Atmosphere/libraries/libstratosphere/source/os/os_sdk_recursive_mutex.cpp

97 lines
3.7 KiB
C++

/*
* Copyright (c) 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>
#if !defined(AMS_OS_INTERNAL_CRITICAL_SECTION_IMPL_CAN_CHECK_LOCKED_BY_CURRENT_THREAD)
#include "impl/os_thread_manager.hpp"
#endif
namespace ams::os {
void InitializeSdkRecursiveMutex(SdkRecursiveMutexType *rmutex) {
/* Initialize the critical section. */
GetReference(rmutex->_storage).Initialize();
/* Set recursive count. */
rmutex->recursive_count = 0;
/* If the underlying critical section can't readily be checked, set owner thread. */
#if !defined(AMS_OS_INTERNAL_CRITICAL_SECTION_IMPL_CAN_CHECK_LOCKED_BY_CURRENT_THREAD)
rmutex->owner_thread = nullptr;
#endif
}
bool IsSdkRecursiveMutexLockedByCurrentThread(const SdkRecursiveMutexType *rmutex) {
#if defined(AMS_OS_INTERNAL_CRITICAL_SECTION_IMPL_CAN_CHECK_LOCKED_BY_CURRENT_THREAD)
/* Check whether the critical section is held. */
return GetReference(rmutex->_storage).IsLockedByCurrentThread();
#else
/* Check if the current thread is owner. */
return rmutex->owner_thread == os::impl::GetCurrentThread();
#endif
}
void LockSdkRecursiveMutex(SdkRecursiveMutexType *rmutex) {
/* If we don't hold the mutex, enter the critical section. */
if (!IsSdkRecursiveMutexLockedByCurrentThread(rmutex)) {
GetReference(rmutex->_storage).Enter();
/* If necessary, set owner thread. */
#if !defined(AMS_OS_INTERNAL_CRITICAL_SECTION_IMPL_CAN_CHECK_LOCKED_BY_CURRENT_THREAD)
rmutex->owner_thread = os::impl::GetCurrentThread();
#endif
}
/* Increment (and check) recursive count. */
++rmutex->recursive_count;
AMS_ABORT_UNLESS(rmutex->recursive_count != 0);
}
bool TryLockSdkRecursiveMutex(SdkRecursiveMutexType *rmutex) {
/* If we don't hold the mutex, try to enter the critical section. */
if (!IsSdkRecursiveMutexLockedByCurrentThread(rmutex)) {
if (!GetReference(rmutex->_storage).TryEnter()) {
return false;
}
/* If necessary, set owner thread. */
#if !defined(AMS_OS_INTERNAL_CRITICAL_SECTION_IMPL_CAN_CHECK_LOCKED_BY_CURRENT_THREAD)
rmutex->owner_thread = os::impl::GetCurrentThread();
#endif
}
/* Increment (and check) recursive count. */
++rmutex->recursive_count;
AMS_ABORT_UNLESS(rmutex->recursive_count != 0);
return true;
}
void UnlockSdkRecursiveMutex(SdkRecursiveMutexType *rmutex) {
/* Check pre-conditions. */
AMS_ABORT_UNLESS(IsSdkRecursiveMutexLockedByCurrentThread(rmutex));
/* Decrement recursive count, and leave critical section if we no longer hold the mutex. */
if ((--rmutex->recursive_count) == 0) {
/* If necessary, clear owner thread. */
#if !defined(AMS_OS_INTERNAL_CRITICAL_SECTION_IMPL_CAN_CHECK_LOCKED_BY_CURRENT_THREAD)
rmutex->owner_thread = nullptr;
#endif
GetReference(rmutex->_storage).Leave();
}
}
}