zephyr/subsys/zbus/zbus.c

578 lines
14 KiB
C

/*
* Copyright (c) 2022 Rodrigo Peixoto <rodrigopex@gmail.com>
* SPDX-License-Identifier: Apache-2.0
*/
#include <zephyr/kernel.h>
#include <zephyr/init.h>
#include <zephyr/sys/iterable_sections.h>
#include <zephyr/logging/log.h>
#include <zephyr/sys/printk.h>
#include <zephyr/net/buf.h>
#include <zephyr/zbus/zbus.h>
LOG_MODULE_REGISTER(zbus, CONFIG_ZBUS_LOG_LEVEL);
#if defined(CONFIG_ZBUS_PRIORITY_BOOST)
/* Available only when the priority boost is enabled */
static struct k_spinlock _zbus_chan_slock;
#endif /* CONFIG_ZBUS_PRIORITY_BOOST */
static struct k_spinlock obs_slock;
#if defined(CONFIG_ZBUS_MSG_SUBSCRIBER)
#if defined(CONFIG_ZBUS_MSG_SUBSCRIBER_BUF_ALLOC_DYNAMIC)
NET_BUF_POOL_HEAP_DEFINE(_zbus_msg_subscribers_pool, CONFIG_ZBUS_MSG_SUBSCRIBER_NET_BUF_POOL_SIZE,
sizeof(struct zbus_channel *), NULL);
BUILD_ASSERT(K_HEAP_MEM_POOL_SIZE > 0, "MSG_SUBSCRIBER feature requires heap memory pool.");
static inline struct net_buf *_zbus_create_net_buf(struct net_buf_pool *pool, size_t size,
k_timeout_t timeout)
{
return net_buf_alloc_len(&_zbus_msg_subscribers_pool, size, timeout);
}
#else
NET_BUF_POOL_FIXED_DEFINE(_zbus_msg_subscribers_pool,
(CONFIG_ZBUS_MSG_SUBSCRIBER_NET_BUF_POOL_SIZE),
(CONFIG_ZBUS_MSG_SUBSCRIBER_NET_BUF_STATIC_DATA_SIZE),
sizeof(struct zbus_channel *), NULL);
static inline struct net_buf *_zbus_create_net_buf(struct net_buf_pool *pool, size_t size,
k_timeout_t timeout)
{
__ASSERT(size <= CONFIG_ZBUS_MSG_SUBSCRIBER_NET_BUF_STATIC_DATA_SIZE,
"CONFIG_ZBUS_MSG_SUBSCRIBER_NET_BUF_STATIC_DATA_SIZE must be greater or equal to "
"%d",
(int)size);
return net_buf_alloc(&_zbus_msg_subscribers_pool, timeout);
}
#endif /* CONFIG_ZBUS_MSG_SUBSCRIBER_BUF_ALLOC_DYNAMIC */
#endif /* CONFIG_ZBUS_MSG_SUBSCRIBER */
int _zbus_init(void)
{
const struct zbus_channel *curr = NULL;
const struct zbus_channel *prev = NULL;
STRUCT_SECTION_FOREACH(zbus_channel_observation, observation) {
curr = observation->chan;
if (prev != curr) {
if (prev == NULL) {
curr->data->observers_start_idx = 0;
curr->data->observers_end_idx = 0;
} else {
curr->data->observers_start_idx = prev->data->observers_end_idx;
curr->data->observers_end_idx = prev->data->observers_end_idx;
}
prev = curr;
}
++(curr->data->observers_end_idx);
}
STRUCT_SECTION_FOREACH(zbus_channel, chan) {
k_sem_init(&chan->data->sem, 1, 1);
#if defined(CONFIG_ZBUS_RUNTIME_OBSERVERS)
sys_slist_init(&chan->data->observers);
#endif /* CONFIG_ZBUS_RUNTIME_OBSERVERS */
}
return 0;
}
SYS_INIT(_zbus_init, APPLICATION, CONFIG_ZBUS_CHANNELS_SYS_INIT_PRIORITY);
static inline int _zbus_notify_observer(const struct zbus_channel *chan,
const struct zbus_observer *obs, k_timepoint_t end_time,
struct net_buf *buf)
{
switch (obs->type) {
case ZBUS_OBSERVER_LISTENER_TYPE: {
obs->callback(chan);
break;
}
case ZBUS_OBSERVER_SUBSCRIBER_TYPE: {
return k_msgq_put(obs->queue, &chan, sys_timepoint_timeout(end_time));
}
#if defined(CONFIG_ZBUS_MSG_SUBSCRIBER)
case ZBUS_OBSERVER_MSG_SUBSCRIBER_TYPE: {
struct net_buf *cloned_buf = net_buf_clone(buf, sys_timepoint_timeout(end_time));
if (cloned_buf == NULL) {
return -ENOMEM;
}
memcpy(net_buf_user_data(cloned_buf), &chan, sizeof(struct zbus_channel *));
net_buf_put(obs->message_fifo, cloned_buf);
break;
}
#endif /* CONFIG_ZBUS_MSG_SUBSCRIBER */
default:
_ZBUS_ASSERT(false, "Unreachable");
}
return 0;
}
static inline int _zbus_vded_exec(const struct zbus_channel *chan, k_timepoint_t end_time)
{
int err = 0;
int last_error = 0;
struct net_buf *buf = NULL;
/* Static observer event dispatcher logic */
struct zbus_channel_observation *observation;
struct zbus_channel_observation_mask *observation_mask;
#if defined(CONFIG_ZBUS_MSG_SUBSCRIBER)
buf = _zbus_create_net_buf(&_zbus_msg_subscribers_pool, zbus_chan_msg_size(chan),
sys_timepoint_timeout(end_time));
_ZBUS_ASSERT(buf != NULL, "net_buf zbus_msg_subscribers_pool is "
"unavailable or heap is full");
net_buf_add_mem(buf, zbus_chan_msg(chan), zbus_chan_msg_size(chan));
#endif /* CONFIG_ZBUS_MSG_SUBSCRIBER */
LOG_DBG("Notifing %s's observers. Starting VDED:", _ZBUS_CHAN_NAME(chan));
int __maybe_unused index = 0;
for (int16_t i = chan->data->observers_start_idx, limit = chan->data->observers_end_idx;
i < limit; ++i) {
STRUCT_SECTION_GET(zbus_channel_observation, i, &observation);
STRUCT_SECTION_GET(zbus_channel_observation_mask, i, &observation_mask);
_ZBUS_ASSERT(observation != NULL, "observation must be not NULL");
const struct zbus_observer *obs = observation->obs;
if (!obs->data->enabled || observation_mask->enabled) {
continue;
}
err = _zbus_notify_observer(chan, obs, end_time, buf);
if (err) {
last_error = err;
LOG_ERR("could not deliver notification to observer %s. Error code %d",
_ZBUS_OBS_NAME(obs), err);
if (err == -ENOMEM) {
if (IS_ENABLED(CONFIG_ZBUS_MSG_SUBSCRIBER)) {
net_buf_unref(buf);
}
return err;
}
}
LOG_DBG(" %d -> %s", index++, _ZBUS_OBS_NAME(obs));
}
#if defined(CONFIG_ZBUS_RUNTIME_OBSERVERS)
/* Dynamic observer event dispatcher logic */
struct zbus_observer_node *obs_nd, *tmp;
SYS_SLIST_FOR_EACH_CONTAINER_SAFE(&chan->data->observers, obs_nd, tmp, node) {
const struct zbus_observer *obs = obs_nd->obs;
if (!obs->data->enabled) {
continue;
}
err = _zbus_notify_observer(chan, obs, end_time, buf);
if (err) {
last_error = err;
}
}
#endif /* CONFIG_ZBUS_RUNTIME_OBSERVERS */
IF_ENABLED(CONFIG_ZBUS_MSG_SUBSCRIBER, (net_buf_unref(buf);))
return last_error;
}
#if defined(CONFIG_ZBUS_PRIORITY_BOOST)
static inline void chan_update_hop(const struct zbus_channel *chan)
{
struct zbus_channel_observation *observation;
struct zbus_channel_observation_mask *observation_mask;
int chan_highest_observer_priority = ZBUS_MIN_THREAD_PRIORITY;
K_SPINLOCK(&_zbus_chan_slock) {
const int limit = chan->data->observers_end_idx;
for (int16_t i = chan->data->observers_start_idx; i < limit; ++i) {
STRUCT_SECTION_GET(zbus_channel_observation, i, &observation);
STRUCT_SECTION_GET(zbus_channel_observation_mask, i, &observation_mask);
__ASSERT(observation != NULL, "observation must be not NULL");
const struct zbus_observer *obs = observation->obs;
if (!obs->data->enabled || observation_mask->enabled) {
continue;
}
if (chan_highest_observer_priority > obs->data->priority) {
chan_highest_observer_priority = obs->data->priority;
}
}
chan->data->highest_observer_priority = chan_highest_observer_priority;
}
}
static inline void update_all_channels_hop(const struct zbus_observer *obs)
{
struct zbus_channel_observation *observation;
int count;
STRUCT_SECTION_COUNT(zbus_channel_observation, &count);
for (int16_t i = 0; i < count; ++i) {
STRUCT_SECTION_GET(zbus_channel_observation, i, &observation);
if (obs != observation->obs) {
continue;
}
chan_update_hop(observation->chan);
}
}
int zbus_obs_attach_to_thread(const struct zbus_observer *obs)
{
_ZBUS_ASSERT(!k_is_in_isr(), "cannot attach to an ISR");
_ZBUS_ASSERT(obs != NULL, "obs is required");
int current_thread_priority = k_thread_priority_get(k_current_get());
K_SPINLOCK(&obs_slock) {
if (obs->data->priority != current_thread_priority) {
obs->data->priority = current_thread_priority;
update_all_channels_hop(obs);
}
}
return 0;
}
int zbus_obs_detach_from_thread(const struct zbus_observer *obs)
{
_ZBUS_ASSERT(!k_is_in_isr(), "cannot detach from an ISR");
_ZBUS_ASSERT(obs != NULL, "obs is required");
K_SPINLOCK(&obs_slock) {
obs->data->priority = ZBUS_MIN_THREAD_PRIORITY;
update_all_channels_hop(obs);
}
return 0;
}
#else
static inline void update_all_channels_hop(const struct zbus_observer *obs)
{
}
#endif /* CONFIG_ZBUS_PRIORITY_BOOST */
static inline int chan_lock(const struct zbus_channel *chan, k_timeout_t timeout, int *prio)
{
bool boosting = false;
#if defined(CONFIG_ZBUS_PRIORITY_BOOST)
if (!k_is_in_isr()) {
*prio = k_thread_priority_get(k_current_get());
K_SPINLOCK(&_zbus_chan_slock) {
if (*prio > chan->data->highest_observer_priority) {
int new_prio = chan->data->highest_observer_priority - 1;
new_prio = MAX(new_prio, 0);
/* Elevating priority since the highest_observer_priority is
* greater than the current thread
*/
k_thread_priority_set(k_current_get(), new_prio);
boosting = true;
}
}
}
#endif /* CONFIG_ZBUS_PRIORITY_BOOST */
int err = k_sem_take(&chan->data->sem, timeout);
if (err) {
/* When the priority boost is disabled, this IF will be optimized out. */
if (boosting) {
/* Restoring thread priority since the semaphore is not available */
k_thread_priority_set(k_current_get(), *prio);
}
return err;
}
return 0;
}
static inline void chan_unlock(const struct zbus_channel *chan, int prio)
{
k_sem_give(&chan->data->sem);
#if defined(CONFIG_ZBUS_PRIORITY_BOOST)
/* During the unlock phase, with the priority boost enabled, the priority must be
* restored to the original value in case it was elevated
*/
if (prio < ZBUS_MIN_THREAD_PRIORITY) {
k_thread_priority_set(k_current_get(), prio);
}
#endif /* CONFIG_ZBUS_PRIORITY_BOOST */
}
int zbus_chan_pub(const struct zbus_channel *chan, const void *msg, k_timeout_t timeout)
{
int err;
_ZBUS_ASSERT(chan != NULL, "chan is required");
_ZBUS_ASSERT(msg != NULL, "msg is required");
if (k_is_in_isr()) {
timeout = K_NO_WAIT;
}
k_timepoint_t end_time = sys_timepoint_calc(timeout);
if (chan->validator != NULL && !chan->validator(msg, chan->message_size)) {
return -ENOMSG;
}
int context_priority = ZBUS_MIN_THREAD_PRIORITY;
err = chan_lock(chan, timeout, &context_priority);
if (err) {
return err;
}
memcpy(chan->message, msg, chan->message_size);
err = _zbus_vded_exec(chan, end_time);
chan_unlock(chan, context_priority);
return err;
}
int zbus_chan_read(const struct zbus_channel *chan, void *msg, k_timeout_t timeout)
{
_ZBUS_ASSERT(chan != NULL, "chan is required");
_ZBUS_ASSERT(msg != NULL, "msg is required");
if (k_is_in_isr()) {
timeout = K_NO_WAIT;
}
int err = k_sem_take(&chan->data->sem, timeout);
if (err) {
return err;
}
memcpy(msg, chan->message, chan->message_size);
k_sem_give(&chan->data->sem);
return 0;
}
int zbus_chan_notify(const struct zbus_channel *chan, k_timeout_t timeout)
{
int err;
_ZBUS_ASSERT(chan != NULL, "chan is required");
if (k_is_in_isr()) {
timeout = K_NO_WAIT;
}
k_timepoint_t end_time = sys_timepoint_calc(timeout);
int context_priority = ZBUS_MIN_THREAD_PRIORITY;
err = chan_lock(chan, timeout, &context_priority);
if (err) {
return err;
}
err = _zbus_vded_exec(chan, end_time);
chan_unlock(chan, context_priority);
return err;
}
int zbus_chan_claim(const struct zbus_channel *chan, k_timeout_t timeout)
{
_ZBUS_ASSERT(chan != NULL, "chan is required");
if (k_is_in_isr()) {
timeout = K_NO_WAIT;
}
int err = k_sem_take(&chan->data->sem, timeout);
if (err) {
return err;
}
return 0;
}
int zbus_chan_finish(const struct zbus_channel *chan)
{
_ZBUS_ASSERT(chan != NULL, "chan is required");
k_sem_give(&chan->data->sem);
return 0;
}
int zbus_sub_wait(const struct zbus_observer *sub, const struct zbus_channel **chan,
k_timeout_t timeout)
{
_ZBUS_ASSERT(!k_is_in_isr(), "zbus_sub_wait cannot be used inside ISRs");
_ZBUS_ASSERT(sub != NULL, "sub is required");
_ZBUS_ASSERT(sub->type == ZBUS_OBSERVER_SUBSCRIBER_TYPE, "sub must be a SUBSCRIBER");
_ZBUS_ASSERT(sub->queue != NULL, "sub queue is required");
_ZBUS_ASSERT(chan != NULL, "chan is required");
return k_msgq_get(sub->queue, chan, timeout);
}
#if defined(CONFIG_ZBUS_MSG_SUBSCRIBER)
int zbus_sub_wait_msg(const struct zbus_observer *sub, const struct zbus_channel **chan, void *msg,
k_timeout_t timeout)
{
_ZBUS_ASSERT(!k_is_in_isr(), "zbus_sub_wait_msg cannot be used inside ISRs");
_ZBUS_ASSERT(sub != NULL, "sub is required");
_ZBUS_ASSERT(sub->type == ZBUS_OBSERVER_MSG_SUBSCRIBER_TYPE,
"sub must be a MSG_SUBSCRIBER");
_ZBUS_ASSERT(sub->message_fifo != NULL, "sub message_fifo is required");
_ZBUS_ASSERT(chan != NULL, "chan is required");
_ZBUS_ASSERT(msg != NULL, "msg is required");
struct net_buf *buf = net_buf_get(sub->message_fifo, timeout);
if (buf == NULL) {
return -ENOMSG;
}
*chan = *((struct zbus_channel **)net_buf_user_data(buf));
memcpy(msg, net_buf_remove_mem(buf, zbus_chan_msg_size(*chan)), zbus_chan_msg_size(*chan));
net_buf_unref(buf);
return 0;
}
#endif /* CONFIG_ZBUS_MSG_SUBSCRIBER */
int zbus_obs_set_chan_notification_mask(const struct zbus_observer *obs,
const struct zbus_channel *chan, bool masked)
{
_ZBUS_ASSERT(obs != NULL, "obs is required");
_ZBUS_ASSERT(chan != NULL, "chan is required");
int err = -ESRCH;
struct zbus_channel_observation *observation;
struct zbus_channel_observation_mask *observation_mask;
K_SPINLOCK(&obs_slock) {
for (int16_t i = chan->data->observers_start_idx,
limit = chan->data->observers_end_idx;
i < limit; ++i) {
STRUCT_SECTION_GET(zbus_channel_observation, i, &observation);
STRUCT_SECTION_GET(zbus_channel_observation_mask, i, &observation_mask);
__ASSERT(observation != NULL, "observation must be not NULL");
if (observation->obs == obs) {
if (observation_mask->enabled != masked) {
observation_mask->enabled = masked;
update_all_channels_hop(obs);
}
err = 0;
K_SPINLOCK_BREAK;
}
}
}
return err;
}
int zbus_obs_is_chan_notification_masked(const struct zbus_observer *obs,
const struct zbus_channel *chan, bool *masked)
{
_ZBUS_ASSERT(obs != NULL, "obs is required");
_ZBUS_ASSERT(chan != NULL, "chan is required");
int err = -ESRCH;
struct zbus_channel_observation *observation;
struct zbus_channel_observation_mask *observation_mask;
K_SPINLOCK(&obs_slock) {
const int limit = chan->data->observers_end_idx;
for (int16_t i = chan->data->observers_start_idx; i < limit; ++i) {
STRUCT_SECTION_GET(zbus_channel_observation, i, &observation);
STRUCT_SECTION_GET(zbus_channel_observation_mask, i, &observation_mask);
__ASSERT(observation != NULL, "observation must be not NULL");
if (observation->obs == obs) {
*masked = observation_mask->enabled;
err = 0;
K_SPINLOCK_BREAK;
}
}
}
return err;
}
int zbus_obs_set_enable(struct zbus_observer *obs, bool enabled)
{
_ZBUS_ASSERT(obs != NULL, "obs is required");
K_SPINLOCK(&obs_slock) {
if (obs->data->enabled != enabled) {
obs->data->enabled = enabled;
update_all_channels_hop(obs);
}
}
return 0;
}