// Gets data from the service config. Invoked when the resolver returns
// its initial result.
static void read_service_config(grpc_exec_ctx *exec_ctx, void *arg,
grpc_error *error) {
grpc_call_element *elem = arg;
channel_data *chand = elem->channel_data;
call_data *calld = elem->call_data;
// If this is an error, there's no point in looking at the service config.
if (error == GRPC_ERROR_NONE) {
// Get the method config table from channel data.
gpr_mu_lock(&chand->mu);
grpc_mdstr_hash_table *method_params_table = NULL;
if (chand->method_params_table != NULL) {
method_params_table =
grpc_mdstr_hash_table_ref(chand->method_params_table);
}
gpr_mu_unlock(&chand->mu);
// If the method config table was present, use it.
if (method_params_table != NULL) {
const method_parameters *method_params =
grpc_method_config_table_get(method_params_table, calld->path);
if (method_params != NULL) {
const bool have_method_timeout =
gpr_time_cmp(method_params->timeout, gpr_time_0(GPR_TIMESPAN)) != 0;
if (have_method_timeout ||
method_params->wait_for_ready != WAIT_FOR_READY_UNSET) {
gpr_mu_lock(&calld->mu);
if (have_method_timeout) {
const gpr_timespec per_method_deadline =
gpr_time_add(calld->call_start_time, method_params->timeout);
if (gpr_time_cmp(per_method_deadline, calld->deadline) < 0) {
calld->deadline = per_method_deadline;
// Reset deadline timer.
grpc_deadline_state_reset(exec_ctx, elem, calld->deadline);
}
}
if (method_params->wait_for_ready != WAIT_FOR_READY_UNSET) {
calld->wait_for_ready_from_service_config =
method_params->wait_for_ready;
}
gpr_mu_unlock(&calld->mu);
}
}
grpc_mdstr_hash_table_unref(method_params_table);
}
}
GRPC_CALL_STACK_UNREF(exec_ctx, calld->owning_call, "read_service_config");
}
/* Destructor for channel_data */
static void cc_destroy_channel_elem(grpc_exec_ctx *exec_ctx,
grpc_channel_element *elem) {
channel_data *chand = elem->channel_data;
if (chand->resolver != NULL) {
grpc_resolver_shutdown(exec_ctx, chand->resolver);
GRPC_RESOLVER_UNREF(exec_ctx, chand->resolver, "channel");
}
if (chand->client_channel_factory != NULL) {
grpc_client_channel_factory_unref(exec_ctx, chand->client_channel_factory);
}
if (chand->lb_policy != NULL) {
grpc_pollset_set_del_pollset_set(exec_ctx,
chand->lb_policy->interested_parties,
chand->interested_parties);
GRPC_LB_POLICY_UNREF(exec_ctx, chand->lb_policy, "channel");
}
if (chand->method_params_table != NULL) {
grpc_mdstr_hash_table_unref(chand->method_params_table);
}
grpc_connectivity_state_destroy(exec_ctx, &chand->state_tracker);
grpc_pollset_set_destroy(chand->interested_parties);
gpr_mu_destroy(&chand->mu);
}
/* Constructor for call_data */
static grpc_error *cc_init_call_elem(grpc_exec_ctx *exec_ctx,
grpc_call_element *elem,
grpc_call_element_args *args) {
channel_data *chand = elem->channel_data;
call_data *calld = elem->call_data;
// Initialize data members.
grpc_deadline_state_init(exec_ctx, elem, args->call_stack);
calld->path = GRPC_MDSTR_REF(args->path);
calld->call_start_time = args->start_time;
calld->deadline = gpr_convert_clock_type(args->deadline, GPR_CLOCK_MONOTONIC);
calld->wait_for_ready_from_service_config = WAIT_FOR_READY_UNSET;
calld->cancel_error = GRPC_ERROR_NONE;
gpr_atm_rel_store(&calld->subchannel_call, 0);
gpr_mu_init(&calld->mu);
calld->connected_subchannel = NULL;
calld->waiting_ops = NULL;
calld->waiting_ops_count = 0;
calld->waiting_ops_capacity = 0;
calld->creation_phase = GRPC_SUBCHANNEL_CALL_HOLDER_NOT_CREATING;
calld->owning_call = args->call_stack;
calld->pollent = NULL;
// If the resolver has already returned results, then we can access
// the service config parameters immediately. Otherwise, we need to
// defer that work until the resolver returns an initial result.
// TODO(roth): This code is almost but not quite identical to the code
// in read_service_config() above. It would be nice to find a way to
// combine them, to avoid having to maintain it twice.
gpr_mu_lock(&chand->mu);
if (chand->lb_policy != NULL) {
// We already have a resolver result, so check for service config.
if (chand->method_params_table != NULL) {
grpc_mdstr_hash_table *method_params_table =
grpc_mdstr_hash_table_ref(chand->method_params_table);
gpr_mu_unlock(&chand->mu);
method_parameters *method_params =
grpc_method_config_table_get(method_params_table, args->path);
if (method_params != NULL) {
if (gpr_time_cmp(method_params->timeout,
gpr_time_0(GPR_CLOCK_MONOTONIC)) != 0) {
gpr_timespec per_method_deadline =
gpr_time_add(calld->call_start_time, method_params->timeout);
calld->deadline = gpr_time_min(calld->deadline, per_method_deadline);
}
if (method_params->wait_for_ready != WAIT_FOR_READY_UNSET) {
calld->wait_for_ready_from_service_config =
method_params->wait_for_ready;
}
}
grpc_mdstr_hash_table_unref(method_params_table);
} else {
gpr_mu_unlock(&chand->mu);
}
} else {
// We don't yet have a resolver result, so register a callback to
// get the service config data once the resolver returns.
// Take a reference to the call stack to be owned by the callback.
GRPC_CALL_STACK_REF(calld->owning_call, "read_service_config");
grpc_closure_init(&calld->read_service_config, read_service_config, elem);
grpc_closure_list_append(&chand->waiting_for_config_closures,
&calld->read_service_config, GRPC_ERROR_NONE);
gpr_mu_unlock(&chand->mu);
}
// Start the deadline timer with the current deadline value. If we
// do not yet have service config data, then the timer may be reset
// later.
grpc_deadline_state_start(exec_ctx, elem, calld->deadline);
return GRPC_ERROR_NONE;
}
static void on_resolver_result_changed(grpc_exec_ctx *exec_ctx, void *arg,
grpc_error *error) {
channel_data *chand = arg;
grpc_lb_policy *lb_policy = NULL;
grpc_lb_policy *old_lb_policy;
grpc_mdstr_hash_table *method_params_table = NULL;
grpc_connectivity_state state = GRPC_CHANNEL_TRANSIENT_FAILURE;
bool exit_idle = false;
grpc_error *state_error = GRPC_ERROR_CREATE("No load balancing policy");
if (chand->resolver_result != NULL) {
grpc_lb_policy_args lb_policy_args;
lb_policy_args.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 *channel_arg =
grpc_channel_args_find(lb_policy_args.args, GRPC_ARG_LB_POLICY_NAME);
if (channel_arg != NULL) {
GPR_ASSERT(channel_arg->type == GRPC_ARG_STRING);
lb_policy_name = channel_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.
channel_arg =
grpc_channel_args_find(lb_policy_args.args, GRPC_ARG_LB_ADDRESSES);
if (channel_arg != NULL) {
GPR_ASSERT(channel_arg->type == GRPC_ARG_POINTER);
grpc_lb_addresses *addresses = channel_arg->value.pointer.p;
bool found_backend_address = false;
for (size_t i = 0; i < addresses->num_addresses; ++i) {
if (!addresses->addresses[i].is_balancer) {
found_backend_address = true;
break;
}
}
if (!found_backend_address) {
if (lb_policy_name != NULL && strcmp(lb_policy_name, "grpclb") != 0) {
gpr_log(GPR_INFO,
"resolver requested LB policy %s but provided only balancer "
"addresses, no backend addresses -- forcing use of grpclb LB "
"policy",
lb_policy_name);
}
lb_policy_name = "grpclb";
}
}
// Use pick_first if nothing was specified and we didn't select grpclb
// above.
if (lb_policy_name == NULL) lb_policy_name = "pick_first";
lb_policy =
grpc_lb_policy_create(exec_ctx, lb_policy_name, &lb_policy_args);
if (lb_policy != NULL) {
GRPC_LB_POLICY_REF(lb_policy, "config_change");
GRPC_ERROR_UNREF(state_error);
state =
grpc_lb_policy_check_connectivity(exec_ctx, lb_policy, &state_error);
}
channel_arg =
grpc_channel_args_find(lb_policy_args.args, GRPC_ARG_SERVICE_CONFIG);
if (channel_arg != NULL) {
GPR_ASSERT(channel_arg->type == GRPC_ARG_POINTER);
method_params_table = grpc_method_config_table_convert(
(grpc_method_config_table *)channel_arg->value.pointer.p,
method_config_convert_value, &method_parameters_vtable);
}
grpc_channel_args_destroy(chand->resolver_result);
chand->resolver_result = 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);
old_lb_policy = chand->lb_policy;
chand->lb_policy = lb_policy;
if (chand->method_params_table != NULL) {
grpc_mdstr_hash_table_unref(chand->method_params_table);
}
chand->method_params_table = method_params_table;
if (lb_policy != NULL) {
grpc_exec_ctx_enqueue_list(exec_ctx, &chand->waiting_for_config_closures,
NULL);
} else if (chand->resolver == NULL /* disconnected */) {
grpc_closure_list_fail_all(
&chand->waiting_for_config_closures,
GRPC_ERROR_CREATE_REFERENCING("Channel disconnected", &error, 1));
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 = true;
chand->exit_idle_when_lb_policy_arrives = false;
}
if (error == GRPC_ERROR_NONE && chand->resolver) {
set_channel_connectivity_state_locked(
exec_ctx, chand, state, GRPC_ERROR_REF(state_error), "new_lb+resolver");
if (lb_policy != NULL) {
watch_lb_policy(exec_ctx, chand, lb_policy, state);
}
GRPC_CHANNEL_STACK_REF(chand->owning_stack, "resolver");
grpc_resolver_next(exec_ctx, chand->resolver, &chand->resolver_result,
&chand->on_resolver_result_changed);
gpr_mu_unlock(&chand->mu);
} else {
if (chand->resolver != NULL) {
grpc_resolver_shutdown(exec_ctx, chand->resolver);
GRPC_RESOLVER_UNREF(exec_ctx, chand->resolver, "channel");
chand->resolver = NULL;
}
grpc_error *refs[] = {error, state_error};
set_channel_connectivity_state_locked(
exec_ctx, chand, GRPC_CHANNEL_SHUTDOWN,
GRPC_ERROR_CREATE_REFERENCING("Got config after disconnection", refs,
GPR_ARRAY_SIZE(refs)),
"resolver_gone");
gpr_mu_unlock(&chand->mu);
}
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");
GRPC_ERROR_UNREF(state_error);
}
// Destructor for channel_data.
static void destroy_channel_elem(grpc_exec_ctx* exec_ctx,
grpc_channel_element* elem) {
channel_data* chand = elem->channel_data;
grpc_mdstr_hash_table_unref(chand->method_limit_table);
}
