uhd

//

// Copyright 2010-2011 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 <uhd/device.hpp>

#include <uhd/types/dict.hpp>

#include <uhd/exception.hpp>

#include <uhd/utils/log.hpp>

#include <uhd/utils/msg.hpp>

#include <uhd/utils/static.hpp>

#include <uhd/utils/algorithm.hpp>

#include <boost/foreach.hpp>

#include <boost/format.hpp>

#include <boost/weak_ptr.hpp>

#include <boost/functional/hash.hpp>

#include <boost/tuple/tuple.hpp>

#include <boost/thread/mutex.hpp>

using namespace uhd;

static boost::mutex _device_mutex;

/***********************************************************************

 * Helper Functions

 **********************************************************************/

/*!

 * Make a device hash that maps 1 to 1 with a device address.

 * The hash will be used to identify created devices.

 * \param dev_addr the device address

 * \return the hash number

 */

static size_t hash_device_addr(

    const device_addr_t &dev_addr

){

    //combine the hashes of sorted keys/value pairs

    size_t hash = 0;

    BOOST_FOREACH(const std::string &key, uhd::sorted(dev_addr.keys())){

        boost::hash_combine(hash, key);

        boost::hash_combine(hash, dev_addr[key]);

    }

    return hash;

}

/***********************************************************************

 * Registration

 **********************************************************************/

typedef boost::tuple<device::find_t, device::make_t> dev_fcn_reg_t;

// instantiate the device function registry container

UHD_SINGLETON_FCN(std::vector<dev_fcn_reg_t>, get_dev_fcn_regs)

void device::register_device(

    const find_t &find,

    const make_t &make

){

    UHD_LOGV(always) << "registering device" << std::endl;

    get_dev_fcn_regs().push_back(dev_fcn_reg_t(find, make));

}

/***********************************************************************

 * Discover

 **********************************************************************/

device_addrs_t device::find(const device_addr_t &hint){

    boost::mutex::scoped_lock lock(_device_mutex);

    device_addrs_t device_addrs;

    BOOST_FOREACH(const dev_fcn_reg_t &fcn, get_dev_fcn_regs()){

        try{

            device_addrs_t discovered_addrs = fcn.get<0>()(hint);

            device_addrs.insert(

                device_addrs.begin(),

                discovered_addrs.begin(),

                discovered_addrs.end()

            );

        }

        catch(const std::exception &e){

            UHD_MSG(error) << "Device discovery error: " << e.what() << std::endl;

        }

    }

    return device_addrs;

}

/***********************************************************************

 * Make

 **********************************************************************/

device::sptr device::make(const device_addr_t &hint, size_t which){

    boost::mutex::scoped_lock lock(_device_mutex);

    typedef boost::tuple<device_addr_t, make_t> dev_addr_make_t;

    std::vector<dev_addr_make_t> dev_addr_makers;

    BOOST_FOREACH(const dev_fcn_reg_t &fcn, get_dev_fcn_regs()){

        BOOST_FOREACH(device_addr_t dev_addr, fcn.get<0>()(hint)){

            //append the discovered address and its factory function

            dev_addr_makers.push_back(dev_addr_make_t(dev_addr, fcn.get<1>()));

        }

    }

    //check that we found any devices

    if (dev_addr_makers.size() == 0){

        throw uhd::key_error(str(

            boost::format("No devices found for ----->\n%s") % hint.to_pp_string()

        ));

    }

    //check that the which index is valid

    if (dev_addr_makers.size() <= which){

        throw uhd::index_error(str(

            boost::format("No device at index %d for ----->\n%s") % which % hint.to_pp_string()

        ));

    }

    //create a unique hash for the device address

    device_addr_t dev_addr; make_t maker;

    boost::tie(dev_addr, maker) = dev_addr_makers.at(which);

    size_t dev_hash = hash_device_addr(dev_addr);

    UHD_LOG << boost::format("Device hash: %u") % dev_hash << std::endl;

    //copy keys that were in hint but not in dev_addr

    //this way, we can pass additional transport arguments

    BOOST_FOREACH(const std::string &key, hint.keys()){

        if (not dev_addr.has_key(key)) dev_addr[key] = hint[key];

    }

    //map device address hash to created devices

    static uhd::dict<size_t, boost::weak_ptr<device> > hash_to_device;

    //try to find an existing device

    try{

        UHD_ASSERT_THROW(hash_to_device.has_key(dev_hash));

        UHD_ASSERT_THROW(not hash_to_device[dev_hash].expired());

        return hash_to_device[dev_hash].lock();

    }

    //create and register a new device

    catch(const uhd::assertion_error &){

        device::sptr dev = maker(dev_addr);

        hash_to_device[dev_hash] = dev;

        return dev;

    }

}