From 0a57193dec25db5e5b44e7a7445fb7b0a55fe571 Mon Sep 17 00:00:00 2001
From: Arjun Roy <arjunroy@google.com>
Date: Thu, 23 May 2019 16:11:23 -0700
Subject: [PATCH 1/2] Replaced gpr_ref with grpc_core::Atomic in call batch
 struct

---
 src/core/lib/surface/call.cc | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/src/core/lib/surface/call.cc b/src/core/lib/surface/call.cc
index 254476f47e3..271b3ddd560 100644
--- a/src/core/lib/surface/call.cc
+++ b/src/core/lib/surface/call.cc
@@ -74,7 +74,7 @@
 #define ESTIMATED_MDELEM_COUNT 16
 
 struct batch_control {
-  batch_control() { gpr_ref_init(&steps_to_complete, 0); }
+  batch_control() = default;
 
   grpc_call* call = nullptr;
   grpc_transport_stream_op_batch op;
@@ -99,8 +99,14 @@ struct batch_control {
   } completion_data;
   grpc_closure start_batch;
   grpc_closure finish_batch;
-  gpr_refcount steps_to_complete;
+  grpc_core::Atomic<uintptr_t> steps_to_complete;
   gpr_atm batch_error = reinterpret_cast<gpr_atm>(GRPC_ERROR_NONE);
+  void set_num_steps_to_complete(uintptr_t steps) {
+    steps_to_complete.Store(steps, grpc_core::MemoryOrder::RELEASE);
+  }
+  bool completed_batch_step() {
+    return steps_to_complete.FetchSub(1, grpc_core::MemoryOrder::ACQ_REL) == 1;
+  }
 };
 
 struct parent_call {
@@ -1225,7 +1231,7 @@ static void post_batch_completion(batch_control* bctl) {
 }
 
 static void finish_batch_step(batch_control* bctl) {
-  if (GPR_UNLIKELY(gpr_unref(&bctl->steps_to_complete))) {
+  if (GPR_UNLIKELY(bctl->completed_batch_step())) {
     post_batch_completion(bctl);
   }
 }
@@ -1866,7 +1872,7 @@ static grpc_call_error call_start_batch(grpc_call* call, const grpc_op* ops,
   if (!is_notify_tag_closure) {
     GPR_ASSERT(grpc_cq_begin_op(call->cq, notify_tag));
   }
-  gpr_ref_init(&bctl->steps_to_complete, (has_send_ops ? 1 : 0) + num_recv_ops);
+  bctl->set_num_steps_to_complete((has_send_ops ? 1 : 0) + num_recv_ops);
 
   if (has_send_ops) {
     GRPC_CLOSURE_INIT(&bctl->finish_batch, finish_batch, bctl,

From 7c8d6f63756ff0871cd8e251973375078f151f4f Mon Sep 17 00:00:00 2001
From: Arjun Roy <arjunroy@google.com>
Date: Tue, 28 May 2019 17:13:41 -0700
Subject: [PATCH 2/2] s/uintptr_t/intptr_t as requested

---
 src/core/lib/surface/call.cc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/core/lib/surface/call.cc b/src/core/lib/surface/call.cc
index 271b3ddd560..e00ac1810de 100644
--- a/src/core/lib/surface/call.cc
+++ b/src/core/lib/surface/call.cc
@@ -99,7 +99,7 @@ struct batch_control {
   } completion_data;
   grpc_closure start_batch;
   grpc_closure finish_batch;
-  grpc_core::Atomic<uintptr_t> steps_to_complete;
+  grpc_core::Atomic<intptr_t> steps_to_complete;
   gpr_atm batch_error = reinterpret_cast<gpr_atm>(GRPC_ERROR_NONE);
   void set_num_steps_to_complete(uintptr_t steps) {
     steps_to_complete.Store(steps, grpc_core::MemoryOrder::RELEASE);