fixes

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

@@ -538,6 +538,20 @@ grpc_chttp2_stream *grpc_chttp2_parsing_accept_stream(grpc_exec_ctx *exec_ctx,
  * OUTPUT PROCESSING
  */
 
+static const char *write_state_name(grpc_chttp2_write_state st) {
+  switch (st) {
+  case GRPC_CHTTP2_WRITE_STATE_IDLE: return "IDLE";
+  case GRPC_CHTTP2_WRITE_STATE_WRITING: return "WRITING";
+  case GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE_TO_COME: return "WRITING+MORE";
+  }
+  GPR_UNREACHABLE_CODE(return "UNKNOWN");
+}
+
+static void set_write_state(grpc_chttp2_transport *t, grpc_chttp2_write_state st) {
+  GRPC_CHTTP2_IF_TRACING(gpr_log(GPR_DEBUG, "W:%p %s state %s -> %s", t, t->is_client ? "CLIENT" : "SERVER", write_state_name(t->write_state), write_state_name(st)));
+                         t->write_state = st;
+}
+
 void grpc_chttp2_initiate_write(grpc_exec_ctx *exec_ctx,
                                 grpc_chttp2_transport *t,
                                 bool covered_by_poller, const char *reason) {
@@ -545,14 +559,14 @@ void grpc_chttp2_initiate_write(grpc_exec_ctx *exec_ctx,
 
   switch (t->write_state) {
     case GRPC_CHTTP2_WRITE_STATE_IDLE:
-      t->write_state = GRPC_CHTTP2_WRITE_STATE_WRITING;
+      set_write_state(t, GRPC_CHTTP2_WRITE_STATE_WRITING);
       GRPC_CHTTP2_REF_TRANSPORT(t, "writing");
       grpc_combiner_execute_finally(exec_ctx, t->combiner,
                                     &t->write_action_begin_locked,
                                     GRPC_ERROR_NONE);
       break;
     case GRPC_CHTTP2_WRITE_STATE_WRITING:
-      t->write_state = GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE_TO_COME;
+      set_write_state(t, GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE_TO_COME);
       break;
     case GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE_TO_COME:
       break;
@@ -576,10 +590,10 @@ static void write_action_begin_locked(grpc_exec_ctx *exec_ctx, void *gt,
   grpc_chttp2_transport *t = gt;
   GPR_ASSERT(t->write_state != GRPC_CHTTP2_WRITE_STATE_IDLE);
   if (!t->closed && grpc_chttp2_begin_write(exec_ctx, t)) {
-    t->write_state = GRPC_CHTTP2_WRITE_STATE_WRITING;
+    set_write_state(t, GRPC_CHTTP2_WRITE_STATE_WRITING);
     grpc_exec_ctx_sched(exec_ctx, &t->write_action, GRPC_ERROR_NONE, NULL);
   } else {
-    t->write_state = GRPC_CHTTP2_WRITE_STATE_IDLE;
+    set_write_state(t, GRPC_CHTTP2_WRITE_STATE_IDLE);
     GRPC_CHTTP2_UNREF_TRANSPORT(exec_ctx, t, "writing");
   }
   GPR_TIMER_END("write_action_begin_locked", 0);
@@ -617,11 +631,11 @@ static void write_action_end_locked(grpc_exec_ctx *exec_ctx, void *tp,
       GPR_UNREACHABLE_CODE(break);
     case GRPC_CHTTP2_WRITE_STATE_WRITING:
       GPR_TIMER_MARK("state=writing", 0);
-      t->write_state = GRPC_CHTTP2_WRITE_STATE_IDLE;
+      set_write_state(t, GRPC_CHTTP2_WRITE_STATE_IDLE);
       break;
     case GRPC_CHTTP2_WRITE_STATE_WRITING_WITH_MORE_TO_COME:
       GPR_TIMER_MARK("state=writing_stale_with_poller", 0);
-      t->write_state = GRPC_CHTTP2_WRITE_STATE_WRITING;
+      set_write_state(t, GRPC_CHTTP2_WRITE_STATE_WRITING);
       GRPC_CHTTP2_REF_TRANSPORT(t, "writing");
       grpc_combiner_execute_finally(exec_ctx, t->combiner,
                                     &t->write_action_begin_locked,

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

@@ -109,6 +109,8 @@ bool grpc_chttp2_begin_write(grpc_exec_ctx *exec_ctx,
     bool sent_initial_metadata = s->sent_initial_metadata;
     bool now_writing = false;
 
+    GRPC_CHTTP2_IF_TRACING(gpr_log(GPR_DEBUG, "W:%p %s[%d] im-(sent,send)=(%d,%d) announce=%d", t, t->is_client?"CLIENT":"SERVER", s->id, sent_initial_metadata, s->send_initial_metadata!=NULL, s->announce_window));
+
     /* send initial metadata if it's available */
     if (!sent_initial_metadata && s->send_initial_metadata) {
       grpc_chttp2_encode_header(&t->hpack_compressor, s->id,
@@ -120,7 +122,7 @@ bool grpc_chttp2_begin_write(grpc_exec_ctx *exec_ctx,
       now_writing = true;
     }
     /* send any window updates */
-    if (s->announce_window > 0 && sent_initial_metadata) {
+    if (s->announce_window > 0) {
       uint32_t announce = s->announce_window;
       gpr_slice_buffer_add(&t->outbuf,
                            grpc_chttp2_window_update_create(

src/core/lib/surface/completion_queue.c

@@ -319,6 +319,7 @@ typedef struct {
   gpr_timespec deadline;
   grpc_cq_completion *stolen_completion;
   void *tag; /* for pluck */
+  bool first_loop;
 } cq_is_finished_arg;
 
 static bool cq_is_next_finished(grpc_exec_ctx *exec_ctx, void *arg) {
@@ -342,7 +343,8 @@ static bool cq_is_next_finished(grpc_exec_ctx *exec_ctx, void *arg) {
     }
     gpr_mu_unlock(cq->mu);
   }
-  return gpr_time_cmp(a->deadline, gpr_now(a->deadline.clock_type)) < 0;
+  return !a->first_loop &&
+         gpr_time_cmp(a->deadline, gpr_now(a->deadline.clock_type)) < 0;
 }
 
 #ifndef NDEBUG
@@ -370,7 +372,6 @@ grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
                                       gpr_timespec deadline, void *reserved) {
   grpc_event ret;
   grpc_pollset_worker *worker = NULL;
-  int first_loop = 1;
   gpr_timespec now;
 
   GPR_TIMER_BEGIN("grpc_completion_queue_next", 0);
@@ -392,8 +393,13 @@ grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
   GRPC_CQ_INTERNAL_REF(cc, "next");
   gpr_mu_lock(cc->mu);
   cq_is_finished_arg is_finished_arg = {
-      gpr_atm_no_barrier_load(&cc->things_queued_ever), cc, deadline, NULL,
-      NULL};
+      .last_seen_things_queued_ever =
+          gpr_atm_no_barrier_load(&cc->things_queued_ever),
+      .cq = cc,
+      .deadline = deadline,
+      .stolen_completion = NULL,
+      .tag = NULL,
+      .first_loop = true};
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT_WITH_FINISH_CHECK(
       cq_is_next_finished, &is_finished_arg);
   for (;;) {
@@ -427,14 +433,13 @@ grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
       break;
     }
     now = gpr_now(GPR_CLOCK_MONOTONIC);
-    if (!first_loop && gpr_time_cmp(now, deadline) >= 0) {
+    if (!is_finished_arg.first_loop && gpr_time_cmp(now, deadline) >= 0) {
       gpr_mu_unlock(cc->mu);
       memset(&ret, 0, sizeof(ret));
       ret.type = GRPC_QUEUE_TIMEOUT;
       dump_pending_tags(cc);
       break;
     }
-    first_loop = 0;
     /* Check alarms - these are a global resource so we just ping
        each time through on every pollset.
        May update deadline to ensure timely wakeups.
@@ -461,6 +466,7 @@ grpc_event grpc_completion_queue_next(grpc_completion_queue *cc,
         break;
       }
     }
+    is_finished_arg.first_loop = false;
   }
   GRPC_SURFACE_TRACE_RETURNED_EVENT(cc, &ret);
   GRPC_CQ_INTERNAL_UNREF(cc, "next");
@@ -523,7 +529,8 @@ static bool cq_is_pluck_finished(grpc_exec_ctx *exec_ctx, void *arg) {
     }
     gpr_mu_unlock(cq->mu);
   }
-  return gpr_time_cmp(a->deadline, gpr_now(a->deadline.clock_type)) < 0;
+  return !a->first_loop &&
+         gpr_time_cmp(a->deadline, gpr_now(a->deadline.clock_type)) < 0;
 }
 
 grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
@@ -533,7 +540,6 @@ grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
   grpc_cq_completion *prev;
   grpc_pollset_worker *worker = NULL;
   gpr_timespec now;
-  int first_loop = 1;
 
   GPR_TIMER_BEGIN("grpc_completion_queue_pluck", 0);
 
@@ -556,8 +562,13 @@ grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
   GRPC_CQ_INTERNAL_REF(cc, "pluck");
   gpr_mu_lock(cc->mu);
   cq_is_finished_arg is_finished_arg = {
-      gpr_atm_no_barrier_load(&cc->things_queued_ever), cc, deadline, NULL,
-      tag};
+      .last_seen_things_queued_ever =
+          gpr_atm_no_barrier_load(&cc->things_queued_ever),
+      .cq = cc,
+      .deadline = deadline,
+      .stolen_completion = NULL,
+      .tag = tag,
+      .first_loop = true};
   grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT_WITH_FINISH_CHECK(
       cq_is_pluck_finished, &is_finished_arg);
   for (;;) {
@@ -607,7 +618,7 @@ grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
       break;
     }
     now = gpr_now(GPR_CLOCK_MONOTONIC);
-    if (!first_loop && gpr_time_cmp(now, deadline) >= 0) {
+    if (!is_finished_arg.first_loop && gpr_time_cmp(now, deadline) >= 0) {
       del_plucker(cc, tag, &worker);
       gpr_mu_unlock(cc->mu);
       memset(&ret, 0, sizeof(ret));
@@ -615,7 +626,6 @@ grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
       dump_pending_tags(cc);
       break;
     }
-    first_loop = 0;
     /* Check alarms - these are a global resource so we just ping
        each time through on every pollset.
        May update deadline to ensure timely wakeups.
@@ -642,6 +652,7 @@ grpc_event grpc_completion_queue_pluck(grpc_completion_queue *cc, void *tag,
         break;
       }
     }
+    is_finished_arg.first_loop = false;
     del_plucker(cc, tag, &worker);
   }
 done: