Mojo: Add a GetType() to MessagePipeEndpoint.

This isn't absolutely required, but it's useful (and will soon be even
more useful) for assertions.

R=darin@chromium.org

Review URL: https://codereview.chromium.org/176863006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@254553 0039d316-1c4b-4281-b951-d872f2087c98

8 files changed, 31 insertions, 2 deletions

diff --git a/mojo/system/channel.cc b/mojo/system/channel.cc
index 1c5d336..804e4d7 100644
--- a/mojo/system/channel.cc
+++ b/mojo/system/channel.cc
@@ -10,6 +10,7 @@
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/stringprintf.h"
+#include "mojo/system/message_pipe_endpoint.h"
 
 namespace mojo {
 namespace system {
@@ -70,6 +71,10 @@ void Channel::Shutdown() {
 
 MessageInTransit::EndpointId Channel::AttachMessagePipeEndpoint(
     scoped_refptr<MessagePipe> message_pipe, unsigned port) {
+  DCHECK(port == 0 || port == 1);
+  // Note: This assertion must *not* be done under |lock_|.
+  DCHECK_EQ(message_pipe->GetType(port), MessagePipeEndpoint::kTypeProxy);
+
   MessageInTransit::EndpointId local_id;
   {
     base::AutoLock locker(lock_);
diff --git a/mojo/system/local_message_pipe_endpoint.cc b/mojo/system/local_message_pipe_endpoint.cc
index 6fdec6d7..19f0761 100644
--- a/mojo/system/local_message_pipe_endpoint.cc
+++ b/mojo/system/local_message_pipe_endpoint.cc
@@ -24,6 +24,10 @@ LocalMessagePipeEndpoint::~LocalMessagePipeEndpoint() {
   DCHECK(message_queue_.empty());  // Should be implied by not being open.
 }
 
+MessagePipeEndpoint::Type LocalMessagePipeEndpoint::GetType() const {
+  return kTypeLocal;
+}
+
 void LocalMessagePipeEndpoint::Close() {
   DCHECK(is_open_);
   is_open_ = false;
diff --git a/mojo/system/local_message_pipe_endpoint.h b/mojo/system/local_message_pipe_endpoint.h
index e9c8502..27de317 100644
--- a/mojo/system/local_message_pipe_endpoint.h
+++ b/mojo/system/local_message_pipe_endpoint.h
@@ -25,6 +25,7 @@ class MOJO_SYSTEM_IMPL_EXPORT LocalMessagePipeEndpoint
   virtual ~LocalMessagePipeEndpoint();
 
   // |MessagePipeEndpoint| implementation:
+  virtual Type GetType() const OVERRIDE;
   virtual void Close() OVERRIDE;
   virtual void OnPeerClose() OVERRIDE;
   virtual void EnqueueMessage(scoped_ptr<MessageInTransit> message) OVERRIDE;
diff --git a/mojo/system/message_pipe.cc b/mojo/system/message_pipe.cc
index 0092abd..b18fb75 100644
--- a/mojo/system/message_pipe.cc
+++ b/mojo/system/message_pipe.cc
@@ -32,6 +32,12 @@ unsigned MessagePipe::GetPeerPort(unsigned port) {
   return port ^ 1;
 }
 
+MessagePipeEndpoint::Type MessagePipe::GetType(unsigned port) {
+  DCHECK(port == 0 || port == 1);
+  base::AutoLock locker(lock_);
+  return endpoints_[port]->GetType();
+}
+
 void MessagePipe::CancelAllWaiters(unsigned port) {
   DCHECK(port == 0 || port == 1);
 
@@ -54,7 +60,6 @@ void MessagePipe::Close(unsigned port) {
   endpoints_[port].reset();
 }
 
-// TODO(vtl): Support sending handles.
 // TODO(vtl): Handle flags.
 MojoResult MessagePipe::WriteMessage(
     unsigned port,
diff --git a/mojo/system/message_pipe.h b/mojo/system/message_pipe.h
index 7bfffd1..33e49a1 100644
--- a/mojo/system/message_pipe.h
+++ b/mojo/system/message_pipe.h
@@ -14,13 +14,13 @@
 #include "mojo/public/system/core.h"
 #include "mojo/system/dispatcher.h"
 #include "mojo/system/message_in_transit.h"
+#include "mojo/system/message_pipe_endpoint.h"
 #include "mojo/system/system_impl_export.h"
 
 namespace mojo {
 namespace system {
 
 class Channel;
-class MessagePipeEndpoint;
 class Waiter;
 
 // |MessagePipe| is the secondary object implementing a message pipe (see the
@@ -40,6 +40,9 @@ class MOJO_SYSTEM_IMPL_EXPORT MessagePipe :
   // Gets the other port number (i.e., 0 -> 1, 1 -> 0).
   static unsigned GetPeerPort(unsigned port);
 
+  // Gets the type of the endpoint (used for assertions, etc.).
+  MessagePipeEndpoint::Type GetType(unsigned port);
+
   // These are called by the dispatcher to implement its methods of
   // corresponding names. In all cases, the port |port| must be open.
   void CancelAllWaiters(unsigned port);
diff --git a/mojo/system/message_pipe_endpoint.h b/mojo/system/message_pipe_endpoint.h
index bd9a206..2cd9c17 100644
--- a/mojo/system/message_pipe_endpoint.h
+++ b/mojo/system/message_pipe_endpoint.h
@@ -35,6 +35,12 @@ class MOJO_SYSTEM_IMPL_EXPORT MessagePipeEndpoint {
  public:
   virtual ~MessagePipeEndpoint() {}
 
+  enum Type {
+    kTypeLocal,
+    kTypeProxy
+  };
+  virtual Type GetType() const = 0;
+
   // All implementations must implement these.
   virtual void Close() = 0;
   virtual void OnPeerClose() = 0;
diff --git a/mojo/system/proxy_message_pipe_endpoint.cc b/mojo/system/proxy_message_pipe_endpoint.cc
index 58c72da..ce4de56 100644
--- a/mojo/system/proxy_message_pipe_endpoint.cc
+++ b/mojo/system/proxy_message_pipe_endpoint.cc
@@ -29,6 +29,10 @@ ProxyMessagePipeEndpoint::~ProxyMessagePipeEndpoint() {
   DCHECK(paused_message_queue_.empty());
 }
 
+MessagePipeEndpoint::Type ProxyMessagePipeEndpoint::GetType() const {
+  return kTypeProxy;
+}
+
 void ProxyMessagePipeEndpoint::Close() {
   DCHECK(is_open_);
   is_open_ = false;
diff --git a/mojo/system/proxy_message_pipe_endpoint.h b/mojo/system/proxy_message_pipe_endpoint.h
index 68f1d89..dd0ee03 100644
--- a/mojo/system/proxy_message_pipe_endpoint.h
+++ b/mojo/system/proxy_message_pipe_endpoint.h
@@ -45,6 +45,7 @@ class MOJO_SYSTEM_IMPL_EXPORT ProxyMessagePipeEndpoint
   virtual ~ProxyMessagePipeEndpoint();
 
   // |MessagePipeEndpoint| implementation:
+  virtual Type GetType() const OVERRIDE;
   virtual void Close() OVERRIDE;
   virtual void OnPeerClose() OVERRIDE;
   virtual void EnqueueMessage(scoped_ptr<MessageInTransit> message) OVERRIDE;