source: mainline/uspace/srv/net/structures/packet/packet.c@ 21580dd

/*
 * 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 <malloc.h>
#include <mem.h>
#include <fibril_synch.h>
//#include <stdio.h>
#include <unistd.h>

#include <sys/mman.h>

#include "../../err.h"

#include "../generic_field.h"

#include "packet.h"
#include "packet_header.h"

/** Packet map page size.
 */
#define PACKET_MAP_SIZE 100

/** Returns the packet map page index.
 *  @param[in] 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[in] 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[in] packet The packet to be released.
 *  @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.
         */
        fibril_rwlock_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;

        fibril_rwlock_initialize( & pm_globals.lock );
        fibril_rwlock_write_lock( & pm_globals.lock );
        ERROR_PROPAGATE( gpm_initialize( & pm_globals.packet_map ));
        fibril_rwlock_write_unlock( & 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;
        fibril_rwlock_read_lock( & pm_globals.lock );
        if( packet_id > PACKET_MAP_SIZE * gpm_count( & pm_globals.packet_map )){
                fibril_rwlock_read_unlock( & pm_globals.lock );
                return NULL;
        }
        map = gpm_get_index( & pm_globals.packet_map, PACKET_MAP_PAGE( packet_id ));
        if( ! map ){
                fibril_rwlock_read_unlock( & pm_globals.lock );
                return NULL;
        }
        packet = ( * map )[ PACKET_MAP_INDEX( packet_id ) ];
        fibril_rwlock_read_unlock( & pm_globals.lock );
        return packet;
}

int pm_add( packet_t packet ){
        ERROR_DECLARE;

        packet_map_ref map;

        if( ! packet_is_valid( packet )) return EINVAL;
        fibril_rwlock_write_lock( & 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 ){
                                fibril_rwlock_write_unlock( & pm_globals.lock );
                                return ENOMEM;
                        }
                        bzero( map, sizeof( packet_map_t ));
                        if(( ERROR_CODE = gpm_add( & pm_globals.packet_map, map )) < 0 ){
                                fibril_rwlock_write_unlock( & pm_globals.lock );
                                free( map );
                                return ERROR_CODE;
                        }
                }while( PACKET_MAP_PAGE( packet->packet_id ) >= gpm_count( & pm_globals.packet_map ));
        }
        ( * map )[ PACKET_MAP_INDEX( packet->packet_id ) ] = packet;
        fibril_rwlock_write_unlock( & pm_globals.lock );
        return EOK;
}

void pm_destroy( void ){
        int count;
        int index;
        packet_map_ref map;
        packet_t packet;

        fibril_rwlock_write_lock( & 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, size_t order, size_t metric ){
        packet_t        item;

        if( ! packet_is_valid( packet )) return NULL;
        pq_set_order( 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 ? first : packet;
                        }
                }while( packet_is_valid( item ));
        }
        return packet;
}

packet_t pq_find( packet_t packet, size_t order ){
        packet_t        item;

        if( ! packet_is_valid( packet )) return NULL;
        if( packet->order == order ) return packet;
        item = pm_find( packet->next );
        while( item && ( item != packet )){
                item = pm_find( item->next );
                if( item->order == order ){
                        return item;
                }
        }
        return NULL;
}

int     pq_insert_after( packet_t packet, packet_t new_packet ){
        packet_t        item;

        if( !( packet_is_valid( packet ) && packet_is_valid( new_packet ))) return EINVAL;
        new_packet->previous = packet->packet_id;
        new_packet->next = packet->next;
        item = pm_find( packet->next );
        if( item ) item->previous = new_packet->packet_id;
        packet->next = new_packet->packet_id;
        return EOK;
}

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_order( packet_t packet, size_t order, size_t metric ){
        if( ! packet_is_valid( packet )) return EINVAL;
        packet->order = order;
        packet->metric = metric;
        return EOK;
}

int pq_get_order( packet_t packet, size_t * order, size_t * metric ){
        if( ! packet_is_valid( packet )) return EINVAL;
        if( order ) * order = packet->order;
        if( metric ) * metric = packet->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;
        }
}

packet_t pq_next( packet_t packet ){
        if( ! packet_is_valid( packet )) return NULL;
        return pm_find( packet->next );
}

packet_t pq_previous( packet_t packet ){
        if( ! packet_is_valid( packet )) return NULL;
        return pm_find( packet->previous );
}

/** @}
 */