/****************************************************************************
*
* Copyright (c) 2015 Mark Charlebois. 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 vcdev_posix.cpp
*
* POSIX-like API for virtual character device
*/
#include "px4_posix.h"
#include "device.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <pthread.h>
#include <unistd.h>
using namespace device;
extern "C" {
struct timerData {
sem_t &sem;
struct timespec &ts;
timerData(sem_t &s, struct timespec &t) : sem(s), ts(t) {}
~timerData() {}
};
static void *timer_handler(void *data)
{
struct timerData *td = (struct timerData *)data;
if (td->ts.tv_sec) {
sleep(td->ts.tv_sec);
}
usleep(td->ts.tv_nsec/1000);
sem_post(&(td->sem));
PX4_DEBUG("timer_handler: Timer expired\n");
return 0;
}
#define PX4_MAX_FD 100
static px4_dev_handle_t *filemap[PX4_MAX_FD] = {};
int px4_errno;
inline bool valid_fd(int fd)
{
return (fd < PX4_MAX_FD && fd >= 0 && filemap[fd] != NULL);
}
int px4_open(const char *path, int flags)
{
CDev *dev = CDev::getDev(path);
int ret = 0;
int i;
if (!dev) {
ret = -EINVAL;
}
else {
for (i=0; i<PX4_MAX_FD; ++i) {
if (filemap[i] == 0) {
filemap[i] = new px4_dev_handle_t(flags,dev,i);
break;
}
}
if (i < PX4_MAX_FD) {
ret = dev->open(filemap[i]);
}
else {
ret = -ENOENT;
}
}
if (ret < 0) {
px4_errno = -ret;
return -1;
}
PX4_DEBUG("px4_open fd = %d", filemap[i]->fd);
return filemap[i]->fd;
}
int px4_close(int fd)
{
int ret;
if (valid_fd(fd)) {
CDev *dev = (CDev *)(filemap[fd]->cdev);
PX4_DEBUG("px4_close fd = %d\n", fd);
ret = dev->close(filemap[fd]);
filemap[fd] = NULL;
}
else {
ret = -EINVAL;
}
if (ret < 0) {
px4_errno = -ret;
}
return ret;
}
ssize_t px4_read(int fd, void *buffer, size_t buflen)
{
int ret;
if (valid_fd(fd)) {
CDev *dev = (CDev *)(filemap[fd]->cdev);
PX4_DEBUG("px4_read fd = %d\n", fd);
ret = dev->read(filemap[fd], (char *)buffer, buflen);
}
else {
ret = -EINVAL;
}
if (ret < 0) {
px4_errno = -ret;
}
return ret;
}
ssize_t px4_write(int fd, const void *buffer, size_t buflen)
{
int ret = PX4_ERROR;
if (valid_fd(fd)) {
CDev *dev = (CDev *)(filemap[fd]->cdev);
PX4_DEBUG("px4_write fd = %d\n", fd);
ret = dev->write(filemap[fd], (const char *)buffer, buflen);
}
else {
ret = -EINVAL;
}
if (ret < 0) {
px4_errno = -ret;
}
return ret;
}
int px4_ioctl(int fd, int cmd, unsigned long arg)
{
int ret = PX4_ERROR;
if (valid_fd(fd)) {
CDev *dev = (CDev *)(filemap[fd]->cdev);
PX4_DEBUG("px4_ioctl fd = %d\n", fd);
ret = dev->ioctl(filemap[fd], cmd, arg);
}
else {
ret = -EINVAL;
}
if (ret < 0) {
px4_errno = -ret;
}
else {
px4_errno = -EINVAL;
}
return ret;
}
int px4_poll(px4_pollfd_struct_t *fds, nfds_t nfds, int timeout)
{
sem_t sem;
int count = 0;
int ret;
unsigned int i;
struct timespec ts;
PX4_DEBUG("Called px4_poll timeout = %d\n", timeout);
sem_init(&sem, 0, 0);
// For each fd
for (i=0; i<nfds; ++i)
{
fds[i].sem = &sem;
fds[i].revents = 0;
fds[i].priv = NULL;
// If fd is valid
if (valid_fd(fds[i].fd))
{
CDev *dev = (CDev *)(filemap[fds[i].fd]->cdev);;
PX4_DEBUG("px4_poll: CDev->poll(setup) %d\n", fds[i].fd);
ret = dev->poll(filemap[fds[i].fd], &fds[i], true);
if (ret < 0)
break;
}
}
if (ret >= 0)
{
if (timeout >= 0)
{
pthread_t pt;
void *res;
ts.tv_sec = timeout/1000;
ts.tv_nsec = (timeout % 1000)*1000;
// Create a timer to unblock
struct timerData td(sem, ts);
int rv = pthread_create(&pt, NULL, timer_handler, (void *)&td);
if (rv != 0) {
count = -1;
goto cleanup;
}
sem_wait(&sem);
// Make sure timer thread is killed before sem goes
// out of scope
(void)pthread_cancel(pt);
(void)pthread_join(pt, &res);
}
else
{
sem_wait(&sem);
}
// For each fd
for (i=0; i<nfds; ++i)
{
// If fd is valid
if (valid_fd(fds[i].fd))
{
CDev *dev = (CDev *)(filemap[fds[i].fd]->cdev);;
PX4_DEBUG("px4_poll: CDev->poll(teardown) %d\n", fds[i].fd);
ret = dev->poll(filemap[fds[i].fd], &fds[i], false);
if (ret < 0)
break;
if (fds[i].revents)
count += 1;
}
}
}
cleanup:
sem_destroy(&sem);
return count;
}
}