diff options
Diffstat (limited to 'host/lib/usrp/usrp1/soft_time_ctrl.cpp')
| -rw-r--r-- | host/lib/usrp/usrp1/soft_time_ctrl.cpp | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/host/lib/usrp/usrp1/soft_time_ctrl.cpp b/host/lib/usrp/usrp1/soft_time_ctrl.cpp new file mode 100644 index 000000000..65bdc36d4 --- /dev/null +++ b/host/lib/usrp/usrp1/soft_time_ctrl.cpp @@ -0,0 +1,231 @@ +// +// Copyright 2011-2012 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/utils/tasks.hpp> +#include <boost/make_shared.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), + _async_msg_queue(1000), + _inline_msg_queue(1000), + _stream_on_off(stream_on_off) + { + //synchronously spawn a new thread + _recv_cmd_task = task::make(boost::bind(&soft_time_ctrl_impl::recv_cmd_task, this)); + + //initialize the time to something + this->set_time(time_spec_t(0.0)); + } + + /******************************************************************* + * 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 + ******************************************************************/ + size_t recv_post(rx_metadata_t &md, const size_t nsamps){ + boost::mutex::scoped_lock lock(_update_mutex); + + //Since it timed out on the receive, check for inline messages... + //Must do a post check because recv() will not wake up for a message. + if (md.error_code == rx_metadata_t::ERROR_CODE_TIMEOUT){ + if (_inline_msg_queue.pop_with_haste(md)) return 0; + } + + //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 nsamps; + + //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) switch(_stream_mode){ + case stream_cmd_t::STREAM_MODE_NUM_SAMPS_AND_MORE:{ + rx_metadata_t metadata; + metadata.has_time_spec = true; + metadata.time_spec = this->time_now(); + metadata.error_code = rx_metadata_t::ERROR_CODE_BROKEN_CHAIN; + _inline_msg_queue.push_with_pop_on_full(metadata); + } //continue to next case... + case stream_cmd_t::STREAM_MODE_NUM_SAMPS_AND_DONE: + md.end_of_burst = true; + this->issue_stream_cmd(stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS); + return _nsamps_remaining; + default: break; + } + + //update the consumed samples + _nsamps_remaining -= nsamps; + return nsamps; + } + + void issue_stream_cmd(const stream_cmd_t &cmd){ + _cmd_queue.push_with_wait(boost::make_shared<stream_cmd_t>(cmd)); + } + + void stream_on_off(bool enb){ + _stream_on_off(enb); + _nsamps_remaining = 0; + } + + /******************************************************************* + * Transmit control + ******************************************************************/ + void send_pre(const tx_metadata_t &md, double &timeout){ + if (not md.has_time_spec) return; + + boost::mutex::scoped_lock lock(_update_mutex); + + time_spec_t time_at(md.time_spec - TWIDDLE); + + //handle late packets + if (time_at < time_now()){ + async_metadata_t metadata; + metadata.channel = 0; + metadata.has_time_spec = true; + metadata.time_spec = this->time_now(); + metadata.event_code = async_metadata_t::EVENT_CODE_TIME_ERROR; + _async_msg_queue.push_with_pop_on_full(metadata); + return; + } + + timeout -= (time_at - time_now()).get_real_secs(); + sleep_until_time(lock, time_at); + } + + /******************************************************************* + * 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()){ + rx_metadata_t metadata; + metadata.has_time_spec = true; + metadata.time_spec = this->time_now(); + metadata.error_code = rx_metadata_t::ERROR_CODE_LATE_COMMAND; + _inline_msg_queue.push_with_pop_on_full(metadata); + this->issue_stream_cmd(stream_cmd_t::STREAM_MODE_STOP_CONTINUOUS); + return; + } + 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_task(void){ //task is looped + boost::shared_ptr<stream_cmd_t> cmd; + _cmd_queue.pop_with_wait(cmd); + recv_cmd_handle_cmd(*cmd); + } + + bounded_buffer<async_metadata_t> &get_async_queue(void){ + return _async_msg_queue; + } + + bounded_buffer<rx_metadata_t> &get_inline_queue(void){ + return _inline_msg_queue; + } + + void stop(void){ + _recv_cmd_task.reset(); + } + +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::shared_ptr<stream_cmd_t> > _cmd_queue; + bounded_buffer<async_metadata_t> _async_msg_queue; + bounded_buffer<rx_metadata_t> _inline_msg_queue; + const cb_fcn_type _stream_on_off; + task::sptr _recv_cmd_task; +}; + +/*********************************************************************** + * 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)); +} |