yuzu/src/core/hle/kernel/thread.cpp
Subv 9cd87a6352 Kernel/Threads: A thread waking up by timeout from a WaitProcessWideKey may already have an assigned lock owner.
This situation may happen like so:
Thread 1 with low priority calls WaitProcessWideKey with timeout.
Thread 2 with high priority calls WaitProcessWideKey without timeout.
Thread 3 calls SignalProcessWideKey
- Thread 2 acquires the lock and awakens.
- Thread 1 can't acquire the lock and is put to sleep with the lock owner being Thread 2.
Thread 1's timeout expires, with the lock owner still being set to Thread 2.
2018-06-02 14:06:35 -05:00

524 lines
18 KiB
C++

// 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 <list>
#include <vector>
#include "common/assert.h"
#include "common/common_types.h"
#include "common/logging/log.h"
#include "common/math_util.h"
#include "common/thread_queue_list.h"
#include "core/arm/arm_interface.h"
#include "core/core.h"
#include "core/core_timing.h"
#include "core/hle/kernel/errors.h"
#include "core/hle/kernel/handle_table.h"
#include "core/hle/kernel/kernel.h"
#include "core/hle/kernel/memory.h"
#include "core/hle/kernel/mutex.h"
#include "core/hle/kernel/process.h"
#include "core/hle/kernel/thread.h"
#include "core/hle/result.h"
#include "core/memory.h"
namespace Kernel {
/// Event type for the thread wake up event
static CoreTiming::EventType* ThreadWakeupEventType = nullptr;
bool Thread::ShouldWait(Thread* thread) const {
return status != THREADSTATUS_DEAD;
}
void Thread::Acquire(Thread* thread) {
ASSERT_MSG(!ShouldWait(thread), "object unavailable!");
}
// TODO(yuriks): This can be removed if Thread objects are explicitly pooled in the future, allowing
// us to simply use a pool index or similar.
static Kernel::HandleTable wakeup_callback_handle_table;
// The first available thread id at startup
static u32 next_thread_id;
/**
* Creates a new thread ID
* @return The new thread ID
*/
inline static u32 const NewThreadId() {
return next_thread_id++;
}
Thread::Thread() {}
Thread::~Thread() {}
void Thread::Stop() {
// Cancel any outstanding wakeup events for this thread
CoreTiming::UnscheduleEvent(ThreadWakeupEventType, callback_handle);
wakeup_callback_handle_table.Close(callback_handle);
callback_handle = 0;
// Clean up thread from ready queue
// This is only needed when the thread is termintated forcefully (SVC TerminateProcess)
if (status == THREADSTATUS_READY) {
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.
u64 tls_page = (tls_address - Memory::TLS_AREA_VADDR) / Memory::PAGE_SIZE;
u64 tls_slot =
((tls_address - Memory::TLS_AREA_VADDR) % Memory::PAGE_SIZE) / Memory::TLS_ENTRY_SIZE;
Core::CurrentProcess()->tls_slots[tls_page].reset(tls_slot);
}
void WaitCurrentThread_Sleep() {
Thread* thread = GetCurrentThread();
thread->status = THREADSTATUS_WAIT_SLEEP;
}
void ExitCurrentThread() {
Thread* thread = GetCurrentThread();
thread->Stop();
Core::System::GetInstance().CurrentScheduler().RemoveThread(thread);
}
/**
* Callback that will wake up the thread it was scheduled for
* @param thread_handle The handle of the thread that's been awoken
* @param cycles_late The number of CPU cycles that have passed since the desired wakeup time
*/
static void ThreadWakeupCallback(u64 thread_handle, int cycles_late) {
const auto proper_handle = static_cast<Handle>(thread_handle);
SharedPtr<Thread> thread = wakeup_callback_handle_table.Get<Thread>(proper_handle);
if (thread == nullptr) {
NGLOG_CRITICAL(Kernel, "Callback fired for invalid thread {:08X}", proper_handle);
return;
}
bool resume = true;
if (thread->status == THREADSTATUS_WAIT_SYNCH_ANY ||
thread->status == THREADSTATUS_WAIT_SYNCH_ALL ||
thread->status == THREADSTATUS_WAIT_HLE_EVENT) {
// Remove the thread from each of its waiting objects' waitlists
for (auto& object : thread->wait_objects)
object->RemoveWaitingThread(thread.get());
thread->wait_objects.clear();
// Invoke the wakeup callback before clearing the wait objects
if (thread->wakeup_callback)
resume = thread->wakeup_callback(ThreadWakeupReason::Timeout, thread, nullptr, 0);
}
if (thread->mutex_wait_address != 0 || thread->condvar_wait_address != 0 ||
thread->wait_handle) {
ASSERT(thread->status == THREADSTATUS_WAIT_MUTEX);
thread->mutex_wait_address = 0;
thread->condvar_wait_address = 0;
thread->wait_handle = 0;
auto lock_owner = thread->lock_owner;
// Threads waking up by timeout from WaitProcessWideKey do not perform priority inheritance
// and don't have a lock owner unless SignalProcessWideKey was called first and the thread
// wasn't awakened due to the mutex already being acquired.
if (lock_owner) {
lock_owner->RemoveMutexWaiter(thread);
}
}
if (resume)
thread->ResumeFromWait();
}
void Thread::WakeAfterDelay(s64 nanoseconds) {
// Don't schedule a wakeup if the thread wants to wait forever
if (nanoseconds == -1)
return;
CoreTiming::ScheduleEvent(CoreTiming::nsToCycles(nanoseconds), ThreadWakeupEventType,
callback_handle);
}
void Thread::CancelWakeupTimer() {
CoreTiming::UnscheduleEvent(ThreadWakeupEventType, callback_handle);
}
static boost::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_WAIT_SYNCH_ALL:
case THREADSTATUS_WAIT_SYNCH_ANY:
case THREADSTATUS_WAIT_HLE_EVENT:
case THREADSTATUS_WAIT_SLEEP:
case THREADSTATUS_WAIT_IPC:
case THREADSTATUS_WAIT_MUTEX:
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;
status = THREADSTATUS_READY;
boost::optional<s32> new_processor_id = GetNextProcessorId(affinity_mask);
if (!new_processor_id) {
new_processor_id = processor_id;
}
if (ideal_core != -1 &&
Core::System().GetInstance().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 = Core::System().GetInstance().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;
Core::System::GetInstance().CpuCore(processor_id).PrepareReschedule();
}
/**
* Finds a free location for the TLS section of a thread.
* @param tls_slots The TLS page array of the thread's owner process.
* Returns a tuple of (page, slot, alloc_needed) where:
* page: The index of the first allocated TLS page that has free slots.
* slot: The index of the first free slot in the indicated page.
* alloc_needed: Whether there's a need to allocate a new TLS page (All pages are full).
*/
std::tuple<u32, u32, bool> GetFreeThreadLocalSlot(std::vector<std::bitset<8>>& tls_slots) {
// Iterate over all the allocated pages, and try to find one where not all slots are used.
for (unsigned page = 0; page < tls_slots.size(); ++page) {
const auto& page_tls_slots = tls_slots[page];
if (!page_tls_slots.all()) {
// We found a page with at least one free slot, find which slot it is
for (unsigned slot = 0; slot < page_tls_slots.size(); ++slot) {
if (!page_tls_slots.test(slot)) {
return std::make_tuple(page, slot, false);
}
}
}
}
return std::make_tuple(0, 0, true);
}
/**
* 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(ARM_Interface::ThreadContext& context, VAddr stack_top,
VAddr entry_point, u64 arg) {
memset(&context, 0, sizeof(ARM_Interface::ThreadContext));
context.cpu_registers[0] = arg;
context.pc = entry_point;
context.sp = stack_top;
context.cpsr = 0;
context.fpscr = 0;
}
ResultVal<SharedPtr<Thread>> Thread::Create(std::string name, VAddr entry_point, u32 priority,
u64 arg, s32 processor_id, VAddr stack_top,
SharedPtr<Process> owner_process) {
// Check if priority is in ranged. Lowest priority -> highest priority id.
if (priority > THREADPRIO_LOWEST) {
NGLOG_ERROR(Kernel_SVC, "Invalid thread priority: {}", priority);
return ERR_OUT_OF_RANGE;
}
if (processor_id > THREADPROCESSORID_MAX) {
NGLOG_ERROR(Kernel_SVC, "Invalid processor id: {}", processor_id);
return ERR_OUT_OF_RANGE_KERNEL;
}
// TODO(yuriks): Other checks, returning 0xD9001BEA
if (!Memory::IsValidVirtualAddress(*owner_process, entry_point)) {
NGLOG_ERROR(Kernel_SVC, "(name={}): invalid entry {:016X}", name, entry_point);
// TODO (bunnei): Find the correct error code to use here
return ResultCode(-1);
}
SharedPtr<Thread> thread(new Thread);
thread->thread_id = NewThreadId();
thread->status = THREADSTATUS_DORMANT;
thread->entry_point = entry_point;
thread->stack_top = stack_top;
thread->nominal_priority = thread->current_priority = priority;
thread->last_running_ticks = 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 = wakeup_callback_handle_table.Create(thread).Unwrap();
thread->owner_process = owner_process;
thread->scheduler = Core::System().GetInstance().Scheduler(processor_id);
thread->scheduler->AddThread(thread, priority);
// Find the next available TLS index, and mark it as used
auto& tls_slots = owner_process->tls_slots;
bool needs_allocation = true;
u32 available_page; // Which allocated page has free space
u32 available_slot; // Which slot within the page is free
std::tie(available_page, available_slot, needs_allocation) = GetFreeThreadLocalSlot(tls_slots);
if (needs_allocation) {
// There are no already-allocated pages with free slots, lets allocate a new one.
// TLS pages are allocated from the BASE region in the linear heap.
MemoryRegionInfo* memory_region = GetMemoryRegion(MemoryRegion::BASE);
auto& linheap_memory = memory_region->linear_heap_memory;
if (linheap_memory->size() + Memory::PAGE_SIZE > memory_region->size) {
NGLOG_ERROR(Kernel_SVC,
"Not enough space in region to allocate a new TLS page for thread");
return ERR_OUT_OF_MEMORY;
}
size_t offset = linheap_memory->size();
// Allocate some memory from the end of the linear heap for this region.
linheap_memory->insert(linheap_memory->end(), Memory::PAGE_SIZE, 0);
memory_region->used += Memory::PAGE_SIZE;
owner_process->linear_heap_used += Memory::PAGE_SIZE;
tls_slots.emplace_back(0); // The page is completely available at the start
available_page = static_cast<u32>(tls_slots.size() - 1);
available_slot = 0; // Use the first slot in the new page
auto& vm_manager = owner_process->vm_manager;
vm_manager.RefreshMemoryBlockMappings(linheap_memory.get());
// Map the page to the current process' address space.
// TODO(Subv): Find the correct MemoryState for this region.
vm_manager.MapMemoryBlock(Memory::TLS_AREA_VADDR + available_page * Memory::PAGE_SIZE,
linheap_memory, offset, Memory::PAGE_SIZE,
MemoryState::ThreadLocal);
}
// Mark the slot as used
tls_slots[available_page].set(available_slot);
thread->tls_address = Memory::TLS_AREA_VADDR + available_page * Memory::PAGE_SIZE +
available_slot * Memory::TLS_ENTRY_SIZE;
// 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;
}
SharedPtr<Thread> SetupMainThread(VAddr entry_point, u32 priority,
SharedPtr<Process> owner_process) {
// Setup page table so we can write to memory
SetCurrentPageTable(&Core::CurrentProcess()->vm_manager.page_table);
// Initialize new "main" thread
auto thread_res = Thread::Create("main", entry_point, priority, 0, THREADPROCESSORID_0,
Memory::STACK_AREA_VADDR_END, owner_process);
SharedPtr<Thread> thread = std::move(thread_res).Unwrap();
// Register 1 must be a handle to the main thread
thread->guest_handle = Kernel::g_handle_table.Create(thread).Unwrap();
thread->context.cpu_registers[1] = thread->guest_handle;
// Threads by default are dormant, wake up the main thread so it runs when the scheduler fires
thread->ResumeFromWait();
return thread;
}
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::AddMutexWaiter(SharedPtr<Thread> thread) {
thread->lock_owner = this;
wait_mutex_threads.emplace_back(std::move(thread));
UpdatePriority();
}
void Thread::RemoveMutexWaiter(SharedPtr<Thread> thread) {
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;
if (status != THREADSTATUS_READY) {
return;
}
boost::optional<s32> new_processor_id{GetNextProcessorId(affinity_mask)};
if (!new_processor_id) {
new_processor_id = processor_id;
}
if (ideal_core != -1 &&
Core::System().GetInstance().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 = Core::System().GetInstance().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;
Core::System::GetInstance().CpuCore(processor_id).PrepareReschedule();
}
////////////////////////////////////////////////////////////////////////////////////////////////////
/**
* Gets the current thread
*/
Thread* GetCurrentThread() {
return Core::System::GetInstance().CurrentScheduler().GetCurrentThread();
}
void ThreadingInit() {
ThreadWakeupEventType = CoreTiming::RegisterEvent("ThreadWakeupCallback", ThreadWakeupCallback);
next_thread_id = 1;
}
void ThreadingShutdown() {
Kernel::ClearProcessList();
}
} // namespace Kernel