| /* |
| * |
| * 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. |
| * |
| */ |
| |
| #include "src/core/lib/surface/channel.h" |
| |
| #include <grpc/support/alloc.h> |
| #include <grpc/support/log.h> |
| |
| #include "src/core/ext/filters/client_channel/client_channel.h" |
| #include "src/core/lib/iomgr/timer.h" |
| #include "src/core/lib/surface/api_trace.h" |
| #include "src/core/lib/surface/completion_queue.h" |
| |
| grpc_connectivity_state grpc_channel_check_connectivity_state( |
| grpc_channel *channel, int try_to_connect) { |
| /* forward through to the underlying client channel */ |
| grpc_channel_element *client_channel_elem = |
| grpc_channel_stack_last_element(grpc_channel_get_channel_stack(channel)); |
| grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT; |
| grpc_connectivity_state state; |
| GRPC_API_TRACE( |
| "grpc_channel_check_connectivity_state(channel=%p, try_to_connect=%d)", 2, |
| (channel, try_to_connect)); |
| if (client_channel_elem->filter == &grpc_client_channel_filter) { |
| state = grpc_client_channel_check_connectivity_state( |
| &exec_ctx, client_channel_elem, try_to_connect); |
| grpc_exec_ctx_finish(&exec_ctx); |
| return state; |
| } |
| gpr_log(GPR_ERROR, |
| "grpc_channel_check_connectivity_state called on something that is " |
| "not a client channel, but '%s'", |
| client_channel_elem->filter->name); |
| grpc_exec_ctx_finish(&exec_ctx); |
| return GRPC_CHANNEL_SHUTDOWN; |
| } |
| |
| typedef enum { |
| WAITING, |
| READY_TO_CALL_BACK, |
| CALLING_BACK_AND_FINISHED, |
| } callback_phase; |
| |
| typedef struct { |
| gpr_mu mu; |
| callback_phase phase; |
| grpc_closure on_complete; |
| grpc_closure on_timeout; |
| grpc_closure watcher_timer_init; |
| grpc_timer alarm; |
| grpc_connectivity_state state; |
| grpc_completion_queue *cq; |
| grpc_cq_completion completion_storage; |
| grpc_channel *channel; |
| grpc_error *error; |
| void *tag; |
| } state_watcher; |
| |
| static void delete_state_watcher(grpc_exec_ctx *exec_ctx, state_watcher *w) { |
| grpc_channel_element *client_channel_elem = grpc_channel_stack_last_element( |
| grpc_channel_get_channel_stack(w->channel)); |
| if (client_channel_elem->filter == &grpc_client_channel_filter) { |
| GRPC_CHANNEL_INTERNAL_UNREF(exec_ctx, w->channel, |
| "watch_channel_connectivity"); |
| } else { |
| abort(); |
| } |
| gpr_mu_destroy(&w->mu); |
| gpr_free(w); |
| } |
| |
| static void finished_completion(grpc_exec_ctx *exec_ctx, void *pw, |
| grpc_cq_completion *ignored) { |
| bool should_delete = false; |
| state_watcher *w = (state_watcher *)pw; |
| gpr_mu_lock(&w->mu); |
| switch (w->phase) { |
| case WAITING: |
| case READY_TO_CALL_BACK: |
| GPR_UNREACHABLE_CODE(return ); |
| case CALLING_BACK_AND_FINISHED: |
| should_delete = true; |
| break; |
| } |
| gpr_mu_unlock(&w->mu); |
| |
| if (should_delete) { |
| delete_state_watcher(exec_ctx, w); |
| } |
| } |
| |
| static void partly_done(grpc_exec_ctx *exec_ctx, state_watcher *w, |
| bool due_to_completion, grpc_error *error) { |
| if (due_to_completion) { |
| grpc_timer_cancel(exec_ctx, &w->alarm); |
| } else { |
| grpc_channel_element *client_channel_elem = grpc_channel_stack_last_element( |
| grpc_channel_get_channel_stack(w->channel)); |
| grpc_client_channel_watch_connectivity_state( |
| exec_ctx, client_channel_elem, |
| grpc_polling_entity_create_from_pollset(grpc_cq_pollset(w->cq)), NULL, |
| &w->on_complete, NULL); |
| } |
| |
| gpr_mu_lock(&w->mu); |
| |
| if (due_to_completion) { |
| if (GRPC_TRACER_ON(grpc_trace_operation_failures)) { |
| GRPC_LOG_IF_ERROR("watch_completion_error", GRPC_ERROR_REF(error)); |
| } |
| GRPC_ERROR_UNREF(error); |
| error = GRPC_ERROR_NONE; |
| } else { |
| if (error == GRPC_ERROR_NONE) { |
| error = GRPC_ERROR_CREATE_FROM_STATIC_STRING( |
| "Timed out waiting for connection state change"); |
| } else if (error == GRPC_ERROR_CANCELLED) { |
| error = GRPC_ERROR_NONE; |
| } |
| } |
| switch (w->phase) { |
| case WAITING: |
| GRPC_ERROR_REF(error); |
| w->error = error; |
| w->phase = READY_TO_CALL_BACK; |
| break; |
| case READY_TO_CALL_BACK: |
| if (error != GRPC_ERROR_NONE) { |
| GPR_ASSERT(!due_to_completion); |
| GRPC_ERROR_UNREF(w->error); |
| GRPC_ERROR_REF(error); |
| w->error = error; |
| } |
| w->phase = CALLING_BACK_AND_FINISHED; |
| grpc_cq_end_op(exec_ctx, w->cq, w->tag, w->error, finished_completion, w, |
| &w->completion_storage); |
| break; |
| case CALLING_BACK_AND_FINISHED: |
| GPR_UNREACHABLE_CODE(return ); |
| break; |
| } |
| gpr_mu_unlock(&w->mu); |
| |
| GRPC_ERROR_UNREF(error); |
| } |
| |
| static void watch_complete(grpc_exec_ctx *exec_ctx, void *pw, |
| grpc_error *error) { |
| partly_done(exec_ctx, (state_watcher *)pw, true, GRPC_ERROR_REF(error)); |
| } |
| |
| static void timeout_complete(grpc_exec_ctx *exec_ctx, void *pw, |
| grpc_error *error) { |
| partly_done(exec_ctx, (state_watcher *)pw, false, GRPC_ERROR_REF(error)); |
| } |
| |
| int grpc_channel_num_external_connectivity_watchers(grpc_channel *channel) { |
| grpc_channel_element *client_channel_elem = |
| grpc_channel_stack_last_element(grpc_channel_get_channel_stack(channel)); |
| return grpc_client_channel_num_external_connectivity_watchers( |
| client_channel_elem); |
| } |
| |
| typedef struct watcher_timer_init_arg { |
| state_watcher *w; |
| gpr_timespec deadline; |
| } watcher_timer_init_arg; |
| |
| static void watcher_timer_init(grpc_exec_ctx *exec_ctx, void *arg, |
| grpc_error *error_ignored) { |
| watcher_timer_init_arg *wa = (watcher_timer_init_arg *)arg; |
| |
| grpc_timer_init(exec_ctx, &wa->w->alarm, |
| gpr_convert_clock_type(wa->deadline, GPR_CLOCK_MONOTONIC), |
| &wa->w->on_timeout, gpr_now(GPR_CLOCK_MONOTONIC)); |
| gpr_free(wa); |
| } |
| |
| int grpc_channel_support_connectivity_watcher(grpc_channel *channel) { |
| grpc_channel_element *client_channel_elem = |
| grpc_channel_stack_last_element(grpc_channel_get_channel_stack(channel)); |
| return client_channel_elem->filter != &grpc_client_channel_filter ? 0 : 1; |
| } |
| |
| void grpc_channel_watch_connectivity_state( |
| grpc_channel *channel, grpc_connectivity_state last_observed_state, |
| gpr_timespec deadline, grpc_completion_queue *cq, void *tag) { |
| grpc_channel_element *client_channel_elem = |
| grpc_channel_stack_last_element(grpc_channel_get_channel_stack(channel)); |
| grpc_exec_ctx exec_ctx = GRPC_EXEC_CTX_INIT; |
| state_watcher *w = (state_watcher *)gpr_malloc(sizeof(*w)); |
| |
| GRPC_API_TRACE( |
| "grpc_channel_watch_connectivity_state(" |
| "channel=%p, last_observed_state=%d, " |
| "deadline=gpr_timespec { tv_sec: %" PRId64 |
| ", tv_nsec: %d, clock_type: %d }, " |
| "cq=%p, tag=%p)", |
| 7, (channel, (int)last_observed_state, deadline.tv_sec, deadline.tv_nsec, |
| (int)deadline.clock_type, cq, tag)); |
| |
| GPR_ASSERT(grpc_cq_begin_op(cq, tag)); |
| |
| gpr_mu_init(&w->mu); |
| GRPC_CLOSURE_INIT(&w->on_complete, watch_complete, w, |
| grpc_schedule_on_exec_ctx); |
| GRPC_CLOSURE_INIT(&w->on_timeout, timeout_complete, w, |
| grpc_schedule_on_exec_ctx); |
| w->phase = WAITING; |
| w->state = last_observed_state; |
| w->cq = cq; |
| w->tag = tag; |
| w->channel = channel; |
| w->error = NULL; |
| |
| watcher_timer_init_arg *wa = |
| (watcher_timer_init_arg *)gpr_malloc(sizeof(watcher_timer_init_arg)); |
| wa->w = w; |
| wa->deadline = deadline; |
| GRPC_CLOSURE_INIT(&w->watcher_timer_init, watcher_timer_init, wa, |
| grpc_schedule_on_exec_ctx); |
| |
| if (client_channel_elem->filter == &grpc_client_channel_filter) { |
| GRPC_CHANNEL_INTERNAL_REF(channel, "watch_channel_connectivity"); |
| grpc_client_channel_watch_connectivity_state( |
| &exec_ctx, client_channel_elem, |
| grpc_polling_entity_create_from_pollset(grpc_cq_pollset(cq)), &w->state, |
| &w->on_complete, &w->watcher_timer_init); |
| } else { |
| abort(); |
| } |
| |
| grpc_exec_ctx_finish(&exec_ctx); |
| } |