164 lines
4.2 KiB
C++
164 lines
4.2 KiB
C++
/*
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* Copyright (c) 2010 The Boeing Company
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation;
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*
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* This program 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 this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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* Author: Tom Goff <thomas.goff@boeing.com>
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*/
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#ifndef FD_READER_H
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#define FD_READER_H
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#include "callback.h"
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#include "event-id.h"
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#include <cstdint>
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#include <thread>
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#ifdef __WIN32__
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#include <BaseTsd.h>
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/**
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* Signed version of size_t
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*/
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typedef SSIZE_T ssize_t;
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#endif
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/**
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* \file
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* \ingroup system
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* ns3::FdReader declaration.
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*/
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namespace ns3
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{
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/**
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* \ingroup system
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* \brief A class that asynchronously reads from a file descriptor.
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*
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* This class can be used to start a system thread that reads from a
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* given file descriptor and invokes a given callback when data is
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* received. This class handles thread management automatically but
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* the \pname{DoRead()} method must be implemented by a subclass.
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*/
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class FdReader : public SimpleRefCount<FdReader>
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{
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public:
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/** Constructor. */
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FdReader();
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/** Destructor. */
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virtual ~FdReader();
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/**
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* Start a new read thread.
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*
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* \param [in] fd A valid file descriptor open for reading.
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*
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* \param [in] readCallback A callback to invoke when new data is
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* available.
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*/
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void Start(int fd, Callback<void, uint8_t*, ssize_t> readCallback);
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/**
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* Stop the read thread and reset internal state. This does not
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* close the file descriptor used for reading.
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*/
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void Stop();
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#ifdef __WIN32__
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/**
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* Keeps track if the Winsock library has been initialized.
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*/
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static bool winsock_initialized;
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#endif
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protected:
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/**
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* \brief A structure representing data read.
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*/
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struct Data
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{
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/** Default constructor, with null buffer and zero length. */
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Data()
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: m_buf(nullptr),
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m_len(0)
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{
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}
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/**
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* Construct from a buffer of a given length.
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*
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* \param [in] buf The buffer.
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* \param [in] len The size of the buffer, in bytes.
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*/
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Data(uint8_t* buf, ssize_t len)
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: m_buf(buf),
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m_len(len)
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{
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}
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/** The read data buffer. */
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uint8_t* m_buf;
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/** The size of the read data buffer, in bytes. */
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ssize_t m_len;
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};
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/**
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* \brief The read implementation.
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*
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* The value of \pname{m_len} returned controls further processing. The
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* callback function is only invoked when \pname{m_len} is positive; any
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* data read is not processed when \pname{m_len} is negative; reading
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* stops when \pname{m_len} is zero.
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*
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* The management of memory associated with \pname{m_buf} must be
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* compatible with the read callback.
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*
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* \return A structure representing what was read.
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*/
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virtual FdReader::Data DoRead() = 0;
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/**
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* \brief The file descriptor to read from.
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*/
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int m_fd;
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private:
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/** The asynchronous function which performs the read. */
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void Run();
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/** Event handler scheduled for destroy time to halt the thread. */
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void DestroyEvent();
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/** The main thread callback function to invoke when we have data. */
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Callback<void, uint8_t*, ssize_t> m_readCallback;
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/** The thread doing the read, created and launched by Start(). */
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std::thread m_readThread;
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/** Pipe used to signal events between threads. */
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int m_evpipe[2];
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/** Signal the read thread to stop. */
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bool m_stop;
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/**
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* The event scheduled for destroy time which will invoke DestroyEvent
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* and halt the thread.
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*/
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EventId m_destroyEvent;
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};
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} // namespace ns3
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#endif /* FD_READER_H */
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