Merge pull request #13647 from y-zeng/send_ping

Add on_initiate callback for the send_ping tranport op

2 files changed, 9 insertions, 3 deletions

diff --git a/src/core/lib/transport/transport.h b/src/core/lib/transport/transport.h
index b3cf04c22d..73264142d9 100644
--- a/src/core/lib/transport/transport.h
+++ b/src/core/lib/transport/transport.h
@@ -245,8 +245,14 @@ typedef struct grpc_transport_op {
   grpc_pollset* bind_pollset;
   /** add this transport to a pollset_set */
   grpc_pollset_set* bind_pollset_set;
-  /** send a ping, call this back if not NULL */
-  grpc_closure* send_ping;
+  /** send a ping, if either on_initiate or on_ack is not NULL */
+  struct {
+    /** Ping may be delayed by the transport, on_initiate callback will be
+        called when the ping is actually being sent. */
+    grpc_closure* on_initiate;
+    /** Called when the ping ack is received */
+    grpc_closure* on_ack;
+  } send_ping;
 
   /***************************************************************************
    * remaining fields are initialized and used at the discretion of the
diff --git a/src/core/lib/transport/transport_op_string.cc b/src/core/lib/transport/transport_op_string.cc
index e69ab02570..c0f82fea0d 100644
--- a/src/core/lib/transport/transport_op_string.cc
+++ b/src/core/lib/transport/transport_op_string.cc
@@ -187,7 +187,7 @@ char* grpc_transport_op_string(grpc_transport_op* op) {
     gpr_strvec_add(&b, gpr_strdup("BIND_POLLSET_SET"));
   }
 
-  if (op->send_ping != nullptr) {
+  if (op->send_ping.on_initiate != nullptr || op->send_ping.on_ack != nullptr) {
     if (!first) gpr_strvec_add(&b, gpr_strdup(" "));
     // first = false;
     gpr_strvec_add(&b, gpr_strdup("SEND_PING"));