Change LB policies to get their input from channel args.
diff --git a/src/core/ext/client_config/client_channel.c b/src/core/ext/client_config/client_channel.c
index d02dd5a..f23da5f 100644
--- a/src/core/ext/client_config/client_channel.c
+++ b/src/core/ext/client_config/client_channel.c
@@ -192,11 +192,17 @@
grpc_resolver_result_get_channel_args(chand->resolver_result);
lb_policy_args.client_channel_factory = chand->client_channel_factory;
+ // Find LB policy name.
+ const char *lb_policy_name = NULL;
+ const grpc_arg *lb_policy_name_arg =
+ grpc_channel_args_find(lb_policy_args.args, GRPC_ARG_LB_POLICY_NAME);
+ if (lb_policy_name_arg != NULL) {
+ GPR_ASSERT(lb_policy_name_arg->type == GRPC_ARG_STRING);
+ lb_policy_name = lb_policy_name_arg->value.string;
+ }
// Special case: If all of the addresses are balancer addresses,
// assume that we should use the grpclb policy, regardless of what the
// resolver actually specified.
- const char *lb_policy_name =
- grpc_resolver_result_get_lb_policy_name(chand->resolver_result);
bool found_backend_address = false;
for (size_t i = 0; i < lb_policy_args.addresses->num_addresses; ++i) {
if (!lb_policy_args.addresses->addresses[i].is_balancer) {
diff --git a/src/core/ext/lb_policy/grpclb/grpclb.c b/src/core/ext/lb_policy/grpclb/grpclb.c
index 1467508..fdc0bec 100644
--- a/src/core/ext/lb_policy/grpclb/grpclb.c
+++ b/src/core/ext/lb_policy/grpclb/grpclb.c
@@ -470,9 +470,17 @@
args.server_name = glb_policy->server_name;
args.client_channel_factory = glb_policy->cc_factory;
args.addresses = process_serverlist(serverlist);
- args.args = glb_policy->args;
+
+ // Replace the LB addresses in the channel args that we pass down to
+ // the subchannel.
+ static const char* keys_to_remove[] = {GRPC_ARG_LB_ADDRESSES};
+ const grpc_arg arg = grpc_lb_addresses_create_channel_arg(args.addresses);
+ args.args = grpc_channel_args_copy_and_add_and_remove(
+ glb_policy->args, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove), &arg,
+ 1);
grpc_lb_policy *rr = grpc_lb_policy_create(exec_ctx, "round_robin", &args);
+ grpc_channel_args_destroy(args.args);
if (glb_policy->addresses != NULL) {
/* dispose of the previous version */
@@ -574,6 +582,13 @@
static grpc_lb_policy *glb_create(grpc_exec_ctx *exec_ctx,
grpc_lb_policy_factory *factory,
grpc_lb_policy_args *args) {
+ /* Get server name. */
+ const grpc_arg* arg =
+ grpc_channel_args_find(args->args, GRPC_ARG_SERVER_NAME);
+ const char* server_name =
+ arg != NULL && arg->type == GRPC_ARG_STRING
+ ? arg->value.string : NULL;
+
/* 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
@@ -581,22 +596,25 @@
* 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. */
+ arg = grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
+ GPR_ASSERT(arg != NULL && arg->type == GRPC_ARG_POINTER);
+ grpc_lb_addresses* addresses = arg->value.pointer.p;
size_t num_grpclb_addrs = 0;
- for (size_t i = 0; i < args->addresses->num_addresses; ++i) {
- if (args->addresses->addresses[i].is_balancer) ++num_grpclb_addrs;
+ for (size_t i = 0; i < addresses->num_addresses; ++i) {
+ if (addresses->addresses[i].is_balancer) ++num_grpclb_addrs;
}
if (num_grpclb_addrs == 0) return NULL;
glb_lb_policy *glb_policy = gpr_malloc(sizeof(*glb_policy));
memset(glb_policy, 0, sizeof(*glb_policy));
- /* All input addresses in args->addresses come from a resolver that claims
+ /* All input addresses in addresses come from a resolver that claims
* they are LB services. It's the resolver's responsibility to make sure
* this
* policy is only instantiated and used in that case.
*
* Create a client channel over them to communicate with a LB service */
- glb_policy->server_name = gpr_strdup(args->server_name);
+ glb_policy->server_name = gpr_strdup(server_name);
glb_policy->cc_factory = args->client_channel_factory;
glb_policy->args = grpc_channel_args_copy(args->args);
GPR_ASSERT(glb_policy->cc_factory != NULL);
@@ -606,20 +624,20 @@
* TODO(dgq): support mixed ip version */
char **addr_strs = gpr_malloc(sizeof(char *) * num_grpclb_addrs);
size_t addr_index = 0;
- for (size_t i = 0; i < args->addresses->num_addresses; i++) {
- if (args->addresses->addresses[i].user_data != NULL) {
+ for (size_t i = 0; i < addresses->num_addresses; i++) {
+ if (addresses->addresses[i].user_data != NULL) {
gpr_log(GPR_ERROR,
"This LB policy doesn't support user data. It will be ignored");
}
- if (args->addresses->addresses[i].is_balancer) {
+ if (addresses->addresses[i].is_balancer) {
if (addr_index == 0) {
addr_strs[addr_index++] = grpc_sockaddr_to_uri(
- (const struct sockaddr *)&args->addresses->addresses[i]
+ (const struct sockaddr *)&addresses->addresses[i]
.address.addr);
} else {
GPR_ASSERT(grpc_sockaddr_to_string(
&addr_strs[addr_index++],
- (const struct sockaddr *)&args->addresses->addresses[i]
+ (const struct sockaddr *)&addresses->addresses[i]
.address.addr,
true) > 0);
}
@@ -629,10 +647,29 @@
char *target_uri_str = gpr_strjoin_sep((const char **)addr_strs,
num_grpclb_addrs, ",", &uri_path_len);
- /* will pick using pick_first */
+ /* Create a channel to talk to the LBs.
+ *
+ * We strip out the channel arg for the LB policy name, since we want
+ * to use the default (pick_first) in this case.
+ *
+ * We also strip out the channel arg for the resolved addresses, since
+ * that will be generated by the name resolver used in the LB channel.
+ * Note that the LB channel will use the sockaddr resolver, so this
+ * won't actually generate a query to DNS (or some other name service).
+ * However, the addresses returned by the sockaddr resolver will have
+ * is_balancer=false, whereas our own addresses have is_balancer=true.
+ * We need the LB channel to return addresses with is_balancer=false
+ * so that it does not wind up recursively using the grpclb LB policy,
+ * as per the special case logic in client_channel.c.
+ */
+ static const char* keys_to_remove[] = {
+ GRPC_ARG_LB_POLICY_NAME, GRPC_ARG_LB_ADDRESSES};
+ grpc_channel_args *new_args = grpc_channel_args_copy_and_remove(
+ args->args, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove));
glb_policy->lb_channel = grpc_client_channel_factory_create_channel(
exec_ctx, glb_policy->cc_factory, target_uri_str,
- GRPC_CLIENT_CHANNEL_TYPE_LOAD_BALANCING, args->args);
+ GRPC_CLIENT_CHANNEL_TYPE_LOAD_BALANCING, new_args);
+ grpc_channel_args_destroy(new_args);
gpr_free(target_uri_str);
for (size_t i = 0; i < num_grpclb_addrs; i++) {
diff --git a/src/core/ext/lb_policy/pick_first/pick_first.c b/src/core/ext/lb_policy/pick_first/pick_first.c
index 3683079..d95f031 100644
--- a/src/core/ext/lb_policy/pick_first/pick_first.c
+++ b/src/core/ext/lb_policy/pick_first/pick_first.c
@@ -34,7 +34,9 @@
#include <string.h>
#include <grpc/support/alloc.h>
+
#include "src/core/ext/client_config/lb_policy_registry.h"
+#include "src/core/lib/channel/channel_args.h"
#include "src/core/lib/transport/connectivity_state.h"
typedef struct pending_pick {
@@ -432,14 +434,23 @@
static grpc_lb_policy *create_pick_first(grpc_exec_ctx *exec_ctx,
grpc_lb_policy_factory *factory,
grpc_lb_policy_args *args) {
- GPR_ASSERT(args->addresses != NULL);
GPR_ASSERT(args->client_channel_factory != NULL);
+ /* Get server name. */
+ const grpc_arg* arg =
+ grpc_channel_args_find(args->args, GRPC_ARG_SERVER_NAME);
+ const char* server_name =
+ arg != NULL && arg->type == GRPC_ARG_STRING
+ ? arg->value.string : NULL;
+
/* Find the number of backend addresses. We ignore balancer
* addresses, since we don't know how to handle them. */
+ arg = grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
+ GPR_ASSERT(arg != NULL && arg->type == GRPC_ARG_POINTER);
+ grpc_lb_addresses* addresses = arg->value.pointer.p;
size_t num_addrs = 0;
- for (size_t i = 0; i < args->addresses->num_addresses; i++) {
- if (!args->addresses->addresses[i].is_balancer) ++num_addrs;
+ for (size_t i = 0; i < addresses->num_addresses; i++) {
+ if (!addresses->addresses[i].is_balancer) ++num_addrs;
}
if (num_addrs == 0) return NULL;
@@ -450,22 +461,22 @@
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->num_addresses; i++) {
+ for (size_t i = 0; i < addresses->num_addresses; i++) {
/* Skip balancer addresses, since we only know how to handle backends. */
- if (args->addresses->addresses[i].is_balancer) continue;
+ if (addresses->addresses[i].is_balancer) continue;
- if (args->addresses->addresses[i].user_data != NULL) {
+ if (addresses->addresses[i].user_data != NULL) {
gpr_log(GPR_ERROR,
"This LB policy doesn't support user data. It will be ignored");
}
memset(&sc_args, 0, sizeof(grpc_subchannel_args));
/* server_name will be copied as part of the subchannel creation. This makes
- * the copying of args->server_name (a borrowed pointer) OK. */
- sc_args.server_name = args->server_name;
+ * the copying of server_name (a borrowed pointer) OK. */
+ sc_args.server_name = server_name;
sc_args.addr =
- (struct sockaddr *)(&args->addresses->addresses[i].address.addr);
- sc_args.addr_len = args->addresses->addresses[i].address.len;
+ (struct sockaddr *)(&addresses->addresses[i].address.addr);
+ sc_args.addr_len = addresses->addresses[i].address.len;
sc_args.args = args->args;
grpc_subchannel *subchannel = grpc_client_channel_factory_create_subchannel(
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 00a1897..2deb0af 100644
--- a/src/core/ext/lb_policy/round_robin/round_robin.c
+++ b/src/core/ext/lb_policy/round_robin/round_robin.c
@@ -64,6 +64,7 @@
#include <grpc/support/alloc.h>
#include "src/core/ext/client_config/lb_policy_registry.h"
+#include "src/core/lib/channel/channel_args.h"
#include "src/core/lib/debug/trace.h"
#include "src/core/lib/transport/connectivity_state.h"
#include "src/core/lib/transport/static_metadata.h"
@@ -598,14 +599,23 @@
static grpc_lb_policy *round_robin_create(grpc_exec_ctx *exec_ctx,
grpc_lb_policy_factory *factory,
grpc_lb_policy_args *args) {
- GPR_ASSERT(args->addresses != NULL);
GPR_ASSERT(args->client_channel_factory != NULL);
+ /* Get server name. */
+ const grpc_arg* arg =
+ grpc_channel_args_find(args->args, GRPC_ARG_SERVER_NAME);
+ const char* server_name =
+ arg != NULL && arg->type == GRPC_ARG_STRING
+ ? arg->value.string : NULL;
+
/* Find the number of backend addresses. We ignore balancer
* addresses, since we don't know how to handle them. */
+ arg = grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES);
+ GPR_ASSERT(arg != NULL && arg->type == GRPC_ARG_POINTER);
+ grpc_lb_addresses* addresses = arg->value.pointer.p;
size_t num_addrs = 0;
- for (size_t i = 0; i < args->addresses->num_addresses; i++) {
- if (!args->addresses->addresses[i].is_balancer) ++num_addrs;
+ for (size_t i = 0; i < addresses->num_addresses; i++) {
+ if (!addresses->addresses[i].is_balancer) ++num_addrs;
}
if (num_addrs == 0) return NULL;
@@ -618,17 +628,17 @@
grpc_subchannel_args sc_args;
size_t subchannel_idx = 0;
- for (size_t i = 0; i < args->addresses->num_addresses; i++) {
+ for (size_t i = 0; i < addresses->num_addresses; i++) {
/* Skip balancer addresses, since we only know how to handle backends. */
- if (args->addresses->addresses[i].is_balancer) continue;
+ if (addresses->addresses[i].is_balancer) continue;
memset(&sc_args, 0, sizeof(grpc_subchannel_args));
/* server_name will be copied as part of the subchannel creation. This makes
- * the copying of args->server_name (a borrowed pointer) OK. */
- sc_args.server_name = args->server_name;
+ * the copying of server_name (a borrowed pointer) OK. */
+ sc_args.server_name = server_name;
sc_args.addr =
- (struct sockaddr *)(&args->addresses->addresses[i].address.addr);
- sc_args.addr_len = args->addresses->addresses[i].address.len;
+ (struct sockaddr *)(&addresses->addresses[i].address.addr);
+ sc_args.addr_len = addresses->addresses[i].address.len;
sc_args.args = args->args;
grpc_subchannel *subchannel = grpc_client_channel_factory_create_subchannel(
@@ -641,7 +651,7 @@
sd->policy = p;
sd->index = subchannel_idx;
sd->subchannel = subchannel;
- sd->user_data = args->addresses->addresses[i].user_data;
+ sd->user_data = addresses->addresses[i].user_data;
++subchannel_idx;
grpc_closure_init(&sd->connectivity_changed_closure,
rr_connectivity_changed, sd);
diff --git a/src/core/lib/channel/channel_args.c b/src/core/lib/channel/channel_args.c
index 2957d2c..0270d6f 100644
--- a/src/core/lib/channel/channel_args.c
+++ b/src/core/lib/channel/channel_args.c
@@ -66,22 +66,59 @@
grpc_channel_args *grpc_channel_args_copy_and_add(const grpc_channel_args *src,
const grpc_arg *to_add,
size_t num_to_add) {
+ return grpc_channel_args_copy_and_add_and_remove(src, NULL, 0, to_add,
+ num_to_add);
+}
+
+grpc_channel_args *grpc_channel_args_copy_and_remove(
+ const grpc_channel_args *src, const char** to_remove,
+ size_t num_to_remove) {
+ return grpc_channel_args_copy_and_add_and_remove(src, to_remove,
+ num_to_remove, NULL, 0);
+}
+
+static bool should_remove_arg(const grpc_arg* arg, const char** to_remove,
+ size_t num_to_remove) {
+ for (size_t i = 0; i < num_to_remove; ++i) {
+ if (strcmp(arg->key, to_remove[i]) == 0) return true;
+ }
+ return false;
+}
+
+grpc_channel_args *grpc_channel_args_copy_and_add_and_remove(
+ const grpc_channel_args *src, const char** to_remove, size_t num_to_remove,
+ const grpc_arg *to_add, size_t num_to_add) {
+ // Figure out how many args we'll be copying.
+ size_t num_args_to_copy = 0;
+ if (src != NULL) {
+ for (size_t i = 0; i < src->num_args; ++i) {
+ if (!should_remove_arg(&src->args[i], to_remove, num_to_remove)) {
+ ++num_args_to_copy;
+ }
+ }
+ }
+ // Create result.
grpc_channel_args *dst = gpr_malloc(sizeof(grpc_channel_args));
- size_t i;
- size_t src_num_args = (src == NULL) ? 0 : src->num_args;
- if (!src && !to_add) {
- dst->num_args = 0;
+ dst->num_args = num_args_to_copy + num_to_add;
+ if (dst->num_args == 0) {
dst->args = NULL;
return dst;
}
- dst->num_args = src_num_args + num_to_add;
dst->args = gpr_malloc(sizeof(grpc_arg) * dst->num_args);
- for (i = 0; i < src_num_args; i++) {
- dst->args[i] = copy_arg(&src->args[i]);
+ // Copy args from src that are not being removed.
+ size_t dst_idx = 0;
+ if (src != NULL) {
+ for (size_t i = 0; i < src->num_args; ++i) {
+ if (!should_remove_arg(&src->args[i], to_remove, num_to_remove)) {
+ dst->args[dst_idx++] = copy_arg(&src->args[i]);
+ }
+ }
}
- for (i = 0; i < num_to_add; i++) {
- dst->args[i + src_num_args] = copy_arg(&to_add[i]);
+ // Add args from to_add.
+ for (size_t i = 0; i < num_to_add; ++i) {
+ dst->args[dst_idx++] = copy_arg(&to_add[i]);
}
+ GPR_ASSERT(dst_idx == dst->num_args);
return dst;
}
diff --git a/src/core/lib/channel/channel_args.h b/src/core/lib/channel/channel_args.h
index a80340c..1508d23 100644
--- a/src/core/lib/channel/channel_args.h
+++ b/src/core/lib/channel/channel_args.h
@@ -51,6 +51,17 @@
const grpc_arg *to_add,
size_t num_to_add);
+/** Copies the arguments in \a src except for those whose keys are in
+ \a to_remove. */
+grpc_channel_args *grpc_channel_args_copy_and_remove(
+ const grpc_channel_args *src, const char** to_remove, size_t num_to_remove);
+
+/** Copies the arguments from \a src except for those whose keys are in
+ \a to_remove and appends the arguments in \a to_add. */
+grpc_channel_args *grpc_channel_args_copy_and_add_and_remove(
+ const grpc_channel_args *src, const char** to_remove, size_t num_to_remove,
+ const grpc_arg *to_add, size_t num_to_add);
+
/** Concatenate args from \a a and \a b into a new instance */
grpc_channel_args *grpc_channel_args_merge(const grpc_channel_args *a,
const grpc_channel_args *b);