mirror of
https://github.com/Atmosphere-NX/Atmosphere
synced 2024-12-15 20:32:28 +00:00
100 lines
3.6 KiB
C++
100 lines
3.6 KiB
C++
/*
|
|
* Copyright (c) 2018-2020 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/>.
|
|
*/
|
|
#include <mesosphere.hpp>
|
|
|
|
namespace ams::kern {
|
|
|
|
void KLightLock::LockSlowPath(uintptr_t _owner, uintptr_t _cur_thread) {
|
|
KThread *cur_thread = reinterpret_cast<KThread *>(_cur_thread);
|
|
|
|
/* Pend the current thread waiting on the owner thread. */
|
|
{
|
|
KScopedSchedulerLock sl;
|
|
|
|
/* Ensure we actually have locking to do. */
|
|
if (AMS_UNLIKELY(this->tag.load(std::memory_order_relaxed) != _owner)) {
|
|
return;
|
|
}
|
|
|
|
/* Add the current thread as a waiter on the owner. */
|
|
KThread *owner_thread = reinterpret_cast<KThread *>(_owner & ~1ul);
|
|
cur_thread->SetAddressKey(reinterpret_cast<uintptr_t>(std::addressof(this->tag)));
|
|
owner_thread->AddWaiter(cur_thread);
|
|
|
|
/* Set thread states. */
|
|
if (AMS_LIKELY(cur_thread->GetState() == KThread::ThreadState_Runnable)) {
|
|
cur_thread->SetState(KThread::ThreadState_Waiting);
|
|
} else {
|
|
KScheduler::SetSchedulerUpdateNeeded();
|
|
}
|
|
|
|
if (owner_thread->IsSuspended()) {
|
|
owner_thread->ContinueIfHasKernelWaiters();
|
|
KScheduler::SetSchedulerUpdateNeeded();
|
|
}
|
|
}
|
|
|
|
/* We're no longer waiting on the lock owner. */
|
|
{
|
|
KScopedSchedulerLock sl;
|
|
KThread *owner_thread = cur_thread->GetLockOwner();
|
|
if (AMS_UNLIKELY(owner_thread)) {
|
|
owner_thread->RemoveWaiter(cur_thread);
|
|
}
|
|
}
|
|
}
|
|
|
|
void KLightLock::UnlockSlowPath(uintptr_t _cur_thread) {
|
|
KThread *owner_thread = reinterpret_cast<KThread *>(_cur_thread);
|
|
|
|
/* Unlock. */
|
|
{
|
|
KScopedSchedulerLock sl;
|
|
|
|
/* Get the next owner. */
|
|
s32 num_waiters = 0;
|
|
KThread *next_owner = owner_thread->RemoveWaiterByKey(std::addressof(num_waiters), reinterpret_cast<uintptr_t>(std::addressof(this->tag)));
|
|
|
|
/* Pass the lock to the next owner. */
|
|
uintptr_t next_tag = 0;
|
|
if (next_owner) {
|
|
next_tag = reinterpret_cast<uintptr_t>(next_owner);
|
|
if (num_waiters > 1) {
|
|
next_tag |= 0x1;
|
|
}
|
|
|
|
if (AMS_LIKELY(next_owner->GetState() == KThread::ThreadState_Waiting)) {
|
|
next_owner->SetState(KThread::ThreadState_Runnable);
|
|
} else {
|
|
KScheduler::SetSchedulerUpdateNeeded();
|
|
}
|
|
|
|
if (next_owner->IsSuspended()) {
|
|
next_owner->ContinueIfHasKernelWaiters();
|
|
}
|
|
}
|
|
|
|
/* We may have unsuspended in the process of acquiring the lock, so we'll re-suspend now if so. */
|
|
if (owner_thread->IsSuspended()) {
|
|
owner_thread->TrySuspend();
|
|
}
|
|
|
|
/* Write the new tag value. */
|
|
this->tag.store(next_tag);
|
|
}
|
|
}
|
|
|
|
}
|