Mojo: Expose error state from Connector through RemotePtr

(This is part 1 of adding better error handling to the bindings system.)

BUG=325321

Review URL: https://codereview.chromium.org/105693005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239305 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 47 insertions, 11 deletions

diff --git a/mojo/public/bindings/lib/connector.h b/mojo/public/bindings/lib/connector.h
index b235437..35e6293 100644
--- a/mojo/public/bindings/lib/connector.h
+++ b/mojo/public/bindings/lib/connector.h
@@ -33,7 +33,7 @@ class Connector : public MessageReceiver {
 
   // Returns true if an error was encountered while reading from or writing to
   // the message pipe.
-  bool EncounteredError() const { return error_; }
+  bool encountered_error() const { return error_; }
 
   // MessageReceiver implementation:
   virtual bool Accept(Message* message) MOJO_OVERRIDE;
diff --git a/mojo/public/bindings/lib/remote_ptr.h b/mojo/public/bindings/lib/remote_ptr.h
index 58f77ad..3b57594 100644
--- a/mojo/public/bindings/lib/remote_ptr.h
+++ b/mojo/public/bindings/lib/remote_ptr.h
@@ -69,8 +69,8 @@ class RemotePtr {
     delete state_;
   }
 
-  bool is_valid() const {
-    return !!state_;
+  bool is_null() const {
+    return !state_;
   }
 
   S* get() {
@@ -92,6 +92,11 @@ class RemotePtr {
     state_ = new State(message_pipe.Pass());
   }
 
+  bool encountered_error() const {
+    assert(state_);
+    return state_->connector.encountered_error();
+  }
+
   void SetPeer(typename S::_Peer::_Stub* peer) {
     assert(state_);
     state_->connector.SetIncomingReceiver(peer);
diff --git a/mojo/public/tests/bindings_connector_unittest.cc b/mojo/public/tests/bindings_connector_unittest.cc
index 737f26a..a20190e 100644
--- a/mojo/public/tests/bindings_connector_unittest.cc
+++ b/mojo/public/tests/bindings_connector_unittest.cc
@@ -168,7 +168,7 @@ TEST_F(BindingsConnectorTest, WriteToClosedPipe) {
   bool ok = connector0->Accept(&message);
   EXPECT_FALSE(ok);
 
-  EXPECT_TRUE(connector0->EncounteredError());
+  EXPECT_TRUE(connector0->encountered_error());
 }
 
 // Enable this test once MojoWriteMessage supports passing handles.
diff --git a/mojo/public/tests/bindings_remote_ptr_unittest.cc b/mojo/public/tests/bindings_remote_ptr_unittest.cc
index c236695..beada47 100644
--- a/mojo/public/tests/bindings_remote_ptr_unittest.cc
+++ b/mojo/public/tests/bindings_remote_ptr_unittest.cc
@@ -12,6 +12,8 @@ namespace test {
 
 class MathCalculatorImpl : public math::CalculatorStub {
  public:
+  virtual ~MathCalculatorImpl() {}
+
   explicit MathCalculatorImpl(ScopedMessagePipeHandle pipe)
       : ui_(pipe.Pass()),
         total_(0.0) {
@@ -45,6 +47,10 @@ class MathCalculatorUIImpl : public math::CalculatorUIStub {
     calculator_.SetPeer(this);
   }
 
+  bool encountered_error() const {
+    return calculator_.encountered_error();
+  }
+
   void Add(double value) {
     calculator_->Add(value);
   }
@@ -115,33 +121,58 @@ TEST_F(BindingsRemotePtrTest, Movable) {
   RemotePtr<math::Calculator> a;
   RemotePtr<math::Calculator> b(pipe0_.Pass());
 
-  EXPECT_FALSE(a.is_valid());
-  EXPECT_TRUE(b.is_valid());
+  EXPECT_TRUE(a.is_null());
+  EXPECT_FALSE(b.is_null());
 
   a = b.Pass();
 
-  EXPECT_TRUE(a.is_valid());
-  EXPECT_FALSE(b.is_valid());
+  EXPECT_FALSE(a.is_null());
+  EXPECT_TRUE(b.is_null());
 }
 
 TEST_F(BindingsRemotePtrTest, Resettable) {
   RemotePtr<math::Calculator> a;
 
-  EXPECT_FALSE(a.is_valid());
+  EXPECT_TRUE(a.is_null());
 
   MessagePipeHandle handle = pipe0_.get();
 
   a.reset(pipe0_.Pass());
 
-  EXPECT_TRUE(a.is_valid());
+  EXPECT_FALSE(a.is_null());
 
   a.reset();
 
-  EXPECT_FALSE(a.is_valid());
+  EXPECT_TRUE(a.is_null());
 
   // Test that handle was closed.
   EXPECT_EQ(MOJO_RESULT_INVALID_ARGUMENT, CloseRaw(handle));
 }
 
+TEST_F(BindingsRemotePtrTest, EncounteredError) {
+  MathCalculatorImpl* calculator = new MathCalculatorImpl(pipe0_.Pass());
+
+  MathCalculatorUIImpl calculator_ui(pipe1_.Pass());
+
+  calculator_ui.Add(2.0);
+  PumpMessages();
+  EXPECT_EQ(2.0, calculator_ui.GetOutput());
+  EXPECT_FALSE(calculator_ui.encountered_error());
+
+  calculator_ui.Multiply(5.0);
+  EXPECT_FALSE(calculator_ui.encountered_error());
+
+  // Close the other side of the pipe.
+  delete calculator;
+
+  // The state change isn't picked up locally yet.
+  EXPECT_FALSE(calculator_ui.encountered_error());
+
+  PumpMessages();
+
+  // OK, now we see the error.
+  EXPECT_TRUE(calculator_ui.encountered_error());
+}
+
 }  // namespace test
 }  // namespace mojo