Linux 中的 Singleton 与共享模块和 Static Z4789F23283B3A61F858B641A1BEF1 访问

Question

I have a process I am starting that is loading in multiple shared libraries. Some of the code in these shared libraries is the same (eg common files) and is using a singleton setup. eg

class MySingleton
{
  public:
    static MySingleton& GetInstance()
    {
      static MySingleton singleton;
      return singleton;
    }

    // ...
  private:
    // ...
}

I have run into a problem now where this MySingleton class is only being initialized once and being shared between the modules in memory (since they are being loaded into the same process). This seems to be a Linux specific problem, as I have had no issues with this on Mac OS or Windows where the application has been functioning fine.

To further emphasize/clarify the question, I have the following code for instance:

// module 1
MySingleton::GetInstance().DoSomething(); // GetInstance() returns 0xABCDEFF

// module 2
MySingleton::GetInstance().DoSomethingElse(); // GetInstance() also returns 0xABCDEFF

My question is the following: Is there a way to force Linux/the shared modules to have independent static memory pools? Or am I at the mercy of the Linux operating system and how it decides to implement this?

In my case I am using this Singleton all over my code for a logging system...and it would be extremely inconvenient to go and have to modify this all over the place. Thanks

Answer 1

After a few days (I know this question is only 30 minutes old, but I did finally find the solution)...I found what I was missing and doing on macOS but not on Linux.

I added the following extra compile flags to my common code and everything fell into place perfectly like it was on macOS -fPIC -fvisibility-inlines-hidden -fvisibility=hidden .

With these extra flags in place, the code is separate from each other and no longer overlapping in memory.