oden/third-party/vendor/objc2/tests/id_retain_autoreleased.rs
2024-03-08 11:03:01 -08:00

76 lines
2.4 KiB
Rust

use std::ffi::c_void;
use objc2::rc::{autoreleasepool, Id, Shared};
use objc2::runtime::Object;
use objc2::{class, msg_send};
#[cfg(feature = "gnustep-1-7")]
#[test]
fn ensure_linkage() {
unsafe { objc2::__gnustep_hack::get_class_to_force_linkage() };
}
fn retain_count(obj: &Object) -> usize {
unsafe { msg_send![obj, retainCount] }
}
fn create_data(bytes: &[u8]) -> Id<Object, Shared> {
let bytes_ptr: *const c_void = bytes.as_ptr().cast();
unsafe {
// let obj: *mut Object = msg_send![
// class!(NSMutableData),
// dataWithBytes: bytes_ptr,
// length: bytes.len(),
// ];
//
// On x86 (and perhaps others), dataWithBytes does not tail call
// `autorelease` and hence the return address points into that instead
// of our code, making the fast autorelease scheme fail.
//
// So instead, we call `autorelease` manually here.
let obj: *mut Object = msg_send![class!(NSMutableData), alloc];
let obj: *mut Object = msg_send![
obj,
initWithBytes: bytes_ptr,
length: bytes.len(),
];
let obj: *mut Object = msg_send![obj, autorelease];
// All code between the `msg_send!` and the `retain_autoreleased` must
// be able to be optimized away for this to work.
Id::retain_autoreleased(obj).unwrap()
}
}
#[test]
fn test_retain_autoreleased() {
autoreleasepool(|_| {
// Run once to allow DYLD to resolve the symbol stubs.
// Required for making `retain_autoreleased` work on x86_64.
let _data = create_data(b"12");
// When compiled in release mode / with optimizations enabled,
// subsequent usage of `retain_autoreleased` will succeed in retaining
// the autoreleased value!
let expected = if cfg!(feature = "gnustep-1-7") {
1
} else if cfg!(any(
debug_assertions,
feature = "exception",
feature = "verify_message"
)) {
2
} else {
1
};
let data = create_data(b"34");
assert_eq!(retain_count(&data), expected);
let data = create_data(b"56");
assert_eq!(retain_count(&data), expected);
// Here we manually clean up the autorelease, so it will always be 1.
let data = autoreleasepool(|_| create_data(b"78"));
assert_eq!(retain_count(&data), 1);
});
}