base_ui.cc

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/*
    Copyright (C) 2000-2007 Paul Davis 

    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 2 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, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

*/

#include <cstring>
#include <stdint.h>
#ifdef COMPILER_MSVC
#include <io.h>      // Microsoft's nearest equivalent to <unistd.h>
#else
#include <unistd.h>
#endif
#include <fcntl.h>
#include <cerrno>
#include <cstring>

#include "pbd/base_ui.h"
#include "pbd/debug.h"
#include "pbd/pthread_utils.h"
#include "pbd/error.h"
#include "pbd/compose.h"
#include "pbd/failed_constructor.h"

#include "i18n.h"

#include "pbd/debug.h"

using namespace std;
using namespace PBD;
using namespace Glib;
        
uint64_t BaseUI::rt_bit = 1;
BaseUI::RequestType BaseUI::CallSlot = BaseUI::new_request_type();
BaseUI::RequestType BaseUI::Quit = BaseUI::new_request_type();

BaseUI::BaseUI (const string& str)
        : m_context(MainContext::get_default())
        , run_loop_thread (0)
        , _name (str)
        , request_channel (true)
{
        base_ui_instance = this;
        request_channel.set_receive_handler (sigc::mem_fun (*this, &BaseUI::request_handler));

        /* derived class must set _ok */
}

BaseUI::~BaseUI()
{
}

BaseUI::RequestType
BaseUI::new_request_type ()
{
        RequestType rt;

        /* XXX catch out-of-range */

        rt = RequestType (rt_bit);
        rt_bit <<= 1;

        return rt;
}

void
BaseUI::main_thread ()
{
        DEBUG_TRACE (DEBUG::EventLoop, string_compose ("%1: event loop running in thread %2\n", name(), pthread_name()));
        set_event_loop_for_thread (this);
        thread_init ();
        _main_loop->get_context()->signal_idle().connect (sigc::mem_fun (*this, &BaseUI::signal_running));
        _main_loop->run ();
}

bool
BaseUI::signal_running ()
{
        Glib::Threads::Mutex::Lock lm (_run_lock);
        _running.signal ();
        
        return false; // don't call it again
}

void
BaseUI::run ()
{
        /* to be called by UI's that need/want their own distinct, self-created event loop thread.
        */

        m_context = MainContext::create();
        _main_loop = MainLoop::create (m_context);
        attach_request_source ();

        Glib::Threads::Mutex::Lock lm (_run_lock);
        run_loop_thread = Glib::Threads::Thread::create (mem_fun (*this, &BaseUI::main_thread));
        _running.wait (_run_lock);
}

void
BaseUI::quit ()
{
        if (_main_loop && _main_loop->is_running()) {
                _main_loop->quit ();
                run_loop_thread->join ();
        }
}

bool
BaseUI::request_handler (Glib::IOCondition ioc)
{
        /* check the request pipe */

        if (ioc & ~IO_IN) {
                _main_loop->quit ();
        }

        if (ioc & IO_IN) {
                request_channel.drain ();
                
                /* there may been an error. we'd rather handle requests first,
                   and then get IO_HUP or IO_ERR on the next loop.
                */

                /* handle requests */

                DEBUG_TRACE (DEBUG::EventLoop, "BaseUI::request_handler\n");
                handle_ui_requests ();
        }

        return true;
}

void
BaseUI::signal_new_request ()
{
        DEBUG_TRACE (DEBUG::EventLoop, "BaseUI::signal_new_request\n");
        request_channel.wakeup ();
}

void
BaseUI::attach_request_source ()
{
        DEBUG_TRACE (DEBUG::EventLoop, "BaseUI::attach_request_source\n");
        request_channel.attach (m_context);
}