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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 <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/arm/skyeye_common/armstate.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 int ThreadWakeupEventType;
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;
// Lists all thread ids that aren't deleted/etc.
static std::vector<SharedPtr<Thread>> thread_list;
// Lists only ready thread ids.
static Common::ThreadQueueList<Thread*, THREADPRIO_LOWEST + 1> ready_queue;
static SharedPtr<Thread> current_thread;
// 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() {}
Thread* GetCurrentThread() {
return current_thread.get();
}
/**
* Check if the specified thread is waiting on the specified address to be arbitrated
* @param thread The thread to test
* @param wait_address The address to test against
* @return True if the thread is waiting, false otherwise
*/
static bool CheckWait_AddressArbiter(const Thread* thread, VAddr wait_address) {
return thread->status == THREADSTATUS_WAIT_ARB && wait_address == thread->wait_address;
}
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) {
ready_queue.remove(current_priority, this);
}
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();
// Release all the mutexes that this thread holds
ReleaseThreadMutexes(this);
// Mark the TLS slot in the thread's page as free.
u32 tls_page = (tls_address - Memory::TLS_AREA_VADDR) / Memory::PAGE_SIZE;
u32 tls_slot =
((tls_address - Memory::TLS_AREA_VADDR) % Memory::PAGE_SIZE) / Memory::TLS_ENTRY_SIZE;
Kernel::g_current_process->tls_slots[tls_page].reset(tls_slot);
}
Thread* ArbitrateHighestPriorityThread(u32 address) {
Thread* highest_priority_thread = nullptr;
s32 priority = THREADPRIO_LOWEST;
// Iterate through threads, find highest priority thread that is waiting to be arbitrated...
for (auto& thread : thread_list) {
if (!CheckWait_AddressArbiter(thread.get(), address))
continue;
if (thread == nullptr)
continue;
if (thread->current_priority <= priority) {
highest_priority_thread = thread.get();
priority = thread->current_priority;
}
}
// If a thread was arbitrated, resume it
if (nullptr != highest_priority_thread) {
highest_priority_thread->ResumeFromWait();
}
return highest_priority_thread;
}
void ArbitrateAllThreads(u32 address) {
// Resume all threads found to be waiting on the address
for (auto& thread : thread_list) {
if (CheckWait_AddressArbiter(thread.get(), address))
thread->ResumeFromWait();
}
}
/**
* Switches the CPU's active thread context to that of the specified thread
* @param new_thread The thread to switch to
*/
static void SwitchContext(Thread* new_thread) {
Thread* previous_thread = GetCurrentThread();
// Save context for previous thread
if (previous_thread) {
previous_thread->last_running_ticks = CoreTiming::GetTicks();
Core::CPU().SaveContext(previous_thread->context);
if (previous_thread->status == THREADSTATUS_RUNNING) {
// This is only the case when a reschedule is triggered without the current thread
// yielding execution (i.e. an event triggered, system core time-sliced, etc)
ready_queue.push_front(previous_thread->current_priority, previous_thread);
previous_thread->status = THREADSTATUS_READY;
}
}
// Load context of new thread
if (new_thread) {
ASSERT_MSG(new_thread->status == THREADSTATUS_READY,
"Thread must be ready to become running.");
// Cancel any outstanding wakeup events for this thread
CoreTiming::UnscheduleEvent(ThreadWakeupEventType, new_thread->callback_handle);
auto previous_process = Kernel::g_current_process;
current_thread = new_thread;
ready_queue.remove(new_thread->current_priority, new_thread);
new_thread->status = THREADSTATUS_RUNNING;
Core::CPU().LoadContext(new_thread->context);
Core::CPU().SetCP15Register(CP15_THREAD_URO, new_thread->GetTLSAddress());
if (previous_process != current_thread->owner_process) {
Kernel::g_current_process = current_thread->owner_process;
Memory::current_page_table = &Kernel::g_current_process->vm_manager.page_table;
// We have switched processes and thus, page tables, clear the instruction cache so we
// don't keep stale data from the previous process.
Core::CPU().ClearInstructionCache();
}
} else {
current_thread = nullptr;
// Note: We do not reset the current process and current page table when idling because
// technically we haven't changed processes, our threads are just paused.
}
}
/**
* Pops and returns the next thread from the thread queue
* @return A pointer to the next ready thread
*/
static Thread* PopNextReadyThread() {
Thread* next;
Thread* thread = GetCurrentThread();
if (thread && thread->status == THREADSTATUS_RUNNING) {
// We have to do better than the current thread.
// This call returns null when that's not possible.
next = ready_queue.pop_first_better(thread->current_priority);
if (!next) {
// Otherwise just keep going with the current thread
next = thread;
}
} else {
next = ready_queue.pop_first();
}
return next;
}
void WaitCurrentThread_Sleep() {
Thread* thread = GetCurrentThread();
thread->status = THREADSTATUS_WAIT_SLEEP;
}
void WaitCurrentThread_ArbitrateAddress(VAddr wait_address) {
Thread* thread = GetCurrentThread();
thread->wait_address = wait_address;
thread->status = THREADSTATUS_WAIT_ARB;
}
void ExitCurrentThread() {
Thread* thread = GetCurrentThread();
thread->Stop();
thread_list.erase(std::remove(thread_list.begin(), thread_list.end(), thread),
thread_list.end());
}
/**
* 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) {
SharedPtr<Thread> thread = wakeup_callback_handle_table.Get<Thread>((Handle)thread_handle);
if (thread == nullptr) {
LOG_CRITICAL(Kernel, "Callback fired for invalid thread %08X", (Handle)thread_handle);
return;
}
if (thread->status == THREADSTATUS_WAIT_SYNCH_ANY ||
thread->status == THREADSTATUS_WAIT_SYNCH_ALL || thread->status == THREADSTATUS_WAIT_ARB) {
thread->wait_set_output = false;
// Remove the thread from each of its waiting objects' waitlists
for (auto& object : thread->wait_objects)
object->RemoveWaitingThread(thread.get());
thread->wait_objects.clear();
thread->SetWaitSynchronizationResult(RESULT_TIMEOUT);
}
thread->ResumeFromWait();
}
void Thread::WakeAfterDelay(s64 nanoseconds) {
// Don't schedule a wakeup if the thread wants to wait forever
if (nanoseconds == -1)
return;
u64 microseconds = nanoseconds / 1000;
CoreTiming::ScheduleEvent(usToCycles(microseconds), ThreadWakeupEventType, callback_handle);
}
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_ARB:
case THREADSTATUS_WAIT_SLEEP:
break;
case THREADSTATUS_READY:
// 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 %u 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 %u cannot be resumed because it's DEAD.",
GetObjectId());
return;
}
ready_queue.push_back(current_priority, this);
status = THREADSTATUS_READY;
Core::System::GetInstance().PrepareReschedule();
}
/**
* Prints the thread queue for debugging purposes
*/
static void DebugThreadQueue() {
Thread* thread = GetCurrentThread();
if (!thread) {
LOG_DEBUG(Kernel, "Current: NO CURRENT THREAD");
} else {
LOG_DEBUG(Kernel, "0x%02X %u (current)", thread->current_priority,
GetCurrentThread()->GetObjectId());
}
for (auto& t : thread_list) {
s32 priority = ready_queue.contains(t.get());
if (priority != -1) {
LOG_DEBUG(Kernel, "0x%02X %u", priority, t->GetObjectId());
}
}
}
/**
* 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, u32 stack_top,
u32 entry_point, u32 arg) {
memset(&context, 0, sizeof(ARM_Interface::ThreadContext));
context.cpu_registers[0] = arg;
context.pc = entry_point;
context.sp = stack_top;
context.cpsr = USER32MODE | ((entry_point & 1) << 5); // Usermode and THUMB mode
}
ResultVal<SharedPtr<Thread>> Thread::Create(std::string name, VAddr entry_point, u32 priority,
u32 arg, s32 processor_id, VAddr stack_top) {
// Check if priority is in ranged. Lowest priority -> highest priority id.
if (priority > THREADPRIO_LOWEST) {
LOG_ERROR(Kernel_SVC, "Invalid thread priority: %d", priority);
return ERR_OUT_OF_RANGE;
}
if (processor_id > THREADPROCESSORID_MAX) {
LOG_ERROR(Kernel_SVC, "Invalid processor id: %d", processor_id);
return ERR_OUT_OF_RANGE_KERNEL;
}
// TODO(yuriks): Other checks, returning 0xD9001BEA
if (!Memory::IsValidVirtualAddress(entry_point)) {
LOG_ERROR(Kernel_SVC, "(name=%s): invalid entry %08x", name.c_str(), entry_point);
// TODO: Verify error
return ResultCode(ErrorDescription::InvalidAddress, ErrorModule::Kernel,
ErrorSummary::InvalidArgument, ErrorLevel::Permanent);
}
SharedPtr<Thread> thread(new Thread);
thread_list.push_back(thread);
ready_queue.prepare(priority);
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->wait_set_output = false;
thread->wait_objects.clear();
thread->wait_address = 0;
thread->name = std::move(name);
thread->callback_handle = wakeup_callback_handle_table.Create(thread).Unwrap();
thread->owner_process = g_current_process;
// Find the next available TLS index, and mark it as used
auto& tls_slots = Kernel::g_current_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) {
LOG_ERROR(Kernel_SVC,
"Not enough space in region to allocate a new TLS page for thread");
return ERR_OUT_OF_MEMORY;
}
u32 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;
Kernel::g_current_process->linear_heap_used += Memory::PAGE_SIZE;
tls_slots.emplace_back(0); // The page is completely available at the start
available_page = tls_slots.size() - 1;
available_slot = 0; // Use the first slot in the new page
auto& vm_manager = Kernel::g_current_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::Private);
}
// 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);
ready_queue.push_back(thread->current_priority, thread.get());
thread->status = THREADSTATUS_READY;
return MakeResult<SharedPtr<Thread>>(std::move(thread));
}
void Thread::SetPriority(s32 priority) {
ASSERT_MSG(priority <= THREADPRIO_LOWEST && priority >= THREADPRIO_HIGHEST,
"Invalid priority value.");
// If thread was ready, adjust queues
if (status == THREADSTATUS_READY)
ready_queue.move(this, current_priority, priority);
else
ready_queue.prepare(priority);
nominal_priority = current_priority = priority;
}
void Thread::UpdatePriority() {
s32 best_priority = nominal_priority;
for (auto& mutex : held_mutexes) {
if (mutex->priority < best_priority)
best_priority = mutex->priority;
}
BoostPriority(best_priority);
}
void Thread::BoostPriority(s32 priority) {
// If thread was ready, adjust queues
if (status == THREADSTATUS_READY)
ready_queue.move(this, current_priority, priority);
else
ready_queue.prepare(priority);
current_priority = priority;
}
SharedPtr<Thread> SetupMainThread(u32 entry_point, s32 priority) {
// Initialize new "main" thread
auto thread_res = Thread::Create("main", entry_point, priority, 0, THREADPROCESSORID_0,
Memory::HEAP_VADDR_END);
SharedPtr<Thread> thread = std::move(thread_res).Unwrap();
thread->context.fpscr =
FPSCR_DEFAULT_NAN | FPSCR_FLUSH_TO_ZERO | FPSCR_ROUND_TOZERO | FPSCR_IXC; // 0x03C00010
// Note: The newly created thread will be run when the scheduler fires.
return thread;
}
bool HaveReadyThreads() {
return ready_queue.get_first() != nullptr;
}
void Reschedule() {
Thread* cur = GetCurrentThread();
Thread* next = PopNextReadyThread();
if (cur && next) {
LOG_TRACE(Kernel, "context switch %u -> %u", cur->GetObjectId(), next->GetObjectId());
} else if (cur) {
LOG_TRACE(Kernel, "context switch %u -> idle", cur->GetObjectId());
} else if (next) {
LOG_TRACE(Kernel, "context switch idle -> %u", next->GetObjectId());
}
SwitchContext(next);
}
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 std::distance(match, wait_objects.rend()) - 1;
}
////////////////////////////////////////////////////////////////////////////////////////////////////
void ThreadingInit() {
ThreadWakeupEventType = CoreTiming::RegisterEvent("ThreadWakeupCallback", ThreadWakeupCallback);
current_thread = nullptr;
next_thread_id = 1;
}
void ThreadingShutdown() {
current_thread = nullptr;
for (auto& t : thread_list) {
t->Stop();
}
thread_list.clear();
ready_queue.clear();
}
const std::vector<SharedPtr<Thread>>& GetThreadList() {
return thread_list;
}
} // namespace
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