Atmosphere/libraries/libstratosphere/source/os/os_mutex.cpp
2020-04-08 02:21:35 -07:00

160 lines
4.7 KiB
C++

/*
* Copyright (c) 2018-2020 Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stratosphere.hpp>
#include "impl/os_thread_manager.hpp"
#include "impl/os_mutex_impl.hpp"
namespace ams::os {
namespace impl {
#ifdef ATMOSPHERE_BUILD_FOR_AUDITING
void PushAndCheckLockLevel(MutexType *mutex) {
/* If auditing isn't specified, don't bother. */
if (mutex->lock_level == 0) {
return;
}
/* TODO: Implement mutex level auditing. */
}
void PopAndCheckLockLevel(MutexType *mutex) {
/* If auditing isn't specified, don't bother. */
if (mutex->lock_level == 0) {
return;
}
/* TODO: Implement mutex level auditing. */
}
#else
void PushAndCheckLockLevel(MutexType *mutex) {
/* ... */
}
void PopAndCheckLockLevel(MutexType *mutex) {
/* ... */
}
#endif
}
namespace {
ALWAYS_INLINE void AfterLockMutex(MutexType *mutex, ThreadType *cur_thread) {
AMS_ASSERT(mutex->nest_count < MutexRecursiveLockCountMax);
impl::PushAndCheckLockLevel(mutex);
++mutex->nest_count;
mutex->owner_thread = cur_thread;
}
}
void InitializeMutex(MutexType *mutex, bool recursive, int lock_level) {
AMS_ASSERT((lock_level == 0) || (MutexLockLevelMin <= lock_level && lock_level <= MutexLockLevelMax));
/* Create object. */
new (GetPointer(mutex->_storage)) impl::InternalCriticalSection;
/* Set member variables. */
mutex->is_recursive = recursive;
mutex->lock_level = lock_level;
mutex->nest_count = 0;
mutex->owner_thread = nullptr;
/* Mark initialized. */
mutex->state = MutexType::State_Initialized;
}
void FinalizeMutex(MutexType *mutex) {
AMS_ASSERT(mutex->state == MutexType::State_Initialized);
/* Mark not intialized. */
mutex->state = MutexType::State_NotInitialized;
/* Destroy object. */
GetReference(mutex->_storage).~InternalCriticalSection();
}
void LockMutex(MutexType *mutex) {
AMS_ASSERT(mutex->state == MutexType::State_Initialized);
ThreadType *current = impl::GetCurrentThread();
if (!mutex->is_recursive) {
AMS_ASSERT(mutex->owner_thread != current);
GetReference(mutex->_storage).Enter();
} else {
if (mutex->owner_thread == current) {
AMS_ASSERT(mutex->nest_count >= 1);
} else {
GetReference(mutex->_storage).Enter();
}
}
AfterLockMutex(mutex, current);
}
bool TryLockMutex(MutexType *mutex) {
AMS_ASSERT(mutex->state == MutexType::State_Initialized);
ThreadType *current = impl::GetCurrentThread();
if (!mutex->is_recursive) {
AMS_ASSERT(mutex->owner_thread != current);
if (!GetReference(mutex->_storage).TryEnter()) {
return false;
}
} else {
if (mutex->owner_thread == current) {
AMS_ASSERT(mutex->nest_count >= 1);
} else {
if (!GetReference(mutex->_storage).TryEnter()) {
return false;
}
}
}
AfterLockMutex(mutex, current);
return true;
}
void UnlockMutex(MutexType *mutex) {
AMS_ASSERT(mutex->state == MutexType::State_Initialized);
AMS_ASSERT(mutex->nest_count > 0);
AMS_ASSERT(mutex->owner_thread == impl::GetCurrentThread());
impl::PopAndCheckLockLevel(mutex);
if ((--mutex->nest_count) == 0) {
mutex->owner_thread = nullptr;
GetReference(mutex->_storage).Leave();
}
}
bool IsMutexLockedByCurrentThread(const MutexType *mutex) {
AMS_ASSERT(mutex->state == MutexType::State_Initialized);
return mutex->owner_thread == impl::GetCurrentThread();
}
}