nes-proj/os/net/mac/tsch/tsch-queue.c

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/*
* Copyright (c) 2014, SICS Swedish ICT.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name of the Institute 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 INSTITUTE 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 INSTITUTE 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.
*
* This file is part of the Contiki operating system.
*
*/
/**
* \file
* Per-neighbor packet queues for TSCH MAC.
* The list of neighbors uses the TSCH lock, but per-neighbor packet array are lock-free.
* Read-only operation on neighbor and packets are allowed from interrupts and outside of them.
* *Other operations are allowed outside of interrupt only.*
* \author
* Simon Duquennoy <simonduq@sics.se>
* Beshr Al Nahas <beshr@sics.se>
* Domenico De Guglielmo <d.deguglielmo@iet.unipi.it >
*/
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/**
* \addtogroup tsch
* @{
*/
#include "contiki.h"
#include "lib/list.h"
#include "lib/memb.h"
#include "lib/random.h"
#include "net/queuebuf.h"
#include "net/mac/tsch/tsch.h"
#include <string.h>
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/* Log configuration */
#include "sys/log.h"
#define LOG_MODULE "TSCH Queue"
#define LOG_LEVEL LOG_LEVEL_MAC
/* Check if TSCH_QUEUE_NUM_PER_NEIGHBOR is power of two */
#if (TSCH_QUEUE_NUM_PER_NEIGHBOR & (TSCH_QUEUE_NUM_PER_NEIGHBOR - 1)) != 0
#error TSCH_QUEUE_NUM_PER_NEIGHBOR must be power of two
#endif
/* We have as many packets are there are queuebuf in the system */
MEMB(packet_memb, struct tsch_packet, QUEUEBUF_NUM);
MEMB(neighbor_memb, struct tsch_neighbor, TSCH_QUEUE_MAX_NEIGHBOR_QUEUES);
LIST(neighbor_list);
/* Broadcast and EB virtual neighbors */
struct tsch_neighbor *n_broadcast;
struct tsch_neighbor *n_eb;
/*---------------------------------------------------------------------------*/
/* Add a TSCH neighbor */
struct tsch_neighbor *
tsch_queue_add_nbr(const linkaddr_t *addr)
{
struct tsch_neighbor *n = NULL;
/* If we have an entry for this neighbor already, we simply update it */
n = tsch_queue_get_nbr(addr);
if(n == NULL) {
if(tsch_get_lock()) {
/* Allocate a neighbor */
n = memb_alloc(&neighbor_memb);
if(n != NULL) {
/* Initialize neighbor entry */
memset(n, 0, sizeof(struct tsch_neighbor));
ringbufindex_init(&n->tx_ringbuf, TSCH_QUEUE_NUM_PER_NEIGHBOR);
linkaddr_copy(&n->addr, addr);
n->is_broadcast = linkaddr_cmp(addr, &tsch_eb_address)
|| linkaddr_cmp(addr, &tsch_broadcast_address);
tsch_queue_backoff_reset(n);
/* Add neighbor to the list */
list_add(neighbor_list, n);
}
tsch_release_lock();
}
}
return n;
}
/*---------------------------------------------------------------------------*/
/* Get a TSCH neighbor */
struct tsch_neighbor *
tsch_queue_get_nbr(const linkaddr_t *addr)
{
if(!tsch_is_locked()) {
struct tsch_neighbor *n = list_head(neighbor_list);
while(n != NULL) {
if(linkaddr_cmp(&n->addr, addr)) {
return n;
}
n = list_item_next(n);
}
}
return NULL;
}
/*---------------------------------------------------------------------------*/
/* Get a TSCH time source (we currently assume there is only one) */
struct tsch_neighbor *
tsch_queue_get_time_source(void)
{
if(!tsch_is_locked()) {
struct tsch_neighbor *curr_nbr = list_head(neighbor_list);
while(curr_nbr != NULL) {
if(curr_nbr->is_time_source) {
return curr_nbr;
}
curr_nbr = list_item_next(curr_nbr);
}
}
return NULL;
}
/*---------------------------------------------------------------------------*/
/* Update TSCH time source */
int
tsch_queue_update_time_source(const linkaddr_t *new_addr)
{
if(!tsch_is_locked()) {
if(!tsch_is_coordinator) {
struct tsch_neighbor *old_time_src = tsch_queue_get_time_source();
struct tsch_neighbor *new_time_src = NULL;
if(new_addr != NULL) {
/* Get/add neighbor, return 0 in case of failure */
new_time_src = tsch_queue_add_nbr(new_addr);
if(new_time_src == NULL) {
return 0;
}
}
if(new_time_src != old_time_src) {
LOG_INFO("update time source: ");
LOG_INFO_LLADDR(old_time_src ? &old_time_src->addr : NULL);
LOG_INFO_(" -> ");
LOG_INFO_LLADDR(new_time_src ? &new_time_src->addr : NULL);
LOG_INFO_("\n");
/* Update time source */
if(new_time_src != NULL) {
new_time_src->is_time_source = 1;
/* (Re)set keep-alive timeout */
tsch_set_ka_timeout(TSCH_KEEPALIVE_TIMEOUT);
} else {
/* Stop sending keepalives */
tsch_set_ka_timeout(0);
}
if(old_time_src != NULL) {
old_time_src->is_time_source = 0;
}
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tsch_stats_reset_neighbor_stats();
#ifdef TSCH_CALLBACK_NEW_TIME_SOURCE
TSCH_CALLBACK_NEW_TIME_SOURCE(old_time_src, new_time_src);
#endif
}
return 1;
}
}
return 0;
}
/*---------------------------------------------------------------------------*/
/* Flush a neighbor queue */
static void
tsch_queue_flush_nbr_queue(struct tsch_neighbor *n)
{
while(!tsch_queue_is_empty(n)) {
struct tsch_packet *p = tsch_queue_remove_packet_from_queue(n);
if(p != NULL) {
/* Set return status for packet_sent callback */
p->ret = MAC_TX_ERR;
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LOG_WARN("! flushing packet\n");
/* Call packet_sent callback */
mac_call_sent_callback(p->sent, p->ptr, p->ret, p->transmissions);
/* Free packet queuebuf */
tsch_queue_free_packet(p);
}
}
}
/*---------------------------------------------------------------------------*/
/* Remove TSCH neighbor queue */
static void
tsch_queue_remove_nbr(struct tsch_neighbor *n)
{
if(n != NULL) {
if(tsch_get_lock()) {
/* Remove neighbor from list */
list_remove(neighbor_list, n);
tsch_release_lock();
/* Flush queue */
tsch_queue_flush_nbr_queue(n);
/* Free neighbor */
memb_free(&neighbor_memb, n);
}
}
}
/*---------------------------------------------------------------------------*/
/* Add packet to neighbor queue. Use same lockfree implementation as ringbuf.c (put is atomic) */
struct tsch_packet *
tsch_queue_add_packet(const linkaddr_t *addr, uint8_t max_transmissions,
mac_callback_t sent, void *ptr)
{
struct tsch_neighbor *n = NULL;
int16_t put_index = -1;
struct tsch_packet *p = NULL;
if(!tsch_is_locked()) {
n = tsch_queue_add_nbr(addr);
if(n != NULL) {
put_index = ringbufindex_peek_put(&n->tx_ringbuf);
if(put_index != -1) {
p = memb_alloc(&packet_memb);
if(p != NULL) {
/* Enqueue packet */
#ifdef TSCH_CALLBACK_PACKET_READY
TSCH_CALLBACK_PACKET_READY();
#endif
p->qb = queuebuf_new_from_packetbuf();
if(p->qb != NULL) {
p->sent = sent;
p->ptr = ptr;
p->ret = MAC_TX_DEFERRED;
p->transmissions = 0;
p->max_transmissions = max_transmissions;
/* Add to ringbuf (actual add committed through atomic operation) */
n->tx_array[put_index] = p;
ringbufindex_put(&n->tx_ringbuf);
LOG_DBG("packet is added put_index %u, packet %p\n",
put_index, p);
return p;
} else {
memb_free(&packet_memb, p);
}
}
}
}
}
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LOG_ERR("! add packet failed: %u %p %d %p %p\n", tsch_is_locked(), n, put_index, p, p ? p->qb : NULL);
return 0;
}
/*---------------------------------------------------------------------------*/
/* Returns the number of packets currently in any TSCH queue */
int
tsch_queue_global_packet_count(void)
{
return QUEUEBUF_NUM - memb_numfree(&packet_memb);
}
/*---------------------------------------------------------------------------*/
/* Returns the number of packets currently in the queue */
int
tsch_queue_packet_count(const linkaddr_t *addr)
{
struct tsch_neighbor *n = NULL;
if(!tsch_is_locked()) {
n = tsch_queue_add_nbr(addr);
if(n != NULL) {
return ringbufindex_elements(&n->tx_ringbuf);
}
}
return -1;
}
/*---------------------------------------------------------------------------*/
/* Remove first packet from a neighbor queue */
struct tsch_packet *
tsch_queue_remove_packet_from_queue(struct tsch_neighbor *n)
{
if(!tsch_is_locked()) {
if(n != NULL) {
/* Get and remove packet from ringbuf (remove committed through an atomic operation */
int16_t get_index = ringbufindex_get(&n->tx_ringbuf);
if(get_index != -1) {
return n->tx_array[get_index];
} else {
return NULL;
}
}
}
return NULL;
}
/*---------------------------------------------------------------------------*/
/* Free a packet */
void
tsch_queue_free_packet(struct tsch_packet *p)
{
if(p != NULL) {
queuebuf_free(p->qb);
memb_free(&packet_memb, p);
}
}
/*---------------------------------------------------------------------------*/
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/* Updates neighbor queue state after a transmission */
int
tsch_queue_packet_sent(struct tsch_neighbor *n, struct tsch_packet *p,
struct tsch_link *link, uint8_t mac_tx_status)
{
int in_queue = 1;
int is_shared_link = link->link_options & LINK_OPTION_SHARED;
int is_unicast = !n->is_broadcast;
if(mac_tx_status == MAC_TX_OK) {
/* Successful transmission */
tsch_queue_remove_packet_from_queue(n);
in_queue = 0;
/* Update CSMA state in the unicast case */
if(is_unicast) {
if(is_shared_link || tsch_queue_is_empty(n)) {
/* If this is a shared link, reset backoff on success.
* Otherwise, do so only is the queue is empty */
tsch_queue_backoff_reset(n);
}
}
} else {
/* Failed transmission */
if(p->transmissions >= p->max_transmissions) {
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/* Drop packet */
tsch_queue_remove_packet_from_queue(n);
in_queue = 0;
}
/* Update CSMA state in the unicast case */
if(is_unicast) {
/* Failures on dedicated (== non-shared) leave the backoff
* window nor exponent unchanged */
if(is_shared_link) {
/* Shared link: increment backoff exponent, pick a new window */
tsch_queue_backoff_inc(n);
}
}
}
return in_queue;
}
/*---------------------------------------------------------------------------*/
/* Flush all neighbor queues */
void
tsch_queue_reset(void)
{
/* Deallocate unneeded neighbors */
if(!tsch_is_locked()) {
struct tsch_neighbor *n = list_head(neighbor_list);
while(n != NULL) {
struct tsch_neighbor *next_n = list_item_next(n);
/* Flush queue */
tsch_queue_flush_nbr_queue(n);
/* Reset backoff exponent */
tsch_queue_backoff_reset(n);
n = next_n;
}
}
}
/*---------------------------------------------------------------------------*/
/* Deallocate neighbors with empty queue */
void
tsch_queue_free_unused_neighbors(void)
{
/* Deallocate unneeded neighbors */
if(!tsch_is_locked()) {
struct tsch_neighbor *n = list_head(neighbor_list);
while(n != NULL) {
struct tsch_neighbor *next_n = list_item_next(n);
/* Queue is empty, no tx link to this neighbor: deallocate.
* Always keep time source and virtual broadcast neighbors. */
if(!n->is_broadcast && !n->is_time_source && !n->tx_links_count
&& tsch_queue_is_empty(n)) {
tsch_queue_remove_nbr(n);
}
n = next_n;
}
}
}
/*---------------------------------------------------------------------------*/
/* Is the neighbor queue empty? */
int
tsch_queue_is_empty(const struct tsch_neighbor *n)
{
return !tsch_is_locked() && n != NULL && ringbufindex_empty(&n->tx_ringbuf);
}
/*---------------------------------------------------------------------------*/
/* Returns the first packet from a neighbor queue */
struct tsch_packet *
tsch_queue_get_packet_for_nbr(const struct tsch_neighbor *n, struct tsch_link *link)
{
if(!tsch_is_locked()) {
int is_shared_link = link != NULL && link->link_options & LINK_OPTION_SHARED;
if(n != NULL) {
int16_t get_index = ringbufindex_peek_get(&n->tx_ringbuf);
if(get_index != -1 &&
!(is_shared_link && !tsch_queue_backoff_expired(n))) { /* If this is a shared link,
make sure the backoff has expired */
#if TSCH_WITH_LINK_SELECTOR
int packet_attr_slotframe = queuebuf_attr(n->tx_array[get_index]->qb, PACKETBUF_ATTR_TSCH_SLOTFRAME);
int packet_attr_timeslot = queuebuf_attr(n->tx_array[get_index]->qb, PACKETBUF_ATTR_TSCH_TIMESLOT);
if(packet_attr_slotframe != 0xffff && packet_attr_slotframe != link->slotframe_handle) {
return NULL;
}
if(packet_attr_timeslot != 0xffff && packet_attr_timeslot != link->timeslot) {
return NULL;
}
#endif
return n->tx_array[get_index];
}
}
}
return NULL;
}
/*---------------------------------------------------------------------------*/
/* Returns the head packet from a neighbor queue (from neighbor address) */
struct tsch_packet *
tsch_queue_get_packet_for_dest_addr(const linkaddr_t *addr, struct tsch_link *link)
{
if(!tsch_is_locked()) {
return tsch_queue_get_packet_for_nbr(tsch_queue_get_nbr(addr), link);
}
return NULL;
}
/*---------------------------------------------------------------------------*/
/* Returns the head packet of any neighbor queue with zero backoff counter.
* Writes pointer to the neighbor in *n */
struct tsch_packet *
tsch_queue_get_unicast_packet_for_any(struct tsch_neighbor **n, struct tsch_link *link)
{
if(!tsch_is_locked()) {
struct tsch_neighbor *curr_nbr = list_head(neighbor_list);
struct tsch_packet *p = NULL;
while(curr_nbr != NULL) {
if(!curr_nbr->is_broadcast && curr_nbr->tx_links_count == 0) {
/* Only look up for non-broadcast neighbors we do not have a tx link to */
p = tsch_queue_get_packet_for_nbr(curr_nbr, link);
if(p != NULL) {
if(n != NULL) {
*n = curr_nbr;
}
return p;
}
}
curr_nbr = list_item_next(curr_nbr);
}
}
return NULL;
}
/*---------------------------------------------------------------------------*/
/* May the neighbor transmit over a shared link? */
int
tsch_queue_backoff_expired(const struct tsch_neighbor *n)
{
return n->backoff_window == 0;
}
/*---------------------------------------------------------------------------*/
/* Reset neighbor backoff */
void
tsch_queue_backoff_reset(struct tsch_neighbor *n)
{
n->backoff_window = 0;
n->backoff_exponent = TSCH_MAC_MIN_BE;
}
/*---------------------------------------------------------------------------*/
/* Increment backoff exponent, pick a new window */
void
tsch_queue_backoff_inc(struct tsch_neighbor *n)
{
/* Increment exponent */
n->backoff_exponent = MIN(n->backoff_exponent + 1, TSCH_MAC_MAX_BE);
/* Pick a window (number of shared slots to skip). Ignore least significant
* few bits, which, on some embedded implementations of rand (e.g. msp430-libc),
* are known to have poor pseudo-random properties. */
n->backoff_window = (random_rand() >> 6) % (1 << n->backoff_exponent);
/* Add one to the window as we will decrement it at the end of the current slot
* through tsch_queue_update_all_backoff_windows */
n->backoff_window++;
}
/*---------------------------------------------------------------------------*/
/* Decrement backoff window for all queues directed at dest_addr */
void
tsch_queue_update_all_backoff_windows(const linkaddr_t *dest_addr)
{
if(!tsch_is_locked()) {
int is_broadcast = linkaddr_cmp(dest_addr, &tsch_broadcast_address);
struct tsch_neighbor *n = list_head(neighbor_list);
while(n != NULL) {
if(n->backoff_window != 0 /* Is the queue in backoff state? */
&& ((n->tx_links_count == 0 && is_broadcast)
|| (n->tx_links_count > 0 && linkaddr_cmp(dest_addr, &n->addr)))) {
n->backoff_window--;
}
n = list_item_next(n);
}
}
}
/*---------------------------------------------------------------------------*/
/* Initialize TSCH queue module */
void
tsch_queue_init(void)
{
list_init(neighbor_list);
memb_init(&neighbor_memb);
memb_init(&packet_memb);
/* Add virtual EB and the broadcast neighbors */
n_eb = tsch_queue_add_nbr(&tsch_eb_address);
n_broadcast = tsch_queue_add_nbr(&tsch_broadcast_address);
}
/*---------------------------------------------------------------------------*/
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/** @} */