// Copyright 2014 Citra Emulator Project / PPSSPP Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include <array>
#include <string>
#include "common/common.h"
#include "core/hle/result.h"
typedef u32 Handle;
typedef s32 Result;
const Handle INVALID_HANDLE = 0;
namespace Kernel {
// 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 = InvalidHandle(ErrorModule::Kernel);
enum KernelHandle : Handle {
CurrentThread = 0xFFFF8000,
CurrentProcess = 0xFFFF8001,
};
enum class HandleType : u32 {
Unknown = 0,
Port = 1,
Session = 2,
Event = 3,
Mutex = 4,
SharedMemory = 5,
Redirection = 6,
Thread = 7,
Process = 8,
AddressArbiter = 9,
Semaphore = 10,
};
enum {
DEFAULT_STACK_SIZE = 0x4000,
};
class HandleTable;
class Object : NonCopyable {
friend class HandleTable;
u32 handle;
public:
virtual ~Object() {}
Handle GetHandle() const { return handle; }
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;
/**
* Wait for kernel object to synchronize.
* @return True if the current thread should wait as a result of the wait
*/
virtual ResultVal<bool> WaitSynchronization() {
LOG_ERROR(Kernel, "(UNIMPLEMENTED)");
return UnimplementedFunction(ErrorModule::Kernel);
}
private:
friend void intrusive_ptr_add_ref(Object*);
friend void intrusive_ptr_release(Object*);
unsigned int ref_count = 0;
};
// Special functions that will later be 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;
}
}
/**
* 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(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.
* @returns Pointer to the looked-up object, or `nullptr` if the handle is not valid.
*/
Object* GetGeneric(Handle handle) const;
/**
* Looks up a handle while verifying its type.
* @returns 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>
T* Get(Handle handle) const {
Object* object = GetGeneric(handle);
if (object != nullptr && object->GetHandleType() == T::HANDLE_TYPE) {
return static_cast<T*>(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 size_t 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<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;
extern Handle g_main_thread;
/// The ID code of the currently running game
/// TODO(Subv): This variable should not be here,
/// we need a way to store information about the currently loaded application
/// for later query during runtime, maybe using the LDR service?
extern u64 g_program_id;
/// Initialize the kernel
void Init();
/// Shutdown the kernel
void Shutdown();
/**
* Loads executable stored at specified address
* @entry_point Entry point in memory of loaded executable
* @return True on success, otherwise false
*/
bool LoadExec(u32 entry_point);
} // namespace
