Get rid of local window, fix qps worker

src/core/ext/transport/chttp2/transport/chttp2_transport.c

@@ -265,7 +265,6 @@ static void init_transport(grpc_exec_ctx *exec_ctx, grpc_chttp2_transport *t,
   t->endpoint_reading = 1;
   t->next_stream_id = is_client ? 1 : 2;
   t->is_client = is_client;
-  t->local_window = DEFAULT_WINDOW;
   t->remote_window = DEFAULT_WINDOW;
   t->announced_window = DEFAULT_WINDOW;
   t->deframe_state = is_client ? GRPC_DTS_FH_0 : GRPC_DTS_CLIENT_PREFIX_0;

src/core/ext/transport/chttp2/transport/flow_control.c

@@ -27,11 +27,14 @@
 
 #include "src/core/lib/support/string.h"
 
+static uint32_t grpc_chttp2_target_announced_window(
+    const grpc_chttp2_transport* t);
+
 #ifndef NDEBUG
 
 typedef struct {
   int64_t remote_window;
-  int64_t local_window;
+  int64_t target_window;
   int64_t announced_window;
   int64_t remote_window_delta;
   int64_t local_window_delta;
@@ -41,7 +44,7 @@ typedef struct {
 static void pretrace(shadow_flow_control* sfc, grpc_chttp2_transport* t,
                      grpc_chttp2_stream* s) {
   sfc->remote_window = t->remote_window;
-  sfc->local_window = t->local_window;
+  sfc->target_window = grpc_chttp2_target_announced_window(t);
   sfc->announced_window = t->announced_window;
   if (s != NULL) {
     sfc->remote_window_delta = s->remote_window_delta;
@@ -69,7 +72,8 @@ static void posttrace(shadow_flow_control* sfc, grpc_chttp2_transport* t,
   uint32_t remote_window =
       t->settings[GRPC_PEER_SETTINGS][GRPC_CHTTP2_SETTINGS_INITIAL_WINDOW_SIZE];
   char* trw_str = fmt_str(sfc->remote_window, t->remote_window);
-  char* tlw_str = fmt_str(sfc->local_window, t->local_window);
+  char* tlw_str =
+      fmt_str(sfc->target_window, grpc_chttp2_target_announced_window(t));
   char* taw_str = fmt_str(sfc->announced_window, t->announced_window);
   char* srw_str;
   char* slw_str;
@@ -87,7 +91,7 @@ static void posttrace(shadow_flow_control* sfc, grpc_chttp2_transport* t,
     saw_str = gpr_leftpad("", ' ', 30);
   }
   gpr_log(GPR_DEBUG,
-          "%p[%u][%s] | %s | trw:%s, tlw:%s, taw:%s, srw:%s, slw:%s, saw:%s", t,
+          "%p[%u][%s] | %s | trw:%s, ttw:%s, taw:%s, srw:%s, slw:%s, saw:%s", t,
           s != NULL ? s->id : 0, t->is_client ? "cli" : "svr", reason, trw_str,
           tlw_str, taw_str, srw_str, slw_str, saw_str);
   gpr_free(trw_str);
@@ -177,10 +181,10 @@ grpc_error* grpc_chttp2_flowctl_recv_data(grpc_chttp2_transport* t,
                                           grpc_chttp2_stream* s,
                                           int64_t incoming_frame_size) {
   PRETRACE(t, s);
-  if (incoming_frame_size > t->local_window) {
+  if (incoming_frame_size > t->announced_window) {
     char* msg;
     gpr_asprintf(&msg, "frame of size %d overflows local window of %" PRId64,
-                 t->incoming_frame_size, t->local_window);
+                 t->incoming_frame_size, t->announced_window);
     grpc_error* err = GRPC_ERROR_CREATE_FROM_COPIED_STRING(msg);
     gpr_free(msg);
     return err;
@@ -228,7 +232,6 @@ grpc_error* grpc_chttp2_flowctl_recv_data(grpc_chttp2_transport* t,
   }
 
   t->announced_window -= incoming_frame_size;
-  t->local_window -= incoming_frame_size;
 
   POSTTRACE(t, s, "  data recv");
   return GRPC_ERROR_NONE;
@@ -243,14 +246,11 @@ uint32_t grpc_chttp2_flowctl_maybe_send_transport_update(
   uint32_t threshold_to_send_transport_window_update =
       t->outbuf.count > 0 ? 3 * target_announced_window / 4
                           : target_announced_window / 2;
-  if (t->announced_window < t->local_window &&
-      t->announced_window <= threshold_to_send_transport_window_update &&
+  if (t->announced_window <= threshold_to_send_transport_window_update &&
       t->announced_window != target_announced_window) {
     uint32_t announce = (uint32_t)GPR_CLAMP(
         target_announced_window - t->announced_window, 0, UINT32_MAX);
     t->announced_window += announce;
-    t->local_window =
-        t->announced_window;  // announced should never be higher than local.
     POSTTRACE(t, NULL, "t updt sent");
     return announce;
   }
@@ -323,7 +323,6 @@ void grpc_chttp2_flowctl_incoming_bs_update(grpc_chttp2_transport* t,
     uint32_t add_max_recv_bytes =
         (uint32_t)(max_recv_bytes - s->local_window_delta);
     s->local_window_delta += add_max_recv_bytes;
-    s->t->local_window += add_max_recv_bytes;
   }
   POSTTRACE(t, s, "app st recv");
 }

src/core/ext/transport/chttp2/transport/internal.h

@@ -337,17 +337,7 @@ struct grpc_chttp2_transport {
   /** Our bookkeeping for the remote peer's available window */
   int64_t remote_window;
 
-  /** Our bookkeeping for our window. Essentially this tracks available buffer
-   * space to hold data that peer sends to us. This is our local view of the
-   * window. It does not reflect how the remote peer sees it. */
-  int64_t local_window;
-
-  /** This is out window according to what we have sent to our remote peer. The
-   * difference between this and local_window is what we use to decide when
-   * to send WINDOW_UPDATE frames. */
-  int64_t announced_window;
-
-  /** calculating what we should give for incoming window:
+  /** calculating what we should give for local window:
       we track the total amount of flow control over initial window size
       across all streams: this is data that we want to receive right now (it
       has an outstanding read)
@@ -358,6 +348,11 @@ struct grpc_chttp2_transport {
   int64_t announced_stream_total_over_incoming_window;
   int64_t announced_stream_total_under_incoming_window;
 
+  /** This is out window according to what we have sent to our remote peer. The
+   * difference between this and target window is what we use to decide when
+   * to send WINDOW_UPDATE frames. */
+  int64_t announced_window;
+
   /* bdp estimation */
   grpc_bdp_estimator bdp_estimator;
 

test/cpp/microbenchmarks/bm_chttp2_transport.cc

@@ -522,7 +522,6 @@ static void BM_TransportStreamRecv(benchmark::State &state) {
         if (!state.KeepRunning()) return;
         // force outgoing window to be yuge
         s.chttp2_stream()->local_window_delta = 1024 * 1024 * 1024;
-        f.chttp2_transport()->local_window = 1024 * 1024 * 1024;
         s.chttp2_stream()->announced_window_delta = 1024 * 1024 * 1024;
         f.chttp2_transport()->announced_window = 1024 * 1024 * 1024;
         received = 0;

test/cpp/microbenchmarks/bm_fullstack_trickle.cc

@@ -74,8 +74,7 @@ class TrickledCHTTP2 : public EndpointPairFixture {
       write_csv(log_.get(), "t", "iteration", "client_backlog",
                 "server_backlog", "client_t_stall", "client_s_stall",
                 "server_t_stall", "server_s_stall", "client_t_remote",
-                "server_t_remote", "client_t_local", "server_t_local",
-                "client_t_announced", "server_t_announced",
+                "server_t_remote", "client_t_announced", "server_t_announced",
                 "client_s_remote_delta", "server_s_remote_delta",
                 "client_s_local_delta", "server_s_local_delta",
                 "client_s_announced_delta", "server_s_announced_delta",
@@ -128,8 +127,7 @@ class TrickledCHTTP2 : public EndpointPairFixture {
         client->lists[GRPC_CHTTP2_LIST_STALLED_BY_STREAM].head != nullptr,
         server->lists[GRPC_CHTTP2_LIST_STALLED_BY_TRANSPORT].head != nullptr,
         server->lists[GRPC_CHTTP2_LIST_STALLED_BY_STREAM].head != nullptr,
-        client->remote_window, server->remote_window, client->local_window,
-        server->local_window, client->announced_window,
+        client->remote_window, server->remote_window, client->announced_window,
         server->announced_window,
         client_stream ? client_stream->remote_window_delta : -1,
         server_stream ? server_stream->remote_window_delta : -1,