diff options
Diffstat (limited to 'src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc')
| -rw-r--r-- | src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc | 477 |
1 files changed, 125 insertions, 352 deletions
diff --git a/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc b/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc index 6812bb50cd..fae40e378b 100644 --- a/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc +++ b/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc @@ -28,6 +28,7 @@ #include <grpc/support/alloc.h> +#include "src/core/ext/filters/client_channel/lb_policy/subchannel_list.h" #include "src/core/ext/filters/client_channel/lb_policy_registry.h" #include "src/core/ext/filters/client_channel/subchannel.h" #include "src/core/ext/filters/client_channel/subchannel_index.h" @@ -64,12 +65,11 @@ typedef struct pending_pick { grpc_closure *on_complete; } pending_pick; -typedef struct rr_subchannel_list rr_subchannel_list; typedef struct round_robin_lb_policy { /** base policy: must be first */ grpc_lb_policy base; - rr_subchannel_list *subchannel_list; + grpc_lb_subchannel_list *subchannel_list; /** have we started picking? */ bool started_picking; @@ -89,157 +89,9 @@ typedef struct round_robin_lb_policy { * lists if they equal \a latest_pending_subchannel_list. In other words, * racing callbacks that reference outdated subchannel lists won't perform any * update. */ - rr_subchannel_list *latest_pending_subchannel_list; + grpc_lb_subchannel_list *latest_pending_subchannel_list; } round_robin_lb_policy; -typedef struct { - /** backpointer to owning subchannel list */ - rr_subchannel_list *subchannel_list; - /** subchannel itself */ - grpc_subchannel *subchannel; - /** notification that connectivity has changed on subchannel */ - grpc_closure connectivity_changed_closure; - /** last observed connectivity. Not updated by - * \a grpc_subchannel_notify_on_state_change. Used to determine the previous - * state while processing the new state in \a rr_connectivity_changed */ - grpc_connectivity_state prev_connectivity_state; - /** current connectivity state. Updated by \a - * grpc_subchannel_notify_on_state_change */ - grpc_connectivity_state curr_connectivity_state; - /** connectivity state to be updated by the watcher, not guarded by - * the combiner. Will be moved to curr_connectivity_state inside of - * the combiner by rr_connectivity_changed_locked(). */ - grpc_connectivity_state pending_connectivity_state_unsafe; - /** the subchannel's target user data */ - void *user_data; - /** vtable to operate over \a user_data */ - const grpc_lb_user_data_vtable *user_data_vtable; -} subchannel_data; - -struct rr_subchannel_list { - /** backpointer to owning policy */ - round_robin_lb_policy *policy; - - /** all our subchannels */ - size_t num_subchannels; - subchannel_data *subchannels; - - /** how many subchannels are in state READY */ - size_t num_ready; - /** how many subchannels are in state TRANSIENT_FAILURE */ - size_t num_transient_failures; - /** how many subchannels are in state SHUTDOWN */ - size_t num_shutdown; - /** how many subchannels are in state IDLE */ - size_t num_idle; - - /** There will be one ref for each entry in subchannels for which there is a - * pending connectivity state watcher callback. */ - gpr_refcount refcount; - - /** Is this list shutting down? This may be true due to the shutdown of the - * policy itself or because a newer update has arrived while this one hadn't - * finished processing. */ - bool shutting_down; -}; - -static rr_subchannel_list *rr_subchannel_list_create(round_robin_lb_policy *p, - size_t num_subchannels) { - rr_subchannel_list *subchannel_list = - (rr_subchannel_list *)gpr_zalloc(sizeof(*subchannel_list)); - subchannel_list->policy = p; - subchannel_list->subchannels = - (subchannel_data *)gpr_zalloc(sizeof(subchannel_data) * num_subchannels); - subchannel_list->num_subchannels = num_subchannels; - gpr_ref_init(&subchannel_list->refcount, 1); - if (GRPC_TRACER_ON(grpc_lb_round_robin_trace)) { - gpr_log(GPR_INFO, "[RR %p] Created subchannel list %p for %lu subchannels", - (void *)p, (void *)subchannel_list, (unsigned long)num_subchannels); - } - return subchannel_list; -} - -static void rr_subchannel_list_destroy(grpc_exec_ctx *exec_ctx, - rr_subchannel_list *subchannel_list) { - GPR_ASSERT(subchannel_list->shutting_down); - if (GRPC_TRACER_ON(grpc_lb_round_robin_trace)) { - gpr_log(GPR_INFO, "[RR %p] Destroying subchannel_list %p", - (void *)subchannel_list->policy, (void *)subchannel_list); - } - for (size_t i = 0; i < subchannel_list->num_subchannels; i++) { - subchannel_data *sd = &subchannel_list->subchannels[i]; - if (sd->subchannel != NULL) { - GRPC_SUBCHANNEL_UNREF(exec_ctx, sd->subchannel, - "rr_subchannel_list_destroy"); - } - sd->subchannel = NULL; - if (sd->user_data != NULL) { - GPR_ASSERT(sd->user_data_vtable != NULL); - sd->user_data_vtable->destroy(exec_ctx, sd->user_data); - sd->user_data = NULL; - } - } - gpr_free(subchannel_list->subchannels); - gpr_free(subchannel_list); -} - -static void rr_subchannel_list_ref(rr_subchannel_list *subchannel_list, - const char *reason) { - gpr_ref_non_zero(&subchannel_list->refcount); - if (GRPC_TRACER_ON(grpc_lb_round_robin_trace)) { - const gpr_atm count = gpr_atm_acq_load(&subchannel_list->refcount.count); - gpr_log(GPR_INFO, "[RR %p] subchannel_list %p REF %lu->%lu (%s)", - (void *)subchannel_list->policy, (void *)subchannel_list, - (unsigned long)(count - 1), (unsigned long)count, reason); - } -} - -static void rr_subchannel_list_unref(grpc_exec_ctx *exec_ctx, - rr_subchannel_list *subchannel_list, - const char *reason) { - const bool done = gpr_unref(&subchannel_list->refcount); - if (GRPC_TRACER_ON(grpc_lb_round_robin_trace)) { - const gpr_atm count = gpr_atm_acq_load(&subchannel_list->refcount.count); - gpr_log(GPR_INFO, "[RR %p] subchannel_list %p UNREF %lu->%lu (%s)", - (void *)subchannel_list->policy, (void *)subchannel_list, - (unsigned long)(count + 1), (unsigned long)count, reason); - } - if (done) { - rr_subchannel_list_destroy(exec_ctx, subchannel_list); - } -} - -/** Mark \a subchannel_list as discarded. Unsubscribes all its subchannels. The - * watcher's callback will ultimately unref \a subchannel_list. */ -static void rr_subchannel_list_shutdown_and_unref( - grpc_exec_ctx *exec_ctx, rr_subchannel_list *subchannel_list, - const char *reason) { - GPR_ASSERT(!subchannel_list->shutting_down); - if (GRPC_TRACER_ON(grpc_lb_round_robin_trace)) { - gpr_log(GPR_DEBUG, "[RR %p] Shutting down subchannel_list %p (%s)", - (void *)subchannel_list->policy, (void *)subchannel_list, reason); - } - GPR_ASSERT(!subchannel_list->shutting_down); - subchannel_list->shutting_down = true; - for (size_t i = 0; i < subchannel_list->num_subchannels; i++) { - subchannel_data *sd = &subchannel_list->subchannels[i]; - if (sd->subchannel != NULL) { // if subchannel isn't shutdown, unsubscribe. - if (GRPC_TRACER_ON(grpc_lb_round_robin_trace)) { - gpr_log( - GPR_DEBUG, - "[RR %p] Unsubscribing from subchannel %p as part of shutting down " - "subchannel_list %p", - (void *)subchannel_list->policy, (void *)sd->subchannel, - (void *)subchannel_list); - } - grpc_subchannel_notify_on_state_change(exec_ctx, sd->subchannel, NULL, - NULL, - &sd->connectivity_changed_closure); - } - } - rr_subchannel_list_unref(exec_ctx, subchannel_list, reason); -} - /** Returns the index into p->subchannel_list->subchannels of the next * subchannel in READY state, or p->subchannel_list->num_subchannels if no * subchannel is READY. @@ -299,8 +151,8 @@ static void update_last_ready_subchannel_index_locked(round_robin_lb_policy *p, "[RR %p] setting last_ready_subchannel_index=%lu (SC %p, CSC %p)", (void *)p, (unsigned long)last_ready_index, (void *)p->subchannel_list->subchannels[last_ready_index].subchannel, - (void *)grpc_subchannel_get_connected_subchannel( - p->subchannel_list->subchannels[last_ready_index].subchannel)); + (void *)p->subchannel_list->subchannels[last_ready_index] + .connected_subchannel); } } @@ -310,42 +162,47 @@ static void rr_destroy(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) { gpr_log(GPR_DEBUG, "[RR %p] Destroying Round Robin policy at %p", (void *)pol, (void *)pol); } + GPR_ASSERT(p->subchannel_list == NULL); + GPR_ASSERT(p->latest_pending_subchannel_list == NULL); grpc_connectivity_state_destroy(exec_ctx, &p->state_tracker); grpc_subchannel_index_unref(); gpr_free(p); } -static void rr_shutdown_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) { - round_robin_lb_policy *p = (round_robin_lb_policy *)pol; +static void shutdown_locked(grpc_exec_ctx *exec_ctx, round_robin_lb_policy *p, + grpc_error *error) { if (GRPC_TRACER_ON(grpc_lb_round_robin_trace)) { - gpr_log(GPR_DEBUG, "[RR %p] Shutting down Round Robin policy at %p", - (void *)pol, (void *)pol); + gpr_log(GPR_DEBUG, "[RR %p] Shutting down", p); } p->shutdown = true; pending_pick *pp; - while ((pp = p->pending_picks)) { + while ((pp = p->pending_picks) != NULL) { p->pending_picks = pp->next; *pp->target = NULL; - GRPC_CLOSURE_SCHED( - exec_ctx, pp->on_complete, - GRPC_ERROR_CREATE_FROM_STATIC_STRING("Channel Shutdown")); + GRPC_CLOSURE_SCHED(exec_ctx, pp->on_complete, GRPC_ERROR_REF(error)); gpr_free(pp); } - grpc_connectivity_state_set( - exec_ctx, &p->state_tracker, GRPC_CHANNEL_SHUTDOWN, - GRPC_ERROR_CREATE_FROM_STATIC_STRING("Channel Shutdown"), "rr_shutdown"); - const bool latest_is_current = - p->subchannel_list == p->latest_pending_subchannel_list; - rr_subchannel_list_shutdown_and_unref(exec_ctx, p->subchannel_list, - "sl_shutdown_rr_shutdown"); - p->subchannel_list = NULL; - if (!latest_is_current && p->latest_pending_subchannel_list != NULL && - !p->latest_pending_subchannel_list->shutting_down) { - rr_subchannel_list_shutdown_and_unref(exec_ctx, - p->latest_pending_subchannel_list, - "sl_shutdown_pending_rr_shutdown"); + grpc_connectivity_state_set(exec_ctx, &p->state_tracker, + GRPC_CHANNEL_SHUTDOWN, GRPC_ERROR_REF(error), + "rr_shutdown"); + if (p->subchannel_list != NULL) { + grpc_lb_subchannel_list_shutdown_and_unref(exec_ctx, p->subchannel_list, + "sl_shutdown_rr_shutdown"); + p->subchannel_list = NULL; + } + if (p->latest_pending_subchannel_list != NULL) { + grpc_lb_subchannel_list_shutdown_and_unref( + exec_ctx, p->latest_pending_subchannel_list, + "sl_shutdown_pending_rr_shutdown"); p->latest_pending_subchannel_list = NULL; } + GRPC_ERROR_UNREF(error); +} + +static void rr_shutdown_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol) { + round_robin_lb_policy *p = (round_robin_lb_policy *)pol; + shutdown_locked(exec_ctx, p, + GRPC_ERROR_CREATE_FROM_STATIC_STRING("Channel Shutdown")); } static void rr_cancel_pick_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, @@ -400,13 +257,10 @@ static void start_picking_locked(grpc_exec_ctx *exec_ctx, round_robin_lb_policy *p) { p->started_picking = true; for (size_t i = 0; i < p->subchannel_list->num_subchannels; i++) { - subchannel_data *sd = &p->subchannel_list->subchannels[i]; - GRPC_LB_POLICY_WEAK_REF(&p->base, "start_picking_locked"); - rr_subchannel_list_ref(sd->subchannel_list, "started_picking"); - grpc_subchannel_notify_on_state_change( - exec_ctx, sd->subchannel, p->base.interested_parties, - &sd->pending_connectivity_state_unsafe, - &sd->connectivity_changed_closure); + grpc_lb_subchannel_list_ref_for_connectivity_watch(p->subchannel_list, + "connectivity_watch"); + grpc_lb_subchannel_data_start_connectivity_watch( + exec_ctx, &p->subchannel_list->subchannels[i]); } } @@ -423,18 +277,19 @@ static int rr_pick_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, grpc_call_context_element *context, void **user_data, grpc_closure *on_complete) { round_robin_lb_policy *p = (round_robin_lb_policy *)pol; - GPR_ASSERT(!p->shutdown); if (GRPC_TRACER_ON(grpc_lb_round_robin_trace)) { - gpr_log(GPR_INFO, "[RR %p] Trying to pick", (void *)pol); + gpr_log(GPR_INFO, "[RR %p] Trying to pick (shutdown: %d)", (void *)pol, + p->shutdown); } + GPR_ASSERT(!p->shutdown); if (p->subchannel_list != NULL) { const size_t next_ready_index = get_next_ready_subchannel_index_locked(p); if (next_ready_index < p->subchannel_list->num_subchannels) { /* readily available, report right away */ - subchannel_data *sd = &p->subchannel_list->subchannels[next_ready_index]; - *target = GRPC_CONNECTED_SUBCHANNEL_REF( - grpc_subchannel_get_connected_subchannel(sd->subchannel), - "rr_picked"); + grpc_lb_subchannel_data *sd = + &p->subchannel_list->subchannels[next_ready_index]; + *target = + GRPC_CONNECTED_SUBCHANNEL_REF(sd->connected_subchannel, "rr_picked"); if (user_data != NULL) { *user_data = sd->user_data; } @@ -465,8 +320,8 @@ static int rr_pick_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, return 0; } -static void update_state_counters_locked(subchannel_data *sd) { - rr_subchannel_list *subchannel_list = sd->subchannel_list; +static void update_state_counters_locked(grpc_lb_subchannel_data *sd) { + grpc_lb_subchannel_list *subchannel_list = sd->subchannel_list; if (sd->prev_connectivity_state == GRPC_CHANNEL_READY) { GPR_ASSERT(subchannel_list->num_ready > 0); --subchannel_list->num_ready; @@ -480,6 +335,7 @@ static void update_state_counters_locked(subchannel_data *sd) { GPR_ASSERT(subchannel_list->num_idle > 0); --subchannel_list->num_idle; } + sd->prev_connectivity_state = sd->curr_connectivity_state; if (sd->curr_connectivity_state == GRPC_CHANNEL_READY) { ++subchannel_list->num_ready; } else if (sd->curr_connectivity_state == GRPC_CHANNEL_TRANSIENT_FAILURE) { @@ -492,12 +348,12 @@ static void update_state_counters_locked(subchannel_data *sd) { } /** Sets the policy's connectivity status based on that of the passed-in \a sd - * (the subchannel_data associted with the updated subchannel) and the + * (the grpc_lb_subchannel_data associted with the updated subchannel) and the * subchannel list \a sd belongs to (sd->subchannel_list). \a error will only be * used upon policy transition to TRANSIENT_FAILURE or SHUTDOWN. Returns the * connectivity status set. */ static grpc_connectivity_state update_lb_connectivity_status_locked( - grpc_exec_ctx *exec_ctx, subchannel_data *sd, grpc_error *error) { + grpc_exec_ctx *exec_ctx, grpc_lb_subchannel_data *sd, grpc_error *error) { /* In priority order. The first rule to match terminates the search (ie, if we * are on rule n, all previous rules were unfulfilled). * @@ -519,8 +375,8 @@ static grpc_connectivity_state update_lb_connectivity_status_locked( * CHECK: p->num_idle == p->subchannel_list->num_subchannels. */ grpc_connectivity_state new_state = sd->curr_connectivity_state; - rr_subchannel_list *subchannel_list = sd->subchannel_list; - round_robin_lb_policy *p = subchannel_list->policy; + grpc_lb_subchannel_list *subchannel_list = sd->subchannel_list; + round_robin_lb_policy *p = (round_robin_lb_policy *)subchannel_list->policy; if (subchannel_list->num_ready > 0) { /* 1) READY */ grpc_connectivity_state_set(exec_ctx, &p->state_tracker, GRPC_CHANNEL_READY, GRPC_ERROR_NONE, "rr_ready"); @@ -538,6 +394,11 @@ static grpc_connectivity_state update_lb_connectivity_status_locked( "rr_shutdown"); p->shutdown = true; new_state = GRPC_CHANNEL_SHUTDOWN; + if (GRPC_TRACER_ON(grpc_lb_round_robin_trace)) { + gpr_log(GPR_INFO, + "[RR %p] Shutting down: all subchannels have gone into shutdown", + (void *)p); + } } else if (subchannel_list->num_transient_failures == p->subchannel_list->num_subchannels) { /* 4) TRANSIENT_FAILURE */ grpc_connectivity_state_set(exec_ctx, &p->state_tracker, @@ -556,8 +417,9 @@ static grpc_connectivity_state update_lb_connectivity_status_locked( static void rr_connectivity_changed_locked(grpc_exec_ctx *exec_ctx, void *arg, grpc_error *error) { - subchannel_data *sd = (subchannel_data *)arg; - round_robin_lb_policy *p = sd->subchannel_list->policy; + grpc_lb_subchannel_data *sd = (grpc_lb_subchannel_data *)arg; + round_robin_lb_policy *p = + (round_robin_lb_policy *)sd->subchannel_list->policy; if (GRPC_TRACER_ON(grpc_lb_round_robin_trace)) { gpr_log( GPR_DEBUG, @@ -572,71 +434,50 @@ static void rr_connectivity_changed_locked(grpc_exec_ctx *exec_ctx, void *arg, } // If the policy is shutting down, unref and return. if (p->shutdown) { - rr_subchannel_list_unref(exec_ctx, sd->subchannel_list, - "pol_shutdown+started_picking"); - GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "pol_shutdown"); + grpc_lb_subchannel_data_stop_connectivity_watch(exec_ctx, sd); + grpc_lb_subchannel_data_unref_subchannel(exec_ctx, sd, "rr_shutdown"); + grpc_lb_subchannel_list_unref_for_connectivity_watch( + exec_ctx, sd->subchannel_list, "rr_shutdown"); return; } - if (sd->subchannel_list->shutting_down && error == GRPC_ERROR_CANCELLED) { - // the subchannel list associated with sd has been discarded. This callback - // corresponds to the unsubscription. The unrefs correspond to the picking - // ref (start_picking_locked or update_started_picking). - rr_subchannel_list_unref(exec_ctx, sd->subchannel_list, - "sl_shutdown+started_picking"); - GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, "sl_shutdown+picking"); - return; - } - // Dispose of outdated subchannel lists. - if (sd->subchannel_list != p->subchannel_list && - sd->subchannel_list != p->latest_pending_subchannel_list) { - const char *reason = NULL; - if (sd->subchannel_list->shutting_down) { - reason = "sl_outdated_straggler"; - rr_subchannel_list_unref(exec_ctx, sd->subchannel_list, reason); - } else { - reason = "sl_outdated"; - rr_subchannel_list_shutdown_and_unref(exec_ctx, sd->subchannel_list, - reason); - } - GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, reason); + // If the subchannel list is shutting down, stop watching. + if (sd->subchannel_list->shutting_down || error == GRPC_ERROR_CANCELLED) { + grpc_lb_subchannel_data_stop_connectivity_watch(exec_ctx, sd); + grpc_lb_subchannel_data_unref_subchannel(exec_ctx, sd, "rr_sl_shutdown"); + grpc_lb_subchannel_list_unref_for_connectivity_watch( + exec_ctx, sd->subchannel_list, "rr_sl_shutdown"); return; } + // If we're still here, the notification must be for a subchannel in + // either the current or latest pending subchannel lists. + GPR_ASSERT(sd->subchannel_list == p->subchannel_list || + sd->subchannel_list == p->latest_pending_subchannel_list); // Now that we're inside the combiner, copy the pending connectivity // state (which was set by the connectivity state watcher) to // curr_connectivity_state, which is what we use inside of the combiner. sd->curr_connectivity_state = sd->pending_connectivity_state_unsafe; // Update state counters and determine new overall state. update_state_counters_locked(sd); - sd->prev_connectivity_state = sd->curr_connectivity_state; const grpc_connectivity_state new_policy_connectivity_state = update_lb_connectivity_status_locked(exec_ctx, sd, GRPC_ERROR_REF(error)); // If the sd's new state is SHUTDOWN, unref the subchannel, and if the new // policy's state is SHUTDOWN, clean up. if (sd->curr_connectivity_state == GRPC_CHANNEL_SHUTDOWN) { - GRPC_SUBCHANNEL_UNREF(exec_ctx, sd->subchannel, "rr_subchannel_shutdown"); - sd->subchannel = NULL; - if (sd->user_data != NULL) { - GPR_ASSERT(sd->user_data_vtable != NULL); - sd->user_data_vtable->destroy(exec_ctx, sd->user_data); - sd->user_data = NULL; - } + grpc_lb_subchannel_data_stop_connectivity_watch(exec_ctx, sd); + grpc_lb_subchannel_data_unref_subchannel(exec_ctx, sd, + "rr_connectivity_shutdown"); + grpc_lb_subchannel_list_unref_for_connectivity_watch( + exec_ctx, sd->subchannel_list, "rr_connectivity_shutdown"); if (new_policy_connectivity_state == GRPC_CHANNEL_SHUTDOWN) { - // the policy is shutting down. Flush all the pending picks... - pending_pick *pp; - while ((pp = p->pending_picks)) { - p->pending_picks = pp->next; - *pp->target = NULL; - GRPC_CLOSURE_SCHED(exec_ctx, pp->on_complete, GRPC_ERROR_NONE); - gpr_free(pp); - } + shutdown_locked(exec_ctx, p, GRPC_ERROR_REF(error)); } - rr_subchannel_list_unref(exec_ctx, sd->subchannel_list, - "sd_shutdown+started_picking"); - // unref the "rr_connectivity_update" weak ref from start_picking. - GRPC_LB_POLICY_WEAK_UNREF(exec_ctx, &p->base, - "rr_connectivity_sd_shutdown"); } else { // sd not in SHUTDOWN if (sd->curr_connectivity_state == GRPC_CHANNEL_READY) { + if (sd->connected_subchannel == NULL) { + sd->connected_subchannel = GRPC_CONNECTED_SUBCHANNEL_REF( + grpc_subchannel_get_connected_subchannel(sd->subchannel), + "connected"); + } if (sd->subchannel_list != p->subchannel_list) { // promote sd->subchannel_list to p->subchannel_list. // sd->subchannel_list must be equal to @@ -657,8 +498,8 @@ static void rr_connectivity_changed_locked(grpc_exec_ctx *exec_ctx, void *arg, } if (p->subchannel_list != NULL) { // dispose of the current subchannel_list - rr_subchannel_list_shutdown_and_unref(exec_ctx, p->subchannel_list, - "sl_phase_out_shutdown"); + grpc_lb_subchannel_list_shutdown_and_unref( + exec_ctx, p->subchannel_list, "sl_phase_out_shutdown"); } p->subchannel_list = p->latest_pending_subchannel_list; p->latest_pending_subchannel_list = NULL; @@ -668,7 +509,7 @@ static void rr_connectivity_changed_locked(grpc_exec_ctx *exec_ctx, void *arg, * p->pending_picks. This preemtively replicates rr_pick()'s actions. */ const size_t next_ready_index = get_next_ready_subchannel_index_locked(p); GPR_ASSERT(next_ready_index < p->subchannel_list->num_subchannels); - subchannel_data *selected = + grpc_lb_subchannel_data *selected = &p->subchannel_list->subchannels[next_ready_index]; if (p->pending_picks != NULL) { // if the selected subchannel is going to be used for the pending @@ -679,8 +520,7 @@ static void rr_connectivity_changed_locked(grpc_exec_ctx *exec_ctx, void *arg, 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"); + selected->connected_subchannel, "rr_picked"); if (pp->user_data != NULL) { *pp->user_data = selected->user_data; } @@ -695,12 +535,8 @@ static void rr_connectivity_changed_locked(grpc_exec_ctx *exec_ctx, void *arg, gpr_free(pp); } } - /* renew notification: reuses the "rr_connectivity_update" weak ref on the - * policy as well as the sd->subchannel_list ref. */ - grpc_subchannel_notify_on_state_change( - exec_ctx, sd->subchannel, p->base.interested_parties, - &sd->pending_connectivity_state_unsafe, - &sd->connectivity_changed_closure); + // Renew notification. + grpc_lb_subchannel_data_start_connectivity_watch(exec_ctx, sd); } } @@ -724,13 +560,12 @@ static void rr_ping_one_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *pol, round_robin_lb_policy *p = (round_robin_lb_policy *)pol; const size_t next_ready_index = get_next_ready_subchannel_index_locked(p); if (next_ready_index < p->subchannel_list->num_subchannels) { - subchannel_data *selected = + grpc_lb_subchannel_data *selected = &p->subchannel_list->subchannels[next_ready_index]; grpc_connected_subchannel *target = GRPC_CONNECTED_SUBCHANNEL_REF( - grpc_subchannel_get_connected_subchannel(selected->subchannel), - "rr_picked"); + selected->connected_subchannel, "rr_ping"); grpc_connected_subchannel_ping(exec_ctx, target, closure); - GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, target, "rr_picked"); + GRPC_CONNECTED_SUBCHANNEL_UNREF(exec_ctx, target, "rr_ping"); } else { GRPC_CLOSURE_SCHED(exec_ctx, closure, GRPC_ERROR_CREATE_FROM_STATIC_STRING( "Round Robin not connected")); @@ -743,130 +578,68 @@ static void rr_update_locked(grpc_exec_ctx *exec_ctx, grpc_lb_policy *policy, const grpc_arg *arg = grpc_channel_args_find(args->args, GRPC_ARG_LB_ADDRESSES); if (arg == NULL || arg->type != GRPC_ARG_POINTER) { + gpr_log(GPR_ERROR, "[RR %p] update provided no addresses; ignoring", p); + // If we don't have a current subchannel list, go into TRANSIENT_FAILURE. + // Otherwise, keep using the current subchannel list (ignore this update). if (p->subchannel_list == NULL) { - // If we don't have a current subchannel list, go into TRANSIENT FAILURE. grpc_connectivity_state_set( exec_ctx, &p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE, GRPC_ERROR_CREATE_FROM_STATIC_STRING("Missing update in args"), "rr_update_missing"); - } else { - // otherwise, keep using the current subchannel list (ignore this update). - gpr_log(GPR_ERROR, - "[RR %p] No valid LB addresses channel arg for update, ignoring.", - (void *)p); } return; } grpc_lb_addresses *addresses = (grpc_lb_addresses *)arg->value.pointer.p; - rr_subchannel_list *subchannel_list = - rr_subchannel_list_create(p, addresses->num_addresses); - if (addresses->num_addresses == 0) { + if (GRPC_TRACER_ON(grpc_lb_round_robin_trace)) { + gpr_log(GPR_DEBUG, "[RR %p] received update with %" PRIuPTR " addresses", p, + addresses->num_addresses); + } + grpc_lb_subchannel_list *subchannel_list = grpc_lb_subchannel_list_create( + exec_ctx, &p->base, &grpc_lb_round_robin_trace, addresses, args, + rr_connectivity_changed_locked); + if (subchannel_list->num_subchannels == 0) { grpc_connectivity_state_set( exec_ctx, &p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE, GRPC_ERROR_CREATE_FROM_STATIC_STRING("Empty update"), "rr_update_empty"); if (p->subchannel_list != NULL) { - rr_subchannel_list_shutdown_and_unref(exec_ctx, p->subchannel_list, - "sl_shutdown_empty_update"); + grpc_lb_subchannel_list_shutdown_and_unref(exec_ctx, p->subchannel_list, + "sl_shutdown_empty_update"); } p->subchannel_list = subchannel_list; // empty list return; } - size_t subchannel_index = 0; - if (p->latest_pending_subchannel_list != NULL && p->started_picking) { - if (GRPC_TRACER_ON(grpc_lb_round_robin_trace)) { - gpr_log(GPR_DEBUG, - "[RR %p] Shutting down latest pending subchannel list %p, about " - "to be replaced by newer latest %p", - (void *)p, (void *)p->latest_pending_subchannel_list, - (void *)subchannel_list); - } - rr_subchannel_list_shutdown_and_unref( - exec_ctx, p->latest_pending_subchannel_list, "sl_outdated_dont_smash"); - } - p->latest_pending_subchannel_list = subchannel_list; - grpc_subchannel_args sc_args; - /* We need to remove the LB addresses in order to be able to compare the - * subchannel keys of subchannels from a different batch of addresses. */ - static const char *keys_to_remove[] = {GRPC_ARG_SUBCHANNEL_ADDRESS, - GRPC_ARG_LB_ADDRESSES}; - /* Create subchannels for addresses in the update. */ - for (size_t i = 0; i < addresses->num_addresses; i++) { - // If there were any balancer, we would have chosen grpclb policy instead. - GPR_ASSERT(!addresses->addresses[i].is_balancer); - memset(&sc_args, 0, sizeof(grpc_subchannel_args)); - grpc_arg addr_arg = - grpc_create_subchannel_address_arg(&addresses->addresses[i].address); - grpc_channel_args *new_args = grpc_channel_args_copy_and_add_and_remove( - args->args, keys_to_remove, GPR_ARRAY_SIZE(keys_to_remove), &addr_arg, - 1); - gpr_free(addr_arg.value.string); - sc_args.args = new_args; - grpc_subchannel *subchannel = grpc_client_channel_factory_create_subchannel( - exec_ctx, args->client_channel_factory, &sc_args); - grpc_channel_args_destroy(exec_ctx, new_args); - grpc_error *error; - // Get the connectivity state of the subchannel. Already existing ones may - // be in a state other than INIT. - const grpc_connectivity_state subchannel_connectivity_state = - grpc_subchannel_check_connectivity(subchannel, &error); - if (error != GRPC_ERROR_NONE) { - // The subchannel is in error (e.g. shutting down). Ignore it. - GRPC_SUBCHANNEL_UNREF(exec_ctx, subchannel, "new_sc_connectivity_error"); - GRPC_ERROR_UNREF(error); - continue; - } - if (GRPC_TRACER_ON(grpc_lb_round_robin_trace)) { - char *address_uri = - grpc_sockaddr_to_uri(&addresses->addresses[i].address); - gpr_log( - GPR_DEBUG, - "[RR %p] index %lu: Created subchannel %p for address uri %s into " - "subchannel_list %p. Connectivity state %s", - (void *)p, (unsigned long)subchannel_index, (void *)subchannel, - address_uri, (void *)subchannel_list, - grpc_connectivity_state_name(subchannel_connectivity_state)); - gpr_free(address_uri); - } - subchannel_data *sd = &subchannel_list->subchannels[subchannel_index++]; - sd->subchannel_list = subchannel_list; - sd->subchannel = subchannel; - GRPC_CLOSURE_INIT(&sd->connectivity_changed_closure, - rr_connectivity_changed_locked, sd, - grpc_combiner_scheduler(args->combiner)); - /* use some sentinel value outside of the range of - * grpc_connectivity_state to signal an undefined previous state. We - * won't be referring to this value again and it'll be overwritten after - * the first call to rr_connectivity_changed_locked */ - sd->prev_connectivity_state = GRPC_CHANNEL_INIT; - sd->curr_connectivity_state = subchannel_connectivity_state; - sd->user_data_vtable = addresses->user_data_vtable; - if (sd->user_data_vtable != NULL) { - sd->user_data = - sd->user_data_vtable->copy(addresses->addresses[i].user_data); + if (p->started_picking) { + if (p->latest_pending_subchannel_list != NULL) { + if (GRPC_TRACER_ON(grpc_lb_round_robin_trace)) { + gpr_log(GPR_DEBUG, + "[RR %p] Shutting down latest pending subchannel list %p, " + "about to be replaced by newer latest %p", + (void *)p, (void *)p->latest_pending_subchannel_list, + (void *)subchannel_list); + } + grpc_lb_subchannel_list_shutdown_and_unref( + exec_ctx, p->latest_pending_subchannel_list, "sl_outdated"); } - if (p->started_picking) { - rr_subchannel_list_ref(sd->subchannel_list, "update_started_picking"); - GRPC_LB_POLICY_WEAK_REF(&p->base, "rr_connectivity_update"); - /* 2. Watch every new subchannel. A subchannel list becomes active the + p->latest_pending_subchannel_list = subchannel_list; + for (size_t i = 0; i < subchannel_list->num_subchannels; ++i) { + /* Watch every new subchannel. A subchannel list becomes active the * moment one of its subchannels is READY. At that moment, we swap * p->subchannel_list for sd->subchannel_list, provided the subchannel * list is still valid (ie, isn't shutting down) */ - grpc_subchannel_notify_on_state_change( - exec_ctx, sd->subchannel, p->base.interested_parties, - &sd->pending_connectivity_state_unsafe, - &sd->connectivity_changed_closure); + grpc_lb_subchannel_list_ref_for_connectivity_watch(subchannel_list, + "connectivity_watch"); + grpc_lb_subchannel_data_start_connectivity_watch( + exec_ctx, &subchannel_list->subchannels[i]); } - } - if (!p->started_picking) { + } else { // The policy isn't picking yet. Save the update for later, disposing of // previous version if any. if (p->subchannel_list != NULL) { - rr_subchannel_list_shutdown_and_unref(exec_ctx, p->subchannel_list, - "rr_update_before_started_picking"); + grpc_lb_subchannel_list_shutdown_and_unref( + exec_ctx, p->subchannel_list, "rr_update_before_started_picking"); } p->subchannel_list = subchannel_list; - p->latest_pending_subchannel_list = NULL; } } |