// Copyright 2014 Citra Emulator Project / PPSSPP Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <algorithm>
#include <array>
#include <cstddef>
#include <string>
#include <vector>
#include <boost/smart_ptr/intrusive_ptr.hpp>
#include "common/common_types.h"
#include "core/hle/hle.h"
#include "core/hle/result.h"
namespace Kernel {
class Thread;
// TODO: Verify code
const ResultCode ERR_OUT_OF_HANDLES(ErrorDescription::OutOfMemory, ErrorModule::Kernel,
ErrorSummary::OutOfResource, ErrorLevel::Temporary);
// TOOD: Verify code
const ResultCode ERR_INVALID_HANDLE(ErrorDescription::InvalidHandle, ErrorModule::Kernel,
ErrorSummary::InvalidArgument, ErrorLevel::Permanent);
enum KernelHandle : Handle {
CurrentThread = 0xFFFF8000,
CurrentProcess = 0xFFFF8001,
};
enum class HandleType : u32 {
Unknown = 0,
Session = 2,
Event = 3,
Mutex = 4,
SharedMemory = 5,
Redirection = 6,
Thread = 7,
Process = 8,
AddressArbiter = 9,
Semaphore = 10,
Timer = 11,
ResourceLimit = 12,
CodeSet = 13,
ClientPort = 14,
ServerPort = 15,
};
enum {
DEFAULT_STACK_SIZE = 0x4000,
};
class Object : NonCopyable {
public:
virtual ~Object() {}
/// Returns a unique identifier for the object. For debugging purposes only.
unsigned int GetObjectId() const {
return object_id;
}
virtual std::string GetTypeName() const {
return "[BAD KERNEL OBJECT TYPE]";
}
virtual std::string GetName() const {
return "[UNKNOWN KERNEL OBJECT]";
}
virtual Kernel::HandleType GetHandleType() const = 0;
/**
* Check if a thread can wait on the object
* @return True if a thread can wait on the object, otherwise false
*/
bool IsWaitable() const {
switch (GetHandleType()) {
case HandleType::Session:
case HandleType::ServerPort:
case HandleType::Event:
case HandleType::Mutex:
case HandleType::Thread:
case HandleType::Semaphore:
case HandleType::Timer:
return true;
case HandleType::Unknown:
case HandleType::SharedMemory:
case HandleType::Redirection:
case HandleType::Process:
case HandleType::AddressArbiter:
case HandleType::ResourceLimit:
case HandleType::CodeSet:
case HandleType::ClientPort:
return false;
}
}
public:
static unsigned int next_object_id;
private:
friend void intrusive_ptr_add_ref(Object*);
friend void intrusive_ptr_release(Object*);
unsigned int ref_count = 0;
unsigned int object_id = next_object_id++;
};
// Special functions used by boost::instrusive_ptr to do automatic ref-counting
inline void intrusive_ptr_add_ref(Object* object) {
++object->ref_count;
}
inline void intrusive_ptr_release(Object* object) {
if (--object->ref_count == 0) {
delete object;
}
}
template <typename T>
using SharedPtr = boost::intrusive_ptr<T>;
/// Class that represents a Kernel object that a thread can be waiting on
class WaitObject : public Object {
public:
/**
* Check if the current thread should wait until the object is available
* @return True if the current thread should wait due to this object being unavailable
*/
virtual bool ShouldWait() = 0;
/// Acquire/lock the object if it is available
virtual void Acquire() = 0;
/**
* Add a thread to wait on this object
* @param thread Pointer to thread to add
*/
void AddWaitingThread(SharedPtr<Thread> thread);
/**
* Removes a thread from waiting on this object (e.g. if it was resumed already)
* @param thread Pointer to thread to remove
*/
void RemoveWaitingThread(Thread* thread);
/// Wake up all threads waiting on this object
void WakeupAllWaitingThreads();
private:
/// Threads waiting for this object to become available
std::vector<SharedPtr<Thread>> waiting_threads;
};
/**
* This class allows the creation of Handles, which are references to objects that can be tested
* for validity and looked up. Here they are used to pass references to kernel objects to/from the
* emulated process. it has been designed so that it follows the same handle format and has
* approximately the same restrictions as the handle manager in the CTR-OS.
*
* Handles contain two sub-fields: a slot index (bits 31:15) and a generation value (bits 14:0).
* The slot index is used to index into the arrays in this class to access the data corresponding
* to the Handle.
*
* To prevent accidental use of a freed Handle whose slot has already been reused, a global counter
* is kept and incremented every time a Handle is created. This is the Handle's "generation". The
* value of the counter is stored into the Handle as well as in the handle table (in the
* "generations" array). When looking up a handle, the Handle's generation must match with the
* value stored on the class, otherwise the Handle is considered invalid.
*
* To find free slots when allocating a Handle without needing to scan the entire object array, the
* generations field of unallocated slots is re-purposed as a linked list of indices to free slots.
* When a Handle is created, an index is popped off the list and used for the new Handle. When it
* is destroyed, it is again pushed onto the list to be re-used by the next allocation. It is
* likely that this allocation strategy differs from the one used in CTR-OS, but this hasn't been
* verified and isn't likely to cause any problems.
*/
class HandleTable final : NonCopyable {
public:
HandleTable();
/**
* Allocates a handle for the given object.
* @return The created Handle or one of the following errors:
* - `ERR_OUT_OF_HANDLES`: the maximum number of handles has been exceeded.
*/
ResultVal<Handle> Create(SharedPtr<Object> obj);
/**
* Returns a new handle that points to the same object as the passed in handle.
* @return The duplicated Handle or one of the following errors:
* - `ERR_INVALID_HANDLE`: an invalid handle was passed in.
* - Any errors returned by `Create()`.
*/
ResultVal<Handle> Duplicate(Handle handle);
/**
* Closes a handle, removing it from the table and decreasing the object's ref-count.
* @return `RESULT_SUCCESS` or one of the following errors:
* - `ERR_INVALID_HANDLE`: an invalid handle was passed in.
*/
ResultCode Close(Handle handle);
/// Checks if a handle is valid and points to an existing object.
bool IsValid(Handle handle) const;
/**
* Looks up a handle.
* @return Pointer to the looked-up object, or `nullptr` if the handle is not valid.
*/
SharedPtr<Object> GetGeneric(Handle handle) const;
/**
* Looks up a handle while verifying its type.
* @return Pointer to the looked-up object, or `nullptr` if the handle is not valid or its
* type differs from the handle type `T::HANDLE_TYPE`.
*/
template <class T>
SharedPtr<T> Get(Handle handle) const {
SharedPtr<Object> object = GetGeneric(handle);
if (object != nullptr && object->GetHandleType() == T::HANDLE_TYPE) {
return boost::static_pointer_cast<T>(std::move(object));
}
return nullptr;
}
/**
* Looks up a handle while verifying that it is an object that a thread can wait on
* @return Pointer to the looked-up object, or `nullptr` if the handle is not valid or it is
* not a waitable object.
*/
SharedPtr<WaitObject> GetWaitObject(Handle handle) const {
SharedPtr<Object> object = GetGeneric(handle);
if (object != nullptr && object->IsWaitable()) {
return boost::static_pointer_cast<WaitObject>(std::move(object));
}
return nullptr;
}
/// Closes all handles held in this table.
void Clear();
private:
/**
* This is the maximum limit of handles allowed per process in CTR-OS. It can be further
* reduced by ExHeader values, but this is not emulated here.
*/
static const size_t MAX_COUNT = 4096;
static u16 GetSlot(Handle handle) {
return handle >> 15;
}
static u16 GetGeneration(Handle handle) {
return handle & 0x7FFF;
}
/// Stores the Object referenced by the handle or null if the slot is empty.
std::array<SharedPtr<Object>, MAX_COUNT> objects;
/**
* The value of `next_generation` when the handle was created, used to check for validity. For
* empty slots, contains the index of the next free slot in the list.
*/
std::array<u16, MAX_COUNT> generations;
/**
* Global counter of the number of created handles. Stored in `generations` when a handle is
* created, and wraps around to 1 when it hits 0x8000.
*/
u16 next_generation;
/// Head of the free slots linked list.
u16 next_free_slot;
};
extern HandleTable g_handle_table;
/// Initialize the kernel
void Init();
/// Shutdown the kernel
void Shutdown();
} // namespace
