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Diffstat (limited to 'src/core/hle/kernel/mutex.cpp')
-rw-r--r-- | src/core/hle/kernel/mutex.cpp | 170 |
1 files changed, 0 insertions, 170 deletions
diff --git a/src/core/hle/kernel/mutex.cpp b/src/core/hle/kernel/mutex.cpp deleted file mode 100644 index 8a0faacf80..0000000000 --- a/src/core/hle/kernel/mutex.cpp +++ /dev/null @@ -1,170 +0,0 @@ -// Copyright 2014 Citra Emulator Project -// Licensed under GPLv2 or any later version -// Refer to the license.txt file included. - -#include <memory> -#include <utility> -#include <vector> - -#include "common/assert.h" -#include "common/logging/log.h" -#include "core/core.h" -#include "core/hle/kernel/errors.h" -#include "core/hle/kernel/handle_table.h" -#include "core/hle/kernel/k_scheduler.h" -#include "core/hle/kernel/kernel.h" -#include "core/hle/kernel/mutex.h" -#include "core/hle/kernel/object.h" -#include "core/hle/kernel/process.h" -#include "core/hle/kernel/thread.h" -#include "core/hle/result.h" -#include "core/memory.h" - -namespace Kernel { - -/// Returns the number of threads that are waiting for a mutex, and the highest priority one among -/// those. -static std::pair<std::shared_ptr<Thread>, u32> GetHighestPriorityMutexWaitingThread( - const std::shared_ptr<Thread>& current_thread, VAddr mutex_addr) { - - std::shared_ptr<Thread> highest_priority_thread; - u32 num_waiters = 0; - - for (const auto& thread : current_thread->GetMutexWaitingThreads()) { - if (thread->GetMutexWaitAddress() != mutex_addr) - continue; - - ++num_waiters; - if (highest_priority_thread == nullptr || - thread->GetPriority() < highest_priority_thread->GetPriority()) { - highest_priority_thread = thread; - } - } - - return {highest_priority_thread, num_waiters}; -} - -/// Update the mutex owner field of all threads waiting on the mutex to point to the new owner. -static void TransferMutexOwnership(VAddr mutex_addr, std::shared_ptr<Thread> current_thread, - std::shared_ptr<Thread> new_owner) { - current_thread->RemoveMutexWaiter(new_owner); - const auto threads = current_thread->GetMutexWaitingThreads(); - for (const auto& thread : threads) { - if (thread->GetMutexWaitAddress() != mutex_addr) - continue; - - ASSERT(thread->GetLockOwner() == current_thread.get()); - current_thread->RemoveMutexWaiter(thread); - if (new_owner != thread) - new_owner->AddMutexWaiter(thread); - } -} - -Mutex::Mutex(Core::System& system) : system{system} {} -Mutex::~Mutex() = default; - -ResultCode Mutex::TryAcquire(VAddr address, Handle holding_thread_handle, - Handle requesting_thread_handle) { - // The mutex address must be 4-byte aligned - if ((address % sizeof(u32)) != 0) { - LOG_ERROR(Kernel, "Address is not 4-byte aligned! address={:016X}", address); - return ERR_INVALID_ADDRESS; - } - - auto& kernel = system.Kernel(); - std::shared_ptr<Thread> current_thread = - SharedFrom(kernel.CurrentScheduler()->GetCurrentThread()); - { - KScopedSchedulerLock lock(kernel); - // The mutex address must be 4-byte aligned - if ((address % sizeof(u32)) != 0) { - return ERR_INVALID_ADDRESS; - } - - const auto& handle_table = kernel.CurrentProcess()->GetHandleTable(); - std::shared_ptr<Thread> holding_thread = handle_table.Get<Thread>(holding_thread_handle); - std::shared_ptr<Thread> requesting_thread = - handle_table.Get<Thread>(requesting_thread_handle); - - // TODO(Subv): It is currently unknown if it is possible to lock a mutex in behalf of - // another thread. - ASSERT(requesting_thread == current_thread); - - current_thread->SetSynchronizationResults(nullptr, RESULT_SUCCESS); - - const u32 addr_value = system.Memory().Read32(address); - - // If the mutex isn't being held, just return success. - if (addr_value != (holding_thread_handle | Mutex::MutexHasWaitersFlag)) { - return RESULT_SUCCESS; - } - - if (holding_thread == nullptr) { - return ERR_INVALID_HANDLE; - } - - // Wait until the mutex is released - current_thread->SetMutexWaitAddress(address); - current_thread->SetWaitHandle(requesting_thread_handle); - - current_thread->SetState(ThreadState::Waiting); - - // Update the lock holder thread's priority to prevent priority inversion. - holding_thread->AddMutexWaiter(current_thread); - } - - { - KScopedSchedulerLock lock(kernel); - auto* owner = current_thread->GetLockOwner(); - if (owner != nullptr) { - owner->RemoveMutexWaiter(current_thread); - } - } - return current_thread->GetSignalingResult(); -} - -std::pair<ResultCode, std::shared_ptr<Thread>> Mutex::Unlock(std::shared_ptr<Thread> owner, - VAddr address) { - // The mutex address must be 4-byte aligned - if ((address % sizeof(u32)) != 0) { - LOG_ERROR(Kernel, "Address is not 4-byte aligned! address={:016X}", address); - return {ERR_INVALID_ADDRESS, nullptr}; - } - - auto [new_owner, num_waiters] = GetHighestPriorityMutexWaitingThread(owner, address); - if (new_owner == nullptr) { - system.Memory().Write32(address, 0); - return {RESULT_SUCCESS, nullptr}; - } - // Transfer the ownership of the mutex from the previous owner to the new one. - TransferMutexOwnership(address, owner, new_owner); - u32 mutex_value = new_owner->GetWaitHandle(); - if (num_waiters >= 2) { - // Notify the guest that there are still some threads waiting for the mutex - mutex_value |= Mutex::MutexHasWaitersFlag; - } - new_owner->SetSynchronizationResults(nullptr, RESULT_SUCCESS); - new_owner->SetLockOwner(nullptr); - new_owner->Wakeup(); - - system.Memory().Write32(address, mutex_value); - return {RESULT_SUCCESS, new_owner}; -} - -ResultCode Mutex::Release(VAddr address) { - auto& kernel = system.Kernel(); - KScopedSchedulerLock lock(kernel); - - std::shared_ptr<Thread> current_thread = - SharedFrom(kernel.CurrentScheduler()->GetCurrentThread()); - - auto [result, new_owner] = Unlock(current_thread, address); - - if (result != RESULT_SUCCESS && new_owner != nullptr) { - new_owner->SetSynchronizationResults(nullptr, result); - } - - return result; -} - -} // namespace Kernel |