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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 <boost/range/algorithm_ext/erase.hpp>
#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(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;
// Clean up thread from ready queue
// This is only needed when the thread is terminated forcefully (SVC TerminateProcess)
if (status == ThreadStatus::Ready || status == ThreadStatus::Paused) {
scheduler->UnscheduleThread(this, current_priority);
}
status = 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();
// Mark the TLS slot in the thread's page as free.
owner_process->FreeTLSSlot(tls_address);
}
void ExitCurrentThread() {
Thread* thread = GetCurrentThread();
thread->Stop();
Core::System::GetInstance().CurrentScheduler().RemoveThread(thread);
}
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.
Core::System::GetInstance().CoreTiming().ScheduleEventThreadsafe(
Core::Timing::nsToCycles(nanoseconds), kernel.ThreadWakeupCallbackEventType(),
callback_handle);
}
void Thread::CancelWakeupTimer() {
Core::System::GetInstance().CoreTiming().UnscheduleEventThreadsafe(
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::WaitSynchAll:
case ThreadStatus::WaitSynchAny:
case ThreadStatus::WaitHLEEvent:
case ThreadStatus::WaitSleep:
case ThreadStatus::WaitIPC:
case ThreadStatus::WaitMutex:
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) {
status = ThreadStatus::Paused;
return;
}
status = ThreadStatus::Ready;
ChangeScheduler();
}
/**
* 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;
thread->scheduler = &system.Scheduler(processor_id);
thread->scheduler->AddThread(thread, priority);
thread->tls_address = thread->owner_process->MarkNextAvailableTLSSlotAsUsed(*thread);
// 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::BoostPriority(u32 priority) {
scheduler->SetThreadPriority(this, priority);
current_priority = priority;
}
void Thread::SetWaitSynchronizationResult(ResultCode result) {
context.cpu_registers[0] = result.raw;
}
void Thread::SetWaitSynchronizationOutput(s32 output) {
context.cpu_registers[1] = output;
}
s32 Thread::GetWaitObjectIndex(WaitObject* object) const {
ASSERT_MSG(!wait_objects.empty(), "Thread is not waiting for anything");
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.
static constexpr int CommandHeaderOffset = 0x80;
return GetTLSAddress() + CommandHeaderOffset;
}
void Thread::SetStatus(ThreadStatus new_status) {
if (new_status == status) {
return;
}
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.
auto itr = std::find(wait_mutex_threads.begin(), wait_mutex_threads.end(), thread);
ASSERT(itr != 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
auto itr = std::find(wait_mutex_threads.begin(), wait_mutex_threads.end(), thread);
ASSERT(itr == wait_mutex_threads.end());
thread->lock_owner = this;
wait_mutex_threads.emplace_back(std::move(thread));
UpdatePriority();
}
void Thread::RemoveMutexWaiter(SharedPtr<Thread> thread) {
ASSERT(thread->lock_owner == this);
// Ensure that the thread is in the list of mutex waiters
auto itr = std::find(wait_mutex_threads.begin(), wait_mutex_threads.end(), thread);
ASSERT(itr != wait_mutex_threads.end());
boost::remove_erase(wait_mutex_threads, thread);
thread->lock_owner = nullptr;
UpdatePriority();
}
void Thread::UpdatePriority() {
// Find the highest priority among all the threads that are waiting for this thread's lock
u32 new_priority = nominal_priority;
for (const auto& thread : wait_mutex_threads) {
if (thread->nominal_priority < new_priority)
new_priority = thread->nominal_priority;
}
if (new_priority == current_priority)
return;
scheduler->SetThreadPriority(this, new_priority);
current_priority = new_priority;
// Recursively update the priority of the thread that depends on the priority of this one.
if (lock_owner)
lock_owner->UpdatePriority();
}
void Thread::ChangeCore(u32 core, u64 mask) {
ideal_core = core;
affinity_mask = mask;
ChangeScheduler();
}
void Thread::ChangeScheduler() {
if (status != ThreadStatus::Ready) {
return;
}
auto& system = Core::System::GetInstance();
std::optional<s32> new_processor_id{GetNextProcessorId(affinity_mask)};
if (!new_processor_id) {
new_processor_id = processor_id;
}
if (ideal_core != -1 && system.Scheduler(ideal_core).GetCurrentThread() == nullptr) {
new_processor_id = ideal_core;
}
ASSERT(*new_processor_id < 4);
// Add thread to new core's scheduler
auto& next_scheduler = system.Scheduler(*new_processor_id);
if (*new_processor_id != processor_id) {
// Remove thread from previous core's scheduler
scheduler->RemoveThread(this);
next_scheduler.AddThread(this, current_priority);
}
processor_id = *new_processor_id;
// If the thread was ready, unschedule from the previous core and schedule on the new core
scheduler->UnscheduleThread(this, current_priority);
next_scheduler.ScheduleThread(this, current_priority);
// Change thread's scheduler
scheduler = &next_scheduler;
system.CpuCore(processor_id).PrepareReschedule();
}
bool Thread::AllWaitObjectsReady() {
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::Paused;
} else if (status == ThreadStatus::Running) {
status = 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);
}
////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Gets the current thread
*/
Thread* GetCurrentThread() {
return Core::System::GetInstance().CurrentScheduler().GetCurrentThread();
}
} // namespace Kernel
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