Move is_balancer into a new struct in the client_config directory.

src/core/ext/client_config/lb_policy_factory.h

@@ -36,7 +36,7 @@
 
 #include "src/core/ext/client_config/client_channel_factory.h"
 #include "src/core/ext/client_config/lb_policy.h"
-#include "src/core/lib/iomgr/resolve_address.h"
+#include "src/core/ext/client_config/resolver_result.h"
 
 #include "src/core/lib/iomgr/exec_ctx.h"
 
@@ -48,7 +48,7 @@ struct grpc_lb_policy_factory {
 };
 
 typedef struct grpc_lb_policy_args {
-  grpc_resolved_addresses *addresses;
+  grpc_addresses *addresses;
   grpc_client_channel_factory *client_channel_factory;
 } grpc_lb_policy_args;
 

src/core/ext/client_config/resolver_result.c

@@ -37,6 +37,30 @@
 
 #include <grpc/support/alloc.h>
 
+grpc_addresses *grpc_addresses_create(size_t num_addresses) {
+  grpc_addresses *addresses = gpr_malloc(sizeof(grpc_addresses));
+  addresses->num_addresses = num_addresses;
+  const size_t addresses_size = sizeof(grpc_address) * num_addresses;
+  addresses->addresses = gpr_malloc(addresses_size);
+  memset(addresses->addresses, 0, addresses_size);
+  return addresses;
+}
+
+void grpc_addresses_set_address(grpc_addresses *addresses, size_t index,
+                                void *address, size_t address_len,
+                                bool is_balancer) {
+  GPR_ASSERT(index < addresses->num_addresses);
+  grpc_address *target = &addresses->addresses[index];
+  memcpy(target->address.addr, address, address_len);
+  target->address.len = address_len;
+  target->is_balancer = is_balancer;
+}
+
+void grpc_addresses_destroy(grpc_addresses *addresses) {
+  gpr_free(addresses->addresses);
+  gpr_free(addresses);
+}
+
 struct grpc_resolver_result {
   gpr_refcount refs;
   grpc_lb_policy *lb_policy;

src/core/ext/client_config/resolver_result.h

@@ -34,7 +34,31 @@
 #ifndef GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_RESULT_H
 #define GRPC_CORE_EXT_CLIENT_CONFIG_RESOLVER_RESULT_H
 
+#include <stdbool.h>
+
 #include "src/core/ext/client_config/lb_policy.h"
+#include "src/core/lib/iomgr/resolve_address.h"
+
+/** Used to represent addresses returned by the resolver. */
+typedef struct grpc_address {
+  grpc_resolved_address address;
+  bool is_balancer;
+} grpc_address;
+
+typedef struct grpc_addresses {
+  size_t num_addresses;
+  grpc_address *addresses;
+} grpc_addresses;
+
+/** Returns a grpc_addresses struct with enough space for
+    \a num_addresses addresses. */
+grpc_addresses *grpc_addresses_create(size_t num_addresses);
+
+void grpc_addresses_set_address(grpc_addresses *addresses, size_t index,
+                                void *address, size_t address_len,
+                                bool is_balancer);
+
+void grpc_addresses_destroy(grpc_addresses *addresses);
 
 /** Results reported from a grpc_resolver. */
 typedef struct grpc_resolver_result grpc_resolver_result;

src/core/ext/lb_policy/grpclb/grpclb.c

@@ -296,10 +296,7 @@ static grpc_lb_policy *create_rr(grpc_exec_ctx *exec_ctx,
 
   grpc_lb_policy_args args;
   args.client_channel_factory = glb_policy->cc_factory;
-  args.addresses = gpr_malloc(sizeof(grpc_resolved_addresses));
-  args.addresses->naddrs = serverlist->num_servers;
-  args.addresses->addrs =
-      gpr_malloc(sizeof(grpc_resolved_address) * args.addresses->naddrs);
+  args.addresses = grpc_addresses_create(serverlist->num_servers);
   size_t out_addrs_idx = 0;
   for (size_t i = 0; i < serverlist->num_servers; ++i) {
     grpc_uri uri;
@@ -307,13 +304,12 @@ static grpc_lb_policy *create_rr(grpc_exec_ctx *exec_ctx,
     size_t sa_len;
     uri.path = host_ports[i];
     if (parse_ipv4(&uri, &sa, &sa_len)) { /* TODO(dgq): add support for ipv6 */
-      memcpy(args.addresses->addrs[out_addrs_idx].addr, &sa, sa_len);
-      args.addresses->addrs[out_addrs_idx].len = sa_len;
-      // These are, of course, actually balancer addresses.  However, we
-      // want the round_robin LB policy to treat them as normal backend
-      // addresses, since we don't need to talk to balancers in order to
-      // find the balancers themselves.
-      args.addresses->addrs[out_addrs_idx].is_balancer = false;
+      /* These are, of course, actually balancer addresses. However, we
+       * want the round_robin LB policy to treat them as normal backend
+       * addresses, since we don't need to talk to balancers in order to
+       * find the balancers themselves, so we set is_balancer=false. */
+      grpc_addresses_set_address(args.addresses, out_addrs_idx, &sa, sa_len,
+                                 false /* is_balancer */);
       ++out_addrs_idx;
     } else {
       gpr_log(GPR_ERROR, "Invalid LB service address '%s', ignoring.",
@@ -328,8 +324,7 @@ static grpc_lb_policy *create_rr(grpc_exec_ctx *exec_ctx,
     gpr_free(host_ports[i]);
   }
   gpr_free(host_ports);
-  gpr_free(args.addresses->addrs);
-  gpr_free(args.addresses);
+  grpc_addresses_destroy(args.addresses);
   return rr;
 }
 
@@ -419,17 +414,16 @@ static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
 static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
                                   grpc_lb_policy_factory *factory,
                                   grpc_lb_policy_args *args) {
-  // Count the number of gRPC-LB addresses.  There must be at least one.
-  // TODO(roth): For now, we ignore non-balancer addresses, so there must be
-  // at least one balancer address.  In the future, we may change the
-  // behavior such that we fall back to using the non-balancer addresses
-  // if we cannot reach any balancers.  At that time, this should be
-  // changed to allow a list with no balancer addresses, since the
-  // resolver might fail to return a balancer address even when this is
-  // the right LB policy to use.
+  /* Count the number of gRPC-LB addresses. There must be at least one.
+   * TODO(roth): For now, we ignore non-balancer addresses, but in the
+   * future, we may change the behavior such that we fall back to using
+   * the non-balancer addresses if we cannot reach any balancers. At that
+   * time, this should be changed to allow a list with no balancer addresses,
+   * since the resolver might fail to return a balancer address even when
+   * this is the right LB policy to use. */
   size_t num_grpclb_addrs = 0;
-  for (size_t i = 0; i < args->addresses->naddrs; ++i) {
-    if (args->addresses->addrs[i].is_balancer) ++num_grpclb_addrs;
+  for (size_t i = 0; i < args->addresses->num_addresses; ++i) {
+    if (args->addresses->addresses[i].is_balancer) ++num_grpclb_addrs;
   }
   if (num_grpclb_addrs == 0) return NULL;
 
@@ -448,14 +442,15 @@ static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
    * ipvX://ip1:port1,ip2:port2,...
    * TODO(dgq): support mixed ip version */
   char **addr_strs = gpr_malloc(sizeof(char *) * num_grpclb_addrs);
-  addr_strs[0] =
-      grpc_sockaddr_to_uri((const struct sockaddr *)&args->addresses->addrs[0]);
+  addr_strs[0] = grpc_sockaddr_to_uri(
+      (const struct sockaddr *)&args->addresses->addresses[0].address.addr);
   size_t addr_index = 1;
-  for (size_t i = 1; i < args->addresses->naddrs; i++) {
-    if (args->addresses->addrs[i].is_balancer) {
+  for (size_t i = 1; i < args->addresses->num_addresses; i++) {
+    if (args->addresses->addresses[i].is_balancer) {
       GPR_ASSERT(grpc_sockaddr_to_string(
                      &addr_strs[addr_index++],
-                     (const struct sockaddr *)&args->addresses->addrs[i],
+                     (const struct sockaddr *)&args->addresses->addresses[i]
+                         .address.addr,
                      true) == 0);
     }
   }

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

@@ -443,11 +443,11 @@ static grpc_lb_policy *create_pick_first(grpc_exec_ctx *exec_ctx,
   GPR_ASSERT(args->addresses != NULL);
   GPR_ASSERT(args->client_channel_factory != NULL);
 
-  // Find the number of backend addresses.  We ignore balancer
-  // addresses, since we don't know how to handle them.
+  /* Find the number of backend addresses. We ignore balancer
+   * addresses, since we don't know how to handle them. */
   size_t num_addrs = 0;
-  for (size_t i = 0; i < args->addresses->naddrs; i++) {
-    if (!args->addresses->addrs[i].is_balancer) ++num_addrs;
+  for (size_t i = 0; i < args->addresses->num_addresses; i++) {
+    if (!args->addresses->addresses[i].is_balancer) ++num_addrs;
   }
   if (num_addrs == 0) return NULL;
 
@@ -458,13 +458,14 @@ static grpc_lb_policy *create_pick_first(grpc_exec_ctx *exec_ctx,
   memset(p->subchannels, 0, sizeof(*p->subchannels) * num_addrs);
   grpc_subchannel_args sc_args;
   size_t subchannel_idx = 0;
-  for (size_t i = 0; i < args->addresses->naddrs; i++) {
-    // Skip balancer addresses, since we only know how to handle backends.
-    if (args->addresses->addrs[i].is_balancer) continue;
+  for (size_t i = 0; i < args->addresses->num_addresses; i++) {
+    /* Skip balancer addresses, since we only know how to handle backends. */
+    if (args->addresses->addresses[i].is_balancer) continue;
 
     memset(&sc_args, 0, sizeof(grpc_subchannel_args));
-    sc_args.addr = (struct sockaddr *)(args->addresses->addrs[i].addr);
-    sc_args.addr_len = (size_t)args->addresses->addrs[i].len;
+    sc_args.addr =
+        (struct sockaddr *)(&args->addresses->addresses[i].address.addr);
+    sc_args.addr_len = args->addresses->addresses[i].address.len;
 
     grpc_subchannel *subchannel = grpc_client_channel_factory_create_subchannel(
         exec_ctx, args->client_channel_factory, &sc_args);

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

@@ -571,11 +571,11 @@ static grpc_lb_policy *round_robin_create(grpc_exec_ctx *exec_ctx,
   GPR_ASSERT(args->addresses != NULL);
   GPR_ASSERT(args->client_channel_factory != NULL);
 
-  // Find the number of backend addresses.  We ignore balancer
-  // addresses, since we don't know how to handle them.
+  /* Find the number of backend addresses. We ignore balancer
+   * addresses, since we don't know how to handle them. */
   size_t num_addrs = 0;
-  for (size_t i = 0; i < args->addresses->naddrs; i++) {
-    if (!args->addresses->addrs[i].is_balancer) ++num_addrs;
+  for (size_t i = 0; i < args->addresses->num_addresses; i++) {
+    if (!args->addresses->addresses[i].is_balancer) ++num_addrs;
   }
   if (num_addrs == 0) return NULL;
 
@@ -587,13 +587,14 @@ static grpc_lb_policy *round_robin_create(grpc_exec_ctx *exec_ctx,
 
   grpc_subchannel_args sc_args;
   size_t subchannel_idx = 0;
-  for (size_t i = 0; i < args->addresses->naddrs; i++) {
-    // Skip balancer addresses, since we only know how to handle backends.
-    if (args->addresses->addrs[i].is_balancer) continue;
+  for (size_t i = 0; i < args->addresses->num_addresses; i++) {
+    /* Skip balancer addresses, since we only know how to handle backends. */
+    if (args->addresses->addresses[i].is_balancer) continue;
 
     memset(&sc_args, 0, sizeof(grpc_subchannel_args));
-    sc_args.addr = (struct sockaddr *)(args->addresses->addrs[i].addr);
-    sc_args.addr_len = (size_t)args->addresses->addrs[i].len;
+    sc_args.addr =
+        (struct sockaddr *)(&args->addresses->addresses[i].address.addr);
+    sc_args.addr_len = args->addresses->addresses[i].address.len;
 
     grpc_subchannel *subchannel = grpc_client_channel_factory_create_subchannel(
         exec_ctx, args->client_channel_factory, &sc_args);

src/core/ext/resolver/dns/native/dns_resolver.c

@@ -170,20 +170,25 @@ static void dns_on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
   gpr_mu_lock(&r->mu);
   GPR_ASSERT(r->resolving);
   r->resolving = 0;
-  grpc_resolved_addresses *addresses = r->addresses;
-  if (addresses != NULL) {
+  if (r->addresses != NULL) {
     grpc_lb_policy_args lb_policy_args;
-    result = grpc_resolver_result_create();
     memset(&lb_policy_args, 0, sizeof(lb_policy_args));
-    lb_policy_args.addresses = addresses;
+    lb_policy_args.addresses = grpc_addresses_create(r->addresses->naddrs);
+    for (size_t i = 0; i < r->addresses->naddrs; ++i) {
+      grpc_addresses_set_address(
+          lb_policy_args.addresses, i, &r->addresses->addrs[i].addr,
+          r->addresses->addrs[i].len, false /* is_balancer */);
+    }
+    grpc_resolved_addresses_destroy(r->addresses);
     lb_policy_args.client_channel_factory = r->client_channel_factory;
     lb_policy =
         grpc_lb_policy_create(exec_ctx, r->lb_policy_name, &lb_policy_args);
+    grpc_addresses_destroy(lb_policy_args.addresses);
+    result = grpc_resolver_result_create();
     if (lb_policy != NULL) {
       grpc_resolver_result_set_lb_policy(result, lb_policy);
       GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "construction");
     }
-    grpc_resolved_addresses_destroy(addresses);
   } else {
     gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
     gpr_timespec next_try = gpr_backoff_step(&r->backoff_state, now);

src/core/ext/resolver/sockaddr/sockaddr_resolver.c

@@ -58,7 +58,7 @@ typedef struct {
   char *lb_policy_name;
 
   /** the addresses that we've 'resolved' */
-  grpc_resolved_addresses *addresses;
+  grpc_addresses *addresses;
 
   /** mutex guarding the rest of the state */
   gpr_mu mu;
@@ -142,7 +142,7 @@ static void sockaddr_destroy(grpc_exec_ctx *exec_ctx, grpc_resolver *gr) {
   sockaddr_resolver *r = (sockaddr_resolver *)gr;
   gpr_mu_destroy(&r->mu);
   grpc_client_channel_factory_unref(exec_ctx, r->client_channel_factory);
-  grpc_resolved_addresses_destroy(r->addresses);
+  grpc_addresses_destroy(r->addresses);
   gpr_free(r->lb_policy_name);
   gpr_free(r);
 }
@@ -216,22 +216,18 @@ static grpc_resolver *sockaddr_create(
   gpr_slice_buffer_init(&path_parts);
 
   gpr_slice_split(path_slice, ",", &path_parts);
-  r->addresses = gpr_malloc(sizeof(grpc_resolved_addresses));
-  r->addresses->naddrs = path_parts.count;
-  r->addresses->addrs =
-      gpr_malloc(sizeof(grpc_resolved_address) * r->addresses->naddrs);
-
-  for (size_t i = 0; i < r->addresses->naddrs; i++) {
+  r->addresses = grpc_addresses_create(path_parts.count);
+  for (size_t i = 0; i < r->addresses->num_addresses; i++) {
     grpc_uri ith_uri = *args->uri;
     char *part_str = gpr_dump_slice(path_parts.slices[i], GPR_DUMP_ASCII);
     ith_uri.path = part_str;
-    if (!parse(&ith_uri,
-               (struct sockaddr_storage *)(&r->addresses->addrs[i].addr),
-               &r->addresses->addrs[i].len)) {
+    if (!parse(&ith_uri, (struct sockaddr_storage *)(&r->addresses->addresses[i]
+                                                          .address.addr),
+               &r->addresses->addresses[i].address.len)) {
       errors_found = true;
     }
     gpr_free(part_str);
-    r->addresses->addrs[i].is_balancer = lb_enabled;
+    r->addresses->addresses[i].is_balancer = lb_enabled;
     if (errors_found) break;
   }
 
@@ -239,7 +235,7 @@ static grpc_resolver *sockaddr_create(
   gpr_slice_unref(path_slice);
   if (errors_found) {
     gpr_free(r->lb_policy_name);
-    grpc_resolved_addresses_destroy(r->addresses);
+    grpc_addresses_destroy(r->addresses);
     gpr_free(r);
     return NULL;
   }

src/core/lib/iomgr/resolve_address.h

@@ -34,7 +34,6 @@
 #ifndef GRPC_CORE_LIB_IOMGR_RESOLVE_ADDRESS_H
 #define GRPC_CORE_LIB_IOMGR_RESOLVE_ADDRESS_H
 
-#include <stdbool.h>
 #include <stddef.h>
 #include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/core/lib/iomgr/iomgr.h"
@@ -44,7 +43,6 @@
 typedef struct {
   char addr[GRPC_MAX_SOCKADDR_SIZE];
   size_t len;
-  bool is_balancer;
 } grpc_resolved_address;
 
 typedef struct {

src/core/lib/iomgr/resolve_address_posix.c

@@ -132,7 +132,6 @@ static grpc_error *blocking_resolve_address_impl(
   for (resp = result; resp != NULL; resp = resp->ai_next) {
     memcpy(&(*addresses)->addrs[i].addr, resp->ai_addr, resp->ai_addrlen);
     (*addresses)->addrs[i].len = resp->ai_addrlen;
-    (*addresses)->addrs[i].is_balancer = false;
     i++;
   }
   err = GRPC_ERROR_NONE;

src/core/lib/iomgr/resolve_address_windows.c

@@ -118,7 +118,6 @@ static grpc_error *blocking_resolve_address_impl(
   for (resp = result; resp != NULL; resp = resp->ai_next) {
     memcpy(&(*addresses)->addrs[i].addr, resp->ai_addr, resp->ai_addrlen);
     (*addresses)->addrs[i].len = resp->ai_addrlen;
-    (*addresses)->addrs[i].is_balancer = false;
     i++;
   }
 

src/core/lib/iomgr/unix_sockets_posix.c

@@ -58,7 +58,6 @@ grpc_error *grpc_resolve_unix_domain_address(const char *name,
   un->sun_family = AF_UNIX;
   strcpy(un->sun_path, name);
   (*addrs)->addrs->len = strlen(un->sun_path) + sizeof(un->sun_family) + 1;
-  (*addrs)->addrs->is_balancer = false;
   return GRPC_ERROR_NONE;
 }