libs/pbd/pbd/selectable.h

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/*
 * Copyright (C) 1998-2013 Paul Davis <paul@linuxaudiosystems.com>
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
#pragma once
 
#include <list>
#include <string>
#include <stdio.h>
 
#include <sigc++/sigc++.h>
 
#include <sys/types.h>
 
#include "pbd/libpbd_visibility.h"
 
namespace Select {
    enum LIBPBD_API Condition {
                Readable = 0x1,
                Writable = 0x2,
                Exception = 0x4
    };
 
class LIBPBD_API Selectable : public sigc::trackable
 
{
  public:
        Selectable (int fd);
        Selectable (const std::string &, int flags, int mode = 0);
        Selectable (FILE *);
        ~Selectable ();
 
        sigc::signal<void,Selectable *,Select::Condition> readable;
        sigc::signal<void,Selectable *,Select::Condition> writable;
        sigc::signal<void,Selectable *,Select::Condition> exceptioned;
 
        int  fd() { return _fd; }
        bool ok() { return _ok; }
 
  protected:
        void selected (unsigned int condition);
        int condition;
        int _fd;
 
        friend class Selector;
 
  private:
        enum {
                fromFD,
                fromPath,
                fromFILE
        };
 
        bool _ok;
        int _type;
        std::string path;
};
 
class LIBPBD_API Selector {
  private:
        int post_select (fd_set *, fd_set *, fd_set *);
        int _max_fd;
 
        typedef std::list<Selectable *> Selectables;
        Selectables selectables;
        pthread_mutex_t list_lock;
 
        static bool use_list_lock;
 
  public:
        Selector ();
 
        void multithreaded (bool yn) {
                use_list_lock = yn;
        }
 
        void add (int condition, Selectable *s);
        void remove (Selectable *);
        int select (unsigned long usecs);
};
 
 
 
} /* namespace */