diff options
Diffstat (limited to 'src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc')
-rw-r--r-- | src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc | 84 |
1 files changed, 31 insertions, 53 deletions
diff --git a/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc index a3b05aacaf..e70f2a8c52 100644 --- a/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc +++ b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc @@ -34,7 +34,7 @@ grpc_core::TraceFlag grpc_lb_pick_first_trace(false, "pick_first"); typedef struct pending_pick { struct pending_pick* next; uint32_t initial_metadata_flags; - grpc_connected_subchannel** target; + grpc_core::ConnectedSubchannel** target; grpc_closure* on_complete; } pending_pick; @@ -102,7 +102,7 @@ static void pf_shutdown_locked(grpc_lb_policy* pol) { } static void pf_cancel_pick_locked(grpc_lb_policy* pol, - grpc_connected_subchannel** target, + grpc_core::ConnectedSubchannel** target, grpc_error* error) { pick_first_lb_policy* p = (pick_first_lb_policy*)pol; pending_pick* pp = p->pending_picks; @@ -174,7 +174,7 @@ static void pf_exit_idle_locked(grpc_lb_policy* pol) { static int pf_pick_locked(grpc_lb_policy* pol, const grpc_lb_policy_pick_args* pick_args, - grpc_connected_subchannel** target, + grpc_core::ConnectedSubchannel** target, grpc_call_context_element* context, void** user_data, grpc_closure* on_complete) { pick_first_lb_policy* p = (pick_first_lb_policy*)pol; @@ -396,6 +396,8 @@ static void pf_connectivity_changed_locked(void* arg, grpc_error* error) { sd->curr_connectivity_state = sd->pending_connectivity_state_unsafe; // Handle updates for the currently selected subchannel. if (p->selected == sd) { + gpr_log(GPR_INFO, "BAR selected. subchannel %p, conn subchannel %p", + sd->subchannel, p->selected->connected_subchannel); // If the new state is anything other than READY and there is a // pending update, switch to the pending update. if (sd->curr_connectivity_state != GRPC_CHANNEL_READY && @@ -412,25 +414,13 @@ static void pf_connectivity_changed_locked(void* arg, grpc_error* error) { &p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE, GRPC_ERROR_REF(error), "selected_not_ready+switch_to_update"); } else { - if (sd->curr_connectivity_state < GRPC_CHANNEL_TRANSIENT_FAILURE) { - // Renew notification. - grpc_lb_subchannel_data_start_connectivity_watch(sd); - } else { // in transient failure or shutdown. Rely on re-resolution to - // recover. - p->selected = nullptr; - grpc_lb_subchannel_data_stop_connectivity_watch(sd); - grpc_lb_subchannel_list_unref_for_connectivity_watch( - sd->subchannel_list, "pf_selected_shutdown"); - grpc_lb_subchannel_data_unref_subchannel( - sd, "pf_selected_shutdown"); // Unrefs connected subchannel - } // TODO(juanlishen): we re-resolve when the selected subchannel goes to // TRANSIENT_FAILURE because we used to shut down in this case before // re-resolution is introduced. But we need to investigate whether we // really want to take any action instead of waiting for the selected // subchannel reconnecting. - if (sd->curr_connectivity_state == GRPC_CHANNEL_SHUTDOWN || - sd->curr_connectivity_state == GRPC_CHANNEL_TRANSIENT_FAILURE) { + GPR_ASSERT(sd->curr_connectivity_state != GRPC_CHANNEL_SHUTDOWN); + if (sd->curr_connectivity_state == GRPC_CHANNEL_TRANSIENT_FAILURE) { // If the selected channel goes bad, request a re-resolution. grpc_connectivity_state_set(&p->state_tracker, GRPC_CHANNEL_IDLE, GRPC_ERROR_NONE, @@ -438,10 +428,20 @@ static void pf_connectivity_changed_locked(void* arg, grpc_error* error) { p->started_picking = false; grpc_lb_policy_try_reresolve(&p->base, &grpc_lb_pick_first_trace, GRPC_ERROR_NONE); + // in transient failure. Rely on re-resolution to recover. + p->selected = nullptr; + grpc_lb_subchannel_data_stop_connectivity_watch(sd); + grpc_lb_subchannel_list_unref_for_connectivity_watch( + sd->subchannel_list, "pf_selected_shutdown"); + grpc_lb_subchannel_data_unref_subchannel( + sd, "pf_selected_shutdown"); // Unrefs connected subchannel + } else { grpc_connectivity_state_set(&p->state_tracker, sd->curr_connectivity_state, GRPC_ERROR_REF(error), "selected_changed"); + // Renew notification. + grpc_lb_subchannel_data_start_connectivity_watch(sd); } } return; @@ -459,6 +459,16 @@ static void pf_connectivity_changed_locked(void* arg, grpc_error* error) { case GRPC_CHANNEL_READY: { // Case 2. Promote p->latest_pending_subchannel_list to // p->subchannel_list. + grpc_core::ConnectedSubchannel* con = + grpc_subchannel_get_connected_subchannel(sd->subchannel); + if (con == nullptr) { + // The subchannel may have become disconnected by the time this callback + // is invoked. Simply ignore and resubscribe: ulterior connectivity + // states + // must be in the pipeline and will eventually be invoked. + grpc_lb_subchannel_data_start_connectivity_watch(sd); + break; + } if (sd->subchannel_list == p->latest_pending_subchannel_list) { GPR_ASSERT(p->subchannel_list != nullptr); grpc_lb_subchannel_list_shutdown_and_unref(p->subchannel_list, @@ -469,9 +479,8 @@ static void pf_connectivity_changed_locked(void* arg, grpc_error* error) { // Cases 1 and 2. grpc_connectivity_state_set(&p->state_tracker, GRPC_CHANNEL_READY, GRPC_ERROR_NONE, "connecting_ready"); - sd->connected_subchannel = GRPC_CONNECTED_SUBCHANNEL_REF( - grpc_subchannel_get_connected_subchannel(sd->subchannel), - "connected"); + sd->connected_subchannel = + GRPC_CONNECTED_SUBCHANNEL_REF(con, "connected"); p->selected = sd; if (grpc_lb_pick_first_trace.enabled()) { gpr_log(GPR_INFO, "Pick First %p selected subchannel %p", (void*)p, @@ -530,39 +539,8 @@ static void pf_connectivity_changed_locked(void* arg, grpc_error* error) { grpc_lb_subchannel_data_start_connectivity_watch(sd); break; } - case GRPC_CHANNEL_SHUTDOWN: { - grpc_lb_subchannel_data_stop_connectivity_watch(sd); - grpc_lb_subchannel_data_unref_subchannel(sd, "pf_candidate_shutdown"); - // Advance to next subchannel and check its state. - grpc_lb_subchannel_data* original_sd = sd; - do { - sd->subchannel_list->checking_subchannel = - (sd->subchannel_list->checking_subchannel + 1) % - sd->subchannel_list->num_subchannels; - sd = &sd->subchannel_list - ->subchannels[sd->subchannel_list->checking_subchannel]; - } while (sd->subchannel == nullptr && sd != original_sd); - if (sd == original_sd) { - grpc_lb_subchannel_list_unref_for_connectivity_watch( - sd->subchannel_list, "pf_exhausted_subchannels"); - if (sd->subchannel_list == p->subchannel_list) { - grpc_connectivity_state_set(&p->state_tracker, GRPC_CHANNEL_IDLE, - GRPC_ERROR_NONE, - "exhausted_subchannels+reresolve"); - p->started_picking = false; - grpc_lb_policy_try_reresolve(&p->base, &grpc_lb_pick_first_trace, - GRPC_ERROR_NONE); - } - } else { - if (sd->subchannel_list == p->subchannel_list) { - grpc_connectivity_state_set( - &p->state_tracker, GRPC_CHANNEL_TRANSIENT_FAILURE, - GRPC_ERROR_REF(error), "subchannel_failed"); - } - // Reuses the connectivity refs from the previous watch. - grpc_lb_subchannel_data_start_connectivity_watch(sd); - } - } + case GRPC_CHANNEL_SHUTDOWN: + GPR_UNREACHABLE_CODE(break); } } |