Mirrors/yuzu
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Kernel/Mutex: Propagate thread priority changes to other threads inheriting the priority via mutexes

Browse source
This commit is contained in:
Subv 2017-01-02 19:38:08 -05:00
parent b6a0355568
commit d3ff5b91e1
5 changed files with 60 additions and 42 deletions
Download patch file Download diff file Expand all files Collapse all files

60
src/core/hle/kernel/mutex.cpp
View file

@ -13,38 +13,6 @@
namespace Kernel {
/**
* Boost's a thread's priority to the best priority among the thread's held mutexes.
* This prevents priority inversion via priority inheritance.
*/
static void UpdateThreadPriority(Thread* thread) {
s32 best_priority = THREADPRIO_LOWEST;
for (auto& mutex : thread->held_mutexes) {
if (mutex->priority < best_priority)
best_priority = mutex->priority;
}
best_priority = std::min(best_priority, thread->nominal_priority);
thread->SetPriority(best_priority);
}
/**
* Elevate the mutex priority to the best priority
* among the priorities of all its waiting threads.
*/
static void UpdateMutexPriority(Mutex* mutex) {
s32 best_priority = THREADPRIO_LOWEST;
for (auto& waiter : mutex->GetWaitingThreads()) {
if (waiter->current_priority < best_priority)
best_priority = waiter->current_priority;
}
if (best_priority != mutex->priority) {
mutex->priority = best_priority;
UpdateThreadPriority(mutex->holding_thread.get());
}
}
void ReleaseThreadMutexes(Thread* thread) {
for (auto& mtx : thread->held_mutexes) {
mtx->lock_count = 0;
@ -83,9 +51,7 @@ void Mutex::Acquire(Thread* thread) {
priority = thread->current_priority;
thread->held_mutexes.insert(this);
holding_thread = thread;
UpdateThreadPriority(thread);
thread->UpdatePriority();
Core::System::GetInstance().PrepareReschedule();
}
@ -100,7 +66,7 @@ void Mutex::Release() {
// Yield to the next thread only if we've fully released the mutex
if (lock_count == 0) {
holding_thread->held_mutexes.erase(this);
UpdateThreadPriority(holding_thread.get());
holding_thread->UpdatePriority();
holding_thread = nullptr;
WakeupAllWaitingThreads();
Core::System::GetInstance().PrepareReschedule();
@ -110,12 +76,30 @@ void Mutex::Release() {
void Mutex::AddWaitingThread(SharedPtr<Thread> thread) {
WaitObject::AddWaitingThread(thread);
UpdateMutexPriority(this);
thread->pending_mutexes.insert(this);
UpdatePriority();
}
void Mutex::RemoveWaitingThread(Thread* thread) {
WaitObject::RemoveWaitingThread(thread);
UpdateMutexPriority(this);
thread->pending_mutexes.erase(this);
UpdatePriority();
}
void Mutex::UpdatePriority() {
if (!holding_thread)
return;
s32 best_priority = THREADPRIO_LOWEST;
for (auto& waiter : GetWaitingThreads()) {
if (waiter->current_priority < best_priority)
best_priority = waiter->current_priority;
}
if (best_priority != priority) {
priority = best_priority;
holding_thread->UpdatePriority();
}
}
} // namespace