Mojo: Start writing some unit tests for mojo::system::Channel.

Also make RawChannels destroyable without DCHECK failures if OnInit()
fails.

R=yzshen@chromium.org

Review URL: https://codereview.chromium.org/251483007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@266193 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 187 insertions, 3 deletions

diff --git a/mojo/system/channel_unittest.cc b/mojo/system/channel_unittest.cc
new file mode 100644
index 0000000..3d676e7
--- /dev/null
+++ b/mojo/system/channel_unittest.cc
@@ -0,0 +1,179 @@
+// Copyright 2014 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 "mojo/system/channel.h"
+
+#include "base/bind.h"
+#include "base/location.h"
+#include "base/message_loop/message_loop.h"
+#include "mojo/embedder/platform_channel_pair.h"
+#include "mojo/system/raw_channel.h"
+#include "mojo/system/test_utils.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace mojo {
+namespace system {
+namespace {
+
+enum Tristate {
+  TRISTATE_UNKNOWN = -1,
+  TRISTATE_FALSE = 0,
+  TRISTATE_TRUE = 1
+};
+
+Tristate BoolToTristate(bool b) {
+  return b ? TRISTATE_TRUE : TRISTATE_FALSE;
+}
+
+class ChannelTest : public testing::Test {
+ public:
+  ChannelTest()
+      : io_thread_(test::TestIOThread::kAutoStart),
+        init_result_(TRISTATE_UNKNOWN) {}
+  virtual ~ChannelTest() {}
+
+  virtual void SetUp() OVERRIDE {
+    io_thread_.PostTaskAndWait(
+        FROM_HERE,
+        base::Bind(&ChannelTest::SetUpOnIOThread, base::Unretained(this)));
+  }
+
+  void CreateChannelOnIOThread() {
+    CHECK_EQ(base::MessageLoop::current(), io_thread()->message_loop());
+    channel_ = new Channel();
+  }
+
+  void InitChannelOnIOThread() {
+    CHECK_EQ(base::MessageLoop::current(), io_thread()->message_loop());
+
+    CHECK(raw_channel_);
+    CHECK(channel_);
+    CHECK_EQ(init_result_, TRISTATE_UNKNOWN);
+
+    init_result_ = BoolToTristate(channel_->Init(raw_channel_.Pass()));
+  }
+
+  void ShutdownChannelOnIOThread() {
+    CHECK_EQ(base::MessageLoop::current(), io_thread()->message_loop());
+
+    CHECK(channel_);
+    channel_->Shutdown();
+  }
+
+  test::TestIOThread* io_thread() { return &io_thread_; }
+  RawChannel* raw_channel() { return raw_channel_.get(); }
+  scoped_ptr<RawChannel>* mutable_raw_channel() { return &raw_channel_; }
+  Channel* channel() { return channel_.get(); }
+  scoped_refptr<Channel>* mutable_channel() { return &channel_; }
+  Tristate init_result() const { return init_result_; }
+
+ private:
+  void SetUpOnIOThread() {
+    CHECK_EQ(base::MessageLoop::current(), io_thread()->message_loop());
+
+    embedder::PlatformChannelPair channel_pair;
+    raw_channel_ = RawChannel::Create(channel_pair.PassServerHandle()).Pass();
+    other_platform_handle_ = channel_pair.PassClientHandle();
+  }
+
+  test::TestIOThread io_thread_;
+  scoped_ptr<RawChannel> raw_channel_;
+  embedder::ScopedPlatformHandle other_platform_handle_;
+  scoped_refptr<Channel> channel_;
+
+  Tristate init_result_;
+
+  DISALLOW_COPY_AND_ASSIGN(ChannelTest);
+};
+
+// ChannelTest.InitShutdown ----------------------------------------------------
+
+TEST_F(ChannelTest, InitShutdown) {
+  io_thread()->PostTaskAndWait(
+      FROM_HERE,
+      base::Bind(&ChannelTest::CreateChannelOnIOThread,
+                 base::Unretained(this)));
+  ASSERT_TRUE(channel());
+
+  io_thread()->PostTaskAndWait(
+      FROM_HERE,
+      base::Bind(&ChannelTest::InitChannelOnIOThread,
+                 base::Unretained(this)));
+  EXPECT_EQ(TRISTATE_TRUE, init_result());
+
+  io_thread()->PostTaskAndWait(
+      FROM_HERE,
+      base::Bind(&ChannelTest::ShutdownChannelOnIOThread,
+                 base::Unretained(this)));
+
+  // Okay to destroy |Channel| on not-the-I/O-thread.
+  EXPECT_TRUE(channel()->HasOneRef());
+  *mutable_channel() = NULL;
+}
+
+// ChannelTest.InitFails -------------------------------------------------------
+
+class MockRawChannelOnInitFails : public RawChannel {
+ public:
+  MockRawChannelOnInitFails() : on_init_called_(false) {}
+  virtual ~MockRawChannelOnInitFails() {}
+
+  virtual IOResult Read(size_t*) OVERRIDE {
+    CHECK(false);
+    return IO_FAILED;
+  }
+  virtual IOResult ScheduleRead() OVERRIDE {
+    CHECK(false);
+    return IO_FAILED;
+  }
+  virtual IOResult WriteNoLock(size_t*) OVERRIDE {
+    CHECK(false);
+    return IO_FAILED;
+  }
+  virtual IOResult ScheduleWriteNoLock() OVERRIDE {
+    CHECK(false);
+    return IO_FAILED;
+  }
+  virtual bool OnInit() OVERRIDE {
+    EXPECT_FALSE(on_init_called_);
+    on_init_called_ = true;
+    return false;
+  }
+  virtual void OnShutdownNoLock(scoped_ptr<ReadBuffer>,
+                                scoped_ptr<WriteBuffer>) OVERRIDE {
+    CHECK(false);
+  }
+
+ private:
+  bool on_init_called_;
+
+  DISALLOW_COPY_AND_ASSIGN(MockRawChannelOnInitFails);
+};
+
+TEST_F(ChannelTest, InitFails) {
+  io_thread()->PostTaskAndWait(
+      FROM_HERE,
+      base::Bind(&ChannelTest::CreateChannelOnIOThread,
+                 base::Unretained(this)));
+  ASSERT_TRUE(channel());
+
+  ASSERT_TRUE(raw_channel());
+  mutable_raw_channel()->reset(new MockRawChannelOnInitFails());
+
+  io_thread()->PostTaskAndWait(
+      FROM_HERE,
+      base::Bind(&ChannelTest::InitChannelOnIOThread,
+                 base::Unretained(this)));
+  EXPECT_EQ(TRISTATE_FALSE, init_result());
+
+  // Should destroy |Channel| with no |Shutdown()| (on not-the-I/O-thread).
+  EXPECT_TRUE(channel()->HasOneRef());
+  *mutable_channel() = NULL;
+}
+
+// TODO(vtl): More.
+
+}  // namespace
+}  // namespace system
+}  // namespace mojo
diff --git a/mojo/system/raw_channel.cc b/mojo/system/raw_channel.cc
index d9febeb..92b9a3d 100644
--- a/mojo/system/raw_channel.cc
+++ b/mojo/system/raw_channel.cc
@@ -126,8 +126,13 @@ bool RawChannel::Init(Delegate* delegate) {
   DCHECK(!write_buffer_);
   write_buffer_.reset(new WriteBuffer);
 
-  if (!OnInit())
+  if (!OnInit()) {
+    delegate_ = NULL;
+    message_loop_for_io_ = NULL;
+    read_buffer_.reset();
+    write_buffer_.reset();
     return false;
+  }
 
   return ScheduleRead() == IO_PENDING;
 }
diff --git a/mojo/system/raw_channel.h b/mojo/system/raw_channel.h
index b4571f8..607a776 100644
--- a/mojo/system/raw_channel.h
+++ b/mojo/system/raw_channel.h
@@ -104,7 +104,7 @@ class MOJO_SYSTEM_IMPL_EXPORT RawChannel {
     IO_PENDING
   };
 
-  class ReadBuffer {
+  class MOJO_SYSTEM_IMPL_EXPORT ReadBuffer {
    public:
     ReadBuffer();
     ~ReadBuffer();
@@ -124,7 +124,7 @@ class MOJO_SYSTEM_IMPL_EXPORT RawChannel {
     DISALLOW_COPY_AND_ASSIGN(ReadBuffer);
   };
 
-  class WriteBuffer {
+  class MOJO_SYSTEM_IMPL_EXPORT WriteBuffer {
    public:
     struct Buffer {
       const char* addr;