Memory management in C++ technology: Differences in memory management between managed code and unmanaged code

Memory management differences between managed and unmanaged code in C: Managed code is managed by the CLR, while unmanaged code is managed by the operating system. Memory allocation and deallocation for managed code is performed automatically by the CLR, while unmanaged code needs to be managed manually. Managed code uses garbage collection, and unmanaged code needs to be wary of memory leaks and segfaults. Memory management for managed code is simple and safe, while unmanaged code is complex and error-prone.

Memory management in C technology: Differences in memory management between managed code and unmanaged code

Introduction

In C, memory management is divided into managed code and unmanaged code. Managed code is managed by the common language runtime (CLR), while unmanaged code is managed directly by the operating system. Understanding the memory management differences between managed and unmanaged code is critical to effectively managing resources in C applications.

Memory management of managed code

• Managed by the CLR: The CLR automatically performs memory allocation and deallocation of managed objects.
• Garbage Collection: The CLR uses a garbage collector to reclaim memory for managed objects that are no longer in use. The garbage collector operates by itself at runtime without developer intervention.
• Safe and Simple: Memory management in managed code is simple and safe because the CLR handles all the low-level details.

Memory management of unmanaged code

• Managed by the operating system: The operating system allocates and releases unmanaged objects Memory.

• Manual allocation and deallocation: Developers must manually manage memory allocation and deallocation of unmanaged objects using:

  • malloc () and free() functions
  • new and delete operators
• Need to be careful: Memory management of unmanaged code can be complex and prone to errors such as memory leaks and segfaults.

Memory management difference comparison

Features	Managed code	Non Managed code
Memory management	Managed by the CLR	Managed by the OS
Memory allocation/release	Automatic	Manual
Requirements	Safe, simple	Complex, Error-prone
Garbage collection	Yes	No

Actual case

The following is a practical example of the difference in memory management between managed and unmanaged code:

// 托管代码示例
using namespace System;

class ManagedClass
{
public:
    void Method()
    {
        // CLR 自动分配和释放此对象
        string* str = new string("Hello World");

        // CLR 自动释放此对象
    }
};

// 非托管代码示例
class UnmanagedClass
{
public:
    void Method()
    {
        // 手动分配
        char* str = (char*) malloc(12);

        // 手动释放
        free(str);
    }
};

In this example, the managed objects in ManagedClass are managed by the CLR Automatically managed, no manual release required. The unmanaged objects in UnmanagedClass need to be allocated and released manually, otherwise memory leaks will occur.

The above is the detailed content of Memory management in C++ technology: Differences in memory management between managed code and unmanaged code. For more information, please follow other related articles on the PHP Chinese website!