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Diffstat (limited to 'host/lib/transport/libusb1_zero_copy.cpp')
| -rw-r--r-- | host/lib/transport/libusb1_zero_copy.cpp | 442 |
1 files changed, 442 insertions, 0 deletions
diff --git a/host/lib/transport/libusb1_zero_copy.cpp b/host/lib/transport/libusb1_zero_copy.cpp new file mode 100644 index 000000000..f589d7c77 --- /dev/null +++ b/host/lib/transport/libusb1_zero_copy.cpp @@ -0,0 +1,442 @@ +// +// Copyright 2010 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 "libusb1_base.hpp" +#include <uhd/transport/usb_zero_copy.hpp> +#include <uhd/transport/bounded_buffer.hpp> +#include <uhd/utils/thread_priority.hpp> +#include <uhd/utils/assert.hpp> +#include <boost/shared_array.hpp> +#include <boost/foreach.hpp> +#include <boost/thread.hpp> +#include <boost/enable_shared_from_this.hpp> +#include <vector> +#include <iostream> + +using namespace uhd; +using namespace uhd::transport; + +static const double CLEANUP_TIMEOUT = 0.2; //seconds +static const size_t DEFAULT_NUM_XFERS = 16; //num xfers +static const size_t DEFAULT_XFER_SIZE = 32*512; //bytes + +/*********************************************************************** + * Helper functions + ***********************************************************************/ +/* + * Print the values of a libusb_transfer struct + * http://libusb.sourceforge.net/api-1.0/structlibusb__transfer.html + */ +void pp_transfer(libusb_transfer *lut) +{ + std::cout << "Libusb transfer" << std::endl; + std::cout << " flags: 0x" << std::hex << (unsigned int) lut->flags << std::endl; + std::cout << " endpoint: 0x" << std::hex << (unsigned int) lut->endpoint << std::endl; + std::cout << " type: 0x" << std::hex << (unsigned int) lut->type << std::endl; + std::cout << " timeout: " << std::dec << lut->timeout << std::endl; + std::cout << " status: 0x" << std::hex << lut->status << std::endl; + std::cout << " length: " << std::dec << lut->length << std::endl; + std::cout << " actual_length: " << std::dec << lut->actual_length << std::endl; +} + +/*********************************************************************** + * USB asynchronous zero_copy endpoint + * This endpoint implementation provides asynchronous I/O to libusb-1.0 + * devices. Each endpoint is directional and two can be combined to + * create a bidirectional interface. It is a zero copy implementation + * with respect to libusb, however, each send and recv requires a copy + * operation from kernel to userspace; this is due to the usbfs + * interface provided by the kernel. + **********************************************************************/ +class usb_endpoint { +public: + typedef boost::shared_ptr<usb_endpoint> sptr; + + usb_endpoint( + libusb::device_handle::sptr handle, + int endpoint, + bool input, + size_t transfer_size, + size_t num_transfers + ); + + ~usb_endpoint(void); + + // Exposed interface for submitting / retrieving transfer buffers + + //! Submit a new transfer that was presumably just filled or emptied. + void submit(libusb_transfer *lut); + + /*! + * Get an available transfer: + * For inputs, this is a just filled transfer. + * For outputs, this is a just emptied transfer. + * \param timeout the timeout to wait for a lut + * \return the transfer pointer or NULL if timeout + */ + libusb_transfer *get_lut_with_wait(double timeout); + + //Callback use only + void callback_handle_transfer(libusb_transfer *lut); + +private: + libusb::device_handle::sptr _handle; + int _endpoint; + bool _input; + + //! hold a bounded buffer of completed transfers + typedef bounded_buffer<libusb_transfer *> lut_buff_type; + lut_buff_type::sptr _completed_list; + + //! a list of all transfer structs we allocated + std::vector<libusb_transfer *> _all_luts; + + //! a block of memory for the transfer buffers + boost::shared_array<char> _buffer; + + // Calls for processing asynchronous I/O + libusb_transfer *allocate_transfer(void *mem, size_t len); + void print_transfer_status(libusb_transfer *lut); +}; + + +/* + * Callback function called when submitted transfers complete. + * The endpoint upon which the transfer is part of is recovered + * and the transfer moved from pending to completed state. + * Callbacks occur during the reaping calls where libusb_handle_events() + * is used. The callback only modifies the transfer state by moving + * it from the pending to completed status list. + * \param lut pointer to libusb_transfer + */ +static void callback(libusb_transfer *lut){ + usb_endpoint *endpoint = (usb_endpoint *) lut->user_data; + endpoint->callback_handle_transfer(lut); +} + + +/* + * Accessor call to allow list access from callback space + * \param pointer to libusb_transfer + */ +void usb_endpoint::callback_handle_transfer(libusb_transfer *lut){ + boost::this_thread::disable_interruption di; //disable because the wait can throw + _completed_list->push_with_wait(lut); +} + + +/* + * Constructor + * Allocate libusb transfers and mark as free. For IN endpoints, + * submit the transfers so that they're ready to return when + * data is available. + */ +usb_endpoint::usb_endpoint( + libusb::device_handle::sptr handle, + int endpoint, + bool input, + size_t transfer_size, + size_t num_transfers +): + _handle(handle), + _endpoint(endpoint), + _input(input) +{ + _completed_list = lut_buff_type::make(num_transfers); + _buffer = boost::shared_array<char>(new char[num_transfers*transfer_size]); + for (size_t i = 0; i < num_transfers; i++){ + _all_luts.push_back(allocate_transfer(_buffer.get() + i*transfer_size, transfer_size)); + + //input luts are immediately submitted to be filled + //output luts go into the completed list as free buffers + if (_input) this->submit(_all_luts.back()); + else _completed_list->push_with_wait(_all_luts.back()); + } +} + + +/* + * Destructor + * Make sure all the memory is freed. Cancel any pending transfers. + * When all completed transfers are moved to the free list, release + * the transfers. Libusb will deallocate the data buffer held by + * each transfer. + */ +usb_endpoint::~usb_endpoint(void){ + //cancel all transfers + BOOST_FOREACH(libusb_transfer *lut, _all_luts){ + libusb_cancel_transfer(lut); + } + + //collect canceled transfers (drain the queue) + while (this->get_lut_with_wait(CLEANUP_TIMEOUT) != NULL){}; + + //free all transfers + BOOST_FOREACH(libusb_transfer *lut, _all_luts){ + libusb_free_transfer(lut); + } +} + + +/* + * Allocate a libusb transfer + * The allocated transfer - and buffer it contains - is repeatedly + * submitted, reaped, and reused and should not be freed until shutdown. + * \param mem a pointer to the buffer memory + * \param len size of the individual buffer + * \return pointer to an allocated libusb_transfer + */ +libusb_transfer *usb_endpoint::allocate_transfer(void *mem, size_t len){ + libusb_transfer *lut = libusb_alloc_transfer(0); + UHD_ASSERT_THROW(lut != NULL); + + unsigned int endpoint = ((_endpoint & 0x7f) | (_input ? 0x80 : 0)); + unsigned char *buff = reinterpret_cast<unsigned char *>(mem); + libusb_transfer_cb_fn lut_callback = libusb_transfer_cb_fn(&callback); + + libusb_fill_bulk_transfer(lut, // transfer + _handle->get(), // dev_handle + endpoint, // endpoint + buff, // buffer + len, // length + lut_callback, // callback + this, // user_data + 0); // timeout + return lut; +} + + +/* + * Asynchonous transfer submission + * Submit a libusb transfer to libusb add pending status + * \param lut pointer to libusb_transfer + * \return true on success or false on error + */ +void usb_endpoint::submit(libusb_transfer *lut){ + UHD_ASSERT_THROW(libusb_submit_transfer(lut) == 0); +} + +/* + * Print status errors of a completed transfer + * \param lut pointer to an libusb_transfer + */ +void usb_endpoint::print_transfer_status(libusb_transfer *lut){ + std::cout << "here " << lut->status << std::endl; + switch (lut->status) { + case LIBUSB_TRANSFER_COMPLETED: + if (lut->actual_length < lut->length) { + std::cerr << "USB: transfer completed with short write," + << " length = " << lut->length + << " actual = " << lut->actual_length << std::endl; + } + + if ((lut->actual_length < 0) || (lut->length < 0)) { + std::cerr << "USB: transfer completed with invalid response" + << std::endl; + } + break; + case LIBUSB_TRANSFER_CANCELLED: + break; + case LIBUSB_TRANSFER_NO_DEVICE: + std::cerr << "USB: device was disconnected" << std::endl; + break; + case LIBUSB_TRANSFER_OVERFLOW: + std::cerr << "USB: device sent more data than requested" << std::endl; + break; + case LIBUSB_TRANSFER_TIMED_OUT: + std::cerr << "USB: transfer timed out" << std::endl; + break; + case LIBUSB_TRANSFER_STALL: + std::cerr << "USB: halt condition detected (stalled)" << std::endl; + break; + case LIBUSB_TRANSFER_ERROR: + std::cerr << "USB: transfer failed" << std::endl; + break; + default: + std::cerr << "USB: received unknown transfer status" << std::endl; + } +} + +libusb_transfer *usb_endpoint::get_lut_with_wait(double timeout){ + boost::this_thread::disable_interruption di; //disable because the wait can throw + libusb_transfer *lut; + if (_completed_list->pop_with_timed_wait(lut, timeout)) return lut; + return NULL; +} + +/*********************************************************************** + * USB zero_copy device class + **********************************************************************/ +class libusb_zero_copy_impl : public usb_zero_copy, public boost::enable_shared_from_this<libusb_zero_copy_impl> { +public: + + libusb_zero_copy_impl( + libusb::device_handle::sptr handle, + size_t recv_endpoint, + size_t send_endpoint, + const device_addr_t &hints + ); + + ~libusb_zero_copy_impl(void){ + _threads_running = false; + _thread_group.join_all(); + } + + managed_recv_buffer::sptr get_recv_buff(double); + managed_send_buffer::sptr get_send_buff(double); + + size_t get_num_recv_frames(void) const { return _num_recv_frames; } + size_t get_num_send_frames(void) const { return _num_send_frames; } + + size_t get_recv_frame_size(void) const { return _recv_frame_size; } + size_t get_send_frame_size(void) const { return _send_frame_size; } + +private: + void release(libusb_transfer *lut){ + _recv_ep->submit(lut); + } + + void commit(libusb_transfer *lut, size_t num_bytes){ + lut->length = num_bytes; + try{ + _send_ep->submit(lut); + } + catch(const std::exception &e){ + std::cerr << "Error in commit: " << e.what() << std::endl; + } + } + + libusb::device_handle::sptr _handle; + const size_t _recv_frame_size, _num_recv_frames; + const size_t _send_frame_size, _num_send_frames; + usb_endpoint::sptr _recv_ep, _send_ep; + + //event handler threads + boost::thread_group _thread_group; + bool _threads_running; + + void run_event_loop(void){ + set_thread_priority_safe(); + libusb::session::sptr session = libusb::session::get_global_session(); + _threads_running = true; + while(_threads_running){ + timeval tv; + tv.tv_sec = 0; + tv.tv_usec = 100000; //100ms + libusb_handle_events_timeout(session->get_context(), &tv); + } + } +}; + +/* + * Constructor + * Initializes libusb, opens devices, and sets up interfaces for I/O. + * Finally, creates endpoints for asynchronous I/O. + */ +libusb_zero_copy_impl::libusb_zero_copy_impl( + libusb::device_handle::sptr handle, + size_t recv_endpoint, + size_t send_endpoint, + const device_addr_t &hints +): + _handle(handle), + _recv_frame_size(size_t(hints.cast<double>("recv_frame_size", DEFAULT_XFER_SIZE))), + _num_recv_frames(size_t(hints.cast<double>("num_recv_frames", DEFAULT_NUM_XFERS))), + _send_frame_size(size_t(hints.cast<double>("send_frame_size", DEFAULT_XFER_SIZE))), + _num_send_frames(size_t(hints.cast<double>("num_send_frames", DEFAULT_NUM_XFERS))) +{ + _handle->claim_interface(2 /*in interface*/); + _handle->claim_interface(1 /*out interface*/); + + _recv_ep = usb_endpoint::sptr(new usb_endpoint( + _handle, // libusb device_handle + recv_endpoint, // USB endpoint number + true, // IN endpoint + this->get_recv_frame_size(), // buffer size per transfer + this->get_num_recv_frames() // number of libusb transfers + )); + + _send_ep = usb_endpoint::sptr(new usb_endpoint( + _handle, // libusb device_handle + send_endpoint, // USB endpoint number + false, // OUT endpoint + this->get_send_frame_size(), // buffer size per transfer + this->get_num_send_frames() // number of libusb transfers + )); + + //spawn the event handler threads + size_t concurrency = hints.cast<size_t>("concurrency_hint", 1); + for (size_t i = 0; i < concurrency; i++) _thread_group.create_thread( + boost::bind(&libusb_zero_copy_impl::run_event_loop, this) + ); +} + +/* + * Construct a managed receive buffer from a completed libusb transfer + * (happy with buffer full of data) obtained from the receive endpoint. + * Return empty pointer if no transfer is available (timeout or error). + * \return pointer to a managed receive buffer + */ +managed_recv_buffer::sptr libusb_zero_copy_impl::get_recv_buff(double timeout){ + libusb_transfer *lut = _recv_ep->get_lut_with_wait(timeout); + if (lut == NULL) { + return managed_recv_buffer::sptr(); + } + else { + return managed_recv_buffer::make_safe( + boost::asio::const_buffer(lut->buffer, lut->actual_length), + boost::bind(&libusb_zero_copy_impl::release, shared_from_this(), lut) + ); + } +} + + +/* + * Construct a managed send buffer from a free libusb transfer (with + * empty buffer). Return empty pointer of no transfer is available + * (timeout or error). + * \return pointer to a managed send buffer + */ +managed_send_buffer::sptr libusb_zero_copy_impl::get_send_buff(double timeout){ + libusb_transfer *lut = _send_ep->get_lut_with_wait(timeout); + if (lut == NULL) { + return managed_send_buffer::sptr(); + } + else { + return managed_send_buffer::make_safe( + boost::asio::mutable_buffer(lut->buffer, this->get_send_frame_size()), + boost::bind(&libusb_zero_copy_impl::commit, shared_from_this(), lut, _1) + ); + } +} + +/*********************************************************************** + * USB zero_copy make functions + **********************************************************************/ +usb_zero_copy::sptr usb_zero_copy::make( + usb_device_handle::sptr handle, + size_t recv_endpoint, + size_t send_endpoint, + const device_addr_t &hints +){ + libusb::device_handle::sptr dev_handle(libusb::device_handle::get_cached_handle( + boost::static_pointer_cast<libusb::special_handle>(handle)->get_device() + )); + return sptr(new libusb_zero_copy_impl( + dev_handle, recv_endpoint, send_endpoint, hints + )); +} |