1 files changed, 48 insertions, 0 deletions

diff --git a/src/core/client_config/lb_policies/pick_first.c b/src/core/client_config/lb_policies/pick_first.c
index 28155d0fbc..e5bf0680ff 100644
--- a/src/core/client_config/lb_policies/pick_first.c
+++ b/src/core/client_config/lb_policies/pick_first.c
@@ -101,6 +101,9 @@ void pf_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
   for (i = 0; i < p->num_subchannels; i++) {
     GRPC_SUBCHANNEL_UNREF(exec_ctx, p->subchannels[i], "pick_first");
   }
+  if (p->selected) {
+    GRPC_SUBCHANNEL_UNREF(exec_ctx, p->selected, "picked_first");
+  }
   grpc_connectivity_state_destroy(exec_ctx, &p->state_tracker);
   gpr_free(p->subchannels);
   gpr_mu_destroy(&p->mu);
@@ -172,6 +175,35 @@ void pf_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   }
 }
 
+static void destroy_subchannels(grpc_exec_ctx *exec_ctx, void *arg,
+                                int iomgr_success) {
+  pick_first_lb_policy *p = arg;
+  size_t i;
+  grpc_transport_op op;
+  size_t num_subchannels = p->num_subchannels;
+  grpc_subchannel **subchannels;
+  grpc_subchannel *exclude_subchannel;
+
+  gpr_mu_lock(&p->mu);
+  subchannels = p->subchannels;
+  p->num_subchannels = 0;
+  p->subchannels = NULL;
+  exclude_subchannel = p->selected;
+  gpr_mu_unlock(&p->mu);
+  GRPC_LB_POLICY_UNREF(exec_ctx, &p->base, "destroy_subchannels");
+
+  for (i = 0; i < num_subchannels; i++) {
+    if (subchannels[i] != exclude_subchannel) {
+      memset(&op, 0, sizeof(op));
+      op.disconnect = 1;
+      grpc_subchannel_process_transport_op(exec_ctx, subchannels[i], &op);
+    }
+    GRPC_SUBCHANNEL_UNREF(exec_ctx, subchannels[i], "pick_first");
+  }
+
+  gpr_free(subchannels);
+}
+
 static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
                                     int iomgr_success) {
   pick_first_lb_policy *p = arg;
@@ -200,6 +232,12 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
         grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
                                     GRPC_CHANNEL_READY, "connecting_ready");
         p->selected = p->subchannels[p->checking_subchannel];
+        GRPC_SUBCHANNEL_REF(p->selected, "picked_first");
+        /* drop the pick list: we are connected now */
+        GRPC_LB_POLICY_REF(&p->base, "destroy_subchannels");
+        grpc_exec_ctx_enqueue(exec_ctx,
+                              grpc_closure_create(destroy_subchannels, p), 1);
+        /* update any calls that were waiting for a pick */
         while ((pp = p->pending_picks)) {
           p->pending_picks = pp->next;
           *pp->target = p->selected;
@@ -279,10 +317,15 @@ static void pf_broadcast(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   size_t i;
   size_t n;
   grpc_subchannel **subchannels;
+  grpc_subchannel *selected;
 
   gpr_mu_lock(&p->mu);
   n = p->num_subchannels;
   subchannels = gpr_malloc(n * sizeof(*subchannels));
+  selected = p->selected;
+  if (selected) {
+    GRPC_SUBCHANNEL_REF(selected, "pf_broadcast_to_selected");
+  }
   for (i = 0; i < n; i++) {
     subchannels[i] = p->subchannels[i];
     GRPC_SUBCHANNEL_REF(subchannels[i], "pf_broadcast");
@@ -290,9 +333,14 @@ static void pf_broadcast(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   gpr_mu_unlock(&p->mu);
 
   for (i = 0; i < n; i++) {
+    if (selected == subchannels[i]) continue;
     grpc_subchannel_process_transport_op(exec_ctx, subchannels[i], op);
     GRPC_SUBCHANNEL_UNREF(exec_ctx, subchannels[i], "pf_broadcast");
   }
+  if (p->selected) {
+    grpc_subchannel_process_transport_op(exec_ctx, selected, op);
+    GRPC_SUBCHANNEL_UNREF(exec_ctx, selected, "pf_broadcast_to_selected");
+  }
   gpr_free(subchannels);
 }