c - 在 C 中释放内存需要什么？

Question

我可能被误导了，但据我所知，操作系统会在程序退出或崩溃后清理内存。

如果是这样，在程序结束时释放内存有多大用处？我知道如果一个程序正在运行并且释放被忽略，那么内存可能会变得“满”，但是如果一个程序已经结束并且操作系统释放了该程序使用的所有内存，那么手动释放该内存有什么意义呢？

Answer 1

引自Memory Deallocation Issues in C :

The operating system is responsible for maintaining the resources of an application, including its memory. When an application terminates, it is the operating system’s responsibility to reallocate this memory for other applications. The state of the terminated application’s memory, corrupted or uncorrupted, is not an issue. In fact, one of the reasons an application may terminate is because its memory is corrupted. With an abnormal program termination, cleanup may not be possible.

With this said, there may be other reasons why memory should be freed when a program terminates normally:

• The conscientious programmer may want to free memory as a quality issue. It is always a good habit to free memory after it is no longer needed, even if the application is terminating.
• If you use a tool to detect memory leaks or similar problems, then deallocating memory will clean up the output of such tools.
• In some less complex operating systems, the operating system may not reclaim memory automatically, and it may be the program’s responsibility to reclaim memory before terminating.
• Also, a later version of the application could add code toward the end of the program. If the previous memory has not been freed, problems could arise.