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/*
*
* 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 <grpc/support/port_platform.h>
#include "src/core/lib/surface/channel.h"
#include <inttypes.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_core::ExecCtx exec_ctx;
grpc_connectivity_state state;
GRPC_API_TRACE(
"grpc_channel_check_connectivity_state(channel=%p, try_to_connect=%d)", 2,
(channel, try_to_connect));
if (GPR_LIKELY(client_channel_elem->filter == &grpc_client_channel_filter)) {
state = grpc_client_channel_check_connectivity_state(client_channel_elem,
try_to_connect);
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);
return GRPC_CHANNEL_SHUTDOWN;
}
typedef enum {
WAITING,
READY_TO_CALL_BACK,
CALLING_BACK_AND_FINISHED,
} callback_phase;
namespace {
struct state_watcher {
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;
};
} // namespace
static void delete_state_watcher(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(w->channel, "watch_channel_connectivity");
} else {
abort();
}
gpr_mu_destroy(&w->mu);
gpr_free(w);
}
static void finished_completion(void* pw, grpc_cq_completion* ignored) {
bool should_delete = false;
state_watcher* w = static_cast<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(w);
}
}
static void partly_done(state_watcher* w, bool due_to_completion,
grpc_error* error) {
if (due_to_completion) {
grpc_timer_cancel(&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(
client_channel_elem,
grpc_polling_entity_create_from_pollset(grpc_cq_pollset(w->cq)),
nullptr, &w->on_complete, nullptr);
}
gpr_mu_lock(&w->mu);
if (due_to_completion) {
if (grpc_trace_operation_failures.enabled()) {
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(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(void* pw, grpc_error* error) {
partly_done(static_cast<state_watcher*>(pw), true, GRPC_ERROR_REF(error));
}
static void timeout_complete(void* pw, grpc_error* error) {
partly_done(static_cast<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(void* arg, grpc_error* error_ignored) {
watcher_timer_init_arg* wa = static_cast<watcher_timer_init_arg*>(arg);
grpc_timer_init(&wa->w->alarm, grpc_timespec_to_millis_round_up(wa->deadline),
&wa->w->on_timeout);
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_core::ExecCtx exec_ctx;
state_watcher* w = static_cast<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 = nullptr;
watcher_timer_init_arg* wa = static_cast<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(
client_channel_elem,
grpc_polling_entity_create_from_pollset(grpc_cq_pollset(cq)), &w->state,
&w->on_complete, &w->watcher_timer_init);
} else {
abort();
}
}
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