Merge pull request #14416 from markdroth/send_message_slice_ownership

Take ownership of byte_buffer contents as soon as send_message op is started.

2 files changed, 23 insertions, 1 deletions

diff --git a/src/core/ext/transport/chttp2/transport/chttp2_transport.cc b/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
index ad8da94cb3..2fc3c4fa41 100644
--- a/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
+++ b/src/core/ext/transport/chttp2/transport/chttp2_transport.cc
@@ -1473,6 +1473,7 @@ static void perform_stream_op_locked(void* stream_op,
       // streaming call might send another message before getting a
       // recv_message failure, breaking out of its loop, and then
       // starting recv_trailing_metadata.
+      grpc_byte_stream_destroy(op->payload->send_message.send_message);
       grpc_chttp2_complete_closure_step(
           t, s, &s->fetching_send_message_finished,
           t->is_client && s->received_trailing_metadata
@@ -2092,7 +2093,10 @@ void grpc_chttp2_fail_pending_writes(grpc_chttp2_transport* t,
                                     GRPC_ERROR_REF(error),
                                     "send_trailing_metadata_finished");
 
-  s->fetching_send_message = nullptr;
+  if (s->fetching_send_message != nullptr) {
+    grpc_byte_stream_destroy(s->fetching_send_message);
+    s->fetching_send_message = nullptr;
+  }
   grpc_chttp2_complete_closure_step(t, s, &s->fetching_send_message_finished,
                                     GRPC_ERROR_REF(error),
                                     "fetching_send_message_finished");
diff --git a/src/core/ext/transport/inproc/inproc_transport.cc b/src/core/ext/transport/inproc/inproc_transport.cc
index 2022eaffe5..e1d4843785 100644
--- a/src/core/ext/transport/inproc/inproc_transport.cc
+++ b/src/core/ext/transport/inproc/inproc_transport.cc
@@ -480,6 +480,8 @@ static void fail_helper_locked(inproc_stream* s, grpc_error* error) {
     s->recv_message_op = nullptr;
   }
   if (s->send_message_op) {
+    grpc_byte_stream_destroy(
+        s->send_message_op->payload->send_message.send_message);
     complete_if_batch_end_locked(
         s, error, s->send_message_op,
         "fail_helper scheduling send-message-on-complete");
@@ -506,6 +508,14 @@ static void fail_helper_locked(inproc_stream* s, grpc_error* error) {
   GRPC_ERROR_UNREF(error);
 }
 
+// TODO(vjpai): It should not be necessary to drain the incoming byte
+// stream and create a new one; instead, we should simply pass the byte
+// stream from the sender directly to the receiver as-is.
+//
+// Note that fixing this will also avoid the assumption in this code
+// that the incoming byte stream's next() call will always return
+// synchronously.  That assumption is true today but may not always be
+// true in the future.
 static void message_transfer_locked(inproc_stream* sender,
                                     inproc_stream* receiver) {
   size_t remaining =
@@ -532,6 +542,8 @@ static void message_transfer_locked(inproc_stream* sender,
     remaining -= GRPC_SLICE_LENGTH(message_slice);
     grpc_slice_buffer_add(&receiver->recv_message, message_slice);
   } while (remaining > 0);
+  grpc_byte_stream_destroy(
+      sender->send_message_op->payload->send_message.send_message);
 
   grpc_slice_buffer_stream_init(&receiver->recv_stream, &receiver->recv_message,
                                 0);
@@ -592,6 +604,8 @@ static void op_state_machine(void* arg, grpc_error* error) {
                (s->trailing_md_sent || other->recv_trailing_md_op)) {
       // A server send will never be matched if the client is waiting
       // for trailing metadata already
+      grpc_byte_stream_destroy(
+          s->send_message_op->payload->send_message.send_message);
       complete_if_batch_end_locked(
           s, GRPC_ERROR_NONE, s->send_message_op,
           "op_state_machine scheduling send-message-on-complete");
@@ -728,6 +742,8 @@ static void op_state_machine(void* arg, grpc_error* error) {
     if ((s->trailing_md_sent || s->t->is_client) && s->send_message_op) {
       // Nothing further will try to receive from this stream, so finish off
       // any outstanding send_message op
+      grpc_byte_stream_destroy(
+          s->send_message_op->payload->send_message.send_message);
       complete_if_batch_end_locked(
           s, new_err, s->send_message_op,
           "op_state_machine scheduling send-message-on-complete");
@@ -785,6 +801,8 @@ static void op_state_machine(void* arg, grpc_error* error) {
       s->send_message_op) {
     // Nothing further will try to receive from this stream, so finish off
     // any outstanding send_message op
+    grpc_byte_stream_destroy(
+        s->send_message_op->payload->send_message.send_message);
     complete_if_batch_end_locked(
         s, new_err, s->send_message_op,
         "op_state_machine scheduling send-message-on-complete");