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/*
*
* Copyright 2015, Google Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include "src/core/lib/surface/channel.h"
#include <grpc/support/alloc.h>
#include <grpc/support/log.h>
#include "src/core/ext/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,
CALLING_BACK,
CALLING_BACK_AND_FINISHED,
CALLED_BACK
} callback_phase;
typedef struct {
gpr_mu mu;
callback_phase phase;
grpc_closure on_complete;
grpc_timer alarm;
grpc_connectivity_state state;
grpc_completion_queue *cq;
grpc_cq_completion completion_storage;
grpc_channel *channel;
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) {
int delete = 0;
state_watcher *w = pw;
gpr_mu_lock(&w->mu);
switch (w->phase) {
case WAITING:
case CALLED_BACK:
GPR_UNREACHABLE_CODE(return );
case CALLING_BACK:
w->phase = CALLED_BACK;
break;
case CALLING_BACK_AND_FINISHED:
delete = 1;
break;
}
gpr_mu_unlock(&w->mu);
if (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) {
int delete = 0;
if (due_to_completion) {
grpc_timer_cancel(exec_ctx, &w->alarm);
}
gpr_mu_lock(&w->mu);
if (due_to_completion) {
if (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("Timed out waiting for connection state change");
} else if (error == GRPC_ERROR_CANCELLED) {
error = GRPC_ERROR_NONE;
}
}
switch (w->phase) {
case WAITING:
w->phase = CALLING_BACK;
grpc_cq_end_op(exec_ctx, w->cq, w->tag, GRPC_ERROR_REF(error),
finished_completion, w, &w->completion_storage);
break;
case CALLING_BACK:
w->phase = CALLING_BACK_AND_FINISHED;
break;
case CALLING_BACK_AND_FINISHED:
GPR_UNREACHABLE_CODE(return );
case CALLED_BACK:
delete = 1;
break;
}
gpr_mu_unlock(&w->mu);
if (delete) {
delete_state_watcher(exec_ctx, w);
}
GRPC_ERROR_UNREF(error);
}
static void watch_complete(grpc_exec_ctx *exec_ctx, void *pw,
grpc_error *error) {
partly_done(exec_ctx, pw, true, GRPC_ERROR_REF(error));
}
static void timeout_complete(grpc_exec_ctx *exec_ctx, void *pw,
grpc_error *error) {
partly_done(exec_ctx, pw, false, GRPC_ERROR_REF(error));
}
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 = 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));
grpc_cq_begin_op(cq, tag);
gpr_mu_init(&w->mu);
grpc_closure_init(&w->on_complete, watch_complete, w);
w->phase = WAITING;
w->state = last_observed_state;
w->cq = cq;
w->tag = tag;
w->channel = channel;
grpc_timer_init(&exec_ctx, &w->alarm,
gpr_convert_clock_type(deadline, GPR_CLOCK_MONOTONIC),
timeout_complete, w, gpr_now(GPR_CLOCK_MONOTONIC));
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_cq_pollset(cq), &w->state,
&w->on_complete);
} else {
abort();
}
grpc_exec_ctx_finish(&exec_ctx);
}
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