Add a PassScopedPtr into base/memory.

base/memory/pass_scoped_ptr_unittest.cc

+// 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/pass_scoped_ptr.h"
+
+#include "base/basictypes.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+
+namespace {
+
+class ConDecLogger {
+ public:
+  ConDecLogger() : ptr_(NULL) { }
+  explicit ConDecLogger(int* ptr) { set_ptr(ptr); }
+  ~ConDecLogger() { --*ptr_; }
+
+ private:
+  void set_ptr(int* ptr) { ptr_ = ptr; ++*ptr_; }
+
+  int* ptr_;
+  DISALLOW_COPY_AND_ASSIGN(ConDecLogger);
+};
+
+PassScopedPtr<ConDecLogger> PassThru(PassScopedPtr<ConDecLogger> logger) {
+  return logger.Pass();
+}
+
+void GrabAndDrop(PassScopedPtr<ConDecLogger> logger) {
+}
+
+}  // namespace
+
+TEST(PassScopedPtrTest, BasicMethods) {
+  int constructed = 0;
+
+  {
+    ConDecLogger* logger = new ConDecLogger(&constructed);
+    PassScopedPtr<ConDecLogger> pass_scoped_ptr(MakePassScopedPtr(logger));
+    EXPECT_EQ(1, constructed);
+    EXPECT_EQ(logger, pass_scoped_ptr.value_.raw_ptr);
+    EXPECT_TRUE(pass_scoped_ptr.is_valid());
+  }
+  EXPECT_EQ(0, constructed);
+
+  // Test ToScopedPtr();
+  {
+    ConDecLogger* logger = new ConDecLogger(&constructed);
+    PassScopedPtr<ConDecLogger> pass_scoped_ptr(MakePassScopedPtr(logger));
+    EXPECT_EQ(1, constructed);
+
+    scoped_ptr<ConDecLogger> scoped;
+    pass_scoped_ptr.ToScopedPtr(&scoped);
+    EXPECT_EQ(logger, scoped.get());
+    EXPECT_TRUE(pass_scoped_ptr.value_.raw_ptr == NULL);
+    EXPECT_FALSE(pass_scoped_ptr.is_valid());
+    EXPECT_EQ(1, constructed);
+  }
+  EXPECT_EQ(0, constructed);
+}
+
+TEST(PassScopedPtrTest, PassBehavior) {
+  int constructed = 0;
+  // Test Pass constructor;
+  {
+    ConDecLogger* logger = new ConDecLogger(&constructed);
+    PassScopedPtr<ConDecLogger> pass_scoped_ptr(MakePassScopedPtr(logger));
+    EXPECT_EQ(1, constructed);
+
+    PassScopedPtr<ConDecLogger> pass_scoped_ptr2(pass_scoped_ptr.Pass());
+    EXPECT_EQ(1, constructed);
+    EXPECT_FALSE(pass_scoped_ptr.is_valid());
+    EXPECT_TRUE(pass_scoped_ptr2.is_valid());
+  }
+
+  // Test uncaught Pass() does not leak.
+  {
+    ConDecLogger* logger = new ConDecLogger(&constructed);
+    PassScopedPtr<ConDecLogger> pass_scoped_ptr(MakePassScopedPtr(logger));
+    EXPECT_EQ(1, constructed);
+
+    // Should auto-destruct logger by end of scope.
+    pass_scoped_ptr.Pass();
+    EXPECT_FALSE(pass_scoped_ptr.is_valid());
+  }
+  EXPECT_EQ(0, constructed);
+
+  // Test that passing to function which does nothing does not leak.
+  {
+    ConDecLogger* logger = new ConDecLogger(&constructed);
+    PassScopedPtr<ConDecLogger> pass_scoped_ptr(MakePassScopedPtr(logger));
+    EXPECT_EQ(1, constructed);
+
+    // Should auto-destruct logger by end of scope.
+    GrabAndDrop(pass_scoped_ptr.Pass());
+    EXPECT_FALSE(pass_scoped_ptr.is_valid());
+  }
+  EXPECT_EQ(0, constructed);
+}
+
+TEST(PassScopedPtrTest, ReturnTypeBehavior) {
+  int constructed = 0;
+
+  // Test that we can return a PassScopedPtr.
+  {
+    ConDecLogger* logger = new ConDecLogger(&constructed);
+    PassScopedPtr<ConDecLogger> pass_scoped_ptr(MakePassScopedPtr(logger));
+    EXPECT_EQ(1, constructed);
+
+    PassThru(pass_scoped_ptr.Pass());
+    EXPECT_FALSE(pass_scoped_ptr.is_valid());
+  }
+  EXPECT_EQ(0, constructed);
+
+
+  // Test uncaught return type not leak.
+  {
+    ConDecLogger* logger = new ConDecLogger(&constructed);
+    PassScopedPtr<ConDecLogger> pass_scoped_ptr(MakePassScopedPtr(logger));
+    EXPECT_EQ(1, constructed);
+
+    // Should auto-destruct logger by end of scope.
+    PassThru(pass_scoped_ptr.Pass());
+    EXPECT_FALSE(pass_scoped_ptr.is_valid());
+  }
+  EXPECT_EQ(0, constructed);
+}
+
+TEST(PassScopedPtrTest, AnchorBehavior) {
+  int constructed = 0;
+  // Test destruction semantics when anchored.
+  {
+    ConDecLogger* logger = new ConDecLogger(&constructed);
+    subtle::PassScopedPtrAnchor<ConDecLogger> anchor(
+        MakePassScopedPtr(logger));
+    EXPECT_EQ(1, constructed);
+    {
+      // Deletion of PassScopedPtr when anchored does nothing.
+      PassScopedPtr<ConDecLogger> pass_scoped_ptr(&anchor);
+      EXPECT_EQ(1, constructed);
+    }
+    EXPECT_EQ(1, constructed);
+
+    PassScopedPtr<ConDecLogger> pass_scoped_ptr(&anchor);
+    pass_scoped_ptr.Pass();
+    EXPECT_EQ(0, constructed);
+    EXPECT_FALSE(pass_scoped_ptr.is_valid());
+
+    // A second PassScopedPtr for an anchor should be immediately invalid.
+    PassScopedPtr<ConDecLogger> pass_scoped_ptr2(&anchor);
+    EXPECT_FALSE(pass_scoped_ptr2.is_valid());
+  }
+  EXPECT_EQ(0, constructed);
+}
+
+}  // namespace base