Smarter pollset/pollset_set propagation

For some definition of "smart"... client_channel simply passes along
pollset/pollset_set, removing the need to instantiate a pollset_set in
the subchannel_call_holder: it's now up to the LB policies to handle the
pollset/pollset_set.

1 files changed, 18 insertions, 11 deletions

diff --git a/src/core/ext/lb_policy/round_robin/round_robin.c b/src/core/ext/lb_policy/round_robin/round_robin.c
index 78ac61923f..f4e3d60a83 100644
--- a/src/core/ext/lb_policy/round_robin/round_robin.c
+++ b/src/core/ext/lb_policy/round_robin/round_robin.c
@@ -36,6 +36,7 @@
 #include <grpc/support/alloc.h>
 
 #include "src/core/ext/client_config/lb_policy_registry.h"
+#include "src/core/ext/lb_policy/common.h"
 #include "src/core/lib/debug/trace.h"
 #include "src/core/lib/transport/connectivity_state.h"
 
@@ -48,7 +49,8 @@ int grpc_lb_round_robin_trace = 0;
  * Once a pick is available, \a target is updated and \a on_complete called. */
 typedef struct pending_pick {
   struct pending_pick *next;
-  grpc_pollset_set *pollset_set;
+  grpc_pollset *pollset;
+  grpc_pollset_set *pollset_set_alternative;
   uint32_t initial_metadata_flags;
   grpc_connected_subchannel **target;
   grpc_closure *on_complete;
@@ -262,8 +264,9 @@ static void rr_cancel_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
   while (pp != NULL) {
     pending_pick *next = pp->next;
     if (pp->target == target) {
-      grpc_pollset_set_del_pollset_set(exec_ctx, p->base.interested_parties,
-                                       pp->pollset_set);
+      del_pollset_or_pollset_set_alternative(
+          exec_ctx, p->base.interested_parties, pp->pollset,
+          pp->pollset_set_alternative);
       *target = NULL;
       grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, false, NULL);
       gpr_free(pp);
@@ -288,8 +291,9 @@ static void rr_cancel_picks(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     pending_pick *next = pp->next;
     if ((pp->initial_metadata_flags & initial_metadata_flags_mask) ==
         initial_metadata_flags_eq) {
-      grpc_pollset_set_del_pollset_set(exec_ctx, p->base.interested_parties,
-                                       pp->pollset_set);
+      del_pollset_or_pollset_set_alternative(
+          exec_ctx, p->base.interested_parties, pp->pollset,
+          pp->pollset_set_alternative);
       *pp->target = NULL;
       grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, false, NULL);
       gpr_free(pp);
@@ -329,7 +333,8 @@ static void rr_exit_idle(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) {
 }
 
 static int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
-                   grpc_pollset_set *pollset_set,
+                   grpc_pollset *pollset,
+                   grpc_pollset_set *pollset_set_alternative,
                    grpc_metadata_batch *initial_metadata,
                    uint32_t initial_metadata_flags,
                    grpc_connected_subchannel **target,
@@ -353,11 +358,12 @@ static int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
     if (!p->started_picking) {
       start_picking(exec_ctx, p);
     }
-    grpc_pollset_set_add_pollset_set(exec_ctx, p->base.interested_parties,
-                                     pollset_set);
+    add_pollset_or_pollset_set_alternative(exec_ctx, p->base.interested_parties,
+                                           pollset, pollset_set_alternative);
     pp = gpr_malloc(sizeof(*pp));
     pp->next = p->pending_picks;
-    pp->pollset_set = pollset_set;
+    pp->pollset = pollset;
+    pp->pollset_set_alternative = pollset_set_alternative;
     pp->target = target;
     pp->on_complete = on_complete;
     pp->initial_metadata_flags = initial_metadata_flags;
@@ -406,8 +412,9 @@ static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
                     "[RR CONN CHANGED] TARGET <-- SUBCHANNEL %p (NODE %p)",
                     selected->subchannel, selected);
           }
-          grpc_pollset_set_del_pollset_set(exec_ctx, p->base.interested_parties,
-                                           pp->pollset_set);
+          del_pollset_or_pollset_set_alternative(
+              exec_ctx, p->base.interested_parties, pp->pollset,
+              pp->pollset_set_alternative);
           grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, true, NULL);
           gpr_free(pp);
         }