Fix bugs with TCP

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

@@ -2022,7 +2022,7 @@ static void incoming_byte_stream_update_flow_control(grpc_exec_ctx *exec_ctx,
         (uint32_t)(max_recv_bytes - s->incoming_window_delta);
     bool new_window_write_is_covered_by_poller =
         s->incoming_window_delta + initial_window_size < (int64_t)have_already;
-    bool force_send = (s->incoming_window_delta - s->announce_window <
+    bool force_send = (s->incoming_window_delta - s->announce_window <=
                        -(int64_t)initial_window_size / 2);
     /*    gpr_log(GPR_DEBUG, "%d %d %d",
                 (int)(s->incoming_window_delta - s->announce_window),

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

@@ -381,7 +381,7 @@ static grpc_error *update_incoming_window(grpc_exec_ctx *exec_ctx,
       1024);
   GRPC_CHTTP2_FLOW_DEBIT_TRANSPORT("parse", t, incoming_window,
                                    incoming_frame_size);
-  if (t->incoming_window < target_incoming_window / 2) {
+  if (t->incoming_window <= target_incoming_window / 2) {
     grpc_chttp2_initiate_write(exec_ctx, t, false, "flow_control");
   }
 
@@ -403,7 +403,8 @@ static grpc_error *update_incoming_window(grpc_exec_ctx *exec_ctx,
   if (s != NULL) {
     GRPC_CHTTP2_FLOW_DEBIT_STREAM("parse", t, s, incoming_window_delta,
                                   incoming_frame_size);
-    if (s->incoming_window_delta < -target_incoming_window / 2) {
+    if (s->incoming_window_delta - s->announce_window <=
+        -(int64_t)target_incoming_window / 2) {
       grpc_chttp2_become_writable(exec_ctx, t, s, false,
                                   "window-update-required");
     }

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

@@ -316,7 +316,7 @@ bool grpc_chttp2_begin_write(grpc_exec_ctx *exec_ctx,
   uint32_t threshold_to_send_transport_window_update =
       t->outbuf.count > 0 ? 3 * target_incoming_window / 4
                           : target_incoming_window / 2;
-  if (t->incoming_window < threshold_to_send_transport_window_update) {
+  if (t->incoming_window <= threshold_to_send_transport_window_update) {
     maybe_initiate_ping(exec_ctx, t,
                         GRPC_CHTTP2_PING_BEFORE_TRANSPORT_WINDOW_UPDATE);
     uint32_t announced = (uint32_t)GPR_CLAMP(