/*
* Copyright (c) 2013-2016, Christian Ferrari <tiian@users.sourceforge.net>
* All rights reserved.
*
* This file is part of FLoM, Free Lock Manager
*
* FLoM is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2.0 as
* published by the Free Software Foundation.
*
* FLoM is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with FLoM. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef FLOM_LOCKER_H
# define FLOM_LOCKER_H
#include <config.h>
#ifdef HAVE_GLIB_H
# include <glib.h>
#endif
#include "flom_conns.h"
#include "flom_rsrc.h"
/* save old FLOM_TRACE_MODULE and set a new value */
#ifdef FLOM_TRACE_MODULE
# define FLOM_TRACE_MODULE_SAVE FLOM_TRACE_MODULE
# undef FLOM_TRACE_MODULE
#else
# undef FLOM_TRACE_MODULE_SAVE
#endif /* FLOM_TRACE_MODULE */
#define FLOM_TRACE_MODULE FLOM_TRACE_MOD_LOCKER
/**
* Used to break poll loop when looking for new/old clients
* This constant will probably become useless after "ping" implementation
*/
#define FLOM_LOCKER_POLL_TIMEOUT 1000
/**
* Data structure used for a locker thread
*/
struct flom_locker_s {
/**
* Identifier of the thread running the locker
*/
GThread *thread;
/**
* Pipe file descriptor: used by main thread (listener) to send commands
*/
int write_pipe;
/**
* Pipe file descriptor: used by locker thread to receive commands
*/
int read_pipe;
/**
* Last sequence number sent by parent (listener) to locker thread:
* parent point of view
*/
int write_sequence;
/**
* Last sequence read by locker thread and sent by parent (listener):
* child point of view
*/
int read_sequence;
/**
* Number of polling periods the locker thread performed nothing (without
* any client)
*/
int idle_periods;
/**
* Minimum number of milliseconds a resource (and a locker) must be kept
* after last usage
*/
int idle_lifespan;
/**
* Resource managed by the locker
*/
flom_resource_t resource;
};
/**
* A pool of lockers
*/
struct flom_locker_array_s {
/**
* Number of available lockers
*/
guint n;
/**
* Array of lockers
*/
GPtrArray *array;
};
/**
* A shorthand to avoid "struct" verb
*/
typedef struct flom_locker_array_s flom_locker_array_t;
/**
* It's the struct passed from parent thread (listener) to child thread
* (locker) when a new client arrive
*/
struct flom_locker_token_s {
/**
* Socket domain associated to client connection
*/
int domain;
/**
* Client connection (accepted) file descriptor
*/
int client_fd;
/**
* Sequence number associated to the token
*/
int sequence;
};
#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */
/**
* Initialize a locker struct
* @param locker IN/OUT struct to be initialized
* @return a reason code
*/
static inline void flom_locker_init(struct flom_locker_s *locker) {
locker->thread = NULL;
locker->write_pipe = locker->read_pipe = FLOM_NULL_FD;
locker->write_sequence = locker->read_sequence =
locker->idle_periods = 0;
memset(&locker->resource, 0, sizeof(flom_resource_t));
}
/**
* Destroy the objects connected to the locker and the locker object
* itself (the pointer is not anymore valid after this call)
* @param locker IN/OUT object to destroy (remove from memory)
*/
void flom_locker_destroy(struct flom_locker_s *locker);
/**
* Initialize an array of lockers
* @param lockers IN/OUT pointer to object to initialize
*/
void flom_locker_array_init(flom_locker_array_t *lockers);
/**
* Remove all objects pointed by locker array and the array itself
* @param lockers IN/OUT pointer to object to release
*/
void flom_locker_array_free(flom_locker_array_t *lockers);
/**
* Add a new locker to locker array
* @param lockers IN/OUT array of lockers
* @param locker IN new locker to add
*/
void flom_locker_array_add(flom_locker_array_t *lockers,
struct flom_locker_s *locker);
/**
* Remove a locker from locker array
* @param lockers IN/OUT array of lockers
* @param locker IN pointer to the element must be deleted
*/
void flom_locker_array_del(flom_locker_array_t *lockers,
struct flom_locker_s *locker);
/**
* Number of active lockers thread
* @param lockers IN/OUT array of lockers
* @return how many lockers are managed by the object
*/
static inline guint flom_locker_array_count(
const flom_locker_array_t *lockers) {
return lockers->n;
}
/**
* Retrieve a pointer to a locker
* @param lockers IN/OUT array of lockers
* @param i IN index of the desired element
* @return NULL if i is an invalid index, the desired locker otherwise
*/
static inline struct flom_locker_s *flom_locker_array_get(
flom_locker_array_t *lockers, guint i) {
if (i < 0 || i >= lockers->n)
return NULL;
else
return g_ptr_array_index(lockers->array, i);
}
/**
* Main loop function for locker thread
* @param data IN pointer to locker context, it must be a pointer to
* @ref flom_locker_s
*/
gpointer flom_locker_loop(gpointer data);
/**
* Manager POLLIN event received from locker thread
* @param locker IN/OUT locker context object
* @param conns IN/OUT connections object
* @param id IN connection id
* @param refresh_conns OUT the conns object must be refreshed due to
* some deletion inside it
* @return a reason code
*/
int flom_locker_loop_pollin(struct flom_locker_s *locker,
flom_conns_t *conns, guint id,
int *refresh_conns);
#ifdef __cplusplus
}
#endif /* __cplusplus */
/* restore old value of FLOM_TRACE_MODULE */
#ifdef FLOM_TRACE_MODULE_SAVE
# undef FLOM_TRACE_MODULE
# define FLOM_TRACE_MODULE FLOM_TRACE_MODULE_SAVE
# undef FLOM_TRACE_MODULE_SAVE
#endif /* FLOM_TRACE_MODULE_SAVE */
#endif /* FLOM_LOCKER_H */