Pepper: unit tests for VarTracker

ppapi/shared_impl/var_tracker_unittest.cc

Index: ppapi/shared_impl/var_tracker_unittest.cc
diff --git a/ppapi/shared_impl/var_tracker_unittest.cc b/ppapi/shared_impl/var_tracker_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..23e2f59d94872dd1bb697ac890d3787ea63037a8
--- /dev/null
+++ b/ppapi/shared_impl/var_tracker_unittest.cc
@@ -0,0 +1,159 @@
+// 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 "testing/gtest/include/gtest/gtest.h"
+
+#include "base/compiler_specific.h"
+#include "ppapi/shared_impl/var.h"
+#include "ppapi/shared_impl/var_tracker.h"
+#include "ppapi/shared_impl/test_globals.h"
+
+namespace ppapi {
+
+namespace {
+
+int mock_var_alive_count = 0;
+
+class MockStringVar : public StringVar {
+ public:
+  MockStringVar(const std::string& str) : StringVar(str) {
+    mock_var_alive_count++;
+  }
+  virtual ~MockStringVar() {
+    mock_var_alive_count--;
+  }
+  bool HasValidVarID() {
+    return GetExistingVarID() != 0;
+  }
+};
+
+class MockObjectVar : public Var {
+ public:
+  MockObjectVar() : Var() {
+    mock_var_alive_count++;
+  }
+  virtual ~MockObjectVar() {
+    mock_var_alive_count--;
+  }
+  virtual PP_VarType GetType() const OVERRIDE {
+    return PP_VARTYPE_OBJECT;
+  }
+  bool HasValidVarID() {
+    return GetExistingVarID() != 0;
+  }
+};
+
+}  // namespace
+
+class VarTrackerTest : public testing::Test {
+ public:
+  VarTrackerTest() {}
+
+  // Test implementation.
+  virtual void SetUp() OVERRIDE {
+    ASSERT_EQ(0, mock_var_alive_count);
+  }
+  virtual void TearDown() OVERRIDE {
+  }
+
+  VarTracker& var_tracker() { return *globals_.GetVarTracker(); }
+
+ private:
+  TestGlobals globals_;
+};
+
+// Test that ResetVarID is called when the last PP_Var ref was deleted but the
+// object lives on.
+TEST_F(VarTrackerTest, LastResourceRef) {
+  scoped_refptr<MockStringVar> var(new MockStringVar(std::string("xyz")));
+  PP_Var pp_var = var->GetPPVar();
+  EXPECT_TRUE(var->HasValidVarID());
+  EXPECT_TRUE(var_tracker().GetVar(var->GetExistingVarID()));
+
+  // Releasing it should keep the object (because we have a ref) but reset the
+  // var_id_.
+  EXPECT_TRUE(var_tracker().ReleaseVar(pp_var));
+  EXPECT_FALSE(var->HasValidVarID());
+  EXPECT_EQ(1, mock_var_alive_count);
+
+  var = NULL;
+  EXPECT_EQ(0, mock_var_alive_count);
+}
+
+TEST_F(VarTrackerTest, GetPluginRefAgain) {
+  scoped_refptr<MockStringVar> var(new MockStringVar(std::string("xyz")));
+  PP_Var pp_var = var->GetPPVar();
+  EXPECT_TRUE(var_tracker().ReleaseVar(pp_var));
+  EXPECT_FALSE(var->HasValidVarID());
+  EXPECT_EQ(1, mock_var_alive_count);
+
+  // Obtaining PP_Var ref again, and add ref from VarTracker.
+  pp_var = var->GetPPVar();
+  EXPECT_TRUE(var->HasValidVarID());
+  EXPECT_TRUE(var_tracker().GetVar(var->GetExistingVarID()));
+  scoped_refptr<MockStringVar> another_var =
+      static_cast<MockStringVar*>(var_tracker().GetVar(pp_var));
+  EXPECT_EQ(1, mock_var_alive_count);
+
+  // Releasing it again.
+  EXPECT_TRUE(var_tracker().ReleaseVar(pp_var));
+  EXPECT_FALSE(var->HasValidVarID());
+  EXPECT_EQ(1, mock_var_alive_count);
+
+  var = NULL;
+  EXPECT_FALSE(var_tracker().GetVar(pp_var));
+  EXPECT_EQ(1, mock_var_alive_count);
+  another_var = NULL;
+  EXPECT_FALSE(var_tracker().GetVar(pp_var));
+  EXPECT_EQ(0, mock_var_alive_count);
+}
+
+// Tests when the plugin is holding a ref to a PP_Var when the instance is
+// owned only by VarTracker.
+TEST_F(VarTrackerTest, PluginRefWithoutVarRef) {
+  // Make a PP_Var with one ref held by the plugin, and release the reference.
+  scoped_refptr<MockStringVar> var(new MockStringVar(std::string("zzz")));
+  PP_Var pp_var = var->GetPPVar();
+  EXPECT_EQ(1, mock_var_alive_count);
+  var = NULL;
+  EXPECT_EQ(1, mock_var_alive_count);
+
+  // The var is owned only by VarTracker. PP_Var must be still valid.
+  EXPECT_TRUE(var_tracker().GetVar(pp_var));
+
+  var_tracker().ReleaseVar(pp_var);
+  EXPECT_EQ(0, mock_var_alive_count);
+  EXPECT_FALSE(var_tracker().GetVar(pp_var));
+}
+
+// Tests on Var having type of PP_VARTYPE_OBJECT.
+TEST_F(VarTrackerTest, ObjectRef) {
+  scoped_refptr<MockObjectVar> var(new MockObjectVar());
+  PP_Var pp_var = var->GetPPVar();
+  EXPECT_TRUE(var_tracker().ReleaseVar(pp_var));
+  EXPECT_FALSE(var->HasValidVarID());
+  EXPECT_EQ(1, mock_var_alive_count);
+
+  // Obtaining PP_Var ref again, and add ref from VarTracker.
+  pp_var = var->GetPPVar();
+  EXPECT_TRUE(var->HasValidVarID());
+  EXPECT_TRUE(var_tracker().GetVar(var->GetExistingVarID()));
+  scoped_refptr<MockObjectVar> another_var =
+      static_cast<MockObjectVar*>(var_tracker().GetVar(pp_var));
+  EXPECT_EQ(1, mock_var_alive_count);
+
+  // Releasing all references, then only VarTracker own the instance.
+  var = NULL;
+  EXPECT_TRUE(var_tracker().GetVar(pp_var));
+  EXPECT_EQ(1, mock_var_alive_count);
+  another_var = NULL;
+  EXPECT_TRUE(var_tracker().GetVar(pp_var));
+  EXPECT_EQ(1, mock_var_alive_count);
+
+  // Releasing plugin reference.
+  EXPECT_TRUE(var_tracker().ReleaseVar(pp_var));
+  EXPECT_EQ(0, mock_var_alive_count);
+}
+
+}  // namespace ppapi