Revert "Merge pull request #15746 from grpc/revert-15709-recv_trailing_metadata_ready2"

This reverts commit 3f9308ce1f8cb42c96901c1700f0b9dbb531f186, reversing
changes made to 92a0ae0b1081840d2c5a488f66bf6550c1a492f4.

1 files changed, 57 insertions, 24 deletions

diff --git a/src/core/lib/surface/call.cc b/src/core/lib/surface/call.cc
index 1cf8ea94e7..8b224b6e7b 100644
--- a/src/core/lib/surface/call.cc
+++ b/src/core/lib/surface/call.cc
@@ -233,6 +233,7 @@ struct grpc_call {
   grpc_closure receiving_slice_ready;
   grpc_closure receiving_stream_ready;
   grpc_closure receiving_initial_metadata_ready;
+  grpc_closure receiving_trailing_metadata_ready;
   uint32_t test_only_last_message_flags;
 
   grpc_closure release_call;
@@ -270,8 +271,17 @@ struct grpc_call {
 grpc_core::TraceFlag grpc_call_error_trace(false, "call_error");
 grpc_core::TraceFlag grpc_compression_trace(false, "compression");
 
-#define CALL_STACK_FROM_CALL(call) ((grpc_call_stack*)((call) + 1))
-#define CALL_FROM_CALL_STACK(call_stack) (((grpc_call*)(call_stack)) - 1)
+/* Given a size, round up to the next multiple of sizeof(void*) */
+#define ROUND_UP_TO_ALIGNMENT_SIZE(x) \
+  (((x) + GPR_MAX_ALIGNMENT - 1u) & ~(GPR_MAX_ALIGNMENT - 1u))
+
+#define CALL_STACK_FROM_CALL(call)   \
+  (grpc_call_stack*)((char*)(call) + \
+                     ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(grpc_call)))
+#define CALL_FROM_CALL_STACK(call_stack) \
+  (grpc_call*)(((char*)(call_stack)) -   \
+               ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(grpc_call)))
+
 #define CALL_ELEM_FROM_CALL(call, idx) \
   grpc_call_stack_element(CALL_STACK_FROM_CALL(call), idx)
 #define CALL_FROM_TOP_ELEM(top_elem) \
@@ -342,8 +352,9 @@ grpc_error* grpc_call_create(const grpc_call_create_args* args,
   size_t initial_size = grpc_channel_get_call_size_estimate(args->channel);
   GRPC_STATS_INC_CALL_INITIAL_SIZE(initial_size);
   gpr_arena* arena = gpr_arena_create(initial_size);
-  call = static_cast<grpc_call*>(gpr_arena_alloc(
-      arena, sizeof(grpc_call) + channel_stack->call_stack_size));
+  call = static_cast<grpc_call*>(
+      gpr_arena_alloc(arena, ROUND_UP_TO_ALIGNMENT_SIZE(sizeof(grpc_call)) +
+                                 channel_stack->call_stack_size));
   gpr_ref_init(&call->ext_ref, 1);
   call->arena = arena;
   grpc_call_combiner_init(&call->call_combiner);
@@ -1209,7 +1220,6 @@ static void post_batch_completion(batch_control* bctl) {
 
   if (bctl->op.send_initial_metadata) {
     grpc_metadata_batch_destroy(
-
         &call->metadata_batch[0 /* is_receiving */][0 /* is_trailing */]);
   }
   if (bctl->op.send_message) {
@@ -1217,14 +1227,9 @@ static void post_batch_completion(batch_control* bctl) {
   }
   if (bctl->op.send_trailing_metadata) {
     grpc_metadata_batch_destroy(
-
         &call->metadata_batch[0 /* is_receiving */][1 /* is_trailing */]);
   }
   if (bctl->op.recv_trailing_metadata) {
-    grpc_metadata_batch* md =
-        &call->metadata_batch[1 /* is_receiving */][1 /* is_trailing */];
-    recv_trailing_filter(call, md);
-
     /* propagate cancellation to any interested children */
     gpr_atm_rel_store(&call->received_final_op_atm, 1);
     parent_call* pc = get_parent_call(call);
@@ -1246,7 +1251,6 @@ static void post_batch_completion(batch_control* bctl) {
       }
       gpr_mu_unlock(&pc->child_list_mu);
     }
-
     if (call->is_client) {
       get_final_status(call, set_status_value_directly,
                        call->final_op.client.status,
@@ -1256,7 +1260,6 @@ static void post_batch_completion(batch_control* bctl) {
       get_final_status(call, set_cancelled_value,
                        call->final_op.server.cancelled, nullptr, nullptr);
     }
-
     GRPC_ERROR_UNREF(error);
     error = GRPC_ERROR_NONE;
   }
@@ -1538,6 +1541,19 @@ static void receiving_initial_metadata_ready(void* bctlp, grpc_error* error) {
   finish_batch_step(bctl);
 }
 
+static void receiving_trailing_metadata_ready(void* bctlp, grpc_error* error) {
+  batch_control* bctl = static_cast<batch_control*>(bctlp);
+  grpc_call* call = bctl->call;
+  GRPC_CALL_COMBINER_STOP(&call->call_combiner, "recv_trailing_metadata_ready");
+  add_batch_error(bctl, GRPC_ERROR_REF(error), false);
+  if (error == GRPC_ERROR_NONE) {
+    grpc_metadata_batch* md =
+        &call->metadata_batch[1 /* is_receiving */][1 /* is_trailing */];
+    recv_trailing_filter(call, md);
+  }
+  finish_batch_step(bctl);
+}
+
 static void finish_batch(void* bctlp, grpc_error* error) {
   batch_control* bctl = static_cast<batch_control*>(bctlp);
   grpc_call* call = bctl->call;
@@ -1558,7 +1574,8 @@ static grpc_call_error call_start_batch(grpc_call* call, const grpc_op* ops,
   size_t i;
   const grpc_op* op;
   batch_control* bctl;
-  int num_completion_callbacks_needed = 1;
+  bool has_send_ops = false;
+  int num_recv_ops = 0;
   grpc_call_error error = GRPC_CALL_OK;
   grpc_transport_stream_op_batch* stream_op;
   grpc_transport_stream_op_batch_payload* stream_op_payload;
@@ -1664,6 +1681,7 @@ static grpc_call_error call_start_batch(grpc_call* call, const grpc_op* ops,
           stream_op_payload->send_initial_metadata.peer_string =
               &call->peer_string;
         }
+        has_send_ops = true;
         break;
       }
       case GRPC_OP_SEND_MESSAGE: {
@@ -1693,6 +1711,7 @@ static grpc_call_error call_start_batch(grpc_call* call, const grpc_op* ops,
             &op->data.send_message.send_message->data.raw.slice_buffer, flags);
         stream_op_payload->send_message.send_message.reset(
             call->sending_stream.get());
+        has_send_ops = true;
         break;
       }
       case GRPC_OP_SEND_CLOSE_FROM_CLIENT: {
@@ -1713,6 +1732,7 @@ static grpc_call_error call_start_batch(grpc_call* call, const grpc_op* ops,
         call->sent_final_op = true;
         stream_op_payload->send_trailing_metadata.send_trailing_metadata =
             &call->metadata_batch[0 /* is_receiving */][1 /* is_trailing */];
+        has_send_ops = true;
         break;
       }
       case GRPC_OP_SEND_STATUS_FROM_SERVER: {
@@ -1777,6 +1797,7 @@ static grpc_call_error call_start_batch(grpc_call* call, const grpc_op* ops,
         }
         stream_op_payload->send_trailing_metadata.send_trailing_metadata =
             &call->metadata_batch[0 /* is_receiving */][1 /* is_trailing */];
+        has_send_ops = true;
         break;
       }
       case GRPC_OP_RECV_INITIAL_METADATA: {
@@ -1804,7 +1825,7 @@ static grpc_call_error call_start_batch(grpc_call* call, const grpc_op* ops,
           stream_op_payload->recv_initial_metadata.peer_string =
               &call->peer_string;
         }
-        num_completion_callbacks_needed++;
+        ++num_recv_ops;
         break;
       }
       case GRPC_OP_RECV_MESSAGE: {
@@ -1826,7 +1847,7 @@ static grpc_call_error call_start_batch(grpc_call* call, const grpc_op* ops,
                           grpc_schedule_on_exec_ctx);
         stream_op_payload->recv_message.recv_message_ready =
             &call->receiving_stream_ready;
-        num_completion_callbacks_needed++;
+        ++num_recv_ops;
         break;
       }
       case GRPC_OP_RECV_STATUS_ON_CLIENT: {
@@ -1852,11 +1873,16 @@ static grpc_call_error call_start_batch(grpc_call* call, const grpc_op* ops,
         call->final_op.client.error_string =
             op->data.recv_status_on_client.error_string;
         stream_op->recv_trailing_metadata = true;
-        stream_op->collect_stats = true;
         stream_op_payload->recv_trailing_metadata.recv_trailing_metadata =
             &call->metadata_batch[1 /* is_receiving */][1 /* is_trailing */];
-        stream_op_payload->collect_stats.collect_stats =
+        stream_op_payload->recv_trailing_metadata.collect_stats =
             &call->final_info.stats.transport_stream_stats;
+        GRPC_CLOSURE_INIT(&call->receiving_trailing_metadata_ready,
+                          receiving_trailing_metadata_ready, bctl,
+                          grpc_schedule_on_exec_ctx);
+        stream_op_payload->recv_trailing_metadata.recv_trailing_metadata_ready =
+            &call->receiving_trailing_metadata_ready;
+        ++num_recv_ops;
         break;
       }
       case GRPC_OP_RECV_CLOSE_ON_SERVER: {
@@ -1877,11 +1903,16 @@ static grpc_call_error call_start_batch(grpc_call* call, const grpc_op* ops,
         call->final_op.server.cancelled =
             op->data.recv_close_on_server.cancelled;
         stream_op->recv_trailing_metadata = true;
-        stream_op->collect_stats = true;
         stream_op_payload->recv_trailing_metadata.recv_trailing_metadata =
             &call->metadata_batch[1 /* is_receiving */][1 /* is_trailing */];
-        stream_op_payload->collect_stats.collect_stats =
+        stream_op_payload->recv_trailing_metadata.collect_stats =
             &call->final_info.stats.transport_stream_stats;
+        GRPC_CLOSURE_INIT(&call->receiving_trailing_metadata_ready,
+                          receiving_trailing_metadata_ready, bctl,
+                          grpc_schedule_on_exec_ctx);
+        stream_op_payload->recv_trailing_metadata.recv_trailing_metadata_ready =
+            &call->receiving_trailing_metadata_ready;
+        ++num_recv_ops;
         break;
       }
     }
@@ -1891,13 +1922,15 @@ static grpc_call_error call_start_batch(grpc_call* call, const grpc_op* ops,
   if (!is_notify_tag_closure) {
     GPR_ASSERT(grpc_cq_begin_op(call->cq, notify_tag));
   }
-  gpr_ref_init(&bctl->steps_to_complete, num_completion_callbacks_needed);
+  gpr_ref_init(&bctl->steps_to_complete, (has_send_ops ? 1 : 0) + num_recv_ops);
 
-  GRPC_CLOSURE_INIT(&bctl->finish_batch, finish_batch, bctl,
-                    grpc_schedule_on_exec_ctx);
-  stream_op->on_complete = &bctl->finish_batch;
-  gpr_atm_rel_store(&call->any_ops_sent_atm, 1);
+  if (has_send_ops) {
+    GRPC_CLOSURE_INIT(&bctl->finish_batch, finish_batch, bctl,
+                      grpc_schedule_on_exec_ctx);
+    stream_op->on_complete = &bctl->finish_batch;
+  }
 
+  gpr_atm_rel_store(&call->any_ops_sent_atm, 1);
   execute_batch(call, stream_op, &bctl->start_batch);
 
 done: