util: LockFreeAtomicType (for time)

This commit is contained in:
Michael Scire 2022-03-27 20:15:10 -07:00
parent c0d5140ef0
commit 8e258bde9d
2 changed files with 66 additions and 0 deletions

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@ -19,3 +19,4 @@
#include <stratosphere/util/util_compression.hpp> #include <stratosphere/util/util_compression.hpp>
#include <stratosphere/util/util_ini.hpp> #include <stratosphere/util/util_ini.hpp>
#include <stratosphere/util/util_singleton_traits.hpp> #include <stratosphere/util/util_singleton_traits.hpp>
#include <stratosphere/util/util_lock_free_atomic_type.hpp>

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@ -0,0 +1,65 @@
/*
* Copyright (c) Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <vapours.hpp>
#include <stratosphere/os/os_memory_fence_api.hpp>
namespace ams::util {
template<typename T>
struct LockFreeAtomicType {
volatile u32 _counter;
T _value[2];
};
template<typename T>
void StoreToLockFreeAtomicType(LockFreeAtomicType<T> *p, const T &value) {
/* Get the current counter. */
auto counter = p->_counter;
/* Increment the counter. */
++counter;
/* Store the updated value. */
p->_value[counter % 2] = value;
/* Fence memory. */
os::FenceMemoryStoreStore();
/* Set the updated counter. */
p->_counter = counter;
}
template<typename T>
T LoadFromLockFreeAtomicType(const LockFreeAtomicType<T> *p) {
while (true) {
/* Get the counter. */
auto counter = p->_counter;
/* Get the value. */
auto value = p->_value[counter % 2];
/* Fence memory. */
os::FenceMemoryLoadLoad();
/* Check that the counter matches. */
if (counter == p->_counter) {
return value;
}
}
}
}