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// Copyright 2014 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <map>
#include <vector>
#include <boost/range/algorithm_ext/erase.hpp>
#include "common/assert.h"
#include "core/core.h"
#include "core/hle/kernel/kernel.h"
#include "core/hle/kernel/mutex.h"
#include "core/hle/kernel/thread.h"
namespace Kernel {
void ReleaseThreadMutexes(Thread* thread) {
for (auto& mtx : thread->held_mutexes) {
mtx->lock_count = 0;
mtx->holding_thread = nullptr;
mtx->WakeupAllWaitingThreads();
}
thread->held_mutexes.clear();
}
Mutex::Mutex() {}
Mutex::~Mutex() {}
SharedPtr<Mutex> Mutex::Create(bool initial_locked, std::string name) {
SharedPtr<Mutex> mutex(new Mutex);
mutex->lock_count = 0;
mutex->name = std::move(name);
mutex->holding_thread = nullptr;
// Acquire mutex with current thread if initialized as locked
if (initial_locked)
mutex->Acquire(GetCurrentThread());
return mutex;
}
bool Mutex::ShouldWait(Thread* thread) const {
return lock_count > 0 && 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();
Core::System::GetInstance().PrepareReschedule();
}
lock_count++;
}
void Mutex::Release() {
// Only release if the mutex is held
if (lock_count > 0) {
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();
Core::System::GetInstance().PrepareReschedule();
}
}
}
void Mutex::AddWaitingThread(SharedPtr<Thread> thread) {
WaitObject::AddWaitingThread(thread);
thread->pending_mutexes.insert(this);
UpdatePriority();
}
void Mutex::RemoveWaitingThread(Thread* thread) {
WaitObject::RemoveWaitingThread(thread);
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
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