Kernel: Remove old and unused Mutex code.

This commit is contained in:
Subv 2018-04-20 14:42:29 -05:00
parent b18ccf9399
commit 5fdfbfe25a
4 changed files with 3 additions and 209 deletions

View file

@ -40,126 +40,6 @@ static std::pair<SharedPtr<Thread>, u32> GetHighestPriorityMutexWaitingThread(VA
return {highest_priority_thread, num_waiters}; return {highest_priority_thread, num_waiters};
} }
void ReleaseThreadMutexes(Thread* thread) {
for (auto& mtx : thread->held_mutexes) {
mtx->SetHasWaiters(false);
mtx->SetHoldingThread(nullptr);
mtx->WakeupAllWaitingThreads();
}
thread->held_mutexes.clear();
}
Mutex::Mutex() {}
Mutex::~Mutex() {}
SharedPtr<Mutex> Mutex::Create(SharedPtr<Kernel::Thread> holding_thread, VAddr guest_addr,
std::string name) {
SharedPtr<Mutex> mutex(new Mutex);
mutex->guest_addr = guest_addr;
mutex->name = std::move(name);
// If mutex was initialized with a holding thread, acquire it by the holding thread
if (holding_thread) {
mutex->Acquire(holding_thread.get());
}
// Mutexes are referenced by guest address, so track this in the kernel
g_object_address_table.Insert(guest_addr, mutex);
return mutex;
}
bool Mutex::ShouldWait(Thread* thread) const {
auto holding_thread = GetHoldingThread();
return holding_thread != nullptr && thread != holding_thread;
}
void Mutex::Acquire(Thread* thread) {
ASSERT_MSG(!ShouldWait(thread), "object unavailable!");
priority = thread->current_priority;
thread->held_mutexes.insert(this);
SetHoldingThread(thread);
thread->UpdatePriority();
Core::System::GetInstance().PrepareReschedule();
}
ResultCode Mutex::Release(Thread* thread) {
auto holding_thread = GetHoldingThread();
ASSERT(holding_thread);
// We can only release the mutex if it's held by the calling thread.
ASSERT(thread == holding_thread);
holding_thread->held_mutexes.erase(this);
holding_thread->UpdatePriority();
SetHoldingThread(nullptr);
SetHasWaiters(!GetWaitingThreads().empty());
WakeupAllWaitingThreads();
Core::System::GetInstance().PrepareReschedule();
return RESULT_SUCCESS;
}
void Mutex::AddWaitingThread(SharedPtr<Thread> thread) {
WaitObject::AddWaitingThread(thread);
thread->pending_mutexes.insert(this);
SetHasWaiters(true);
UpdatePriority();
}
void Mutex::RemoveWaitingThread(Thread* thread) {
WaitObject::RemoveWaitingThread(thread);
thread->pending_mutexes.erase(this);
if (!GetHasWaiters())
SetHasWaiters(!GetWaitingThreads().empty());
UpdatePriority();
}
void Mutex::UpdatePriority() {
if (!GetHoldingThread())
return;
u32 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;
GetHoldingThread()->UpdatePriority();
}
}
Handle Mutex::GetOwnerHandle() const {
GuestState guest_state{Memory::Read32(guest_addr)};
return guest_state.holding_thread_handle;
}
SharedPtr<Thread> Mutex::GetHoldingThread() const {
GuestState guest_state{Memory::Read32(guest_addr)};
return g_handle_table.Get<Thread>(guest_state.holding_thread_handle);
}
void Mutex::SetHoldingThread(SharedPtr<Thread> thread) {
GuestState guest_state{Memory::Read32(guest_addr)};
guest_state.holding_thread_handle.Assign(thread ? thread->guest_handle : 0);
Memory::Write32(guest_addr, guest_state.raw);
}
bool Mutex::GetHasWaiters() const {
GuestState guest_state{Memory::Read32(guest_addr)};
return guest_state.has_waiters != 0;
}
void Mutex::SetHasWaiters(bool has_waiters) {
GuestState guest_state{Memory::Read32(guest_addr)};
guest_state.has_waiters.Assign(has_waiters ? 1 : 0);
Memory::Write32(guest_addr, guest_state.raw);
}
ResultCode Mutex::TryAcquire(VAddr address, Handle holding_thread_handle, ResultCode Mutex::TryAcquire(VAddr address, Handle holding_thread_handle,
Handle requesting_thread_handle) { Handle requesting_thread_handle) {
// The mutex address must be 4-byte aligned // The mutex address must be 4-byte aligned

View file

@ -15,68 +15,8 @@ namespace Kernel {
class Thread; class Thread;
class Mutex final : public WaitObject { class Mutex final {
public: public:
/**
* Creates a mutex.
* @param holding_thread Specifies a thread already holding the mutex. If not nullptr, this
* thread will acquire the mutex.
* @param guest_addr Address of the object tracking the mutex in guest memory. If specified,
* this mutex will update the guest object when its state changes.
* @param name Optional name of mutex
* @return Pointer to new Mutex object
*/
static SharedPtr<Mutex> Create(SharedPtr<Kernel::Thread> holding_thread, VAddr guest_addr = 0,
std::string name = "Unknown");
std::string GetTypeName() const override {
return "Mutex";
}
std::string GetName() const override {
return name;
}
static const HandleType HANDLE_TYPE = HandleType::Mutex;
HandleType GetHandleType() const override {
return HANDLE_TYPE;
}
u32 priority; ///< The priority of the mutex, used for priority inheritance.
std::string name; ///< Name of mutex (optional)
VAddr guest_addr; ///< Address of the guest mutex value
/**
* Elevate the mutex priority to the best priority
* among the priorities of all its waiting threads.
*/
void UpdatePriority();
bool ShouldWait(Thread* thread) const override;
void Acquire(Thread* thread) override;
void AddWaitingThread(SharedPtr<Thread> thread) override;
void RemoveWaitingThread(Thread* thread) override;
/**
* Attempts to release the mutex from the specified thread.
* @param thread Thread that wants to release the mutex.
* @returns The result code of the operation.
*/
ResultCode Release(Thread* thread);
/// Gets the handle to the holding process stored in the guest state.
Handle GetOwnerHandle() const;
/// Gets the Thread pointed to by the owner handle
SharedPtr<Thread> GetHoldingThread() const;
/// Sets the holding process handle in the guest state.
void SetHoldingThread(SharedPtr<Thread> thread);
/// Returns the has_waiters bit in the guest state.
bool GetHasWaiters() const;
/// Sets the has_waiters bit in the guest state.
void SetHasWaiters(bool has_waiters);
/// Flag that indicates that a mutex still has threads waiting for it. /// Flag that indicates that a mutex still has threads waiting for it.
static constexpr u32 MutexHasWaitersFlag = 0x40000000; static constexpr u32 MutexHasWaitersFlag = 0x40000000;
/// Mask of the bits in a mutex address value that contain the mutex owner. /// Mask of the bits in a mutex address value that contain the mutex owner.
@ -90,24 +30,8 @@ public:
static ResultCode Release(VAddr address); static ResultCode Release(VAddr address);
private: private:
Mutex(); Mutex() = default;
~Mutex() override; ~Mutex() = default;
/// Object in guest memory used to track the mutex state
union GuestState {
u32_le raw;
/// Handle of the thread that currently holds the mutex, 0 if available
BitField<0, 30, u32_le> holding_thread_handle;
/// 1 when there are threads waiting for this mutex, otherwise 0
BitField<30, 1, u32_le> has_waiters;
};
static_assert(sizeof(GuestState) == 4, "GuestState size is incorrect");
}; };
/**
* Releases all the mutexes held by the specified thread
* @param thread Thread that is holding the mutexes
*/
void ReleaseThreadMutexes(Thread* thread);
} // namespace Kernel } // namespace Kernel

View file

@ -77,9 +77,6 @@ void Thread::Stop() {
} }
wait_objects.clear(); wait_objects.clear();
// Release all the mutexes that this thread holds
ReleaseThreadMutexes(this);
// Mark the TLS slot in the thread's page as free. // Mark the TLS slot in the thread's page as free.
u64 tls_page = (tls_address - Memory::TLS_AREA_VADDR) / Memory::PAGE_SIZE; u64 tls_page = (tls_address - Memory::TLS_AREA_VADDR) / Memory::PAGE_SIZE;
u64 tls_slot = u64 tls_slot =

View file

@ -55,7 +55,6 @@ enum class ThreadWakeupReason {
namespace Kernel { namespace Kernel {
class Mutex;
class Process; class Process;
class Thread final : public WaitObject { class Thread final : public WaitObject {
@ -206,12 +205,6 @@ public:
VAddr tls_address; ///< Virtual address of the Thread Local Storage of the thread VAddr tls_address; ///< Virtual address of the Thread Local Storage of the thread
/// Mutexes currently held by this thread, which will be released when it exits.
boost::container::flat_set<SharedPtr<Mutex>> held_mutexes;
/// Mutexes that this thread is currently waiting for.
boost::container::flat_set<SharedPtr<Mutex>> pending_mutexes;
SharedPtr<Process> owner_process; ///< Process that owns this thread SharedPtr<Process> owner_process; ///< Process that owns this thread
/// Objects that the thread is waiting on, in the same order as they were /// Objects that the thread is waiting on, in the same order as they were