| /* |
| * |
| * Copyright 2015 gRPC authors. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| */ |
| |
| #ifndef GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_SUBCHANNEL_LIST_H |
| #define GRPC_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/lib/debug/trace.h" |
| #include "src/core/lib/transport/connectivity_state.h" |
| |
| // TODO(roth): This code is intended to be shared between pick_first and |
| // round_robin. However, the interface needs more work to provide clean |
| // encapsulation. For example, the structs here have some fields that are |
| // only used in one of the two (e.g., the state counters in |
| // grpc_lb_subchannel_list and the prev_connectivity_state field in |
| // grpc_lb_subchannel_data are only used in round_robin, and the |
| // checking_subchannel field in grpc_lb_subchannel_list is only used by |
| // pick_first). Also, there is probably some code duplication between the |
| // connectivity state notification callback code in both pick_first and |
| // round_robin that could be refactored and moved here. In a future PR, |
| // need to clean this up. |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| typedef struct grpc_lb_subchannel_list grpc_lb_subchannel_list; |
| |
| typedef struct { |
| /** backpointer to owning subchannel list */ |
| grpc_lb_subchannel_list* subchannel_list; |
| /** subchannel itself */ |
| grpc_subchannel* subchannel; |
| grpc_connected_subchannel* connected_subchannel; |
| /** Is a connectivity notification pending? */ |
| bool connectivity_notification_pending; |
| /** notification that connectivity has changed on subchannel */ |
| grpc_closure connectivity_changed_closure; |
| /** previous and current connectivity states. Updated by \a |
| * \a connectivity_changed_closure based on |
| * \a pending_connectivity_state_unsafe. */ |
| grpc_connectivity_state prev_connectivity_state; |
| grpc_connectivity_state curr_connectivity_state; |
| /** connectivity state to be updated by |
| * grpc_subchannel_notify_on_state_change(), not guarded by |
| * the combiner. To be copied to \a curr_connectivity_state by |
| * \a connectivity_changed_closure. */ |
| 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; |
| } grpc_lb_subchannel_data; |
| |
| /// Unrefs the subchannel contained in sd. |
| void grpc_lb_subchannel_data_unref_subchannel(grpc_exec_ctx* exec_ctx, |
| grpc_lb_subchannel_data* sd, |
| const char* reason); |
| |
| /// Starts watching the connectivity state of the subchannel. |
| /// The connectivity_changed_cb callback must invoke either |
| /// grpc_lb_subchannel_data_stop_connectivity_watch() or again call |
| /// grpc_lb_subchannel_data_start_connectivity_watch(). |
| void grpc_lb_subchannel_data_start_connectivity_watch( |
| grpc_exec_ctx* exec_ctx, grpc_lb_subchannel_data* sd); |
| |
| /// Stops watching the connectivity state of the subchannel. |
| void grpc_lb_subchannel_data_stop_connectivity_watch( |
| grpc_exec_ctx* exec_ctx, grpc_lb_subchannel_data* sd); |
| |
| struct grpc_lb_subchannel_list { |
| /** backpointer to owning policy */ |
| grpc_lb_policy* policy; |
| |
| grpc_core::TraceFlag* tracer; |
| |
| /** all our subchannels */ |
| size_t num_subchannels; |
| grpc_lb_subchannel_data* subchannels; |
| |
| /** Index into subchannels of the one we're currently checking. |
| * Used when connecting to subchannels serially instead of in parallel. */ |
| // TODO(roth): When we have time, we can probably make this go away |
| // and compute the index dynamically by subtracting |
| // subchannel_list->subchannels from the subchannel_data pointer. |
| size_t checking_subchannel; |
| |
| /** 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; |
| }; |
| |
| grpc_lb_subchannel_list* grpc_lb_subchannel_list_create( |
| grpc_exec_ctx* exec_ctx, grpc_lb_policy* p, grpc_core::TraceFlag* tracer, |
| const grpc_lb_addresses* addresses, const grpc_lb_policy_args* args, |
| grpc_iomgr_cb_func connectivity_changed_cb); |
| |
| void grpc_lb_subchannel_list_ref(grpc_lb_subchannel_list* subchannel_list, |
| const char* reason); |
| |
| void grpc_lb_subchannel_list_unref(grpc_exec_ctx* exec_ctx, |
| grpc_lb_subchannel_list* subchannel_list, |
| const char* reason); |
| |
| /// Takes and releases refs needed for a connectivity notification. |
| /// This includes a ref to subchannel_list and a weak ref to the LB policy. |
| void grpc_lb_subchannel_list_ref_for_connectivity_watch( |
| grpc_lb_subchannel_list* subchannel_list, const char* reason); |
| void grpc_lb_subchannel_list_unref_for_connectivity_watch( |
| grpc_exec_ctx* exec_ctx, grpc_lb_subchannel_list* subchannel_list, |
| const char* reason); |
| |
| /// Mark subchannel_list as discarded. Unsubscribes all its subchannels. The |
| /// connectivity state notification callback will ultimately unref it. |
| void grpc_lb_subchannel_list_shutdown_and_unref( |
| grpc_exec_ctx* exec_ctx, grpc_lb_subchannel_list* subchannel_list, |
| const char* reason); |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* GRPC_CORE_EXT_FILTERS_CLIENT_CHANNEL_LB_POLICY_SUBCHANNEL_LIST_H */ |