
+ public:
+  CheckDerivedMemberAccess() {
+    // This shouldn't compile if we don't have access to the member variable.
+    SelfAssign** pptr = &ptr_;
+    EXPECT_EQ(*pptr, ptr_);
+  }
+};
+
+}  // end namespace
+
+TEST(RefCountedUnitTest, TestSelfAssignment) {
+  SelfAssign* p = new SelfAssign;
+  scoped_refptr<SelfAssign> var(p);
+  var = var;
+  EXPECT_EQ(var.get(), p);
+}
+
+TEST(RefCountedUnitTest, ScopedRefPtrMemberAccess) {
+  CheckDerivedMemberAccess check;
+}