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kern: implement lightlock slowpath (works on hw)

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This commit is contained in:
Michael Scire 2020-02-14 15:27:34 -08:00
parent b3e6571586
commit 11f70759ce
7 changed files with 258 additions and 5 deletions
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70
libraries/libmesosphere/source/kern_k_light_lock.cpp
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@ -17,12 +17,74 @@
namespace ams::kern {
void KLightLock::LockSlowPath(uintptr_t owner, uintptr_t cur_thread) {
MESOSPHERE_TODO_IMPLEMENT();
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);
}
if (owner_thread->IsSuspended()) {
owner_thread->ContinueIfHasKernelWaiters();
}
}
/* 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) {
MESOSPHERE_TODO_IMPLEMENT();
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);
}
}
/* 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);
}
}
}