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ethercat
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Datagram queue race fixed: insert datagrams into master-fsm_queue with fsm_queue list_head

This commit is contained in:
Martin Troxler 2011-01-14 11:36:53 +01:00
parent 85822a6242
commit cc4f691d6c
3 changed files with 25 additions and 11 deletions
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7
master/datagram.c
View File

@ -87,7 +87,10 @@ static const char *type_strings[] = {
*/
void ec_datagram_init(ec_datagram_t *datagram /**< EtherCAT datagram. */)
{
INIT_LIST_HEAD(&datagram->list); // mark as unqueued
INIT_LIST_HEAD(&datagram->queue); // mark as unqueued
INIT_LIST_HEAD(&datagram->fsm_queue); // mark as unqueued
INIT_LIST_HEAD(&datagram->sent); // mark as unqueued
datagram->type = EC_DATAGRAM_NONE;
memset(datagram->address, 0x00, EC_ADDR_LEN);
datagram->data = NULL;
@ -131,8 +134,8 @@ void ec_datagram_clear(ec_datagram_t *datagram /**< EtherCAT datagram. */)
*/
void ec_datagram_unqueue(ec_datagram_t *datagram /**< EtherCAT datagram. */)
{
if (!list_empty(&datagram->queue)) {
list_del_init(&datagram->queue);
if (!list_empty(&datagram->fsm_queue)) {
list_del_init(&datagram->fsm_queue);
}
}

3
master/datagram.h
View File

@ -86,7 +86,8 @@ typedef enum {
*/
typedef struct {
struct list_head list; /**< Needed by domain datagram lists. */
struct list_head queue; /**< Master datagram queue item. */
struct list_head queue; /**< Master datagram send-receive queue item. */
struct list_head fsm_queue; /**< Master datagram fsm queue item. */
struct list_head sent; /**< Master list item for sent datagrams. */
ec_datagram_type_t type; /**< Datagram type (APRD, BWR, etc.). */
uint8_t address[EC_ADDR_LEN]; /**< Recipient address. */

26
master/master.c
View File

@ -416,11 +416,18 @@ void ec_master_clear_slaves(ec_master_t *master)
wake_up(&master->reg_queue);
}
// we must lock the fsm_queue here because the slave's fsm_datagram will be unqueued
if (master->fsm_queue_lock_cb)
master->fsm_queue_lock_cb(master->fsm_queue_locking_data);
ec_mutex_lock(&master->fsm_queue_mutex);
for (slave = master->slaves;
slave < master->slaves + master->slave_count;
slave++) {
ec_slave_clear(slave);
}
ec_mutex_unlock(&master->fsm_queue_mutex);
if (master->fsm_queue_unlock_cb)
master->fsm_queue_unlock_cb(master->fsm_queue_locking_data);
if (master->slaves) {
kfree(master->slaves);
@ -668,8 +675,11 @@ void ec_master_inject_fsm_datagrams(
if (master->fsm_queue_lock_cb)
master->fsm_queue_lock_cb(master->fsm_queue_locking_data);
if (ec_mutex_trylock(&master->fsm_queue_mutex) == 0)
return;
if (ec_mutex_trylock(&master->fsm_queue_mutex) == 0) {
if (master->fsm_queue_unlock_cb)
master->fsm_queue_unlock_cb(master->fsm_queue_locking_data);
return;
}
if (list_empty(&master->fsm_datagram_queue)) {
ec_mutex_unlock(&master->fsm_queue_mutex);
if (master->fsm_queue_unlock_cb)
@ -681,10 +691,10 @@ void ec_master_inject_fsm_datagrams(
}
list_for_each_entry_safe(datagram, n, &master->fsm_datagram_queue,
queue) {
fsm_queue) {
queue_size += datagram->data_size;
if (queue_size <= master->max_queue_size) {
list_del_init(&datagram->queue);
list_del_init(&datagram->fsm_queue);
#if DEBUG_INJECT
EC_MASTER_DBG(master, 2, "Injecting fsm datagram %p"
" size=%zu, queue_size=%zu\n", datagram,
@ -698,7 +708,7 @@ void ec_master_inject_fsm_datagrams(
}
else {
if (datagram->data_size > master->max_queue_size) {
list_del_init(&datagram->queue);
list_del_init(&datagram->fsm_queue);
datagram->state = EC_DATAGRAM_ERROR;
EC_MASTER_ERR(master, "Fsm datagram %p is too large,"
" size=%zu, max_queue_size=%zu\n",
@ -717,7 +727,7 @@ void ec_master_inject_fsm_datagrams(
{
unsigned int time_us;
list_del_init(&datagram->queue);
list_del_init(&datagram->fsm_queue);
datagram->state = EC_DATAGRAM_ERROR;
#ifdef EC_HAVE_CYCLES
time_us = (unsigned int)
@ -794,7 +804,7 @@ void ec_master_queue_fsm_datagram(
// check, if the datagram is already queued
list_for_each_entry(queued_datagram, &master->fsm_datagram_queue,
queue) {
fsm_queue) {
if (queued_datagram == datagram) {
datagram->state = EC_DATAGRAM_QUEUED;
ec_mutex_unlock(&master->fsm_queue_mutex);
@ -809,7 +819,7 @@ void ec_master_queue_fsm_datagram(
datagram, datagram->data_size);
#endif
list_add_tail(&datagram->queue, &master->fsm_datagram_queue);
list_add_tail(&datagram->fsm_queue, &master->fsm_datagram_queue);
datagram->state = EC_DATAGRAM_QUEUED;
#ifdef EC_HAVE_CYCLES
datagram->cycles_sent = get_cycles();