diff options
Diffstat (limited to 'libs/pbd/pbd/atomic_counter.h')
-rw-r--r-- | libs/pbd/pbd/atomic_counter.h | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/libs/pbd/pbd/atomic_counter.h b/libs/pbd/pbd/atomic_counter.h new file mode 100644 index 0000000000..1e1998e1f1 --- /dev/null +++ b/libs/pbd/pbd/atomic_counter.h @@ -0,0 +1,99 @@ +/* + Copyright (C) 2010 Tim Mayberry + + 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. + +*/ + +#ifndef PBD_ATOMIC_COUNTER_H +#define PBD_ATOMIC_COUNTER_H + +#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(value) + { } + + gint get() const + { + return g_atomic_int_get (&m_value); + } + + void set (gint new_value) + { + g_atomic_int_set (&m_value, new_value); + } + + void increment () + { + g_atomic_int_inc (&m_value); + } + + void operator++ () + { + increment (); + } + + bool decrement_and_test () + { + return g_atomic_int_dec_and_test (&m_value); + } + + bool operator-- () + { + return decrement_and_test (); + } + + bool compare_and_exchange (gint old_value, gint new_value) + { + return g_atomic_int_compare_and_exchange + ( + &m_value, + 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: + + // Has to be mutable when using the apple version of gcc. + mutable volatile gint m_value; + +}; + +} // namespace PBD + +#endif // PBD_ATOMIC_COUNTER_H |