On Saturday, 14 March 2015 at 18:26:34 UTC, Robert M. Münch wrote:
Hi, I have a question about how the GC handles this case:export extern(C) char* foo(){ char[] x = "This is a dynamic D string.".dup; return(cast(char*)x); }
Returning `x.ptr` would look a little nicer.
Since x is "pointer to array data & length" if it goes out of scope, it's destroyed and the last reference to the array data is gone. Hence, the GC could kick in and free the array data. Is this correct?
No.
Or will the GC know, that there was a pointer to the array data returned and hence a new reference exists as long until someone tells the GC that the pointer is no longer used?
Yes. The returned pointer is a reference. Once that reference is gone, the GC can collect the array. You don't need to explicitly inform the GC when you're done with the pointer.
My situation is, that the returned pointer is used to copy the result to some interpreter internal state. Depending on the answers above, there could be a short time where the memory state is "collectable" before the coyping was finished.
I think you're safe.
