ardour/libs/pbd/pbd/atomic_counter.h

94 lines
1.9 KiB
C++

/*
* Copyright (C) 2010 Tim Mayberry <mojofunk@gmail.com>
* Copyright (C) 2013-2015 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.
*/
#ifndef PBD_ATOMIC_COUNTER_H
#define PBD_ATOMIC_COUNTER_H
#include <atomic>
#include <glib.h>
namespace PBD {
class atomic_counter
{
/**
* Prevent copying and assignment
*/
atomic_counter (const atomic_counter&);
atomic_counter& operator= (const atomic_counter&);
public:
atomic_counter (gint value = 0)
{
m_value.store (value);
}
gint get() const
{
return m_value.load ();
}
void set (gint new_value)
{
m_value.store (new_value);
}
void increment ()
{
m_value.fetch_add (1);
}
void operator++ ()
{
increment ();
}
bool decrement_and_test ()
{
return PBD::atomic_dec_and_test (m_value);
}
bool operator-- ()
{
return decrement_and_test ();
}
bool compare_and_exchange (gint old_value, gint new_value)
{
return m_value.compare_exchange_strong (old_value, new_value);
}
/**
* convenience method, \see compare_and_exchange
*/
bool cas (gint old_value, gint new_value)
{
return compare_and_exchange (old_value, new_value);
}
private:
mutable std::atomic<int> m_value;
};
} // namespace PBD
#endif // PBD_ATOMIC_COUNTER_H