PuqiAR
0f635ccf2b
- 更新了类型系统，新增了类型并优化了结构。 - 引入了基类型和派生类，用于函数、结构体和接口类型。 - 实现了类型上下文，用于管理内置类型和类型解析。 - 添加了诊断类，用于收集和报告警告和错误。 - 通过改进错误处理增强了虚拟机执行，以应对递归限制问题。 - 实现了反汇编器，将字节码转换为代码，以改善调试和分析。 - 添加了新的抽象语法树节点，用于成员表达式、对象初始化、接口和结构体定义。 - 引入了语义错误测试，包括重定义、未声明的变量和无效的结构字段。
116 lines
3.5 KiB
C++
116 lines
3.5 KiB
C++
/*!
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@file src/Utils/Arena.hpp
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@brief 线性分配内存池，支持非平凡析构对象的自动清理
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@author PuqiAR (im@puqiar.top)
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@date 2026-03-08
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*/
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#pragma once
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#include <cstddef>
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#include <vector>
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#include <memory>
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#include <type_traits>
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namespace Fig
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{
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class Arena
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{
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private:
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struct DestructorNode
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{
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void (*destructor)(void *);
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void *object;
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DestructorNode *next;
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};
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static constexpr std::size_t CHUNK_SIZE = 64 * 1024; // 64KB 块大小
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std::vector<char *> chunks;
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char *currentPtr = nullptr;
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std::size_t remaining = 0;
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DestructorNode *destructorHead = nullptr;
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public:
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Arena() = default;
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~Arena()
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{
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// 逆序调用析构函数
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DestructorNode *node = destructorHead;
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while (node)
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{
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node->destructor(node->object);
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node = node->next;
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}
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// 释放所有分配的内存块
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for (char *chunk : chunks)
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{
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delete[] chunk;
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}
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}
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// 禁止拷贝和移动，防止内存所有权混乱
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Arena(const Arena &) = delete;
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Arena &operator=(const Arena &) = delete;
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template <typename T, typename... Args>
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T *Allocate(Args &&...args)
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{
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std::size_t size = sizeof(T);
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std::size_t alignment = alignof(T);
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// 在当前块中尝试对齐并分配
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void *ptr = allocateRaw(size, alignment);
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// 在分配的内存上构造对象
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T *obj = new (ptr) T(std::forward<Args>(args)...);
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// 如果 T 需要析构（如包含 String），注册到销毁链表
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if constexpr (!std::is_trivially_destructible_v<T>)
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{
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// 注意: DestructorNode 本身是 POD，直接在 Arena 里分配，不需要注册析构
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void *nodeRaw = allocateRaw(sizeof(DestructorNode), alignof(DestructorNode));
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DestructorNode *node = new (nodeRaw) DestructorNode();
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node->object = obj;
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node->destructor = [](void *p) { static_cast<T *>(p)->~T(); };
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node->next = destructorHead;
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destructorHead = node;
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}
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return obj;
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}
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private:
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void *allocateRaw(std::size_t size, std::size_t alignment)
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{
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// 对齐计算
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std::size_t adjustment = 0;
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std::size_t currentAddr = reinterpret_cast<std::size_t>(currentPtr);
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if (alignment > 0 && (currentAddr % alignment) != 0)
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{
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adjustment = alignment - (currentAddr % alignment);
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}
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if (remaining < (size + adjustment))
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{
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// 当前块空间不足，分配新块
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std::size_t nextChunkSize = (size > CHUNK_SIZE) ? size : CHUNK_SIZE;
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currentPtr = new char[nextChunkSize];
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chunks.push_back(currentPtr);
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remaining = nextChunkSize;
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adjustment = 0; // 新分配的块通常是最大对齐的
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}
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currentPtr += adjustment;
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void *res = currentPtr;
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currentPtr += size;
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remaining -= (size + adjustment);
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return res;
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}
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};
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} // namespace Fig
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