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// Copyright 2014 Citra Emulator Project / PPSSPP Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <algorithm>
#include <cinttypes>
#include <optional>
#include <vector>
#include "common/assert.h"
#include "common/common_types.h"
#include "common/logging/log.h"
#include "common/thread_queue_list.h"
#include "core/arm/arm_interface.h"
#include "core/core.h"
#include "core/core_cpu.h"
#include "core/core_timing.h"
#include "core/core_timing_util.h"
#include "core/hle/kernel/errors.h"
#include "core/hle/kernel/handle_table.h"
#include "core/hle/kernel/kernel.h"
#include "core/hle/kernel/object.h"
#include "core/hle/kernel/process.h"
#include "core/hle/kernel/scheduler.h"
#include "core/hle/kernel/thread.h"
#include "core/hle/result.h"
#include "core/memory.h"
namespace Kernel {
bool Thread::ShouldWait(const Thread* thread) const {
return status != ThreadStatus::Dead;
}
void Thread::Acquire(Thread* thread) {
ASSERT_MSG(!ShouldWait(thread), "object unavailable!");
}
Thread::Thread(KernelCore& kernel) : WaitObject{kernel} {}
Thread::~Thread() = default;
void Thread::Stop() {
// Cancel any outstanding wakeup events for this thread
Core::System::GetInstance().CoreTiming().UnscheduleEvent(kernel.ThreadWakeupCallbackEventType(),
callback_handle);
kernel.ThreadWakeupCallbackHandleTable().Close(callback_handle);
callback_handle = 0;
SetStatus(ThreadStatus::Dead);
WakeupAllWaitingThreads();
// Clean up any dangling references in objects that this thread was waiting for
for (auto& wait_object : wait_objects) {
wait_object->RemoveWaitingThread(this);
}
wait_objects.clear();
owner_process->UnregisterThread(this);
// Mark the TLS slot in the thread's page as free.
owner_process->FreeTLSRegion(tls_address);
}
void Thread::WakeAfterDelay(s64 nanoseconds) {
// Don't schedule a wakeup if the thread wants to wait forever
if (nanoseconds == -1)
return;
// This function might be called from any thread so we have to be cautious and use the
// thread-safe version of ScheduleEvent.
const s64 cycles = Core::Timing::nsToCycles(std::chrono::nanoseconds{nanoseconds});
Core::System::GetInstance().CoreTiming().ScheduleEvent(
cycles, kernel.ThreadWakeupCallbackEventType(), callback_handle);
}
void Thread::CancelWakeupTimer() {
Core::System::GetInstance().CoreTiming().UnscheduleEvent(kernel.ThreadWakeupCallbackEventType(),
callback_handle);
}
static std::optional<s32> GetNextProcessorId(u64 mask) {
for (s32 index = 0; index < Core::NUM_CPU_CORES; ++index) {
if (mask & (1ULL << index)) {
if (!Core::System::GetInstance().Scheduler(index).GetCurrentThread()) {
// Core is enabled and not running any threads, use this one
return index;
}
}
}
return {};
}
void Thread::ResumeFromWait() {
ASSERT_MSG(wait_objects.empty(), "Thread is waking up while waiting for objects");
switch (status) {
case ThreadStatus::WaitSynch:
case ThreadStatus::WaitHLEEvent:
case ThreadStatus::WaitSleep:
case ThreadStatus::WaitIPC:
case ThreadStatus::WaitMutex:
case ThreadStatus::WaitCondVar:
case ThreadStatus::WaitArb:
break;
case ThreadStatus::Ready:
// The thread's wakeup callback must have already been cleared when the thread was first
// awoken.
ASSERT(wakeup_callback == nullptr);
// If the thread is waiting on multiple wait objects, it might be awoken more than once
// before actually resuming. We can ignore subsequent wakeups if the thread status has
// already been set to ThreadStatus::Ready.
return;
case ThreadStatus::Running:
DEBUG_ASSERT_MSG(false, "Thread with object id {} has already resumed.", GetObjectId());
return;
case ThreadStatus::Dead:
// This should never happen, as threads must complete before being stopped.
DEBUG_ASSERT_MSG(false, "Thread with object id {} cannot be resumed because it's DEAD.",
GetObjectId());
return;
}
wakeup_callback = nullptr;
if (activity == ThreadActivity::Paused) {
SetStatus(ThreadStatus::Paused);
return;
}
SetStatus(ThreadStatus::Ready);
}
void Thread::CancelWait() {
if (GetSchedulingStatus() != ThreadSchedStatus::Paused) {
is_sync_cancelled = true;
return;
}
is_sync_cancelled = false;
SetWaitSynchronizationResult(ERR_SYNCHRONIZATION_CANCELED);
ResumeFromWait();
}
/**
* Resets a thread context, making it ready to be scheduled and run by the CPU
* @param context Thread context to reset
* @param stack_top Address of the top of the stack
* @param entry_point Address of entry point for execution
* @param arg User argument for thread
*/
static void ResetThreadContext(Core::ARM_Interface::ThreadContext& context, VAddr stack_top,
VAddr entry_point, u64 arg) {
context = {};
context.cpu_registers[0] = arg;
context.pc = entry_point;
context.sp = stack_top;
// TODO(merry): Perform a hardware test to determine the below value.
// AHP = 0, DN = 1, FTZ = 1, RMode = Round towards zero
context.fpcr = 0x03C00000;
}
ResultVal<SharedPtr<Thread>> Thread::Create(KernelCore& kernel, std::string name, VAddr entry_point,
u32 priority, u64 arg, s32 processor_id,
VAddr stack_top, Process& owner_process) {
// Check if priority is in ranged. Lowest priority -> highest priority id.
if (priority > THREADPRIO_LOWEST) {
LOG_ERROR(Kernel_SVC, "Invalid thread priority: {}", priority);
return ERR_INVALID_THREAD_PRIORITY;
}
if (processor_id > THREADPROCESSORID_MAX) {
LOG_ERROR(Kernel_SVC, "Invalid processor id: {}", processor_id);
return ERR_INVALID_PROCESSOR_ID;
}
if (!Memory::IsValidVirtualAddress(owner_process, entry_point)) {
LOG_ERROR(Kernel_SVC, "(name={}): invalid entry {:016X}", name, entry_point);
// TODO (bunnei): Find the correct error code to use here
return ResultCode(-1);
}
auto& system = Core::System::GetInstance();
SharedPtr<Thread> thread(new Thread(kernel));
thread->thread_id = kernel.CreateNewThreadID();
thread->status = ThreadStatus::Dormant;
thread->entry_point = entry_point;
thread->stack_top = stack_top;
thread->tpidr_el0 = 0;
thread->nominal_priority = thread->current_priority = priority;
thread->last_running_ticks = system.CoreTiming().GetTicks();
thread->processor_id = processor_id;
thread->ideal_core = processor_id;
thread->affinity_mask = 1ULL << processor_id;
thread->wait_objects.clear();
thread->mutex_wait_address = 0;
thread->condvar_wait_address = 0;
thread->wait_handle = 0;
thread->name = std::move(name);
thread->callback_handle = kernel.ThreadWakeupCallbackHandleTable().Create(thread).Unwrap();
thread->owner_process = &owner_process;
auto& scheduler = kernel.GlobalScheduler();
scheduler.AddThread(thread);
thread->tls_address = thread->owner_process->CreateTLSRegion();
thread->owner_process->RegisterThread(thread.get());
// TODO(peachum): move to ScheduleThread() when scheduler is added so selected core is used
// to initialize the context
ResetThreadContext(thread->context, stack_top, entry_point, arg);
return MakeResult<SharedPtr<Thread>>(std::move(thread));
}
void Thread::SetPriority(u32 priority) {
ASSERT_MSG(priority <= THREADPRIO_LOWEST && priority >= THREADPRIO_HIGHEST,
"Invalid priority value.");
nominal_priority = priority;
UpdatePriority();
}
void Thread::SetWaitSynchronizationResult(ResultCode result) {
context.cpu_registers[0] = result.raw;
}
void Thread::SetWaitSynchronizationOutput(s32 output) {
context.cpu_registers[1] = output;
}
s32 Thread::GetWaitObjectIndex(const WaitObject* object) const {
ASSERT_MSG(!wait_objects.empty(), "Thread is not waiting for anything");
const auto match = std::find(wait_objects.rbegin(), wait_objects.rend(), object);
return static_cast<s32>(std::distance(match, wait_objects.rend()) - 1);
}
VAddr Thread::GetCommandBufferAddress() const {
// Offset from the start of TLS at which the IPC command buffer begins.
constexpr u64 command_header_offset = 0x80;
return GetTLSAddress() + command_header_offset;
}
void Thread::SetStatus(ThreadStatus new_status) {
if (new_status == status) {
return;
}
switch (new_status) {
case ThreadStatus::Ready:
case ThreadStatus::Running:
SetSchedulingStatus(ThreadSchedStatus::Runnable);
break;
case ThreadStatus::Dormant:
SetSchedulingStatus(ThreadSchedStatus::None);
break;
case ThreadStatus::Dead:
SetSchedulingStatus(ThreadSchedStatus::Exited);
break;
default:
SetSchedulingStatus(ThreadSchedStatus::Paused);
break;
}
if (status == ThreadStatus::Running) {
last_running_ticks = Core::System::GetInstance().CoreTiming().GetTicks();
}
status = new_status;
}
void Thread::AddMutexWaiter(SharedPtr<Thread> thread) {
if (thread->lock_owner == this) {
// If the thread is already waiting for this thread to release the mutex, ensure that the
// waiters list is consistent and return without doing anything.
const auto iter = std::find(wait_mutex_threads.begin(), wait_mutex_threads.end(), thread);
ASSERT(iter != wait_mutex_threads.end());
return;
}
// A thread can't wait on two different mutexes at the same time.
ASSERT(thread->lock_owner == nullptr);
// Ensure that the thread is not already in the list of mutex waiters
const auto iter = std::find(wait_mutex_threads.begin(), wait_mutex_threads.end(), thread);
ASSERT(iter == wait_mutex_threads.end());
// Keep the list in an ordered fashion
const auto insertion_point = std::find_if(
wait_mutex_threads.begin(), wait_mutex_threads.end(),
[&thread](const auto& entry) { return entry->GetPriority() > thread->GetPriority(); });
wait_mutex_threads.insert(insertion_point, thread);
thread->lock_owner = this;
UpdatePriority();
}
void Thread::RemoveMutexWaiter(SharedPtr<Thread> thread) {
ASSERT(thread->lock_owner == this);
// Ensure that the thread is in the list of mutex waiters
const auto iter = std::find(wait_mutex_threads.begin(), wait_mutex_threads.end(), thread);
ASSERT(iter != wait_mutex_threads.end());
wait_mutex_threads.erase(iter);
thread->lock_owner = nullptr;
UpdatePriority();
}
void Thread::UpdatePriority() {
// If any of the threads waiting on the mutex have a higher priority
// (taking into account priority inheritance), then this thread inherits
// that thread's priority.
u32 new_priority = nominal_priority;
if (!wait_mutex_threads.empty()) {
if (wait_mutex_threads.front()->current_priority < new_priority) {
new_priority = wait_mutex_threads.front()->current_priority;
}
}
if (new_priority == current_priority) {
return;
}
SetCurrentPriority(new_priority);
if (!lock_owner) {
return;
}
// Ensure that the thread is within the correct location in the waiting list.
auto old_owner = lock_owner;
lock_owner->RemoveMutexWaiter(this);
old_owner->AddMutexWaiter(this);
// Recursively update the priority of the thread that depends on the priority of this one.
lock_owner->UpdatePriority();
}
void Thread::ChangeCore(u32 core, u64 mask) {
SetCoreAndAffinityMask(core, mask);
}
bool Thread::AllWaitObjectsReady() const {
return std::none_of(
wait_objects.begin(), wait_objects.end(),
[this](const SharedPtr<WaitObject>& object) { return object->ShouldWait(this); });
}
bool Thread::InvokeWakeupCallback(ThreadWakeupReason reason, SharedPtr<Thread> thread,
SharedPtr<WaitObject> object, std::size_t index) {
ASSERT(wakeup_callback);
return wakeup_callback(reason, std::move(thread), std::move(object), index);
}
void Thread::SetActivity(ThreadActivity value) {
activity = value;
if (value == ThreadActivity::Paused) {
// Set status if not waiting
if (status == ThreadStatus::Ready || status == ThreadStatus::Running) {
SetStatus(ThreadStatus::Paused);
Core::System::GetInstance().CpuCore(processor_id).PrepareReschedule();
}
} else if (status == ThreadStatus::Paused) {
// Ready to reschedule
ResumeFromWait();
}
}
void Thread::Sleep(s64 nanoseconds) {
// Sleep current thread and check for next thread to schedule
SetStatus(ThreadStatus::WaitSleep);
// Create an event to wake the thread up after the specified nanosecond delay has passed
WakeAfterDelay(nanoseconds);
}
bool Thread::YieldSimple() {
auto& scheduler = kernel.GlobalScheduler();
return scheduler.YieldThread(this);
}
bool Thread::YieldAndBalanceLoad() {
auto& scheduler = kernel.GlobalScheduler();
return scheduler.YieldThreadAndBalanceLoad(this);
}
bool Thread::YieldAndWaitForLoadBalancing() {
auto& scheduler = kernel.GlobalScheduler();
return scheduler.YieldThreadAndWaitForLoadBalancing(this);
}
void Thread::SetSchedulingStatus(ThreadSchedStatus new_status) {
const u32 old_flags = scheduling_state;
scheduling_state = (scheduling_state & static_cast<u32>(ThreadSchedMasks::HighMask)) |
static_cast<u32>(new_status);
AdjustSchedulingOnStatus(old_flags);
}
void Thread::SetCurrentPriority(u32 new_priority) {
const u32 old_priority = std::exchange(current_priority, new_priority);
AdjustSchedulingOnPriority(old_priority);
}
ResultCode Thread::SetCoreAndAffinityMask(s32 new_core, u64 new_affinity_mask) {
const auto HighestSetCore = [](u64 mask, u32 max_cores) {
for (s32 core = max_cores - 1; core >= 0; core--) {
if (((mask >> core) & 1) != 0) {
return core;
}
}
return -1;
};
const bool use_override = affinity_override_count != 0;
if (new_core == THREADPROCESSORID_DONT_UPDATE) {
new_core = use_override ? ideal_core_override : ideal_core;
if ((new_affinity_mask & (1ULL << new_core)) == 0) {
return ERR_INVALID_COMBINATION;
}
}
if (use_override) {
ideal_core_override = new_core;
affinity_mask_override = new_affinity_mask;
} else {
const u64 old_affinity_mask = std::exchange(affinity_mask, new_affinity_mask);
ideal_core = new_core;
if (old_affinity_mask != new_affinity_mask) {
const s32 old_core = processor_id;
if (processor_id >= 0 && ((affinity_mask >> processor_id) & 1) == 0) {
if (ideal_core < 0) {
processor_id = HighestSetCore(affinity_mask, GlobalScheduler::NUM_CPU_CORES);
} else {
processor_id = ideal_core;
}
}
AdjustSchedulingOnAffinity(old_affinity_mask, old_core);
}
}
return RESULT_SUCCESS;
}
void Thread::AdjustSchedulingOnStatus(u32 old_flags) {
if (old_flags == scheduling_state) {
return;
}
auto& scheduler = kernel.GlobalScheduler();
if (static_cast<ThreadSchedStatus>(old_flags & static_cast<u32>(ThreadSchedMasks::LowMask)) ==
ThreadSchedStatus::Runnable) {
// In this case the thread was running, now it's pausing/exitting
if (processor_id >= 0) {
scheduler.Unschedule(current_priority, processor_id, this);
}
for (s32 core = 0; core < GlobalScheduler::NUM_CPU_CORES; core++) {
if (core != processor_id && ((affinity_mask >> core) & 1) != 0) {
scheduler.Unsuggest(current_priority, static_cast<u32>(core), this);
}
}
} else if (GetSchedulingStatus() == ThreadSchedStatus::Runnable) {
// The thread is now set to running from being stopped
if (processor_id >= 0) {
scheduler.Schedule(current_priority, processor_id, this);
}
for (s32 core = 0; core < GlobalScheduler::NUM_CPU_CORES; core++) {
if (core != processor_id && ((affinity_mask >> core) & 1) != 0) {
scheduler.Suggest(current_priority, static_cast<u32>(core), this);
}
}
}
scheduler.SetReselectionPending();
}
void Thread::AdjustSchedulingOnPriority(u32 old_priority) {
if (GetSchedulingStatus() != ThreadSchedStatus::Runnable) {
return;
}
auto& scheduler = Core::System::GetInstance().GlobalScheduler();
if (processor_id >= 0) {
scheduler.Unschedule(old_priority, processor_id, this);
}
for (u32 core = 0; core < GlobalScheduler::NUM_CPU_CORES; core++) {
if (core != processor_id && ((affinity_mask >> core) & 1) != 0) {
scheduler.Unsuggest(old_priority, core, this);
}
}
// Add thread to the new priority queues.
Thread* current_thread = GetCurrentThread();
if (processor_id >= 0) {
if (current_thread == this) {
scheduler.SchedulePrepend(current_priority, processor_id, this);
} else {
scheduler.Schedule(current_priority, processor_id, this);
}
}
for (u32 core = 0; core < GlobalScheduler::NUM_CPU_CORES; core++) {
if (core != processor_id && ((affinity_mask >> core) & 1) != 0) {
scheduler.Suggest(current_priority, core, this);
}
}
scheduler.SetReselectionPending();
}
void Thread::AdjustSchedulingOnAffinity(u64 old_affinity_mask, s32 old_core) {
auto& scheduler = Core::System::GetInstance().GlobalScheduler();
if (GetSchedulingStatus() != ThreadSchedStatus::Runnable ||
current_priority >= THREADPRIO_COUNT) {
return;
}
for (u32 core = 0; core < GlobalScheduler::NUM_CPU_CORES; core++) {
if (((old_affinity_mask >> core) & 1) != 0) {
if (core == old_core) {
scheduler.Unschedule(current_priority, core, this);
} else {
scheduler.Unsuggest(current_priority, core, this);
}
}
}
for (u32 core = 0; core < GlobalScheduler::NUM_CPU_CORES; core++) {
if (((affinity_mask >> core) & 1) != 0) {
if (core == processor_id) {
scheduler.Schedule(current_priority, core, this);
} else {
scheduler.Suggest(current_priority, core, this);
}
}
}
scheduler.SetReselectionPending();
}
////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Gets the current thread
*/
Thread* GetCurrentThread() {
return Core::System::GetInstance().CurrentScheduler().GetCurrentThread();
}
} // namespace Kernel
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