Allow data pipe producer/consumer handles to be re-sent.

mojo/edk/system/remote_consumer_data_pipe_impl.cc

Index: mojo/edk/system/remote_consumer_data_pipe_impl.cc
diff --git a/mojo/edk/system/remote_consumer_data_pipe_impl.cc b/mojo/edk/system/remote_consumer_data_pipe_impl.cc
index 9bb3b8495fd6a2c8f43f97e7573deaaeb9ee2152..fa59df06e6ecc830582a7698ff7e9b4ff009c904 100644
--- a/mojo/edk/system/remote_consumer_data_pipe_impl.cc
+++ b/mojo/edk/system/remote_consumer_data_pipe_impl.cc
@@ -10,6 +10,7 @@
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
+#include "mojo/edk/system/channel.h"
 #include "mojo/edk/system/channel_endpoint.h"
 #include "mojo/edk/system/configuration.h"
 #include "mojo/edk/system/data_pipe.h"
@@ -255,9 +256,8 @@ void RemoteConsumerDataPipeImpl::ProducerStartSerialize(
     Channel* channel,
     size_t* max_size,
     size_t* max_platform_handles) {
-  // TODO(vtl): Support serializing producer data pipe handles.
-  NOTIMPLEMENTED();  // FIXME
-  *max_size = 0;
+  *max_size = sizeof(SerializedDataPipeProducerDispatcher) +
+              channel->GetSerializedEndpointSize();
   *max_platform_handles = 0;
 }
 
@@ -266,10 +266,33 @@ bool RemoteConsumerDataPipeImpl::ProducerEndSerialize(
     void* destination,
     size_t* actual_size,
     embedder::PlatformHandleVector* platform_handles) {
-  // TODO(vtl): Support serializing producer data pipe handles.
-  NOTIMPLEMENTED();  // FIXME
-  owner()->ProducerCloseNoLock();
-  return false;
+  SerializedDataPipeProducerDispatcher* s =
+      static_cast<SerializedDataPipeProducerDispatcher*>(destination);
+  s->validated_options = validated_options();
+  void* destination_for_endpoint = static_cast<char*>(destination) +
+                                   sizeof(SerializedDataPipeProducerDispatcher);
+
+  if (!consumer_open()) {
+    // Case 1: The consumer is closed.
+    s->consumer_num_bytes = static_cast<size_t>(-1);
+    *actual_size = sizeof(SerializedDataPipeProducerDispatcher);
+    return true;
+  }
+
+  // Case 2: The consumer isn't closed. We pass |channel_endpoint| back to the
+  // |Channel|. There's no reason for us to continue to exist afterwards.
+
+  s->consumer_num_bytes = consumer_num_bytes_;
+  // Note: We don't use |port|.
+  scoped_refptr<ChannelEndpoint> channel_endpoint;
+  channel_endpoint.swap(channel_endpoint_);
+  channel->SerializeEndpointWithRemotePeer(destination_for_endpoint, nullptr,
+                                           channel_endpoint);
+  owner()->SetConsumerClosedNoLock();

[Hajime Morrita, 2015/03/03 03:00:38]

This isn't directly related to this CL, but it'd be nice if the naming indicates
that consumer_open() and SetConsumeClosedNoLock() refers the same flag, or even
there is no flag and it just sees channel_endpoint_ to decide open-ness. The
flag seems a bit too delicate.

[viettrungluu, 2015/03/03 05:17:45]

Yeah, things aren't factored quite right (partly a consequence of my moving the
implementation of DataPipe into the ...DataPipeImpl subclasses). :-/

I kind of want to just make the the impls are in charge of this information
(rather than having flags in DataPipe) ... but I'd have to do this carefully
since impls can be swapped (and sometimes there may not be an impl, even if
momentarily, which would complicate various DCHECKs and such).

+
+  *actual_size = sizeof(SerializedDataPipeProducerDispatcher) +
+                 channel->GetSerializedEndpointSize();
+  return true;
 }
 
 void RemoteConsumerDataPipeImpl::ConsumerClose() {