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Kernel: Properly keep track of mutex lock data in the guest memory. This fixes userland locking/unlocking.

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Subv 2018-01-08 14:12:03 -05:00 • committed by bunnei
parent 2a3f8e8484
commit 1bbe9309da
4 changed files with 63 additions and 67 deletions
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97
src/core/hle/kernel/mutex.cpp
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@ -17,8 +17,8 @@ namespace Kernel {
void ReleaseThreadMutexes(Thread* thread) {
for (auto& mtx : thread->held_mutexes) {
mtx->lock_count = 0;
mtx->holding_thread = nullptr;
mtx->SetHasWaiters(false);
mtx->SetHoldingThread(nullptr);
mtx->WakeupAllWaitingThreads();
}
thread->held_mutexes.clear();
@ -31,10 +31,8 @@ SharedPtr<Mutex> Mutex::Create(SharedPtr<Kernel::Thread> holding_thread, VAddr g
std::string name) {
SharedPtr<Mutex> mutex(new Mutex);
mutex->lock_count = 0;
mutex->guest_addr = guest_addr;
mutex->name = std::move(name);
mutex->holding_thread = nullptr;
// If mutex was initialized with a holding thread, acquire it by the holding thread
if (holding_thread) {
@ -51,56 +49,32 @@ SharedPtr<Mutex> Mutex::Create(SharedPtr<Kernel::Thread> holding_thread, VAddr g
}
bool Mutex::ShouldWait(Thread* thread) const {
return lock_count > 0 && thread != holding_thread;
auto holding_thread = GetHoldingThread();
return holding_thread != nullptr && thread != holding_thread;
}
void Mutex::Acquire(Thread* thread) {
ASSERT_MSG(!ShouldWait(thread), "object unavailable!");
// Actually "acquire" the mutex only if we don't already have it
if (lock_count == 0) {
priority = thread->current_priority;
thread->held_mutexes.insert(this);
holding_thread = thread;
thread->UpdatePriority();
UpdateGuestState();
Core::System::GetInstance().PrepareReschedule();
}
lock_count++;
priority = thread->current_priority;
thread->held_mutexes.insert(this);
SetHoldingThread(thread);
thread->UpdatePriority();
Core::System::GetInstance().PrepareReschedule();
}
ResultCode Mutex::Release(Thread* thread) {
auto holding_thread = GetHoldingThread();
ASSERT(holding_thread);
// We can only release the mutex if it's held by the calling thread.
if (thread != holding_thread) {
if (holding_thread) {
LOG_ERROR(
Kernel,
"Tried to release a mutex (owned by thread id %u) from a different thread id %u",
holding_thread->thread_id, thread->thread_id);
}
// TODO(bunnei): Use correct error code
return ResultCode(-1);
}
ASSERT(thread == holding_thread);
// Note: It should not be possible for the situation where the mutex has a holding thread with a
// zero lock count to occur. The real kernel still checks for this, so we do too.
if (lock_count <= 0) {
// TODO(bunnei): Use correct error code
return ResultCode(-1);
}
lock_count--;
// Yield to the next thread only if we've fully released the mutex
if (lock_count == 0) {
holding_thread->held_mutexes.erase(this);
holding_thread->UpdatePriority();
holding_thread = nullptr;
WakeupAllWaitingThreads();
UpdateGuestState();
Core::System::GetInstance().PrepareReschedule();
}
holding_thread->held_mutexes.erase(this);
holding_thread->UpdatePriority();
SetHoldingThread(nullptr);
WakeupAllWaitingThreads();
Core::System::GetInstance().PrepareReschedule();
return RESULT_SUCCESS;
}
@ -108,19 +82,20 @@ ResultCode Mutex::Release(Thread* thread) {
void Mutex::AddWaitingThread(SharedPtr<Thread> thread) {
WaitObject::AddWaitingThread(thread);
thread->pending_mutexes.insert(this);
SetHasWaiters(true);
UpdatePriority();
UpdateGuestState();
}
void Mutex::RemoveWaitingThread(Thread* thread) {
WaitObject::RemoveWaitingThread(thread);
thread->pending_mutexes.erase(this);
if (!GetHasWaiters())
SetHasWaiters(!GetWaitingThreads().empty());
UpdatePriority();
UpdateGuestState();
}
void Mutex::UpdatePriority() {
if (!holding_thread)
if (!GetHoldingThread())
return;
u32 best_priority = THREADPRIO_LOWEST;
@ -131,21 +106,35 @@ void Mutex::UpdatePriority() {
if (best_priority != priority) {
priority = best_priority;
holding_thread->UpdatePriority();
GetHoldingThread()->UpdatePriority();
}
}
void Mutex::UpdateGuestState() {
Handle Mutex::GetOwnerHandle() const {
GuestState guest_state{Memory::Read32(guest_addr)};
guest_state.has_waiters.Assign(!GetWaitingThreads().empty());
guest_state.holding_thread_handle.Assign(holding_thread ? holding_thread->guest_handle : 0);
return guest_state.holding_thread_handle;
}
SharedPtr<Thread> Mutex::GetHoldingThread() const {
GuestState guest_state{Memory::Read32(guest_addr)};
return g_handle_table.Get<Thread>(guest_state.holding_thread_handle);
}
void Mutex::SetHoldingThread(SharedPtr<Thread> thread) {
GuestState guest_state{Memory::Read32(guest_addr)};
guest_state.holding_thread_handle.Assign(thread ? thread->guest_handle : 0);
Memory::Write32(guest_addr, guest_state.raw);
}
void Mutex::VerifyGuestState() {
bool Mutex::GetHasWaiters() const {
GuestState guest_state{Memory::Read32(guest_addr)};
ASSERT(guest_state.has_waiters == !GetWaitingThreads().empty());
ASSERT(guest_state.holding_thread_handle == holding_thread->guest_handle);
return guest_state.has_waiters != 0;
}
void Mutex::SetHasWaiters(bool has_waiters) {
GuestState guest_state{Memory::Read32(guest_addr)};
guest_state.has_waiters.Assign(has_waiters ? 1 : 0);
Memory::Write32(guest_addr, guest_state.raw);
}
} // namespace Kernel