dbus-cplusplus/include/dbus-c++/dispatcher.h

/*
 *
 *  D-Bus++ - C++ bindings for D-Bus
 *
 *  Copyright (C) 2005-2007  Paolo Durante <shackan@gmail.com>
 *
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */


#ifndef __DBUSXX_DISPATCHER_H
#define __DBUSXX_DISPATCHER_H

#include "api.h"
#include "connection.h"
#include "eventloop.h"

namespace DBus
{

class DXXAPI Timeout
{
public:

  class Internal;

  Timeout(Internal *i);

  virtual ~Timeout() {}

  /*!
   * \brief Gets the timeout interval.
   *
   * The handle() should be called each time this interval elapses,
   * starting after it elapses once.
   *
   * The interval may change during the life of the timeout; if so, the timeout
   * will be disabled and re-enabled (calling the "timeout toggled function") to
   * notify you of the change.
   *
   * return The interval in miliseconds.
   */
  int interval() const;

  bool enabled() const;

  /*!
   * \brief Calls the timeout handler for this timeout.
   *
   * This function should be called when the timeout occurs.
   *
   * If this function returns FALSE, then there wasn't enough memory to handle
   * the timeout. Typically just letting the timeout fire again next time it
   * naturally times out is an adequate response to that problem, but you could
   * try to do more if you wanted.
   *
   * return false If there wasn't enough memory.
   */
  bool handle();

  virtual void toggle() = 0;

private:

  DXXAPILOCAL Timeout(const Timeout &);

private:

  Internal *_int;
};

class DXXAPI Watch
{
public:

  class Internal;

  Watch(Internal *i);

  virtual ~Watch() {}

  /*!
   * \brief A main loop could poll this descriptor to integrate dbus-c++.
   *
   * This function calls dbus_watch_get_socket() on win32 and
   * dbus_watch_get_unix_fd() on all other systems. (see dbus documentation)
   *
   * @return The file descriptor.
   */
  int descriptor() const;

  /*!
   * \brief Gets flags from DBusWatchFlags indicating what conditions should be
   *        monitored on the file descriptor.
   *
   * The flags returned will only contain DBUS_WATCH_READABLE and DBUS_WATCH_WRITABLE,
   * never DBUS_WATCH_HANGUP or DBUS_WATCH_ERROR; all watches implicitly include
   * a watch for hangups, errors, and other exceptional conditions.
   *
   * @return The conditions to watch.
   */
  int flags() const;

  bool enabled() const;

  /*!
   * \brief Called to notify the D-Bus library when a previously-added watch
   *        is ready for reading or writing, or has an exception such as a hangup.
   *
   * If this function returns FALSE, then the file descriptor may still be
   * ready for reading or writing, but more memory is needed in order to do the
   * reading or writing. If you ignore the FALSE return, your application may
   * spin in a busy loop on the file descriptor until memory becomes available,
   * but nothing more catastrophic should happen.
   *
   * dbus_watch_handle() cannot be called during the DBusAddWatchFunction, as the
   * connection will not be ready to handle that watch yet.
   *
   * It is not allowed to reference a DBusWatch after it has been passed to remove_function.
   *
   * @param flags The poll condition using DBusWatchFlags values.
   * @return false If there wasn't enough memory.
   */
  bool handle(int flags);

  virtual void toggle() = 0;

private:

  DXXAPILOCAL Watch(const Watch &);

private:

  Internal *_int;
};

class DXXAPI Dispatcher
{
public:

  virtual ~Dispatcher()
  {}

  void queue_connection(Connection::Private *);

  void dispatch_pending();
  bool has_something_to_dispatch();

  virtual void enter() = 0;

  virtual void leave() = 0;

  virtual Timeout *add_timeout(Timeout::Internal *) = 0;

  virtual void rem_timeout(Timeout *) = 0;

  virtual Watch *add_watch(Watch::Internal *) = 0;

  virtual void rem_watch(Watch *) = 0;

  struct Private;

private:
  void dispatch_pending(Connection::PrivatePList &pending_queue);

  DefaultMutex _mutex_p;
  DefaultMutex _mutex_p_copy;

  Connection::PrivatePList _pending_queue;
};

extern DXXAPI Dispatcher *default_dispatcher;

/* classes for multithreading support
*/

class DXXAPI Mutex
{
public:

  virtual ~Mutex() {}

  virtual void lock() = 0;

  virtual void unlock() = 0;

  struct Internal;

protected:

  Internal *_int;
};

class DXXAPI CondVar
{
public:

  virtual ~CondVar() {}

  virtual void wait(Mutex *) = 0;

  virtual bool wait_timeout(Mutex *, int timeout) = 0;

  virtual void wake_one() = 0;

  virtual void wake_all() = 0;

  struct Internal;

protected:

  Internal *_int;
};

typedef Mutex *(*MutexNewFn)();
typedef void (*MutexUnlockFn)(Mutex *mx);

#ifndef DBUS_HAS_RECURSIVE_MUTEX
typedef bool (*MutexFreeFn)(Mutex *mx);
typedef bool (*MutexLockFn)(Mutex *mx);
#else
typedef void (*MutexFreeFn)(Mutex *mx);
typedef void (*MutexLockFn)(Mutex *mx);
#endif//DBUS_HAS_RECURSIVE_MUTEX

typedef CondVar *(*CondVarNewFn)();
typedef void (*CondVarFreeFn)(CondVar *cv);
typedef void (*CondVarWaitFn)(CondVar *cv, Mutex *mx);
typedef bool (*CondVarWaitTimeoutFn)(CondVar *cv, Mutex *mx, int timeout);
typedef void (*CondVarWakeOneFn)(CondVar *cv);
typedef void (*CondVarWakeAllFn)(CondVar *cv);

void DXXAPI _init_threading();

void DXXAPI _init_threading(
  MutexNewFn, MutexFreeFn, MutexLockFn, MutexUnlockFn,
  CondVarNewFn, CondVarFreeFn, CondVarWaitFn, CondVarWaitTimeoutFn, CondVarWakeOneFn, CondVarWakeAllFn
);

template<class Mx, class Cv>
struct Threading
{
  static void init()
  {
    _init_threading(
      mutex_new, mutex_free, mutex_lock, mutex_unlock,
      condvar_new, condvar_free, condvar_wait, condvar_wait_timeout, condvar_wake_one, condvar_wake_all
    );
  }

  static Mutex *mutex_new()
  {
    return new Mx;
  }

  static void mutex_free(Mutex *mx)
  {
    delete mx;
  }

  static void mutex_lock(Mutex *mx)
  {
    mx->lock();
  }

  static void mutex_unlock(Mutex *mx)
  {
    mx->unlock();
  }

  static CondVar *condvar_new()
  {
    return new Cv;
  }

  static void condvar_free(CondVar *cv)
  {
    delete cv;
  }

  static void condvar_wait(CondVar *cv, Mutex *mx)
  {
    cv->wait(mx);
  }

  static bool condvar_wait_timeout(CondVar *cv, Mutex *mx, int timeout)
  {
    return cv->wait_timeout(mx, timeout);
  }

  static void condvar_wake_one(CondVar *cv)
  {
    cv->wake_one();
  }

  static void condvar_wake_all(CondVar *cv)
  {
    cv->wake_all();
  }
};

} /* namespace DBus */

#endif//__DBUSXX_DISPATCHER_H