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can: make can_read non-blockin using recv() instead of read()

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This commit is contained in:
Niklas Eiling 2020-07-08 16:07:39 +02:00 • committed by Steffen Vogel
parent 62d6ef56e1
commit 9fd6bae450
1 changed files with 51 additions and 52 deletions
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103
lib/nodes/can.cpp
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@ -294,8 +294,8 @@ int can_resume(struct node *n)
int can_read(struct node *n, struct sample *smps[], unsigned cnt, unsigned *release)
{
int nbytes;
unsigned nread;
unsigned signal_num;
unsigned nread = 0;
unsigned signal_num = 0;
struct can_frame frame;
struct timeval tv;
bool found_id = false;
@ -304,55 +304,53 @@ int can_read(struct node *n, struct sample *smps[], unsigned cnt, unsigned *rele
assert(cnt >= 1 && smps[0]->capacity >= 1);
for (nread=0; nread < cnt; nread++) {
signal_num = 0;
found_id = false;
while (signal_num < (unsigned)vlist_length(&(n->in.signals))) {
if ((nbytes = read(c->socket, &frame, sizeof(struct can_frame))) == -1) {
error("CAN read() returned -1. Is the CAN interface up?");
return 0;
}
if ((unsigned)nbytes != sizeof(struct can_frame)) {
error("CAN read() error. read() returned %d bytes but expected %zu",
nbytes, sizeof(struct can_frame));
return 0;
}
debug(0,"received can message: (id:%d, len:%u, data: 0x%x:0x%x)",
frame.can_id,
frame.can_dlc,
((uint32_t*)&frame.data)[0],
((uint32_t*)&frame.data)[1]);
if (ioctl(c->socket, SIOCGSTAMP, &tv) != 0) {
warning("Could not get timestamp from CAN driver on interface \"%s\".", c->interface_name);
smps[nread]->ts.received = time_now();
} else {
TIMEVAL_TO_TIMESPEC(&tv, &smps[nread]->ts.received);
}
for (size_t i=0; i < vlist_length(&(n->in.signals)); i++) {
if (c->in[i].id == frame.can_id) {
/* This is a bit ugly. But there is no clean way to
* clear the union. */
smps[nread]->data[i].i = 0;
memcpy(&smps[nread]->data[i],
((uint8_t*)&frame.data) + c->in[i].offset,
c->in[i].size);
signal_num++;
found_id = true;
}
}
if (!found_id) {
error("did not find signal for can id %d\n", frame.can_id);
return 0;
}
}
/* Set signals, because other VILLASnode parts expect us to */
smps[nread]->signals = &n->in.signals;
smps[nread]->length = signal_num;
nbytes = recv(c->socket, &frame, sizeof(struct can_frame), MSG_DONTWAIT);
if (nbytes == -1 && (errno == EAGAIN || errno == EWOULDBLOCK)) {
return 0;
}
return nread;
if (nbytes == -1) {
error("CAN read() returned -1. Is the CAN interface up?");
return 0;
}
if ((unsigned)nbytes != sizeof(struct can_frame)) {
error("CAN read() error. read() returned %d bytes but expected %zu",
nbytes, sizeof(struct can_frame));
return 0;
}
debug(0,"received can message: (id:%d, len:%u, data: 0x%x:0x%x)",
frame.can_id,
frame.can_dlc,
((uint32_t*)&frame.data)[0],
((uint32_t*)&frame.data)[1]);
if (ioctl(c->socket, SIOCGSTAMP, &tv) != 0) {
warning("Could not get timestamp from CAN driver on interface \"%s\".", c->interface_name);
smps[nread]->ts.received = time_now();
} else {
TIMEVAL_TO_TIMESPEC(&tv, &smps[nread]->ts.received);
}
for (size_t i=0; i < vlist_length(&(n->in.signals)); i++) {
if (c->in[i].id == frame.can_id) {
/* This is a bit ugly. But there is no clean way to
* clear the union. */
smps[nread]->data[i].i = 0;
memcpy(&smps[nread]->data[i],
((uint8_t*)&frame.data) + c->in[i].offset,
c->in[i].size);
signal_num++;
found_id = true;
}
}
if (!found_id) {
error("did not find signal for can id %d\n", frame.can_id);
return 0;
}
/* Set signals, because other VILLASnode parts expect us to */
smps[nread]->signals = &n->in.signals;
smps[nread]->length = signal_num;
return 1;
}
int can_write(struct node *n, struct sample *smps[], unsigned cnt, unsigned *release)
@ -426,11 +424,12 @@ int can_reverse(struct node *n)
int can_poll_fds(struct node *n, int fds[])
{
//struct can *c = (struct can *) n->_vd;
struct can *c = (struct can *) n->_vd;
fds[0] = c->socket;
/* TODO: Add implementation here. */
return 0; /* The number of file descriptors which have been set in fds */
return 1; /* The number of file descriptors which have been set in fds */
}
int can_netem_fds(struct node *n, int fds[])