用cgo在C语言中编写go字符串

Question

I'm trying to make a go string from C. I have the pointer and the length, so if I was doing it from go, I could call the C.GoStringN function.

cgo generates the GoString struct, so I was wondering if I could use it directly:

// struct generated by cgo
typedef struct { const char *p; GoInt n; } GoString;

// I have s and n from somewhere else, can I do this ?
const char* s = ... ; // I own this and dont want go to free it
int n = ... ;

GoString st = {s, n } ;

I'm using this in here to make a go string out of a char* whose lifetime I control. The GoString is then used as an argument to a go function:

//export Nbytes
func Nbytes(s string) int {
  ...
}

Will go's garbage collector attempt to reclaim the memory ?

Answer 1

Go's garbage collector will not try to reclaim memory allocated using the C memory allocator. What you are describing should be safe. Of course, you may not be able to free the C memory, because you don't know when Go will be done with it.