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kern: KConditionVariable::SignalImpl

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This commit is contained in:
Michael Scire 2020-07-22 03:29:27 -07:00 • committed by SciresM
parent 7aa3120f60
commit 632a75eee7
4 changed files with 80 additions and 1 deletions
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50
libraries/libmesosphere/source/kern_k_condition_variable.cpp
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@ -29,6 +29,10 @@ namespace ams::kern {
return UserspaceAccess::CopyMemoryToUserSize32Bit(GetVoidPointer(address), p);
}
ALWAYS_INLINE bool UpdateLockAtomic(u32 *out, KProcessAddress address, u32 if_zero, u32 new_orr_mask) {
return UserspaceAccess::UpdateLockAtomic(out, GetPointer<u32>(address), if_zero, new_orr_mask);
}
}
Result KConditionVariable::SignalToAddress(KProcessAddress addr) {
@ -117,7 +121,51 @@ namespace ams::kern {
}
KThread *KConditionVariable::SignalImpl(KThread *thread) {
MESOSPHERE_UNIMPLEMENTED();
/* Check pre-conditions. */
MESOSPHERE_ASSERT(KScheduler::IsSchedulerLockedByCurrentThread());
/* Update the tag. */
KProcessAddress address = thread->GetAddressKey();
u32 own_tag = thread->GetAddressKeyValue();
u32 prev_tag;
bool can_access;
{
KScopedInterruptDisable di;
can_access = cpu::CanAccessAtomic(address);
if (AMS_LIKELY(can_access)) {
UpdateLockAtomic(std::addressof(prev_tag), address, own_tag, ams::svc::HandleWaitMask);
}
}
KThread *thread_to_close = nullptr;
if (AMS_LIKELY(can_access)) {
if (prev_tag == ams::svc::InvalidHandle) {
/* If nobody held the lock previously, we're all good. */
thread->SetSyncedObject(nullptr, ResultSuccess());
thread->Wakeup();
} else {
/* Get the previous owner. */
KThread *owner_thread = GetCurrentProcess().GetHandleTable().GetObjectWithoutPseudoHandle<KThread>(static_cast<ams::svc::Handle>(prev_tag & ~ams::svc::HandleWaitMask))
.ReleasePointerUnsafe();
if (AMS_LIKELY(owner_thread != nullptr)) {
/* Add the thread as a waiter on the owner. */
owner_thread->AddWaiter(thread);
thread_to_close = owner_thread;
} else {
/* The lock was tagged with a thread that doesn't exist. */
thread->SetSyncedObject(nullptr, svc::ResultInvalidState());
thread->Wakeup();
}
}
} else {
/* If the address wasn't accessible, note so. */
thread->SetSyncedObject(nullptr, svc::ResultInvalidCurrentMemory());
thread->Wakeup();
}
return thread_to_close;
}
void KConditionVariable::Signal(uintptr_t cv_key, s32 count) {