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/*
* Copyright (c) 2009, 2010, 2012 Nicira, Inc.
*
* 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 RECONNECT_H
#define RECONNECT_H 1
/* This library implements a finite-state machine for connecting and
* reconnecting to a network resource with exponential backoff. It also
* provides optional support for detecting a connection on which the peer is no
* longer responding.
*
* The library does not implement anything networking related, only an FSM for
* networking code to use.
*
* Many "reconnect" functions take a "now" argument. This makes testing easier
* since there is no hidden state. When not testing, just pass the return
* value of time_msec() from timeval.h. (Perhaps this design should be
* revisited later.) */
#include <stdbool.h>
struct reconnect *reconnect_create(long long int now);
void reconnect_destroy(struct reconnect *);
void reconnect_set_quiet(struct reconnect *, bool quiet);
const char *reconnect_get_name(const struct reconnect *);
void reconnect_set_name(struct reconnect *, const char *name);
/* Defaults, all in msecs. */
#define RECONNECT_DEFAULT_MIN_BACKOFF 1000
#define RECONNECT_DEFAULT_MAX_BACKOFF 8000
#define RECONNECT_DEFAULT_PROBE_INTERVAL 5000
int reconnect_get_min_backoff(const struct reconnect *);
int reconnect_get_max_backoff(const struct reconnect *);
int reconnect_get_probe_interval(const struct reconnect *);
void reconnect_set_max_tries(struct reconnect *, unsigned int max_tries);
unsigned int reconnect_get_max_tries(struct reconnect *);
void reconnect_set_backoff(struct reconnect *,
int min_backoff, int max_backoff);
void reconnect_set_probe_interval(struct reconnect *, int probe_interval);
bool reconnect_is_passive(const struct reconnect *);
void reconnect_set_passive(struct reconnect *, bool passive,
long long int now);
bool reconnect_is_enabled(const struct reconnect *);
void reconnect_enable(struct reconnect *, long long int now);
void reconnect_disable(struct reconnect *, long long int now);
void reconnect_force_reconnect(struct reconnect *, long long int now);
bool reconnect_is_connected(const struct reconnect *);
unsigned int reconnect_get_last_connect_elapsed(const struct reconnect *,
long long int now);
unsigned int reconnect_get_last_disconnect_elapsed(const struct reconnect *,
long long int now);
void reconnect_disconnected(struct reconnect *, long long int now, int error);
void reconnect_connecting(struct reconnect *, long long int now);
void reconnect_listening(struct reconnect *, long long int now);
void reconnect_listen_error(struct reconnect *, long long int now, int error);
void reconnect_connected(struct reconnect *, long long int now);
void reconnect_connect_failed(struct reconnect *, long long int now,
int error);
void reconnect_activity(struct reconnect *, long long int now);
enum reconnect_action {
RECONNECT_CONNECT = 1,
RECONNECT_DISCONNECT,
RECONNECT_PROBE,
};
enum reconnect_action reconnect_run(struct reconnect *, long long int now);
void reconnect_wait(struct reconnect *, long long int now);
int reconnect_timeout(struct reconnect *, long long int now);
struct reconnect_stats {
/* All times and durations in this structure are in milliseconds. */
long long int creation_time; /* Time reconnect_create() called. */
long long int last_activity; /* Last call to reconnect_activity(). */
long long int last_connected; /* Last call to reconnect_connected(). */
long long int last_disconnected; /* Last call to reconnect_disconnected(). */
int backoff; /* Current backoff duration. */
unsigned int seqno; /* # of connections + # of disconnections. */
bool is_connected; /* Currently connected? */
unsigned int msec_since_connect; /* Time since last connect. */
unsigned int msec_since_disconnect; /* Time since last disconnect. */
unsigned int total_connected_duration; /* Sum of all connections. */
unsigned int n_attempted_connections;
unsigned int n_successful_connections;
/* These should only be provided to a human user for debugging purposes.
* The client should not attempt to interpret them. */
const char *state; /* FSM state. */
unsigned int state_elapsed; /* Time since FSM state entered. */
};
void reconnect_get_stats(const struct reconnect *, long long int now,
struct reconnect_stats *);
#endif /* reconnect.h */
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