/* -*- c++ -*- */ /* * Copyright 2004,2009,2010,2011 Free Software Foundation, Inc. * * This file is part of GNU Radio * * GNU Radio 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, or (at your option) * any later version. * * GNU Radio 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 GNU Radio; see the file COPYING. If not, write to * the Free Software Foundation, Inc., 51 Franklin Street, * Boston, MA 02110-1301, USA. */ #ifndef INCLUDED_GR_BUFFER_H #define INCLUDED_GR_BUFFER_H #include #include #include #include #include #include class gr_vmcircbuf; /*! * \brief Allocate a buffer that holds at least \p nitems of size \p sizeof_item. * * The total size of the buffer will be rounded up to a system * dependent boundary. This is typically the system page size, but * under MS windows is 64KB. * * \param nitems is the minimum number of items the buffer will hold. * \param sizeof_item is the size of an item in bytes. * \param link is the block that writes to this buffer. */ GR_CORE_API gr_buffer_sptr gr_make_buffer (int nitems, size_t sizeof_item, gr_block_sptr link=gr_block_sptr()); /*! * \brief Single writer, multiple reader fifo. * \ingroup internal */ class GR_CORE_API gr_buffer { public: virtual ~gr_buffer (); /*! * \brief return number of items worth of space available for writing */ int space_available (); /*! * \brief return size of this buffer in items */ int bufsize() const { return d_bufsize; } /*! * \brief return pointer to write buffer. * * The return value points at space that can hold at least * space_available() items. */ void *write_pointer (); /*! * \brief tell buffer that we wrote \p nitems into it */ void update_write_pointer (int nitems); void set_done (bool done); bool done () const { return d_done; } /*! * \brief Return the block that writes to this buffer. */ gr_block_sptr link() { return gr_block_sptr(d_link); } size_t nreaders() const { return d_readers.size(); } gr_buffer_reader* reader(size_t index) { return d_readers[index]; } gruel::mutex *mutex() { return &d_mutex; } uint64_t nitems_written() { return d_abs_write_offset; } size_t get_sizeof_item() { return d_sizeof_item; } /*! * \brief Adds a new tag to the buffer. * * \param tag the new tag */ void add_item_tag(const gr_tag_t &tag); /*! * \brief Removes an existing tag from the buffer. * * If no such tag is found, does nothing. * * \param tag the tag that needs to be removed */ void remove_item_tag(const gr_tag_t &tag); /*! * \brief Removes all tags before \p max_time from buffer * * \param max_time the time (item number) to trim up until. */ void prune_tags(uint64_t max_time); std::deque::iterator get_tags_begin() { return d_item_tags.begin(); } std::deque::iterator get_tags_end() { return d_item_tags.end(); } // ------------------------------------------------------------------------- private: friend class gr_buffer_reader; friend GR_CORE_API gr_buffer_sptr gr_make_buffer (int nitems, size_t sizeof_item, gr_block_sptr link); friend GR_CORE_API gr_buffer_reader_sptr gr_buffer_add_reader (gr_buffer_sptr buf, int nzero_preload, gr_block_sptr link); protected: char *d_base; // base address of buffer unsigned int d_bufsize; // in items private: gr_vmcircbuf *d_vmcircbuf; size_t d_sizeof_item; // in bytes std::vector d_readers; boost::weak_ptr d_link; // block that writes to this buffer // // The mutex protects d_write_index, d_abs_write_offset, d_done, d_item_tags // and the d_read_index's and d_abs_read_offset's in the buffer readers. // gruel::mutex d_mutex; unsigned int d_write_index; // in items [0,d_bufsize) uint64_t d_abs_write_offset; // num items written since the start bool d_done; std::deque d_item_tags; uint64_t d_last_min_items_read; unsigned index_add (unsigned a, unsigned b) { unsigned s = a + b; if (s >= d_bufsize) s -= d_bufsize; assert (s < d_bufsize); return s; } unsigned index_sub (unsigned a, unsigned b) { int s = a - b; if (s < 0) s += d_bufsize; assert ((unsigned) s < d_bufsize); return s; } virtual bool allocate_buffer (int nitems, size_t sizeof_item); /*! * \brief constructor is private. Use gr_make_buffer to create instances. * * Allocate a buffer that holds at least \p nitems of size \p sizeof_item. * * \param nitems is the minimum number of items the buffer will hold. * \param sizeof_item is the size of an item in bytes. * \param link is the block that writes to this buffer. * * The total size of the buffer will be rounded up to a system * dependent boundary. This is typically the system page size, but * under MS windows is 64KB. */ gr_buffer (int nitems, size_t sizeof_item, gr_block_sptr link); /*! * \brief disassociate \p reader from this buffer */ void drop_reader (gr_buffer_reader *reader); }; /*! * \brief Create a new gr_buffer_reader and attach it to buffer \p buf * \param buf is the buffer the \p gr_buffer_reader reads from. * \param nzero_preload -- number of zero items to "preload" into buffer. * \param link is the block that reads from the buffer using this gr_buffer_reader. */ GR_CORE_API gr_buffer_reader_sptr gr_buffer_add_reader (gr_buffer_sptr buf, int nzero_preload, gr_block_sptr link=gr_block_sptr()); //! returns # of gr_buffers currently allocated GR_CORE_API long gr_buffer_ncurrently_allocated (); // --------------------------------------------------------------------------- /*! * \brief How we keep track of the readers of a gr_buffer. * \ingroup internal */ class GR_CORE_API gr_buffer_reader { public: ~gr_buffer_reader (); /*! * \brief Return number of items available for reading. */ int items_available () const; /*! * \brief Return buffer this reader reads from. */ gr_buffer_sptr buffer () const { return d_buffer; } /*! * \brief Return maximum number of items that could ever be available for reading. * This is used as a sanity check in the scheduler to avoid looping forever. */ int max_possible_items_available () const { return d_buffer->d_bufsize - 1; } /*! * \brief return pointer to read buffer. * * The return value points to items_available() number of items */ const void *read_pointer (); /* * \brief tell buffer we read \p items from it */ void update_read_pointer (int nitems); void set_done (bool done) { d_buffer->set_done (done); } bool done () const { return d_buffer->done (); } gruel::mutex *mutex() { return d_buffer->mutex(); } uint64_t nitems_read() { return d_abs_read_offset; } size_t get_sizeof_item() { return d_buffer->get_sizeof_item(); } /*! * \brief Return the block that reads via this reader. * */ gr_block_sptr link() { return gr_block_sptr(d_link); } /*! * \brief Given a [start,end), returns a vector all tags in the range. * * Get a vector of tags in given range. Range of counts is from start to end-1. * * Tags are tuples of: * (item count, source id, key, value) * * \param v a vector reference to return tags into * \param abs_start a uint64 count of the start of the range of interest * \param abs_end a uint64 count of the end of the range of interest */ void get_tags_in_range(std::vector &v, uint64_t abs_start, uint64_t abs_end); // ------------------------------------------------------------------------- private: friend class gr_buffer; friend GR_CORE_API gr_buffer_reader_sptr gr_buffer_add_reader (gr_buffer_sptr buf, int nzero_preload, gr_block_sptr link); gr_buffer_sptr d_buffer; unsigned int d_read_index; // in items [0,d->buffer.d_bufsize) uint64_t d_abs_read_offset; // num items seen since the start boost::weak_ptr d_link; // block that reads via this buffer reader //! constructor is private. Use gr_buffer::add_reader to create instances gr_buffer_reader (gr_buffer_sptr buffer, unsigned int read_index, gr_block_sptr link); }; //! returns # of gr_buffer_readers currently allocated GR_CORE_API long gr_buffer_reader_ncurrently_allocated (); #endif /* INCLUDED_GR_BUFFER_H */