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//
// Copyright 2011 Ettus Research LLC
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
//
#include "soft_time_ctrl.hpp"
#include <uhd/transport/bounded_buffer.hpp>
#include <boost/any.hpp>
#include <boost/thread/thread.hpp>
#include <boost/thread/condition_variable.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
#include <iostream>
using namespace uhd;
using namespace uhd::usrp;
using namespace uhd::transport;
namespace pt = boost::posix_time;
static const time_spec_t TWIDDLE(0.0011);
/***********************************************************************
* Soft time control implementation
**********************************************************************/
class soft_time_ctrl_impl : public soft_time_ctrl{
public:
soft_time_ctrl_impl(const cb_fcn_type &stream_on_off):
_nsamps_remaining(0),
_stream_mode(stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS),
_cmd_queue(2),
_stream_on_off(stream_on_off)
{
//synchronously spawn a new thread
_update_mutex.lock(); //lock mutex before spawned
_thread_group.create_thread(boost::bind(&soft_time_ctrl_impl::recv_cmd_dispatcher, this));
_update_mutex.lock(); //lock blocks until spawned
_update_mutex.unlock(); //unlock mutex before done
//initialize the time to something
this->set_time(time_spec_t(0.0));
}
~soft_time_ctrl_impl(void){
_thread_group.interrupt_all();
_thread_group.join_all();
}
/*******************************************************************
* Time control
******************************************************************/
void set_time(const time_spec_t &time){
boost::mutex::scoped_lock lock(_update_mutex);
_time_offset = time_spec_t::get_system_time() - time;
}
time_spec_t get_time(void){
boost::mutex::scoped_lock lock(_update_mutex);
return time_now();
}
UHD_INLINE time_spec_t time_now(void){
//internal get time without scoped lock
return time_spec_t::get_system_time() - _time_offset;
}
UHD_INLINE void sleep_until_time(
boost::mutex::scoped_lock &lock, const time_spec_t &time
){
boost::condition_variable cond;
//use a condition variable to unlock, sleep, lock
double seconds_to_sleep = (time - time_now()).get_real_secs();
cond.timed_wait(lock, pt::microseconds(long(seconds_to_sleep*1e6)));
}
/*******************************************************************
* Receive control
******************************************************************/
void recv_post(rx_metadata_t &md, size_t &nsamps){
boost::mutex::scoped_lock lock(_update_mutex);
//load the metadata with the expected time
md.has_time_spec = true;
md.time_spec = time_now();
//none of the stuff below matters in continuous streaming mode
if (_stream_mode == stream_cmd_t::STREAM_MODE_START_CONTINUOUS) return;
//When to stop streaming:
//The samples have been received and the stream mode is non-continuous.
//Rewrite the sample count to clip to the requested number of samples.
if (_nsamps_remaining <= nsamps){
nsamps = _nsamps_remaining; //set nsamps, then stop
md.end_of_burst = true;
stream_on_off(false);
return;
}
//update the consumed samples
_nsamps_remaining -= nsamps;
}
void issue_stream_cmd(const stream_cmd_t &cmd){
_cmd_queue.push_with_wait(cmd);
}
void stream_on_off(bool enb){
_stream_on_off(enb);
_nsamps_remaining = 0;
}
/*******************************************************************
* Transmit control
******************************************************************/
bool send_pre(const tx_metadata_t &md, double &timeout){
if (not md.has_time_spec) return false;
boost::mutex::scoped_lock lock(_update_mutex);
time_spec_t time_at(md.time_spec - TWIDDLE);
//handle late packets
if (time_at < time_now()){
//TODO post async message
return true;
}
timeout -= (time_at - time_now()).get_real_secs();
sleep_until_time(lock, time_at);
return false;
}
/*******************************************************************
* Thread control
******************************************************************/
void recv_cmd_handle_cmd(const stream_cmd_t &cmd){
boost::mutex::scoped_lock lock(_update_mutex);
//handle the stream at time by sleeping
if (not cmd.stream_now){
time_spec_t time_at(cmd.time_spec - TWIDDLE);
if (time_at < time_now()){
//TODO inject late cmd inline error
}
else{
sleep_until_time(lock, time_at);
}
}
//When to stop streaming:
//Stop streaming when the command is a stop and streaming.
if (cmd.stream_mode == stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS
and _stream_mode != stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS
) stream_on_off(false);
//When to start streaming:
//Start streaming when the command is not a stop and not streaming.
if (cmd.stream_mode != stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS
and _stream_mode == stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS
) stream_on_off(true);
//update the state
_nsamps_remaining += cmd.num_samps;
_stream_mode = cmd.stream_mode;
}
void recv_cmd_dispatcher(void){
_update_mutex.unlock();
try{
boost::any cmd;
while (true){
_cmd_queue.pop_with_wait(cmd);
recv_cmd_handle_cmd(boost::any_cast<stream_cmd_t>(cmd));
}
} catch(const boost::thread_interrupted &){}
}
private:
boost::mutex _update_mutex;
size_t _nsamps_remaining;
stream_cmd_t::stream_mode_t _stream_mode;
time_spec_t _time_offset;
bounded_buffer<boost::any> _cmd_queue;
const cb_fcn_type _stream_on_off;
boost::thread_group _thread_group;
};
/***********************************************************************
* Soft time control factor
**********************************************************************/
soft_time_ctrl::sptr soft_time_ctrl::make(const cb_fcn_type &stream_on_off){
return sptr(new soft_time_ctrl_impl(stream_on_off));
}
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