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");
}
static grpc_ares_request *my_dns_lookup_ares(
grpc_exec_ctx *exec_ctx, const char *dns_server, const char *addr,
const char *default_port, grpc_pollset_set *interested_parties,
grpc_closure *on_done, grpc_lb_addresses **lb_addrs, bool check_grpclb,
char **service_config_json) {
gpr_mu_lock(&g_mu);
GPR_ASSERT(0 == strcmp("test", addr));
grpc_error *error = GRPC_ERROR_NONE;
if (g_fail_resolution) {
g_fail_resolution = false;
gpr_mu_unlock(&g_mu);
error = GRPC_ERROR_CREATE_FROM_STATIC_STRING("Forced Failure");
} else {
gpr_mu_unlock(&g_mu);
*lb_addrs = grpc_lb_addresses_create(1, NULL);
grpc_lb_addresses_set_address(*lb_addrs, 0, NULL, 0, false, NULL, NULL);
}
GRPC_CLOSURE_SCHED(exec_ctx, on_done, error);
return NULL;
}
