What does it mean: "A child-process can inherit the handle"?
handle, winapi, windows
Solution
If you create/open an object and allow that handle to be inherited, child processes which are allowed to inherit handles (e.g. you can specify `bInheritHandles = TRUE` for CreateProcess) will have copies of those handles. Those inherited handles will have the same handle values as the parent handles. So for example:
- `CreateEvent` returns a handle to an event object, handle is `0x1234`.
- You allow that handle to be inherited.
- You create a child process that inherits your handles.
- That child process can now use handle `0x1234` without having to call `CreateEvent` or `OpenEvent`. You could for example pass the handle value in the command line of the child process.
This is useful for unnamed objects - since they're unnamed, other processes can't open them. Using handle inheritance child processes can obtain handles to unnamed objects if you want them to.
Problem
There are some Win32 objects which according to the SDK can be "inherited" to the child-processes created by the given process. (Events, mutexes, pipes, ...) What does that actually mean? Let's say I have a named event object, created with `CreateEvent`, one time with `bInheritHandle == true`, and another time `== false`. Now I start a child process. How do those two event handles affect the child process? In which scenarios do they differ?