static void dns_on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
grpc_resolved_addresses *addresses) {
dns_resolver *r = arg;
grpc_client_config *config = NULL;
grpc_subchannel **subchannels;
grpc_subchannel_args args;
grpc_lb_policy *lb_policy;
size_t i;
gpr_mu_lock(&r->mu);
GPR_ASSERT(r->resolving);
r->resolving = 0;
if (addresses != NULL) {
grpc_lb_policy_args lb_policy_args;
config = grpc_client_config_create();
subchannels = gpr_malloc(sizeof(grpc_subchannel *) * addresses->naddrs);
size_t naddrs = 0;
for (i = 0; i < addresses->naddrs; i++) {
memset(&args, 0, sizeof(args));
args.addr = (struct sockaddr *)(addresses->addrs[i].addr);
args.addr_len = (size_t)addresses->addrs[i].len;
grpc_subchannel *subchannel = grpc_subchannel_factory_create_subchannel(
exec_ctx, r->subchannel_factory, &args);
if (subchannel != NULL) {
subchannels[naddrs++] = subchannel;
}
}
memset(&lb_policy_args, 0, sizeof(lb_policy_args));
lb_policy_args.subchannels = subchannels;
lb_policy_args.num_subchannels = naddrs;
lb_policy = grpc_lb_policy_create(r->lb_policy_name, &lb_policy_args);
if (lb_policy != NULL) {
grpc_client_config_set_lb_policy(config, lb_policy);
GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "construction");
}
grpc_resolved_addresses_destroy(addresses);
gpr_free(subchannels);
} else {
int retry_seconds = 15;
gpr_log(GPR_DEBUG, "dns resolution failed: retrying in %d seconds",
retry_seconds);
GPR_ASSERT(!r->have_retry_timer);
r->have_retry_timer = true;
gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
GRPC_RESOLVER_REF(&r->base, "retry-timer");
grpc_timer_init(
exec_ctx, &r->retry_timer,
gpr_time_add(now, gpr_time_from_seconds(retry_seconds, GPR_TIMESPAN)),
dns_on_retry_timer, r, now);
}
if (r->resolved_config) {
grpc_client_config_unref(exec_ctx, r->resolved_config);
}
r->resolved_config = config;
r->resolved_version++;
dns_maybe_finish_next_locked(exec_ctx, r);
gpr_mu_unlock(&r->mu);
GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "dns-resolving");
}
static void dns_start_resolving_locked(grpc_exec_ctx *exec_ctx,
dns_resolver *r) {
GRPC_RESOLVER_REF(&r->base, "dns-resolving");
GPR_ASSERT(!r->resolving);
r->resolving = true;
r->addresses = NULL;
grpc_resolve_address(exec_ctx, r->name_to_resolve, r->default_port,
grpc_closure_create(dns_on_resolved, r), &r->addresses);
}
static void dns_on_resolved(grpc_exec_ctx *exec_ctx, void *arg,
grpc_error *error) {
dns_resolver *r = arg;
grpc_channel_args *result = NULL;
gpr_mu_lock(&r->mu);
GPR_ASSERT(r->resolving);
r->resolving = false;
if (r->addresses != NULL) {
grpc_lb_addresses *addresses = grpc_lb_addresses_create(
r->addresses->naddrs, NULL /* user_data_vtable */);
for (size_t i = 0; i < r->addresses->naddrs; ++i) {
grpc_lb_addresses_set_address(
addresses, i, &r->addresses->addrs[i].addr,
r->addresses->addrs[i].len, false /* is_balancer */,
NULL /* balancer_name */, NULL /* user_data */);
}
grpc_arg new_arg = grpc_lb_addresses_create_channel_arg(addresses);
result = grpc_channel_args_copy_and_add(r->channel_args, &new_arg, 1);
grpc_resolved_addresses_destroy(r->addresses);
grpc_lb_addresses_destroy(addresses);
} else {
gpr_timespec now = gpr_now(GPR_CLOCK_MONOTONIC);
gpr_timespec next_try = gpr_backoff_step(&r->backoff_state, now);
gpr_timespec timeout = gpr_time_sub(next_try, now);
const char *msg = grpc_error_string(error);
gpr_log(GPR_DEBUG, "dns resolution failed: %s", msg);
grpc_error_free_string(msg);
GPR_ASSERT(!r->have_retry_timer);
r->have_retry_timer = true;
GRPC_RESOLVER_REF(&r->base, "retry-timer");
if (gpr_time_cmp(timeout, gpr_time_0(timeout.clock_type)) > 0) {
gpr_log(GPR_DEBUG, "retrying in %" PRId64 ".%09d seconds", timeout.tv_sec,
timeout.tv_nsec);
} else {
gpr_log(GPR_DEBUG, "retrying immediately");
}
grpc_timer_init(exec_ctx, &r->retry_timer, next_try, dns_on_retry_timer, r,
now);
}
if (r->resolved_result != NULL) {
grpc_channel_args_destroy(r->resolved_result);
}
r->resolved_result = result;
r->resolved_version++;
dns_maybe_finish_next_locked(exec_ctx, r);
gpr_mu_unlock(&r->mu);
GRPC_RESOLVER_UNREF(exec_ctx, &r->base, "dns-resolving");
}
void grpc_client_channel_set_resolver(grpc_exec_ctx *exec_ctx,
grpc_channel_stack *channel_stack,
grpc_resolver *resolver) {
/* post construction initialization: set the transport setup pointer */
grpc_channel_element *elem = grpc_channel_stack_last_element(channel_stack);
channel_data *chand = elem->channel_data;
gpr_mu_lock(&chand->mu);
GPR_ASSERT(!chand->resolver);
chand->resolver = resolver;
GRPC_RESOLVER_REF(resolver, "channel");
if (!grpc_closure_list_empty(chand->waiting_for_config_closures) ||
chand->exit_idle_when_lb_policy_arrives) {
chand->started_resolving = true;
GRPC_CHANNEL_STACK_REF(chand->owning_stack, "resolver");
grpc_resolver_next(exec_ctx, resolver, &chand->resolver_result,
&chand->on_resolver_result_changed);
}
gpr_mu_unlock(&chand->mu);
}
static void dns_start_resolving_locked(dns_resolver *r) {
GRPC_RESOLVER_REF(&r->base, "dns-resolving");
GPR_ASSERT(!r->resolving);
r->resolving = 1;
grpc_resolve_address(r->name, r->default_port, dns_on_resolved, r);
}
static void cc_on_config_changed(grpc_exec_ctx *exec_ctx, void *arg,
bool iomgr_success) {
channel_data *chand = arg;
grpc_lb_policy *lb_policy = NULL;
grpc_lb_policy *old_lb_policy;
grpc_resolver *old_resolver;
grpc_connectivity_state state = GRPC_CHANNEL_TRANSIENT_FAILURE;
int exit_idle = 0;
if (chand->incoming_configuration != NULL) {
lb_policy = grpc_client_config_get_lb_policy(chand->incoming_configuration);
if (lb_policy != NULL) {
GRPC_LB_POLICY_REF(lb_policy, "channel");
GRPC_LB_POLICY_REF(lb_policy, "config_change");
state = grpc_lb_policy_check_connectivity(exec_ctx, lb_policy);
}
grpc_client_config_unref(exec_ctx, chand->incoming_configuration);
}
chand->incoming_configuration = NULL;
if (lb_policy != NULL) {
grpc_pollset_set_add_pollset_set(exec_ctx, &lb_policy->interested_parties,
&chand->interested_parties);
}
gpr_mu_lock(&chand->mu_config);
old_lb_policy = chand->lb_policy;
chand->lb_policy = lb_policy;
if (lb_policy != NULL || chand->resolver == NULL /* disconnected */) {
grpc_exec_ctx_enqueue_list(exec_ctx, &chand->waiting_for_config_closures,
NULL);
}
if (lb_policy != NULL && chand->exit_idle_when_lb_policy_arrives) {
GRPC_LB_POLICY_REF(lb_policy, "exit_idle");
exit_idle = 1;
chand->exit_idle_when_lb_policy_arrives = 0;
}
if (iomgr_success && chand->resolver) {
grpc_resolver *resolver = chand->resolver;
GRPC_RESOLVER_REF(resolver, "channel-next");
grpc_connectivity_state_set(exec_ctx, &chand->state_tracker, state,
"new_lb+resolver");
if (lb_policy != NULL) {
watch_lb_policy(exec_ctx, chand, lb_policy, state);
}
gpr_mu_unlock(&chand->mu_config);
GRPC_CHANNEL_STACK_REF(chand->owning_stack, "resolver");
grpc_resolver_next(exec_ctx, resolver, &chand->incoming_configuration,
&chand->on_config_changed);
GRPC_RESOLVER_UNREF(exec_ctx, resolver, "channel-next");
} else {
old_resolver = chand->resolver;
chand->resolver = NULL;
grpc_connectivity_state_set(exec_ctx, &chand->state_tracker,
GRPC_CHANNEL_FATAL_FAILURE, "resolver_gone");
gpr_mu_unlock(&chand->mu_config);
if (old_resolver != NULL) {
grpc_resolver_shutdown(exec_ctx, old_resolver);
GRPC_RESOLVER_UNREF(exec_ctx, old_resolver, "channel");
}
}
if (exit_idle) {
grpc_lb_policy_exit_idle(exec_ctx, lb_policy);
GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "exit_idle");
}
if (old_lb_policy != NULL) {
grpc_pollset_set_del_pollset_set(exec_ctx,
&old_lb_policy->interested_parties,
&chand->interested_parties);
GRPC_LB_POLICY_UNREF(exec_ctx, old_lb_policy, "channel");
}
if (lb_policy != NULL) {
GRPC_LB_POLICY_UNREF(exec_ctx, lb_policy, "config_change");
}
GRPC_CHANNEL_STACK_UNREF(exec_ctx, chand->owning_stack, "resolver");
}
static void zookeeper_start_resolving_locked(zookeeper_resolver *r) {
GRPC_RESOLVER_REF(&r->base, "zookeeper-resolving");
GPR_ASSERT(r->resolving == 0);
r->resolving = 1;
zookeeper_resolve_address(r);
}