int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_pollset *pollset,
grpc_metadata_batch *initial_metadata,
grpc_connected_subchannel **target, grpc_closure *on_complete) {
round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
pending_pick *pp;
ready_list *selected;
gpr_mu_lock(&p->mu);
if ((selected = peek_next_connected_locked(p))) {
gpr_mu_unlock(&p->mu);
*target = grpc_subchannel_get_connected_subchannel(selected->subchannel);
if (grpc_lb_round_robin_trace) {
gpr_log(GPR_DEBUG,
"[RR PICK] TARGET <-- CONNECTED SUBCHANNEL %p (NODE %p)",
selected->subchannel, selected);
}
/* only advance the last picked pointer if the selection was used */
advance_last_picked_locked(p);
return 1;
} else {
if (!p->started_picking) {
start_picking(exec_ctx, p);
}
grpc_pollset_set_add_pollset(exec_ctx, p->base.interested_parties, pollset);
pp = gpr_malloc(sizeof(*pp));
pp->next = p->pending_picks;
pp->pollset = pollset;
pp->target = target;
pp->on_complete = on_complete;
p->pending_picks = pp;
gpr_mu_unlock(&p->mu);
return 0;
}
}
void rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
grpc_pollset *pollset, grpc_metadata_batch *initial_metadata,
grpc_subchannel **target, grpc_closure *on_complete) {
size_t i;
round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
pending_pick *pp;
ready_list *selected;
gpr_mu_lock(&p->mu);
if ((selected = peek_next_connected_locked(p))) {
gpr_mu_unlock(&p->mu);
*target = selected->subchannel;
if (grpc_lb_round_robin_trace) {
gpr_log(GPR_DEBUG, "[RR PICK] TARGET <-- SUBCHANNEL %p (NODE %p)",
selected->subchannel, selected);
}
/* only advance the last picked pointer if the selection was used */
advance_last_picked_locked(p);
on_complete->cb(exec_ctx, on_complete->cb_arg, 1);
} else {
if (!p->started_picking) {
start_picking(exec_ctx, p);
}
for (i = 0; i < p->num_subchannels; i++) {
grpc_subchannel_add_interested_party(exec_ctx, p->subchannels[i],
pollset);
}
pp = gpr_malloc(sizeof(*pp));
pp->next = p->pending_picks;
pp->pollset = pollset;
pp->target = target;
pp->on_complete = on_complete;
p->pending_picks = pp;
gpr_mu_unlock(&p->mu);
}
}
static void rr_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
grpc_closure *closure) {
round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
ready_list *selected;
grpc_connected_subchannel *target;
gpr_mu_lock(&p->mu);
if ((selected = peek_next_connected_locked(p))) {
gpr_mu_unlock(&p->mu);
target = grpc_subchannel_get_connected_subchannel(selected->subchannel);
grpc_connected_subchannel_ping(exec_ctx, target, closure);
} else {
gpr_mu_unlock(&p->mu);
grpc_exec_ctx_enqueue(exec_ctx, closure, false, NULL);
}
}
static int rr_pick(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
const grpc_lb_policy_pick_args *pick_args,
grpc_connected_subchannel **target, void **user_data,
grpc_closure *on_complete) {
round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
pending_pick *pp;
ready_list *selected;
gpr_mu_lock(&p->mu);
if (grpc_lb_round_robin_trace) {
gpr_log(GPR_INFO, "Round Robin %p trying to pick", (void *)pol);
}
if ((selected = peek_next_connected_locked(p))) {
/* readily available, report right away */
*target = GRPC_CONNECTED_SUBCHANNEL_REF(
grpc_subchannel_get_connected_subchannel(selected->subchannel),
"rr_picked");
if (user_data != NULL) {
*user_data = selected->user_data;
}
if (grpc_lb_round_robin_trace) {
gpr_log(GPR_DEBUG,
"[RR PICK] TARGET <-- CONNECTED SUBCHANNEL %p (NODE %p)",
(void *)*target, (void *)selected);
}
/* only advance the last picked pointer if the selection was used */
advance_last_picked_locked(p);
gpr_mu_unlock(&p->mu);
return 1;
} else {
/* no pick currently available. Save for later in list of pending picks */
if (!p->started_picking) {
start_picking(exec_ctx, p);
}
pp = gpr_malloc(sizeof(*pp));
pp->next = p->pending_picks;
pp->target = target;
pp->on_complete = on_complete;
pp->initial_metadata_flags = pick_args->initial_metadata_flags;
pp->user_data = user_data;
p->pending_picks = pp;
gpr_mu_unlock(&p->mu);
return 0;
}
}
static void rr_ping_one(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol,
grpc_closure *closure) {
round_robin_lb_policy *p = (round_robin_lb_policy *)pol;
ready_list *selected;
grpc_connected_subchannel *target;
gpr_mu_lock(&p->mu);
if ((selected = peek_next_connected_locked(p))) {
gpr_mu_unlock(&p->mu);
target = GRPC_CONNECTED_SUBCHANNEL_REF(
grpc_subchannel_get_connected_subchannel(selected->subchannel),
"rr_picked");
grpc_connected_subchannel_ping(exec_ctx, target, closure);
GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, target, "rr_picked");
} else {
gpr_mu_unlock(&p->mu);
grpc_exec_ctx_sched(exec_ctx, closure,
GRPC_ERROR_CREATE("Round Robin not connected"), NULL);
}
}
static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
bool iomgr_success) {
subchannel_data *sd = arg;
round_robin_lb_policy *p = sd->policy;
pending_pick *pp;
ready_list *selected;
int unref = 0;
gpr_mu_lock(&p->mu);
if (p->shutdown) {
unref = 1;
} else {
switch (sd->connectivity_state) {
case GRPC_CHANNEL_READY:
grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
GRPC_CHANNEL_READY, "connecting_ready");
/* add the newly connected subchannel to the list of connected ones.
* Note that it goes to the "end of the line". */
sd->ready_list_node = add_connected_sc_locked(p, sd->subchannel);
/* at this point we know there's at least one suitable subchannel. Go
* ahead and pick one and notify the pending suitors in
* p->pending_picks. This preemtively replicates rr_pick()'s actions. */
selected = peek_next_connected_locked(p);
if (p->pending_picks != NULL) {
/* if the selected subchannel is going to be used for the pending
* picks, update the last picked pointer */
advance_last_picked_locked(p);
}
while ((pp = p->pending_picks)) {
p->pending_picks = pp->next;
*pp->target =
grpc_subchannel_get_connected_subchannel(selected->subchannel);
if (grpc_lb_round_robin_trace) {
gpr_log(GPR_DEBUG,
"[RR CONN CHANGED] TARGET <-- SUBCHANNEL %p (NODE %p)",
selected->subchannel, selected);
}
grpc_pollset_set_del_pollset(exec_ctx, p->base.interested_parties,
pp->pollset);
grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, true, NULL);
gpr_free(pp);
}
grpc_subchannel_notify_on_state_change(
exec_ctx, sd->subchannel, p->base.interested_parties,
&sd->connectivity_state, &sd->connectivity_changed_closure);
break;
case GRPC_CHANNEL_CONNECTING:
case GRPC_CHANNEL_IDLE:
grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
sd->connectivity_state,
"connecting_changed");
grpc_subchannel_notify_on_state_change(
exec_ctx, sd->subchannel, p->base.interested_parties,
&sd->connectivity_state, &sd->connectivity_changed_closure);
break;
case GRPC_CHANNEL_TRANSIENT_FAILURE:
/* renew state notification */
grpc_subchannel_notify_on_state_change(
exec_ctx, sd->subchannel, p->base.interested_parties,
&sd->connectivity_state, &sd->connectivity_changed_closure);
/* remove from ready list if still present */
if (sd->ready_list_node != NULL) {
remove_disconnected_sc_locked(p, sd->ready_list_node);
sd->ready_list_node = NULL;
}
grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
GRPC_CHANNEL_TRANSIENT_FAILURE,
"connecting_transient_failure");
break;
case GRPC_CHANNEL_FATAL_FAILURE:
if (sd->ready_list_node != NULL) {
remove_disconnected_sc_locked(p, sd->ready_list_node);
sd->ready_list_node = NULL;
}
p->num_subchannels--;
GPR_SWAP(subchannel_data *, p->subchannels[sd->index],
p->subchannels[p->num_subchannels]);
GRPC_SUBCHANNEL_UNREF(exec_ctx, sd->subchannel, "round_robin");
p->subchannels[sd->index]->index = sd->index;
gpr_free(sd);
unref = 1;
if (p->num_subchannels == 0) {
grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
GRPC_CHANNEL_FATAL_FAILURE,
"no_more_channels");
while ((pp = p->pending_picks)) {
p->pending_picks = pp->next;
*pp->target = NULL;
grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, true, NULL);
gpr_free(pp);
}
} else {
grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
GRPC_CHANNEL_TRANSIENT_FAILURE,
"subchannel_failed");
}
} /* switch */
} /* !unref */
gpr_mu_unlock(&p->mu);
if (unref) {
GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "round_robin_connectivity");
}
}
static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
grpc_error *error) {
subchannel_data *sd = arg;
round_robin_lb_policy *p = sd->policy;
pending_pick *pp;
GRPC_ERROR_REF(error);
gpr_mu_lock(&p->mu);
if (p->shutdown) {
gpr_mu_unlock(&p->mu);
GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "rr_connectivity");
GRPC_ERROR_UNREF(error);
return;
}
switch (sd->curr_connectivity_state) {
case GRPC_CHANNEL_INIT:
GPR_UNREACHABLE_CODE(return );
case GRPC_CHANNEL_READY:
/* add the newly connected subchannel to the list of connected ones.
* Note that it goes to the "end of the line". */
sd->ready_list_node = add_connected_sc_locked(p, sd);
/* at this point we know there's at least one suitable subchannel. Go
* ahead and pick one and notify the pending suitors in
* p->pending_picks. This preemtively replicates rr_pick()'s actions. */
ready_list *selected = peek_next_connected_locked(p);
GPR_ASSERT(selected != NULL);
if (p->pending_picks != NULL) {
/* if the selected subchannel is going to be used for the pending
* picks, update the last picked pointer */
advance_last_picked_locked(p);
}
while ((pp = p->pending_picks)) {
p->pending_picks = pp->next;
*pp->target = GRPC_CONNECTED_SUBCHANNEL_REF(
grpc_subchannel_get_connected_subchannel(selected->subchannel),
"rr_picked");
if (pp->user_data != NULL) {
*pp->user_data = selected->user_data;
}
if (grpc_lb_round_robin_trace) {
gpr_log(GPR_DEBUG,
"[RR CONN CHANGED] TARGET <-- SUBCHANNEL %p (NODE %p)",
(void *)selected->subchannel, (void *)selected);
}
grpc_exec_ctx_sched(exec_ctx, pp->on_complete, GRPC_ERROR_NONE, NULL);
gpr_free(pp);
}
update_lb_connectivity_status(exec_ctx, sd, error);
sd->prev_connectivity_state = sd->curr_connectivity_state;
/* renew notification: reuses the "rr_connectivity" weak ref */
grpc_subchannel_notify_on_state_change(
exec_ctx, sd->subchannel, p->base.interested_parties,
&sd->curr_connectivity_state, &sd->connectivity_changed_closure);
break;
case GRPC_CHANNEL_IDLE:
++p->num_idle;
/* fallthrough */
case GRPC_CHANNEL_CONNECTING:
update_state_counters(sd);
update_lb_connectivity_status(exec_ctx, sd, error);
sd->prev_connectivity_state = sd->curr_connectivity_state;
/* renew notification: reuses the "rr_connectivity" weak ref */
grpc_subchannel_notify_on_state_change(
exec_ctx, sd->subchannel, p->base.interested_parties,
&sd->curr_connectivity_state, &sd->connectivity_changed_closure);
break;
case GRPC_CHANNEL_TRANSIENT_FAILURE:
++p->num_transient_failures;
/* remove from ready list if still present */
if (sd->ready_list_node != NULL) {
remove_disconnected_sc_locked(p, sd->ready_list_node);
sd->ready_list_node = NULL;
}
update_lb_connectivity_status(exec_ctx, sd, error);
sd->prev_connectivity_state = sd->curr_connectivity_state;
/* renew notification: reuses the "rr_connectivity" weak ref */
grpc_subchannel_notify_on_state_change(
exec_ctx, sd->subchannel, p->base.interested_parties,
&sd->curr_connectivity_state, &sd->connectivity_changed_closure);
break;
case GRPC_CHANNEL_SHUTDOWN:
update_state_counters(sd);
if (sd->ready_list_node != NULL) {
remove_disconnected_sc_locked(p, sd->ready_list_node);
sd->ready_list_node = NULL;
}
--p->num_subchannels;
GPR_SWAP(subchannel_data *, p->subchannels[sd->index],
p->subchannels[p->num_subchannels]);
GRPC_SUBCHANNEL_UNREF(exec_ctx, sd->subchannel, "rr_subchannel_shutdown");
p->subchannels[sd->index]->index = sd->index;
if (update_lb_connectivity_status(exec_ctx, sd, error) ==
GRPC_CHANNEL_SHUTDOWN) {
/* the policy is shutting down. Flush all the pending picks... */
while ((pp = p->pending_picks)) {
p->pending_picks = pp->next;
*pp->target = NULL;
grpc_exec_ctx_sched(exec_ctx, pp->on_complete, GRPC_ERROR_NONE, NULL);
gpr_free(pp);
}
}
gpr_free(sd);
/* unref the "rr_connectivity" weak ref from start_picking */
GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "rr_connectivity");
break;
}
gpr_mu_unlock(&p->mu);
GRPC_ERROR_UNREF(error);
}
static void rr_connectivity_changed(grpc_exec_ctx *exec_ctx, void *arg,
int iomgr_success) {
connectivity_changed_cb_arg *cb_arg = arg;
round_robin_lb_policy *p = cb_arg->p;
/* index over p->subchannels of this cb's subchannel */
const size_t this_idx = cb_arg->subchannel_idx;
pending_pick *pp;
ready_list *selected;
int unref = 0;
/* connectivity state of this cb's subchannel */
grpc_connectivity_state *this_connectivity;
gpr_mu_lock(&p->mu);
this_connectivity = &p->subchannel_connectivity[this_idx];
if (p->shutdown) {
unref = 1;
} else {
switch (*this_connectivity) {
case GRPC_CHANNEL_READY:
grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
GRPC_CHANNEL_READY, "connecting_ready");
/* add the newly connected subchannel to the list of connected ones.
* Note that it goes to the "end of the line". */
p->subchannel_index_to_readylist_node[this_idx] =
add_connected_sc_locked(p, p->subchannels[this_idx]);
/* at this point we know there's at least one suitable subchannel. Go
* ahead and pick one and notify the pending suitors in
* p->pending_picks. This preemtively replicates rr_pick()'s actions. */
selected = peek_next_connected_locked(p);
if (p->pending_picks != NULL) {
/* if the selected subchannel is going to be used for the pending
* picks, update the last picked pointer */
advance_last_picked_locked(p);
}
while ((pp = p->pending_picks)) {
p->pending_picks = pp->next;
*pp->target = selected->subchannel;
if (grpc_lb_round_robin_trace) {
gpr_log(GPR_DEBUG,
"[RR CONN CHANGED] TARGET <-- SUBCHANNEL %p (NODE %p)",
selected->subchannel, selected);
}
grpc_subchannel_del_interested_party(exec_ctx, selected->subchannel,
pp->pollset);
grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, 1);
gpr_free(pp);
}
grpc_subchannel_notify_on_state_change(
exec_ctx, p->subchannels[this_idx], this_connectivity,
&p->connectivity_changed_cbs[this_idx]);
break;
case GRPC_CHANNEL_CONNECTING:
case GRPC_CHANNEL_IDLE:
grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
*this_connectivity, "connecting_changed");
grpc_subchannel_notify_on_state_change(
exec_ctx, p->subchannels[this_idx], this_connectivity,
&p->connectivity_changed_cbs[this_idx]);
break;
case GRPC_CHANNEL_TRANSIENT_FAILURE:
del_interested_parties_locked(exec_ctx, p, this_idx);
/* renew state notification */
grpc_subchannel_notify_on_state_change(
exec_ctx, p->subchannels[this_idx], this_connectivity,
&p->connectivity_changed_cbs[this_idx]);
/* remove from ready list if still present */
if (p->subchannel_index_to_readylist_node[this_idx] != NULL) {
remove_disconnected_sc_locked(
p, p->subchannel_index_to_readylist_node[this_idx]);
p->subchannel_index_to_readylist_node[this_idx] = NULL;
}
grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
GRPC_CHANNEL_TRANSIENT_FAILURE,
"connecting_transient_failure");
break;
case GRPC_CHANNEL_FATAL_FAILURE:
del_interested_parties_locked(exec_ctx, p, this_idx);
if (p->subchannel_index_to_readylist_node[this_idx] != NULL) {
remove_disconnected_sc_locked(
p, p->subchannel_index_to_readylist_node[this_idx]);
p->subchannel_index_to_readylist_node[this_idx] = NULL;
}
GPR_SWAP(grpc_subchannel *, p->subchannels[this_idx],
p->subchannels[p->num_subchannels - 1]);
p->num_subchannels--;
GRPC_SUBCHANNEL_UNREF(exec_ctx, p->subchannels[p->num_subchannels],
"round_robin");
if (p->num_subchannels == 0) {
grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
GRPC_CHANNEL_FATAL_FAILURE,
"no_more_channels");
while ((pp = p->pending_picks)) {
p->pending_picks = pp->next;
*pp->target = NULL;
grpc_exec_ctx_enqueue(exec_ctx, pp->on_complete, 1);
gpr_free(pp);
}
unref = 1;
} else {
grpc_connectivity_state_set(exec_ctx, &p->state_tracker,
GRPC_CHANNEL_TRANSIENT_FAILURE,
"subchannel_failed");
}
} /* switch */
} /* !unref */
gpr_mu_unlock(&p->mu);
if (unref) {
GRPC_LB_POLICY_UNREF(exec_ctx, &p->base, "round_robin_connectivity");
}
}