wanproxy/event/callback_queue.h
2015-08-31 14:01:44 +02:00

150 lines
3.9 KiB
C++

/*
* Copyright (c) 2010-2011 Juli Mallett. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef EVENT_CALLBACK_QUEUE_H
#define EVENT_CALLBACK_QUEUE_H
#include <deque>
#include <event/callback.h>
#include <event/action.h>
////////////////////////////////////////////////////////////////////////////////
// //
// File: callback_queue.h //
// Description: collection classes for event callback management //
// Project: WANProxy XTech //
// Adapted by: Andreu Vidal Bramfeld-Software //
// Last modified: 2015-04-01 //
// //
////////////////////////////////////////////////////////////////////////////////
class CallbackQueue
{
class QueuedAction : public Action
{
CallbackQueue& queue_;
uint64_t generation_;
Callback* callback_;
public:
QueuedAction (CallbackQueue& q, uint64_t g, Callback* cb)
: queue_(q),
generation_(g),
callback_(cb)
{
}
~QueuedAction ()
{
delete callback_;
}
virtual void cancel ()
{
cancelled_ = true;
queue_.cancel (this);
}
friend class CallbackQueue;
};
std::deque<QueuedAction*> queue_;
uint64_t generation_;
public:
CallbackQueue ()
: queue_(),
generation_(0)
{ }
~CallbackQueue ()
{
std::deque<QueuedAction*>::iterator it;
for (it = queue_.begin (); it != queue_.end (); ++it)
{
delete *it;
*it = 0;
}
}
Action* schedule (Callback* cb)
{
QueuedAction* a = new QueuedAction (*this, generation_, cb);
queue_.push_back (a);
return (a);
}
/*
* Runs all callbacks that have already been queued, but none that
* are added by callbacks that are called as part of the drain
* operation. Returns true if there are queued callbacks that were
* added during drain.
*/
bool drain (void)
{
generation_++;
while (! queue_.empty ())
{
QueuedAction* a = queue_.front ();
if (a->generation_ >= generation_)
return (true);
queue_.pop_front ();
if (a->callback_)
a->callback_->execute ();
}
return (false);
}
bool empty () const
{
return (queue_.empty ());
}
void perform ()
{
if (! queue_.empty ())
{
QueuedAction* a = queue_.front ();
if (a->callback_)
a->callback_->execute ();
}
}
void cancel (QueuedAction* a)
{
std::deque<QueuedAction*>::iterator it;
for (it = queue_.begin (); it != queue_.end (); ++it)
{
if (*it == a)
{
queue_.erase (it);
break;
}
}
delete a;
}
};
#endif /* !EVENT_CALLBACK_QUEUE_H */