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suyu/src/core/hle/kernel/kernel.h
Yuri Kunde Schlesner 7e2903cb74 Kernel: New handle manager
This handle manager more closely mirrors the behaviour of the CTR-OS
one. In addition object ref-counts and support for DuplicateHandle have
been added.

Note that support for DuplicateHandle is still experimental, since parts
of the kernel still use Handles internally, which will likely cause
troubles if two different handles to the same object are used to e.g.
wait on a synchronization primitive.
2014-12-28 11:52:55 -02:00

213 lines
7.1 KiB
C++

// 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