1 files changed, 6 insertions, 4 deletions
diff --git a/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc b/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc
index fea84331d8..4195c1e9d1 100644
--- a/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc
@@ -36,6 +36,7 @@
 #include "src/core/ext/filters/client_channel/subchannel_index.h"
 #include "src/core/lib/channel/channel_args.h"
 #include "src/core/lib/debug/trace.h"
+#include "src/core/lib/gprpp/mutex_lock.h"
 #include "src/core/lib/gprpp/ref_counted_ptr.h"
 #include "src/core/lib/iomgr/combiner.h"
 #include "src/core/lib/iomgr/sockaddr_utils.h"
@@ -138,7 +139,8 @@ class RoundRobin : public LoadBalancingPolicy {
         grpc_client_channel_factory* client_channel_factory,
         const grpc_channel_args& args)
         : SubchannelList(policy, tracer, addresses, combiner,
-                         client_channel_factory, args) {
+                         client_channel_factory, args),
+          last_ready_index_(num_subchannels() - 1) {
       // Need to maintain a ref to the LB policy as long as we maintain
       // any references to subchannels, since the subchannels'
       // pollset_sets will include the LB policy's pollset_set.
@@ -179,7 +181,7 @@ class RoundRobin : public LoadBalancingPolicy {
     size_t num_connecting_ = 0;
     size_t num_transient_failure_ = 0;
     grpc_error* last_transient_failure_error_ = GRPC_ERROR_NONE;
-    size_t last_ready_index_ = -1;  // Index into list of last pick.
+    size_t last_ready_index_;  // Index into list of last pick.
   };
 
   // Helper class to ensure that any function that modifies the child refs
@@ -400,7 +402,7 @@ bool RoundRobin::PickLocked(PickState* pick, grpc_error** error) {
 
 void RoundRobin::FillChildRefsForChannelz(
     ChildRefsList* child_subchannels_to_fill, ChildRefsList* ignored) {
-  mu_guard guard(&child_refs_mu_);
+  MutexLock lock(&child_refs_mu_);
   for (size_t i = 0; i < child_subchannels_.size(); ++i) {
     // TODO(ncteisen): implement a de dup loop that is not O(n^2). Might
     // have to implement lightweight set. For now, we don't care about
@@ -427,7 +429,7 @@ void RoundRobin::UpdateChildRefsLocked() {
     latest_pending_subchannel_list_->PopulateChildRefsList(&cs);
   }
   // atomically update the data that channelz will actually be looking at.
-  mu_guard guard(&child_refs_mu_);
+  MutexLock lock(&child_refs_mu_);
   child_subchannels_ = std::move(cs);
 }