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|
/****************************************************************************
*
* Copyright (C) 2012 PX4 Development Team. 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 PX4 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 COPYRIGHT HOLDERS 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
* COPYRIGHT OWNER 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.
*
****************************************************************************/
/**
* @file uORB.cpp
* A lightweight object broker.
*/
#include <nuttx/config.h>
#include <drivers/device/device.h>
#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>
#include <string.h>
#include <stdlib.h>
#include <fcntl.h>
#include <poll.h>
#include <errno.h>
#include <stdio.h>
#include <math.h>
#include <unistd.h>
#include <nuttx/arch.h>
#include <nuttx/wqueue.h>
#include <nuttx/clock.h>
#include <drivers/drv_hrt.h>
#include <drivers/drv_orb_dev.h>
#include "uORB.h"
/**
* Utility functions.
*/
namespace
{
static const unsigned orb_maxpath = 64;
/* oddly, ERROR is not defined for c++ */
#ifdef ERROR
# undef ERROR
#endif
const int ERROR = -1;
enum Flavor {
PUBSUB,
PARAM
};
int
node_mkpath(char *buf, Flavor f, const struct orb_metadata *meta)
{
unsigned len;
len = snprintf(buf, orb_maxpath, "/%s/%s",
(f == PUBSUB) ? "obj" : "param",
meta->o_name);
if (len >= orb_maxpath)
return -ENAMETOOLONG;
return OK;
}
}
/**
* Per-object device instance.
*/
class ORBDevNode : public device::CDev
{
public:
ORBDevNode(const struct orb_metadata *meta, const char *name, const char *path);
~ORBDevNode();
virtual int open(struct file *filp);
virtual int close(struct file *filp);
virtual ssize_t read(struct file *filp, char *buffer, size_t buflen);
virtual ssize_t write(struct file *filp, const char *buffer, size_t buflen);
virtual int ioctl(struct file *filp, int cmd, unsigned long arg);
static ssize_t publish(const orb_metadata *meta, orb_advert_t handle, const void *data);
protected:
virtual pollevent_t poll_state(struct file *filp);
virtual void poll_notify_one(struct pollfd *fds, pollevent_t events);
private:
struct SubscriberData {
unsigned generation; /**< last generation the subscriber has seen */
unsigned update_interval; /**< if nonzero minimum interval between updates */
struct hrt_call update_call; /**< deferred wakeup call if update_period is nonzero */
void *poll_priv; /**< saved copy of fds->f_priv while poll is active */
bool update_reported; /**< true if we have reported the update via poll/check */
};
const struct orb_metadata *_meta; /**< object metadata information */
uint8_t *_data; /**< allocated object buffer */
hrt_abstime _last_update; /**< time the object was last updated */
volatile unsigned _generation; /**< object generation count */
pid_t _publisher; /**< if nonzero, current publisher */
SubscriberData *filp_to_sd(struct file *filp) {
SubscriberData *sd = (SubscriberData *)(filp->f_priv);
return sd;
}
/**
* Perform a deferred update for a rate-limited subscriber.
*/
void update_deferred();
/**
* Bridge from hrt_call to update_deferred
*
* void *arg ORBDevNode pointer for which the deferred update is performed.
*/
static void update_deferred_trampoline(void *arg);
/**
* Check whether a topic appears updated to a subscriber.
*
* @param sd The subscriber for whom to check.
* @return True if the topic should appear updated to the subscriber
*/
bool appears_updated(SubscriberData *sd);
};
ORBDevNode::ORBDevNode(const struct orb_metadata *meta, const char *name, const char *path) :
CDev(name, path),
_meta(meta),
_data(nullptr),
_last_update(0),
_generation(0),
_publisher(0)
{
// enable debug() calls
_debug_enabled = true;
}
ORBDevNode::~ORBDevNode()
{
if (_data != nullptr)
delete[] _data;
}
int
ORBDevNode::open(struct file *filp)
{
int ret;
/* is this a publisher? */
if (filp->f_oflags == O_WRONLY) {
/* become the publisher if we can */
lock();
if (_publisher == 0) {
_publisher = getpid();
ret = OK;
} else {
ret = -EBUSY;
}
unlock();
/* now complete the open */
if (ret == OK) {
ret = CDev::open(filp);
/* open failed - not the publisher anymore */
if (ret != OK)
_publisher = 0;
}
return ret;
}
/* is this a new subscriber? */
if (filp->f_oflags == O_RDONLY) {
/* allocate subscriber data */
SubscriberData *sd = new SubscriberData;
if (nullptr == sd)
return -ENOMEM;
memset(sd, 0, sizeof(*sd));
/* default to no pending update */
sd->generation = _generation;
filp->f_priv = (void *)sd;
ret = CDev::open(filp);
if (ret != OK)
free(sd);
return ret;
}
/* can only be pub or sub, not both */
return -EINVAL;
}
int
ORBDevNode::close(struct file *filp)
{
/* is this the publisher closing? */
if (getpid() == _publisher) {
_publisher = 0;
} else {
SubscriberData *sd = filp_to_sd(filp);
if (sd != nullptr) {
hrt_cancel(&sd->update_call);
delete sd;
}
}
return CDev::close(filp);
}
ssize_t
ORBDevNode::read(struct file *filp, char *buffer, size_t buflen)
{
SubscriberData *sd = (SubscriberData *)filp_to_sd(filp);
/* if the object has not been written yet, return zero */
if (_data == nullptr)
return 0;
/* if the caller's buffer is the wrong size, that's an error */
if (buflen != _meta->o_size)
return -EIO;
/*
* Perform an atomic copy & state update
*/
irqstate_t flags = irqsave();
/* if the caller doesn't want the data, don't give it to them */
if (nullptr != buffer)
memcpy(buffer, _data, _meta->o_size);
/* track the last generation that the file has seen */
sd->generation = _generation;
/*
* Clear the flag that indicates that an update has been reported, as
* we have just collected it.
*/
sd->update_reported = false;
irqrestore(flags);
return _meta->o_size;
}
ssize_t
ORBDevNode::write(struct file *filp, const char *buffer, size_t buflen)
{
/*
* Writes are legal from interrupt context as long as the
* object has already been initialised from thread context.
*
* Writes outside interrupt context will allocate the object
* if it has not yet been allocated.
*
* Note that filp will usually be NULL.
*/
if (nullptr == _data) {
if (!up_interrupt_context()) {
lock();
/* re-check size */
if (nullptr == _data)
_data = new uint8_t[_meta->o_size];
unlock();
}
/* failed or could not allocate */
if (nullptr == _data)
return -ENOMEM;
}
/* If write size does not match, that is an error */
if (_meta->o_size != buflen)
return -EIO;
/* Perform an atomic copy. */
irqstate_t flags = irqsave();
memcpy(_data, buffer, _meta->o_size);
irqrestore(flags);
/* update the timestamp and generation count */
_last_update = hrt_absolute_time();
_generation++;
/* notify any poll waiters */
poll_notify(POLLIN);
return _meta->o_size;
}
int
ORBDevNode::ioctl(struct file *filp, int cmd, unsigned long arg)
{
SubscriberData *sd = filp_to_sd(filp);
switch (cmd) {
case ORBIOCLASTUPDATE:
*(hrt_abstime *)arg = _last_update;
return OK;
case ORBIOCUPDATED:
*(bool *)arg = appears_updated(sd);
return OK;
case ORBIOCSETINTERVAL:
sd->update_interval = arg;
return OK;
case ORBIOCGADVERTISER:
*(uintptr_t *)arg = (uintptr_t)this;
return OK;
default:
/* give it to the superclass */
return CDev::ioctl(filp, cmd, arg);
}
}
ssize_t
ORBDevNode::publish(const orb_metadata *meta, orb_advert_t handle, const void *data)
{
ORBDevNode *devnode = (ORBDevNode *)handle;
int ret;
/* this is a bit risky, since we are trusting the handle in order to deref it */
if (devnode->_meta != meta) {
errno = EINVAL;
return ERROR;
}
/* call the devnode write method with no file pointer */
ret = devnode->write(nullptr, (const char *)data, meta->o_size);
if (ret < 0)
return ERROR;
if (ret != (int)meta->o_size) {
errno = EIO;
return ERROR;
}
return OK;
}
pollevent_t
ORBDevNode::poll_state(struct file *filp)
{
SubscriberData *sd = filp_to_sd(filp);
/*
* If the topic appears updated to the subscriber, say so.
*/
if (appears_updated(sd))
return POLLIN;
return 0;
}
void
ORBDevNode::poll_notify_one(struct pollfd *fds, pollevent_t events)
{
SubscriberData *sd = filp_to_sd((struct file *)fds->priv);
/*
* If the topic looks updated to the subscriber, go ahead and notify them.
*/
if (appears_updated(sd))
CDev::poll_notify_one(fds, events);
}
bool
ORBDevNode::appears_updated(SubscriberData *sd)
{
/* assume it doesn't look updated */
bool ret = false;
/* avoid racing between interrupt and non-interrupt context calls */
irqstate_t state = irqsave();
/* check if this topic has been published yet, if not bail out */
if (_data == nullptr) {
ret = false;
goto out;
}
/*
* If the subscriber's generation count matches the update generation
* count, there has been no update from their perspective; if they
* don't match then we might have a visible update.
*/
while (sd->generation != _generation) {
/*
* Handle non-rate-limited subscribers.
*/
if (sd->update_interval == 0) {
ret = true;
break;
}
/*
* If we have previously told the subscriber that there is data,
* and they have not yet collected it, continue to tell them
* that there has been an update. This mimics the non-rate-limited
* behaviour where checking / polling continues to report an update
* until the topic is read.
*/
if (sd->update_reported) {
ret = true;
break;
}
/*
* If the interval timer is still running, the topic should not
* appear updated, even though at this point we know that it has.
* We have previously been through here, so the subscriber
* must have collected the update we reported, otherwise
* update_reported would still be true.
*/
if (!hrt_called(&sd->update_call))
break;
/*
* Make sure that we don't consider the topic to be updated again
* until the interval has passed once more by restarting the interval
* timer and thereby re-scheduling a poll notification at that time.
*/
hrt_call_after(&sd->update_call,
sd->update_interval,
&ORBDevNode::update_deferred_trampoline,
(void *)this);
/*
* Remember that we have told the subscriber that there is data.
*/
sd->update_reported = true;
ret = true;
break;
}
out:
irqrestore(state);
/* consider it updated */
return ret;
}
void
ORBDevNode::update_deferred()
{
/*
* Instigate a poll notification; any subscribers whose intervals have
* expired will be woken.
*/
poll_notify(POLLIN);
}
void
ORBDevNode::update_deferred_trampoline(void *arg)
{
ORBDevNode *node = (ORBDevNode *)arg;
node->update_deferred();
}
/**
* Master control device for ObjDev.
*
* Used primarily to create new objects via the ORBIOCCREATE
* ioctl.
*/
class ORBDevMaster : public device::CDev
{
public:
ORBDevMaster(Flavor f);
~ORBDevMaster();
virtual int ioctl(struct file *filp, int cmd, unsigned long arg);
private:
Flavor _flavor;
};
ORBDevMaster::ORBDevMaster(Flavor f) :
CDev((f == PUBSUB) ? "obj_master" : "param_master",
(f == PUBSUB) ? TOPIC_MASTER_DEVICE_PATH : PARAM_MASTER_DEVICE_PATH),
_flavor(f)
{
// enable debug() calls
_debug_enabled = true;
}
ORBDevMaster::~ORBDevMaster()
{
}
int
ORBDevMaster::ioctl(struct file *filp, int cmd, unsigned long arg)
{
int ret;
switch (cmd) {
case ORBIOCADVERTISE: {
const struct orb_metadata *meta = (const struct orb_metadata *)arg;
const char *objname;
char nodepath[orb_maxpath];
ORBDevNode *node;
/* construct a path to the node - this also checks the node name */
ret = node_mkpath(nodepath, _flavor, meta);
if (ret != OK)
return ret;
/* driver wants a permanent copy of the node name, so make one here */
objname = strdup(meta->o_name);
if (objname == nullptr)
return -ENOMEM;
/* construct the new node */
node = new ORBDevNode(meta, objname, nodepath);
/* initialise the node - this may fail if e.g. a node with this name already exists */
if (node != nullptr)
ret = node->init();
/* if we didn't get a device, that's bad */
if (node == nullptr)
return -ENOMEM;
/* if init failed, discard the node and its name */
if (ret != OK) {
delete node;
free((void *)objname);
}
return ret;
}
default:
/* give it to the superclass */
return CDev::ioctl(filp, cmd, arg);
}
}
/**
* Local functions in support of the shell command.
*/
namespace
{
ORBDevMaster *g_dev;
struct orb_test {
int val;
};
ORB_DEFINE(orb_test, struct orb_test);
int
test_fail(const char *fmt, ...)
{
va_list ap;
fprintf(stderr, "FAIL: ");
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
fprintf(stderr, "\n");
fflush(stderr);
return ERROR;
}
int
test_note(const char *fmt, ...)
{
va_list ap;
fprintf(stderr, "note: ");
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
fprintf(stderr, "\n");
fflush(stderr);
return OK;
}
ORB_DECLARE(sensor_combined);
int
test()
{
struct orb_test t, u;
int pfd, sfd;
bool updated;
t.val = 0;
pfd = orb_advertise(ORB_ID(orb_test), &t);
if (pfd < 0)
return test_fail("advertise failed: %d", errno);
test_note("publish handle 0x%08x", pfd);
sfd = orb_subscribe(ORB_ID(orb_test));
if (sfd < 0)
return test_fail("subscribe failed: %d", errno);
test_note("subscribe fd %d", sfd);
u.val = 1;
if (OK != orb_copy(ORB_ID(orb_test), sfd, &u))
return test_fail("copy(1) failed: %d", errno);
if (u.val != t.val)
return test_fail("copy(1) mismatch: %d expected %d", u.val, t.val);
if (OK != orb_check(sfd, &updated))
return test_fail("check(1) failed");
if (updated)
return test_fail("spurious updated flag");
t.val = 2;
test_note("try publish");
if (OK != orb_publish(ORB_ID(orb_test), pfd, &t))
return test_fail("publish failed");
if (OK != orb_check(sfd, &updated))
return test_fail("check(2) failed");
if (!updated)
return test_fail("missing updated flag");
if (OK != orb_copy(ORB_ID(orb_test), sfd, &u))
return test_fail("copy(2) failed: %d", errno);
if (u.val != t.val)
return test_fail("copy(2) mismatch: %d expected %d", u.val, t.val);
orb_unsubscribe(sfd);
close(pfd);
#if 0
/* this is a hacky test that exploits the sensors app to test rate-limiting */
sfd = orb_subscribe(ORB_ID(sensor_combined));
hrt_abstime start, end;
unsigned count;
start = hrt_absolute_time();
count = 0;
do {
orb_check(sfd, &updated);
if (updated) {
orb_copy(ORB_ID(sensor_combined), sfd, nullptr);
count++;
}
} while (count < 100);
end = hrt_absolute_time();
test_note("full-speed, 100 updates in %llu", end - start);
orb_set_interval(sfd, 10);
start = hrt_absolute_time();
count = 0;
do {
orb_check(sfd, &updated);
if (updated) {
orb_copy(ORB_ID(sensor_combined), sfd, nullptr);
count++;
}
} while (count < 100);
end = hrt_absolute_time();
test_note("100Hz, 100 updates in %llu", end - start);
orb_unsubscribe(sfd);
#endif
return test_note("PASS");
}
int
info()
{
return OK;
}
} // namespace
/*
* uORB server 'main'.
*/
extern "C" { __EXPORT int uorb_main(int argc, char *argv[]); }
int
uorb_main(int argc, char *argv[])
{
/*
* Start/load the driver.
*
* XXX it would be nice to have a wrapper for this...
*/
if (!strcmp(argv[1], "start")) {
if (g_dev != nullptr) {
fprintf(stderr, "[uorb] already loaded\n");
/* user wanted to start uorb, its already running, no error */
return 0;
}
/* create the driver */
g_dev = new ORBDevMaster(PUBSUB);
if (g_dev == nullptr) {
fprintf(stderr, "[uorb] driver alloc failed\n");
return -ENOMEM;
}
if (OK != g_dev->init()) {
fprintf(stderr, "[uorb] driver init failed\n");
delete g_dev;
g_dev = nullptr;
return -EIO;
}
printf("[uorb] ready\n");
return OK;
}
/*
* Test the driver/device.
*/
if (!strcmp(argv[1], "test"))
return test();
/*
* Print driver information.
*/
if (!strcmp(argv[1], "status"))
return info();
fprintf(stderr, "unrecognised command, try 'start', 'test' or 'status'\n");
return -EINVAL;
}
/*
* Library functions.
*/
namespace
{
/**
* Advertise a node; don't consider it an error if the node has
* already been advertised.
*
* @todo verify that the existing node is the same as the one
* we tried to advertise.
*/
int
node_advertise(const struct orb_metadata *meta)
{
int fd = -1;
int ret = ERROR;
/* open the control device */
fd = open(TOPIC_MASTER_DEVICE_PATH, 0);
if (fd < 0)
goto out;
/* advertise the object */
ret = ioctl(fd, ORBIOCADVERTISE, (unsigned long)(uintptr_t)meta);
/* it's OK if it already exists */
if ((OK != ret) && (EEXIST == errno))
ret = OK;
out:
if (fd >= 0)
close(fd);
return ret;
}
/**
* Common implementation for orb_advertise and orb_subscribe.
*
* Handles creation of the object and the initial publication for
* advertisers.
*/
int
node_open(Flavor f, const struct orb_metadata *meta, const void *data, bool advertiser)
{
char path[orb_maxpath];
int fd, ret;
/*
* If meta is null, the object was not defined, i.e. it is not
* known to the system. We can't advertise/subscribe such a thing.
*/
if (nullptr == meta) {
errno = ENOENT;
return ERROR;
}
/*
* Advertiser must publish an initial value.
*/
if (advertiser && (data == nullptr)) {
errno = EINVAL;
return ERROR;
}
/*
* Generate the path to the node and try to open it.
*/
ret = node_mkpath(path, f, meta);
if (ret != OK) {
errno = -ret;
return ERROR;
}
/* open the path as either the advertiser or the subscriber */
fd = open(path, (advertiser) ? O_WRONLY : O_RDONLY);
/* we may need to advertise the node... */
if (fd < 0) {
/* try to create the node */
ret = node_advertise(meta);
/* on success, try the open again */
if (ret == OK)
fd = open(path, (advertiser) ? O_WRONLY : O_RDONLY);
}
if (fd < 0) {
errno = EIO;
return ERROR;
}
/* everything has been OK, we can return the handle now */
return fd;
}
} // namespace
orb_advert_t
orb_advertise(const struct orb_metadata *meta, const void *data)
{
int result, fd;
orb_advert_t advertiser;
/* open the node as an advertiser */
fd = node_open(PUBSUB, meta, data, true);
if (fd == ERROR)
return ERROR;
/* get the advertiser handle and close the node */
result = ioctl(fd, ORBIOCGADVERTISER, (unsigned long)&advertiser);
close(fd);
if (result == ERROR)
return ERROR;
/* the advertiser must perform an initial publish to initialise the object */
result= orb_publish(meta, advertiser, data);
if (result == ERROR)
return ERROR;
return advertiser;
}
int
orb_subscribe(const struct orb_metadata *meta)
{
return node_open(PUBSUB, meta, nullptr, false);
}
int
orb_unsubscribe(int handle)
{
return close(handle);
}
int
orb_publish(const struct orb_metadata *meta, orb_advert_t handle, const void *data)
{
return ORBDevNode::publish(meta, handle, data);
}
int
orb_copy(const struct orb_metadata *meta, int handle, void *buffer)
{
int ret;
ret = read(handle, buffer, meta->o_size);
if (ret < 0)
return ERROR;
if (ret != (int)meta->o_size) {
errno = EIO;
return ERROR;
}
return OK;
}
int
orb_check(int handle, bool *updated)
{
return ioctl(handle, ORBIOCUPDATED, (unsigned long)(uintptr_t)updated);
}
int
orb_stat(int handle, uint64_t *time)
{
return ioctl(handle, ORBIOCLASTUPDATE, (unsigned long)(uintptr_t)time);
}
int
orb_set_interval(int handle, unsigned interval)
{
return ioctl(handle, ORBIOCSETINTERVAL, interval * 1000);
}
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