dlib C++ Library - threaded_object_extension.cpp

    // Copyright (C) 2007  Davis E. King (davis@dlib.net)
    // License: Boost Software License   See LICENSE.txt for the full license.
    #ifndef DLIB_THREADED_OBJECT_EXTENSIOn_CPP
    #define DLIB_THREADED_OBJECT_EXTENSIOn_CPP

    #include "threaded_object_extension.h"
    #include "create_new_thread_extension.h"

    namespace dlib
    {

    // ----------------------------------------------------------------------------------------

        threaded_object::
        threaded_object (
        ):
            s(m_),
            id1(0),
            is_running_(false),
            is_alive_(false),
            should_stop_(false),
            id_valid(false)
        {
        }

    // ----------------------------------------------------------------------------------------

        threaded_object::
        ~threaded_object (
        )
        {
            try
            {
                DLIB_ASSERT(is_alive() == false,
                       "\tthreaded_object::~threaded_object()"
                       << "\n\tYou have let a threaded object destruct itself before terminating its thread"
                       << "\n\tthis: " << this
                );
            }
            catch (std::exception& e)
            {
                std::cerr << e.what() << std::endl;
                assert(false);
                abort();
            }
        }

    // ----------------------------------------------------------------------------------------

        bool threaded_object::
        is_running (
        ) const
        {
            auto_mutex M(m_);

            DLIB_ASSERT(id1 != get_thread_id() || id_valid == false,
                   "\tbool threaded_object::is_running()"
                   << "\n\tYou can NOT call this function from the thread that executes threaded_object::thread"
                   << "\n\tthis: " << this
            );

            return is_running_;
        }

    // ----------------------------------------------------------------------------------------

        bool threaded_object::
        is_alive (
        ) const
        {
            auto_mutex M(m_);

            DLIB_ASSERT(id1 != get_thread_id() || id_valid == false,
                   "\tbool threaded_object::is_alive()"
                   << "\n\tYou can NOT call this function from the thread that executes threaded_object::thread"
                   << "\n\tthis: " << this
            );

            return is_alive_;
        }

    // ----------------------------------------------------------------------------------------

        void threaded_object::
        wait (
        ) const
        {
            auto_mutex M(m_);

            DLIB_ASSERT(id1 != get_thread_id() || id_valid == false,
                   "\tvoid threaded_object::wait()"
                   << "\n\tYou can NOT call this function from the thread that executes threaded_object::thread"
                   << "\n\tthis: " << this
            );

            while (is_alive_)
                s.wait();
        }

    // ----------------------------------------------------------------------------------------

        void threaded_object::
        start (
        )
        {
            auto_mutex M(m_);

            DLIB_ASSERT(id1 != get_thread_id() || id_valid == false,
                   "\tvoid threaded_object::start()"
                   << "\n\tYou can NOT call this function from the thread that executes threaded_object::thread"
                   << "\n\tthis: " << this
            );

            if (is_alive_ == false)
            {
                if (create_new_thread<threaded_object,&threaded_object::thread_helper>(*this) == false)
                {
                    is_running_ = false;
                    throw thread_error();
                }
            }
            is_alive_ = true;
            is_running_ = true;
            should_stop_ = false;
            s.broadcast();
        }

    // ----------------------------------------------------------------------------------------

        void threaded_object::
        restart (
        )
        {
            auto_mutex M(m_);

            DLIB_ASSERT(id1 != get_thread_id() || id_valid == false,
                   "\tvoid threaded_object::restart()"
                   << "\n\tYou can NOT call this function from the thread that executes threaded_object::thread"
                   << "\n\tthis: " << this
            );

            if (is_alive_ == false)
            {
                if (create_new_thread<threaded_object,&threaded_object::thread_helper>(*this) == false)
                {
                    is_running_ = false;
                    throw thread_error();
                }
                should_respawn_ = false;
            }
            else
            {
                should_respawn_ = true;
            }
            is_alive_ = true;
            is_running_ = true;
            should_stop_ = false;
            s.broadcast();
        }

    // ----------------------------------------------------------------------------------------

        void threaded_object::
        set_respawn (
        )
        {
            auto_mutex M(m_);

            DLIB_ASSERT(id1 != get_thread_id() || id_valid == false,
                   "\tvoid threaded_object::set_respawn()"
                   << "\n\tYou can NOT call this function from the thread that executes threaded_object::thread"
                   << "\n\tthis: " << this
            );

            should_respawn_ = true;
        }

    // ----------------------------------------------------------------------------------------

        bool threaded_object::
        should_respawn (
        ) const
        {
            auto_mutex M(m_);

            DLIB_ASSERT(id1 != get_thread_id() || id_valid == false,
                   "\tbool threaded_object::should_respawn()"
                   << "\n\tYou can NOT call this function from the thread that executes threaded_object::thread"
                   << "\n\tthis: " << this
            );

            return should_respawn_;
        }

    // ----------------------------------------------------------------------------------------

        void threaded_object::
        pause (
        )
        {
            auto_mutex M(m_);

            DLIB_ASSERT(id1 != get_thread_id() || id_valid == false,
                   "\tvoid threaded_object::pause()"
                   << "\n\tYou can NOT call this function from the thread that executes threaded_object::thread"
                   << "\n\tthis: " << this
            );

            is_running_ = false;
        }

    // ----------------------------------------------------------------------------------------

        void threaded_object::
        stop (
        )
        {
            auto_mutex M(m_);

            DLIB_ASSERT(id1 != get_thread_id() || id_valid == false,
                   "\tvoid threaded_object::stop()"
                   << "\n\tYou can NOT call this function from the thread that executes threaded_object::thread"
                   << "\n\tthis: " << this
            );

            should_stop_ = true;
            is_running_ = false;
            should_respawn_ = false;
            s.broadcast();
        }

    // ----------------------------------------------------------------------------------------

        bool threaded_object::
        should_stop (
        ) const
        {
            auto_mutex M(m_);
            DLIB_ASSERT(is_alive_ && id1 == get_thread_id() && id_valid == true,
                   "\tbool threaded_object::should_stop()"
                   << "\n\tYou can only call this function from the thread that executes threaded_object::thread"
                   << "\n\tthis: " << this
            );
            while (is_running_ == false && should_stop_ == false)
                s.wait();
            return should_stop_;
        }

    // ----------------------------------------------------------------------------------------

        void threaded_object::
        thread_helper(
        )
        {
    #ifdef ENABLE_ASSERTS
            id1 = get_thread_id();
            id_valid = true;
    #endif
            while (true)
            {
                m_.lock();
                should_respawn_ = false;
                m_.unlock();

                thread();

                auto_mutex M(m_);

                if (should_respawn_)
                    continue;

    #ifdef ENABLE_ASSERTS
                id_valid = false;
    #endif

                is_alive_ = false;
                is_running_ = false;
                should_stop_ = false;
                s.broadcast();

                return;
            }
        }

    // ----------------------------------------------------------------------------------------

    }

    #endif // DLIB_THREADED_OBJECT_EXTENSIOn_CPP