Memory control¶

It is important to understand the lifetime of different objects to prevent memory leaks.

Some objects require deallocating, and some do not.

Function arguments¶

Array and string arguments are deallocated when the function returns, so they must not be stored beyond the function's lifetime.

This does not apply to arguments of type callback.

String and Array¶

String and Arrays are passed as a struct by value.

To free them up, you should clean their inner pointers:

• String: free(myString.data);
• Array: free(myArray.elements);

Example:

void pass(KString stringArg) {

    KString someString = KString_new("test", 4);
    KIntArray someArray = KIntArray_of(1, 2, 3);

    free(someString.data);
    free(someArray.elements);
    // DO NOT FREE FUNCTION ARGUMENTS !!!
}

Callbacks¶

To free them up, call callback->free function.

Example:

void pass(MyCallback* callback) {
    callback->free(callback);
}

[Dealloc] annotation¶

Tells the generator that this element should be cleared after the function call.

Can be used when returning a string, array or callback from function whose ownership is no longer in the native world.

Example:

namespace global {
    [Dealloc] Array<int> returnInts();
}

KIntArray returnInts() {
    // Here we allocate int array and lost it after returning.
    // As soon as we annotate function with [Dealloc], generator will free it up
    return KIntArray_of(1, 2, 3);
}