Mechanism for reporting stats up

src/core/surface/call.c

@@ -174,6 +174,9 @@ struct grpc_call {
   /* Received call statuses from various sources */
   received_status status[STATUS_SOURCE_COUNT];
 
+  /* Call stats: only valid after trailing metadata received */
+  grpc_transport_stream_stats stats;
+
   /* Compression algorithm for the call */
   grpc_compression_algorithm compression_algorithm;
   /* Supported encodings (compression algorithms), a bitset */
@@ -1371,6 +1374,7 @@ static grpc_call_error call_start_batch(grpc_exec_ctx *exec_ctx,
         bctl->recv_final_op = 1;
         stream_op.recv_trailing_metadata =
             &call->metadata_batch[1 /* is_receiving */][1 /* is_trailing */];
+        stream_op.collect_stats = &call->stats;
         break;
       case GRPC_OP_RECV_CLOSE_ON_SERVER:
         /* Flag validation: currently allow no flags */
@@ -1392,6 +1396,7 @@ static grpc_call_error call_start_batch(grpc_exec_ctx *exec_ctx,
         bctl->recv_final_op = 1;
         stream_op.recv_trailing_metadata =
             &call->metadata_batch[1 /* is_receiving */][1 /* is_trailing */];
+        stream_op.collect_stats = &call->stats;
         break;
     }
   }

src/core/transport/chttp2/internal.h

@@ -394,6 +394,9 @@ typedef struct {
   grpc_metadata_batch *recv_trailing_metadata;
   grpc_closure *recv_trailing_metadata_finished;
 
+  grpc_transport_stream_stats *collecting_stats;
+  grpc_transport_stream_stats stats;
+
   /** when the application requests writes be closed, the write_closed is
       'queued'; when the close is flow controlled into the send path, we are
       'sending' it; when the write has been performed it is 'sent' */
@@ -635,6 +638,7 @@ void grpc_chttp2_parsing_become_skip_parser(
     grpc_exec_ctx *exec_ctx, grpc_chttp2_transport_parsing *transport_parsing);
 
 void grpc_chttp2_complete_closure_step(grpc_exec_ctx *exec_ctx,
+                                       grpc_chttp2_stream_global *stream_global,
                                        grpc_closure **pclosure, int success);
 
 #define GRPC_CHTTP2_CLIENT_CONNECT_STRING "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n"

src/core/transport/chttp2/writing.c

@@ -328,17 +328,19 @@ void grpc_chttp2_cleanup_writing(
       transport_global, transport_writing, &stream_global, &stream_writing)) {
     if (stream_writing->sent_initial_metadata) {
       grpc_chttp2_complete_closure_step(
-          exec_ctx, &stream_global->send_initial_metadata_finished, 1);
+          exec_ctx, stream_global,
+          &stream_global->send_initial_metadata_finished, 1);
     }
     if (stream_writing->sent_message) {
       GPR_ASSERT(stream_writing->send_message == NULL);
       grpc_chttp2_complete_closure_step(
-          exec_ctx, &stream_global->send_message_finished, 1);
+          exec_ctx, stream_global, &stream_global->send_message_finished, 1);
       stream_writing->sent_message = 0;
     }
     if (stream_writing->sent_trailing_metadata) {
       grpc_chttp2_complete_closure_step(
-          exec_ctx, &stream_global->send_trailing_metadata_finished, 1);
+          exec_ctx, stream_global,
+          &stream_global->send_trailing_metadata_finished, 1);
     }
     if (stream_writing->sent_trailing_metadata) {
       grpc_chttp2_mark_stream_closed(exec_ctx, transport_global, stream_global,

src/core/transport/chttp2_transport.c

@@ -758,23 +758,35 @@ static void maybe_start_some_streams(
   }
 }
 
+#define CLOSURE_BARRIER_STATS_BIT (1 << 0)
+#define CLOSURE_BARRIER_FAILURE_BIT (1 << 1)
+#define CLOSURE_BARRIER_FIRST_REF_BIT (1 << 16)
+
 static grpc_closure *add_closure_barrier(grpc_closure *closure) {
-  closure->final_data += 2;
+  closure->final_data += CLOSURE_BARRIER_FIRST_REF_BIT;
   return closure;
 }
 
 void grpc_chttp2_complete_closure_step(grpc_exec_ctx *exec_ctx,
+                                       grpc_chttp2_stream_global *stream_global,
                                        grpc_closure **pclosure, int success) {
   grpc_closure *closure = *pclosure;
   if (closure == NULL) {
     return;
   }
-  closure->final_data -= 2;
+  closure->final_data -= CLOSURE_BARRIER_FIRST_REF_BIT;
   if (!success) {
-    closure->final_data |= 1;
+    closure->final_data |= CLOSURE_BARRIER_FAILURE_BIT;
   }
-  if (closure->final_data < 2) {
-    grpc_exec_ctx_enqueue(exec_ctx, closure, closure->final_data == 0, NULL);
+  if (closure->final_data < CLOSURE_BARRIER_FIRST_REF_BIT) {
+    if (closure->final_data & CLOSURE_BARRIER_STATS_BIT) {
+      grpc_transport_move_stats(&stream_global->stats,
+                                stream_global->collecting_stats);
+      stream_global->collecting_stats = NULL;
+    }
+    grpc_exec_ctx_enqueue(
+        exec_ctx, closure,
+        (closure->final_data & CLOSURE_BARRIER_FAILURE_BIT) == 0, NULL);
   }
   *pclosure = NULL;
 }
@@ -807,7 +819,13 @@ static void perform_stream_op_locked(
   }
   /* use final_data as a barrier until enqueue time; the inital counter is
      dropped at the end of this function */
-  on_complete->final_data = 2;
+  on_complete->final_data = CLOSURE_BARRIER_FIRST_REF_BIT;
+
+  if (op->collect_stats != NULL) {
+    GPR_ASSERT(stream_global->collecting_stats == NULL);
+    stream_global->collecting_stats = op->collect_stats;
+    on_complete->final_data |= CLOSURE_BARRIER_STATS_BIT;
+  }
 
   if (op->cancel_with_status != GRPC_STATUS_OK) {
     cancel_from_api(exec_ctx, transport_global, stream_global,
@@ -840,7 +858,8 @@ static void perform_stream_op_locked(
       }
     } else {
       grpc_chttp2_complete_closure_step(
-          exec_ctx, &stream_global->send_initial_metadata_finished, 0);
+          exec_ctx, stream_global,
+          &stream_global->send_initial_metadata_finished, 0);
     }
   }
 
@@ -850,7 +869,7 @@ static void perform_stream_op_locked(
     stream_global->send_message_finished = add_closure_barrier(on_complete);
     if (stream_global->write_closed) {
       grpc_chttp2_complete_closure_step(
-          exec_ctx, &stream_global->send_message_finished, 0);
+          exec_ctx, stream_global, &stream_global->send_message_finished, 0);
     } else if (stream_global->id != 0) {
       stream_global->send_message = op->send_message;
       grpc_chttp2_become_writable(transport_global, stream_global);
@@ -868,7 +887,8 @@ static void perform_stream_op_locked(
     }
     if (stream_global->write_closed) {
       grpc_chttp2_complete_closure_step(
-          exec_ctx, &stream_global->send_trailing_metadata_finished,
+          exec_ctx, stream_global,
+          &stream_global->send_trailing_metadata_finished,
           grpc_metadata_batch_is_empty(op->send_trailing_metadata));
     } else if (stream_global->id != 0) {
       /* TODO(ctiller): check if there's flow control for any outstanding
@@ -907,7 +927,7 @@ static void perform_stream_op_locked(
     grpc_chttp2_list_add_check_read_ops(transport_global, stream_global);
   }
 
-  grpc_chttp2_complete_closure_step(exec_ctx, &on_complete, 1);
+  grpc_chttp2_complete_closure_step(exec_ctx, stream_global, &on_complete, 1);
 
   GPR_TIMER_END("perform_stream_op_locked", 0);
 }
@@ -1078,7 +1098,8 @@ static void check_read_ops(grpc_exec_ctx *exec_ctx,
             &stream_global->received_trailing_metadata,
             stream_global->recv_trailing_metadata);
         grpc_chttp2_complete_closure_step(
-            exec_ctx, &stream_global->recv_trailing_metadata_finished, 1);
+            exec_ctx, stream_global,
+            &stream_global->recv_trailing_metadata_finished, 1);
       }
     }
   }
@@ -1177,10 +1198,12 @@ void grpc_chttp2_fake_status(grpc_exec_ctx *exec_ctx,
 static void fail_pending_writes(grpc_exec_ctx *exec_ctx,
                                 grpc_chttp2_stream_global *stream_global) {
   grpc_chttp2_complete_closure_step(
-      exec_ctx, &stream_global->send_initial_metadata_finished, 0);
+      exec_ctx, stream_global, &stream_global->send_initial_metadata_finished,
+      0);
   grpc_chttp2_complete_closure_step(
-      exec_ctx, &stream_global->send_trailing_metadata_finished, 0);
-  grpc_chttp2_complete_closure_step(exec_ctx,
+      exec_ctx, stream_global, &stream_global->send_trailing_metadata_finished,
+      0);
+  grpc_chttp2_complete_closure_step(exec_ctx, stream_global,
                                     &stream_global->send_message_finished, 0);
 }
 

src/core/transport/transport.c

@@ -77,15 +77,22 @@ void grpc_stream_ref_init(grpc_stream_refcount *refcount, int initial_refs,
   grpc_closure_init(&refcount->destroy, cb, cb_arg);
 }
 
-static void one_way_stats_init(grpc_transport_one_way_stats *stats) {
-  gpr_stats_init(&stats->framing_bytes, 0);
-  gpr_stats_init(&stats->data_bytes, 0);
-  gpr_stats_init(&stats->header_bytes, 0);
+static void move64(uint64_t *from, uint64_t *to) {
+  *to += *from;
+  *from = 0;
 }
 
-void grpc_transport_stream_stats_init(grpc_transport_stream_stats *stats) {
-  one_way_stats_init(&stats->incoming);
-  one_way_stats_init(&stats->outgoing);
+void grpc_transport_move_one_way_stats(grpc_transport_one_way_stats *from,
+                                       grpc_transport_one_way_stats *to) {
+  move64(&from->framing_bytes, &to->framing_bytes);
+  move64(&from->data_bytes, &to->data_bytes);
+  move64(&from->header_bytes, &to->header_bytes);
+}
+
+void grpc_transport_move_stats(grpc_transport_stream_stats *from,
+                               grpc_transport_stream_stats *to) {
+  grpc_transport_move_one_way_stats(&from->incoming, &to->incoming);
+  grpc_transport_move_one_way_stats(&from->outgoing, &to->outgoing);
 }
 
 size_t grpc_transport_stream_size(grpc_transport *transport) {

src/core/transport/transport.h

@@ -78,6 +78,23 @@ void grpc_stream_unref(grpc_exec_ctx *exec_ctx, grpc_stream_refcount *refcount);
   grpc_stream_ref_init(rc, ir, cb, cb_arg)
 #endif
 
+typedef struct {
+  uint64_t framing_bytes;
+  uint64_t data_bytes;
+  uint64_t header_bytes;
+} grpc_transport_one_way_stats;
+
+typedef struct grpc_transport_stream_stats {
+  grpc_transport_one_way_stats incoming;
+  grpc_transport_one_way_stats outgoing;
+} grpc_transport_stream_stats;
+
+void grpc_transport_move_one_way_stats(grpc_transport_one_way_stats *from,
+                                       grpc_transport_one_way_stats *to);
+
+void grpc_transport_move_stats(grpc_transport_stream_stats *from,
+                               grpc_transport_stream_stats *to);
+
 /* Transport stream op: a set of operations to perform on a transport
    against a single stream */
 typedef struct grpc_transport_stream_op {
@@ -104,6 +121,9 @@ typedef struct grpc_transport_stream_op {
    */
   grpc_metadata_batch *recv_trailing_metadata;
 
+  /** Collect any stats into provided buffer, zero internal stat counters */
+  grpc_transport_stream_stats *collect_stats;
+
   /** Should be enqueued when all requested operations (excluding recv_message
       and recv_initial_metadata which have their own closures) in a given batch
       have been completed. */
@@ -154,19 +174,6 @@ typedef struct grpc_transport_op {
   grpc_closure *send_ping;
 } grpc_transport_op;
 
-typedef struct {
-  gpr_stats_counter framing_bytes;
-  gpr_stats_counter data_bytes;
-  gpr_stats_counter header_bytes;
-} grpc_transport_one_way_stats;
-
-typedef struct grpc_transport_stream_stats {
-  grpc_transport_one_way_stats incoming;
-  grpc_transport_one_way_stats outgoing;
-} grpc_transport_stream_stats;
-
-void grpc_transport_stream_stats_init(grpc_transport_stream_stats *stats);
-
 /* Returns the amount of memory required to store a grpc_stream for this
    transport */
 size_t grpc_transport_stream_size(grpc_transport *transport);