在共享内存中保存函数指针

Question

我知道使用共享内存的多个应用程序可以保存和使用数据。我想知道是否可以将函数指针保存在共享内存中？我的目的是从我的共享对象回调到具有相同功能的函数不同应用程序的返回值和参数。

Answer 1

No.

Unless you have somehow loaded your code into the shared memory region, or otherwise caused the code to be loaded at the same address in both processes, the function pointer will not be valid.

Answer 2

除非您完全确定自己在做什么，否则将函数指针保存在共享内存段中对我来说听起来是个坏主意，您最终可能会访问您的进程没有特权的函数指针，并且可能最终崩溃你的程序。

Answer 3

It is not guaranteed that a shared library will be loaded to the same address for two different applications. Even worse, a library could be loaded to any random address due to address space layout randomization. Hence, a function pointer is not invariant and hence can't be stored anywhere.

As solution, you could create a function table with all possible callbacks in both processes and store offset to a function in shared memory. For sure, those tables should be exactly the same.

Answer 4

不，不能共享函数指针，如果需要，您需要制作该函数的库并在您的过程中使用它