forked from sdr/gr-osmosdr
103 lines
3.0 KiB
C++
103 lines
3.0 KiB
C++
/* -*- c++ -*- */
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/*
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* Copyright 2005-2011 Free Software Foundation, Inc.
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*
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* This file is part of GNU Radio
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*
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* GNU Radio is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 3, or (at your option)
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* any later version.
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*
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* GNU Radio is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GNU Radio; see the file COPYING. If not, write to
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* the Free Software Foundation, Inc., 51 Franklin Street,
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* Boston, MA 02110-1301, USA.
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include "throttle_impl.h"
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#include <gnuradio/io_signature.h>
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#include <cstring>
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#include <boost/thread/thread.hpp>
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namespace gr {
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namespace blocks {
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throttle::sptr
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throttle::make(size_t itemsize, double samples_per_sec)
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{
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return gnuradio::get_initial_sptr
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(new throttle_impl(itemsize, samples_per_sec));
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}
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throttle_impl::throttle_impl(size_t itemsize,
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double samples_per_second)
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: sync_block("throttle",
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io_signature::make(1, 1, itemsize),
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io_signature::make(1, 1, itemsize)),
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d_itemsize(itemsize)
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{
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set_sample_rate(samples_per_second);
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}
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throttle_impl::~throttle_impl()
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{
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}
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void
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throttle_impl::set_sample_rate(double rate)
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{
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//changing the sample rate performs a reset of state params
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d_start = boost::get_system_time();
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d_total_samples = 0;
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d_samps_per_tick = rate/boost::posix_time::time_duration::ticks_per_second();
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d_samps_per_us = rate/1e6;
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}
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double
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throttle_impl::sample_rate() const
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{
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return d_samps_per_us * 1e6;
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}
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int
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throttle_impl::work(int noutput_items,
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gr_vector_const_void_star &input_items,
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gr_vector_void_star &output_items)
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{
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//calculate the expected number of samples to have passed through
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boost::system_time now = boost::get_system_time();
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boost::int64_t ticks = (now - d_start).ticks();
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uint64_t expected_samps = uint64_t(d_samps_per_tick*ticks);
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//if the expected samples was less, we need to throttle back
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if(d_total_samples > expected_samps) {
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boost::this_thread::sleep(boost::posix_time::microseconds
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(long((d_total_samples - expected_samps)/d_samps_per_us)));
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}
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//copy all samples output[i] <= input[i]
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const char *in = (const char *)input_items[0];
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char *out = (char *)output_items[0];
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std::memcpy(out, in, noutput_items * d_itemsize);
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d_total_samples += noutput_items;
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return noutput_items;
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}
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void
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throttle_impl::setup_rpc()
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{
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}
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} /* namespace blocks */
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} /* namespace gr */
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