/*
* Copyright (c) 2009 Lukas Mejdrech
* 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.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
/** @addtogroup packet
* @{
*/
/** @file
* Packet map and queue implementation.
* This file has to be compiled with both the packet server and the client.
*/
#include <errno.h>
#include <futex.h>
#include <malloc.h>
//#include <stdio.h>
#include <string.h>
#include <sys/mman.h>
#include "../../err.h"
#include "../generic_field.h"
#include "packet_header.h"
#include "packet.h"
// TODO power of 2 aritmetic => div and mod speedup?
/** Packet map page size.
*/
#define PACKET_MAP_SIZE 100
/** Returns the packet map page index.
* @param packet_id The packet identifier.
*/
#define PACKET_MAP_PAGE( packet_id ) ((( packet_id ) - 1 ) / PACKET_MAP_SIZE )
/** Returns the packet index in the corresponding packet map page.
* @param packet_id The packet identifier.
*/
#define PACKET_MAP_INDEX( packet_id ) ((( packet_id ) - 1 ) % PACKET_MAP_SIZE )
/** Type definition of the packet map page.
*/
typedef packet_t packet_map_t[ PACKET_MAP_SIZE ];
/** Type definition of the packet map page pointer.
*/
typedef packet_map_t * packet_map_ref;
/** Packet map.
* Maps packet identifiers to the packet references.
* @see generic_field.h
*/
GENERIC_FIELD_DECLARE( gpm, packet_map_t );
/** Releases the packet.
* @param packet The packet to be released. Input parameter.
* @returns EOK on success.
* @returns EINVAL if the packet is not valid.
*/
int packet_destroy( packet_t packet );
/** Packet map global data.
*/
static struct{
/** Safety lock.
* Used as a mutex.
*/
futex_t lock;
/** Packet map.
*/
gpm_t packet_map;
} pm_globals;
GENERIC_FIELD_IMPLEMENT( gpm, packet_map_t );
int packet_destroy( packet_t packet ){
if( ! packet_is_valid( packet )) return EINVAL;
return munmap( packet, packet->length );
}
int pm_init( void ){
ERROR_DECLARE;
// start locked
futex_initialize( & pm_globals.lock, 0 );
ERROR_PROPAGATE( gpm_initialize( & pm_globals.packet_map ));
// release the lock
futex_up( & pm_globals.lock );
return EOK;
}
packet_t pm_find( packet_id_t packet_id ){
packet_map_ref map;
packet_t packet;
if( ! packet_id ) return NULL;
futex_down( & pm_globals.lock );
if( packet_id > PACKET_MAP_SIZE * gpm_count( & pm_globals.packet_map )){
futex_up( & pm_globals.lock );
return NULL;
}
map = gpm_get_index( & pm_globals.packet_map, PACKET_MAP_PAGE( packet_id ));
if( ! map ){
futex_up( & pm_globals.lock );
return NULL;
}
packet = ( * map )[ PACKET_MAP_INDEX( packet_id ) ];
futex_up( & pm_globals.lock );
return packet;
}
int pm_add( packet_t packet ){
ERROR_DECLARE;
packet_map_ref map;
if( ! packet_is_valid( packet )) return EINVAL;
futex_down( & pm_globals.lock );
if( PACKET_MAP_PAGE( packet->packet_id ) < gpm_count( & pm_globals.packet_map )){
map = gpm_get_index( & pm_globals.packet_map, PACKET_MAP_PAGE( packet->packet_id ));
}else{
do{
map
= ( packet_map_ref
) malloc( sizeof( packet_map_t
)); if( ! map ){
futex_up( & pm_globals.lock );
return ENOMEM;
}
memset( map
, 0, sizeof( packet_map_t
)); if(( ERROR_CODE = gpm_add( & pm_globals.packet_map, map )) < 0 ){
futex_up( & pm_globals.lock );
return ERROR_CODE;
}
}while( PACKET_MAP_PAGE( packet->packet_id ) >= gpm_count( & pm_globals.packet_map ));
}
( * map )[ PACKET_MAP_INDEX( packet->packet_id ) ] = packet;
futex_up( & pm_globals.lock );
return EOK;
}
void pm_destroy( void ){
int count;
int index;
packet_map_ref map;
packet_t packet;
futex_down( & pm_globals.lock );
count = gpm_count( & pm_globals.packet_map );
while( count > 0 ){
map = gpm_get_index( & pm_globals.packet_map, count - 1 );
for( index = PACKET_MAP_SIZE - 1; index >= 0; -- index ){
packet = ( * map )[ index ];
if( packet_is_valid( packet )){
munmap( packet, packet->length );
}
}
}
gpm_destroy( & pm_globals.packet_map );
// leave locked
}
packet_t pq_add( packet_t first, packet_t packet, int order, size_t metric ){
packet_t item;
if( ! packet_is_valid( packet )) return NULL;
pq_set( packet, order, metric );
if( packet_is_valid( first )){
item = first;
do{
if( item->order < order ){
if( item->next ){
item = pm_find( item->next );
}else{
item->next = packet->packet_id;
packet->previous = item->packet_id;
return first;
}
}else{
packet->previous = item->previous;
packet->next = item->packet_id;
item->previous = packet->packet_id;
item = pm_find( packet->previous );
if( item ) item->next = packet->packet_id;
return item;
}
}while( packet_is_valid( item ));
}
return packet;
}
packet_t pq_detach( packet_t packet ){
packet_t next;
packet_t previous;
if( ! packet_is_valid( packet )) return NULL;
next = pm_find( packet->next );
if( next ){
next->previous = packet->previous;
previous = pm_find( next->previous );
if( previous ){
previous->next = next->packet_id;
}
}
packet->previous = 0;
packet->next = 0;
return next;
}
int pq_set( packet_t packet, int order, size_t metric ){
if( ! packet_is_valid( packet )) return EINVAL;
packet->order = order;
packet->metric = metric;
return EOK;
}
void pq_destroy( packet_t first, void ( * packet_release )( packet_t packet )){
packet_t actual;
packet_t next;
actual = first;
while( packet_is_valid( actual )){
next = pm_find( actual->next );
actual->next = 0;
actual->previous = 0;
if( packet_release ) packet_release( actual );
actual = next;
}
}
/** @}
*/