mirror of
https://gitlab.com/sortix/sortix.git
synced 2023-02-13 20:55:38 -05:00
78 lines
2.1 KiB
C++
78 lines
2.1 KiB
C++
/*******************************************************************************
|
|
|
|
Copyright(C) Jonas 'Sortie' Termansen 2012, 2013.
|
|
|
|
This file is part of Sortix.
|
|
|
|
Sortix 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 3 of the License, or (at your option) any later
|
|
version.
|
|
|
|
Sortix 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
|
|
Sortix. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
interlock.cpp
|
|
Functions that perform non-atomic operations in an atomic manner.
|
|
|
|
*******************************************************************************/
|
|
|
|
#include <sortix/kernel/platform.h>
|
|
#include <sortix/kernel/interlock.h>
|
|
|
|
namespace Sortix {
|
|
|
|
// TODO: This is likely not the most optimal way to perform these operations.
|
|
|
|
ilret_t InterlockedModify(unsigned long* ptr,
|
|
ilockfunc f,
|
|
unsigned long user)
|
|
{
|
|
unsigned long old_value, new_value;
|
|
do
|
|
{
|
|
old_value = *((volatile unsigned long*) ptr); /* TODO: Need volatile? */
|
|
new_value = f(old_value, user);
|
|
} while ( !__sync_bool_compare_and_swap(ptr, old_value, new_value) );
|
|
ilret_t ret;
|
|
ret.o = old_value;
|
|
ret.n = new_value;
|
|
return ret;
|
|
}
|
|
|
|
static unsigned long AddFunction(unsigned long val, unsigned long arg)
|
|
{
|
|
return val + arg;
|
|
}
|
|
|
|
static unsigned long SubFunction(unsigned long val, unsigned long arg)
|
|
{
|
|
return val - arg;
|
|
}
|
|
|
|
ilret_t InterlockedIncrement(unsigned long* ptr)
|
|
{
|
|
return InterlockedModify(ptr, AddFunction, 1);
|
|
}
|
|
|
|
ilret_t InterlockedDecrement(unsigned long* ptr)
|
|
{
|
|
return InterlockedModify(ptr, SubFunction, 1);
|
|
}
|
|
|
|
ilret_t InterlockedAdd(unsigned long* ptr, unsigned long arg)
|
|
{
|
|
return InterlockedModify(ptr, AddFunction, arg);
|
|
}
|
|
|
|
ilret_t InterlockedSub(unsigned long* ptr, unsigned long arg)
|
|
{
|
|
return InterlockedModify(ptr, SubFunction, arg);
|
|
}
|
|
|
|
} // namespace Sortix
|