top_block.h

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/* -*- c++ -*- */
/*
 * Copyright 2007-2009,2013 Free Software Foundation, Inc.
 *
 * This file is part of GNU Radio
 *
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 */
 
#ifndef INCLUDED_GR_TOP_BLOCK_H
#define INCLUDED_GR_TOP_BLOCK_H
 
#include <gnuradio/api.h>
#include <gnuradio/hier_block2.h>
 
namespace gr {
 
class top_block_impl;
 
GR_RUNTIME_API top_block_sptr make_top_block(const std::string& name,
                                             bool catch_exceptions = true);
 
/*!
 *\brief Top-level hierarchical block representing a flowgraph
 * \ingroup container_blk
 */
class GR_RUNTIME_API top_block : public hier_block2
{
private:
    template <typename T, typename... Args>
    friend std::shared_ptr<T> gnuradio::make_block_sptr(Args&&... args);
 
 
    std::unique_ptr<top_block_impl> d_impl;
 
protected:
    top_block(const std::string& name, bool catch_exceptions = true);
 
public:
    ~top_block() override;
 
    /*!
     * \brief The simple interface to running a flowgraph.
     *
     * Calls start() then wait(). Used to run a flowgraph that will
     * stop on its own, or when another thread will call stop().
     *
     * \param max_noutput_items the maximum number of output items
     * allowed for any block in the flowgraph. This passes through to
     * the start function; see that function for more details.
     */
    void run(int max_noutput_items = 100000000);
 
    /*!
     * Start the contained flowgraph. Creates one or more threads to
     * execute the flow graph. Returns to the caller once the threads
     * are created. Calling start() on a top_block that is already
     * started IS an error.
     *
     * \param max_noutput_items the maximum number of output items
     * allowed for any block in the flowgraph; the noutput_items can
     * always be less than this, but this will cap it as a
     * maximum. Use this to adjust the maximum latency a flowgraph can
     * exhibit.
     */
    void start(int max_noutput_items = 100000000);
 
    /*!
     * Stop the running flowgraph. Notifies each thread created by the
     * scheduler to shutdown, then returns to caller. Calling stop()
     * on a top_block that is already stopped IS NOT an error.
     */
    void stop();
 
    /*!
     * Wait for a flowgraph to complete. Flowgraphs complete when
     * either (1) all blocks indicate that they are done (typically
     * only when using blocks.file_source, or blocks.head, or (2)
     * after stop() has been called to request shutdown. Calling wait
     * on a top_block that is not running IS NOT an error (wait
     * returns w/o blocking).
     */
    void wait();
 
    /*!
     * Lock a flowgraph in preparation for reconfiguration. When an
     * equal number of calls to lock() and unlock() have occurred, the
     * flowgraph will be reconfigured.
     *
     * N.B. lock() and unlock() may not be called from a flowgraph
     * thread (E.g., block::work method) or deadlock will occur
     * when reconfiguration happens.
     */
    void lock() override;
 
    /*!
     * Unlock a flowgraph in preparation for reconfiguration. When an
     * equal number of calls to lock() and unlock() have occurred, the
     * flowgraph will be reconfigured.
     *
     * N.B. lock() and unlock() may not be called from a flowgraph thread
     * (E.g., block::work method) or deadlock will occur when
     * reconfiguration happens.
     */
    void unlock() override;
 
    /*!
     * Returns a string that lists the edge connections in the
     * flattened flowgraph.
     */
    std::string edge_list();
 
    /*!
     * Returns a string that lists the msg edge connections in the
     * flattened flowgraph.
     */
    std::string msg_edge_list();
 
    /*!
     * Displays flattened flowgraph edges and block connectivity
     */
    void dump();
 
    //! Get the number of max noutput_items in the flowgraph
    int max_noutput_items();
 
    //! Set the maximum number of noutput_items in the flowgraph
    void set_max_noutput_items(int nmax);
 
    top_block_sptr to_top_block(); // Needed for Python type coercion
 
    void setup_rpc() override;
};
 
inline top_block_sptr cast_to_top_block_sptr(basic_block_sptr block)
{
    return std::dynamic_pointer_cast<top_block, basic_block>(block);
}
 
} // namespace gr
 
#endif /* INCLUDED_GR_TOP_BLOCK_H */