yuzu/src/core/hle/kernel/handle_table.cpp
2020-10-20 19:07:39 -07:00

128 lines
3.6 KiB
C++

// Copyright 2014 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <utility>
#include "common/assert.h"
#include "common/logging/log.h"
#include "core/core.h"
#include "core/hle/kernel/errors.h"
#include "core/hle/kernel/handle_table.h"
#include "core/hle/kernel/kernel.h"
#include "core/hle/kernel/process.h"
#include "core/hle/kernel/scheduler.h"
#include "core/hle/kernel/thread.h"
namespace Kernel {
namespace {
constexpr u16 GetSlot(Handle handle) {
return static_cast<u16>(handle >> 15);
}
constexpr u16 GetGeneration(Handle handle) {
return static_cast<u16>(handle & 0x7FFF);
}
} // Anonymous namespace
HandleTable::HandleTable(KernelCore& kernel) : kernel{kernel} {
Clear();
}
HandleTable::~HandleTable() = default;
ResultCode HandleTable::SetSize(s32 handle_table_size) {
if (static_cast<u32>(handle_table_size) > MAX_COUNT) {
LOG_ERROR(Kernel, "Handle table size {} is greater than {}", handle_table_size, MAX_COUNT);
return ERR_OUT_OF_MEMORY;
}
// Values less than or equal to zero indicate to use the maximum allowable
// size for the handle table in the actual kernel, so we ignore the given
// value in that case, since we assume this by default unless this function
// is called.
if (handle_table_size > 0) {
table_size = static_cast<u16>(handle_table_size);
}
return RESULT_SUCCESS;
}
ResultVal<Handle> HandleTable::Create(std::shared_ptr<Object> obj) {
DEBUG_ASSERT(obj != nullptr);
const u16 slot = next_free_slot;
if (slot >= table_size) {
LOG_ERROR(Kernel, "Unable to allocate Handle, too many slots in use.");
return ERR_HANDLE_TABLE_FULL;
}
next_free_slot = generations[slot];
const u16 generation = next_generation++;
// Overflow count so it fits in the 15 bits dedicated to the generation in the handle.
// Horizon OS uses zero to represent an invalid handle, so skip to 1.
if (next_generation >= (1 << 15)) {
next_generation = 1;
}
generations[slot] = generation;
objects[slot] = std::move(obj);
Handle handle = generation | (slot << 15);
return MakeResult<Handle>(handle);
}
ResultVal<Handle> HandleTable::Duplicate(Handle handle) {
std::shared_ptr<Object> object = GetGeneric(handle);
if (object == nullptr) {
LOG_ERROR(Kernel, "Tried to duplicate invalid handle: {:08X}", handle);
return ERR_INVALID_HANDLE;
}
return Create(std::move(object));
}
ResultCode HandleTable::Close(Handle handle) {
if (!IsValid(handle)) {
LOG_ERROR(Kernel, "Handle is not valid! handle={:08X}", handle);
return ERR_INVALID_HANDLE;
}
const u16 slot = GetSlot(handle);
objects[slot] = nullptr;
generations[slot] = next_free_slot;
next_free_slot = slot;
return RESULT_SUCCESS;
}
bool HandleTable::IsValid(Handle handle) const {
const std::size_t slot = GetSlot(handle);
const u16 generation = GetGeneration(handle);
return slot < table_size && objects[slot] != nullptr && generations[slot] == generation;
}
std::shared_ptr<Object> HandleTable::GetGeneric(Handle handle) const {
if (handle == CurrentThread) {
return SharedFrom(kernel.CurrentScheduler().GetCurrentThread());
} else if (handle == CurrentProcess) {
return SharedFrom(kernel.CurrentProcess());
}
if (!IsValid(handle)) {
return nullptr;
}
return objects[GetSlot(handle)];
}
void HandleTable::Clear() {
for (u16 i = 0; i < table_size; ++i) {
generations[i] = static_cast<u16>(i + 1);
objects[i] = nullptr;
}
next_free_slot = 0;
}
} // namespace Kernel