Merge branch 'master' of https://github.com/grpc/grpc into channel-tracing

1 files changed, 19 insertions, 56 deletions

diff --git a/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc
index 60385272cf..725b78d478 100644
--- a/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc
@@ -81,7 +81,7 @@ static void pf_shutdown_locked(grpc_lb_policy* pol,
         GRPC_CLOSURE_SCHED(pick->on_complete, GRPC_ERROR_NONE);
       }
     } else {
-      pick->connected_subchannel = nullptr;
+      pick->connected_subchannel.reset();
       GRPC_CLOSURE_SCHED(pick->on_complete, GRPC_ERROR_REF(error));
     }
   }
@@ -111,7 +111,7 @@ static void pf_cancel_pick_locked(grpc_lb_policy* pol,
   while (pp != nullptr) {
     grpc_lb_policy_pick_state* next = pp->next;
     if (pp == pick) {
-      pick->connected_subchannel = nullptr;
+      pick->connected_subchannel.reset();
       GRPC_CLOSURE_SCHED(pick->on_complete,
                          GRPC_ERROR_CREATE_REFERENCING_FROM_STATIC_STRING(
                              "Pick Cancelled", &error, 1));
@@ -176,8 +176,7 @@ static int pf_pick_locked(grpc_lb_policy* pol,
   pick_first_lb_policy* p = (pick_first_lb_policy*)pol;
   // If we have a selected subchannel already, return synchronously.
   if (p->selected != nullptr) {
-    pick->connected_subchannel = GRPC_CONNECTED_SUBCHANNEL_REF(
-        p->selected->connected_subchannel, "picked");
+    pick->connected_subchannel = p->selected->connected_subchannel;
     return 1;
   }
   // No subchannel selected yet, so handle asynchronously.
@@ -217,8 +216,7 @@ static void pf_ping_one_locked(grpc_lb_policy* pol, grpc_closure* on_initiate,
                                grpc_closure* on_ack) {
   pick_first_lb_policy* p = (pick_first_lb_policy*)pol;
   if (p->selected) {
-    grpc_connected_subchannel_ping(p->selected->connected_subchannel,
-                                   on_initiate, on_ack);
+    p->selected->connected_subchannel->Ping(on_initiate, on_ack);
   } else {
     GRPC_CLOSURE_SCHED(on_initiate,
                        GRPC_ERROR_CREATE_FROM_STATIC_STRING("Not connected"));
@@ -297,8 +295,7 @@ static void pf_update_locked(grpc_lb_policy* policy,
                   subchannel_list->num_subchannels);
         }
         if (p->selected->connected_subchannel != nullptr) {
-          sd->connected_subchannel = GRPC_CONNECTED_SUBCHANNEL_REF(
-              p->selected->connected_subchannel, "pf_update_includes_selected");
+          sd->connected_subchannel = p->selected->connected_subchannel;
         }
         p->selected = sd;
         if (p->subchannel_list != nullptr) {
@@ -410,8 +407,8 @@ static void pf_connectivity_changed_locked(void* arg, grpc_error* error) {
       // re-resolution is introduced. But we need to investigate whether we
       // really want to take any action instead of waiting for the selected
       // subchannel reconnecting.
-      if (sd->curr_connectivity_state == GRPC_CHANNEL_SHUTDOWN ||
-          sd->curr_connectivity_state == GRPC_CHANNEL_TRANSIENT_FAILURE) {
+      GPR_ASSERT(sd->curr_connectivity_state != GRPC_CHANNEL_SHUTDOWN);
+      if (sd->curr_connectivity_state == GRPC_CHANNEL_TRANSIENT_FAILURE) {
         // If the selected channel goes bad, request a re-resolution.
         grpc_connectivity_state_set(&p->state_tracker, GRPC_CHANNEL_IDLE,
                                     GRPC_ERROR_NONE,
@@ -419,20 +416,19 @@ static void pf_connectivity_changed_locked(void* arg, grpc_error* error) {
         p->started_picking = false;
         grpc_lb_policy_try_reresolve(&p->base, &grpc_lb_pick_first_trace,
                                      GRPC_ERROR_NONE);
+        // in transient failure. Rely on re-resolution to recover.
+        p->selected = nullptr;
+        grpc_lb_subchannel_data_stop_connectivity_watch(sd);
+        grpc_lb_subchannel_list_unref_for_connectivity_watch(
+            sd->subchannel_list, "pf_selected_shutdown");
+        grpc_lb_subchannel_data_unref_subchannel(
+            sd, "pf_selected_shutdown");  // Unrefs connected subchannel
       } else {
         grpc_connectivity_state_set(&p->state_tracker,
                                     sd->curr_connectivity_state,
                                     GRPC_ERROR_REF(error), "selected_changed");
-      }
-      if (sd->curr_connectivity_state != GRPC_CHANNEL_SHUTDOWN) {
         // Renew notification.
         grpc_lb_subchannel_data_start_connectivity_watch(sd);
-      } else {
-        p->selected = nullptr;
-        grpc_lb_subchannel_data_stop_connectivity_watch(sd);
-        grpc_lb_subchannel_list_unref_for_connectivity_watch(
-            sd->subchannel_list, "pf_selected_shutdown");
-        grpc_lb_subchannel_data_unref_subchannel(sd, "pf_selected_shutdown");
       }
     }
     return;
@@ -450,6 +446,8 @@ static void pf_connectivity_changed_locked(void* arg, grpc_error* error) {
     case GRPC_CHANNEL_READY: {
       // Case 2.  Promote p->latest_pending_subchannel_list to
       // p->subchannel_list.
+      sd->connected_subchannel =
+          grpc_subchannel_get_connected_subchannel(sd->subchannel);
       if (sd->subchannel_list == p->latest_pending_subchannel_list) {
         GPR_ASSERT(p->subchannel_list != nullptr);
         grpc_lb_subchannel_list_shutdown_and_unref(p->subchannel_list,
@@ -460,9 +458,6 @@ static void pf_connectivity_changed_locked(void* arg, grpc_error* error) {
       // Cases 1 and 2.
       grpc_connectivity_state_set(&p->state_tracker, GRPC_CHANNEL_READY,
                                   GRPC_ERROR_NONE, "connecting_ready");
-      sd->connected_subchannel = GRPC_CONNECTED_SUBCHANNEL_REF(
-          grpc_subchannel_get_connected_subchannel(sd->subchannel),
-          "connected");
       p->selected = sd;
       if (grpc_lb_pick_first_trace.enabled()) {
         gpr_log(GPR_INFO, "Pick First %p selected subchannel %p", (void*)p,
@@ -474,8 +469,7 @@ static void pf_connectivity_changed_locked(void* arg, grpc_error* error) {
       grpc_lb_policy_pick_state* pick;
       while ((pick = p->pending_picks)) {
         p->pending_picks = pick->next;
-        pick->connected_subchannel = GRPC_CONNECTED_SUBCHANNEL_REF(
-            p->selected->connected_subchannel, "picked");
+        pick->connected_subchannel = p->selected->connected_subchannel;
         if (grpc_lb_pick_first_trace.enabled()) {
           gpr_log(GPR_INFO,
                   "Servicing pending pick with selected subchannel %p",
@@ -520,39 +514,8 @@ static void pf_connectivity_changed_locked(void* arg, grpc_error* error) {
       grpc_lb_subchannel_data_start_connectivity_watch(sd);
       break;
     }
-    case GRPC_CHANNEL_SHUTDOWN: {
-      grpc_lb_subchannel_data_stop_connectivity_watch(sd);
-      grpc_lb_subchannel_data_unref_subchannel(sd, "pf_candidate_shutdown");
-      // Advance to next subchannel and check its state.
-      grpc_lb_subchannel_data* original_sd = sd;
-      do {
-        sd->subchannel_list->checking_subchannel =
-            (sd->subchannel_list->checking_subchannel + 1) %
-            sd->subchannel_list->num_subchannels;
-        sd = &sd->subchannel_list
-                  ->subchannels[sd->subchannel_list->checking_subchannel];
-      } while (sd->subchannel == nullptr && sd != original_sd);
-      if (sd == original_sd) {
-        grpc_lb_subchannel_list_unref_for_connectivity_watch(
-            sd->subchannel_list, "pf_exhausted_subchannels");
-        if (sd->subchannel_list == p->subchannel_list) {
-          grpc_connectivity_state_set(&p->state_tracker, GRPC_CHANNEL_IDLE,
-                                      GRPC_ERROR_NONE,
-                                      "exhausted_subchannels+reresolve");
-          p->started_picking = false;
-          grpc_lb_policy_try_reresolve(&p->base, &grpc_lb_pick_first_trace,
-                                       GRPC_ERROR_NONE);
-        }
-      } else {
-        if (sd->subchannel_list == p->subchannel_list) {
-          grpc_connectivity_state_set(
-              &p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE,
-              GRPC_ERROR_REF(error), "subchannel_failed");
-        }
-        // Reuses the connectivity refs from the previous watch.
-        grpc_lb_subchannel_data_start_connectivity_watch(sd);
-      }
-    }
+    case GRPC_CHANNEL_SHUTDOWN:
+      GPR_UNREACHABLE_CODE(break);
   }
 }