Added INIT state to grpc_connectivity_state

include/grpc/impl/codegen/connectivity_state.h

@@ -40,6 +40,8 @@ extern "C" {
 
 /** Connectivity state of a channel. */
 typedef enum {
+  /** channel has just been initialized */
+  GRPC_CHANNEL_INIT = -1,
   /** channel is idle */
   GRPC_CHANNEL_IDLE,
   /** channel is connecting */

src/core/ext/lb_policy/pick_first/pick_first.c

@@ -292,6 +292,8 @@ static void pf_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
   } else {
   loop:
     switch (p->checking_connectivity) {
+      case GRPC_CHANNEL_INIT:
+        GPR_UNREACHABLE_CODE();
       case GRPC_CHANNEL_READY:
         grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
                                     GRPC_CHANNEL_READY, GRPC_ERROR_NONE,

src/core/ext/lb_policy/round_robin/round_robin.c

@@ -59,7 +59,6 @@
  *   the subchannel by the caller.
  */
 
-#include <limits.h>
 #include <string.h>
 
 #include <grpc/support/alloc.h>
@@ -401,7 +400,7 @@ static void start_picking(grpc_exec_ctx *exec_ctx, round_robin_lb_policy *p) {
      * to signal an undefined previous state. We won't be referring to this
      * value again and it'll be overwritten after the first call to
      * rr_connectivity_changed */
-    sd->prev_connectivity_state = INT_MAX;
+    sd->prev_connectivity_state = GRPC_CHANNEL_INIT;
     sd->curr_connectivity_state = GRPC_CHANNEL_IDLE;
     GRPC_LB_POLICY_WEAK_REF(&p->base, "rr_connectivity");
     grpc_subchannel_notify_on_state_change(
@@ -553,6 +552,8 @@ static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
     return;
   }
   switch (sd->curr_connectivity_state) {
+    case GRPC_CHANNEL_INIT:
+      GPR_UNREACHABLE_CODE();
     case GRPC_CHANNEL_READY:
       /* add the newly connected subchannel to the list of connected ones.
        * Note that it goes to the "end of the line". */

src/core/lib/transport/connectivity_state.c

@@ -43,6 +43,8 @@ int grpc_connectivity_state_trace = 0;
 
 const char *grpc_connectivity_state_name(grpc_connectivity_state state) {
   switch (state) {
+    case GRPC_CHANNEL_INIT:
+      return "INIT";
     case GRPC_CHANNEL_IDLE:
       return "IDLE";
     case GRPC_CHANNEL_CONNECTING:
@@ -159,6 +161,7 @@ void grpc_connectivity_state_set(grpc_exec_ctx *exec_ctx,
     grpc_error_free_string(error_string);
   }
   switch (state) {
+    case GRPC_CHANNEL_INIT:
     case GRPC_CHANNEL_CONNECTING:
     case GRPC_CHANNEL_IDLE:
     case GRPC_CHANNEL_READY: