qir_stdlib/
tuples.rs

1// Copyright (c) Microsoft Corporation.
2// Licensed under the MIT License.
3
4use crate::update_counts;
5use std::{
6    mem::{size_of, ManuallyDrop},
7    rc::Rc,
8};
9
10#[allow(clippy::cast_ptr_alignment)]
11#[no_mangle]
12pub extern "C" fn __quantum__rt__tuple_create(size: u64) -> *mut *const Vec<u8> {
13    let mut mem = vec![
14        0_u8;
15        <usize as std::convert::TryFrom<u64>>::try_from(size)
16            .expect("Tuple size too large for `usize` type on this platform.")
17            + size_of::<*const Vec<u8>>()
18    ];
19
20    unsafe {
21        let header = mem.as_mut_ptr().cast::<*const Vec<u8>>();
22        *header = Rc::into_raw(Rc::new(mem));
23        header.wrapping_add(1)
24    }
25}
26
27#[allow(clippy::cast_ptr_alignment)]
28#[no_mangle]
29pub unsafe extern "C" fn __quantum__rt__tuple_copy(
30    raw_tup: *mut *const Vec<u8>,
31    force: bool,
32) -> *mut *const Vec<u8> {
33    let rc = ManuallyDrop::new(Rc::from_raw(*(raw_tup).wrapping_sub(1)));
34    if force || Rc::weak_count(&rc) > 0 {
35        let mut copy = rc.as_ref().clone();
36        let header = copy.as_mut_ptr().cast::<*const Vec<u8>>();
37        *header = Rc::into_raw(Rc::new(copy));
38        header.wrapping_add(1)
39    } else {
40        let _ = Rc::into_raw(Rc::clone(&rc));
41        raw_tup
42    }
43}
44
45#[no_mangle]
46pub unsafe extern "C" fn __quantum__rt__tuple_update_reference_count(
47    raw_tup: *mut *const Vec<u8>,
48    update: i32,
49) {
50    update_counts(*raw_tup.wrapping_sub(1), update, false);
51}
52
53#[no_mangle]
54pub unsafe extern "C" fn __quantum__rt__tuple_update_alias_count(
55    raw_tup: *mut *const Vec<u8>,
56    update: i32,
57) {
58    update_counts(*raw_tup.wrapping_sub(1), update, true);
59}
60
61#[cfg(test)]
62mod tests {
63    use super::*;
64
65    #[test]
66    fn test_tuple_create() {
67        let tup = __quantum__rt__tuple_create(size_of::<u32>() as u64);
68        unsafe {
69            *tup.cast::<u32>() = 42;
70            __quantum__rt__tuple_update_reference_count(tup, -1);
71        }
72    }
73
74    #[test]
75    fn test_tuple_update_reference_count() {
76        let tup = __quantum__rt__tuple_create(size_of::<u32>() as u64);
77        unsafe {
78            let rc = ManuallyDrop::new(Rc::from_raw(*tup.cast::<*const Vec<u8>>().wrapping_sub(1)));
79            assert_eq!(Rc::strong_count(&rc), 1);
80            __quantum__rt__tuple_update_reference_count(tup, 2);
81            assert_eq!(Rc::strong_count(&rc), 3);
82            __quantum__rt__tuple_update_reference_count(tup, -2);
83            assert_eq!(Rc::strong_count(&rc), 1);
84            __quantum__rt__tuple_update_reference_count(tup, -1);
85        }
86    }
87
88    #[test]
89    fn test_tuple_update_alias_count() {
90        let tup = __quantum__rt__tuple_create(size_of::<u32>() as u64);
91        unsafe {
92            let rc = ManuallyDrop::new(Rc::from_raw(*tup.cast::<*const Vec<u8>>().wrapping_sub(1)));
93            assert_eq!(Rc::strong_count(&rc), 1);
94            assert_eq!(Rc::weak_count(&rc), 0);
95            __quantum__rt__tuple_update_alias_count(tup, 2);
96            assert_eq!(Rc::weak_count(&rc), 2);
97            __quantum__rt__tuple_update_alias_count(tup, -2);
98            assert_eq!(Rc::weak_count(&rc), 0);
99            __quantum__rt__tuple_update_reference_count(tup, -1);
100        }
101    }
102
103    #[test]
104    fn test_tuple_copy() {
105        let tup1 = __quantum__rt__tuple_create(size_of::<u32>() as u64);
106        unsafe {
107            *tup1.cast::<u32>() = 42;
108            let tup2 = __quantum__rt__tuple_copy(tup1, false);
109            assert_eq!(tup2, tup1);
110            assert_eq!(*tup2.cast::<u32>(), 42);
111            __quantum__rt__tuple_update_reference_count(tup2, -1);
112            assert_eq!(*tup1.cast::<u32>(), 42);
113            let tup3 = __quantum__rt__tuple_copy(tup1, true);
114            assert_ne!(tup3, tup1);
115            assert_eq!(*tup3.cast::<u32>(), 42);
116            __quantum__rt__tuple_update_reference_count(tup3, -1);
117            assert_eq!(*tup1.cast::<u32>(), 42);
118            __quantum__rt__tuple_update_alias_count(tup1, 1);
119            let tup4 = __quantum__rt__tuple_copy(tup1, false);
120            assert_ne!(tup4, tup1);
121            assert_eq!(*tup4.cast::<u32>(), 42);
122            __quantum__rt__tuple_update_reference_count(tup4, -1);
123            assert_eq!(*tup1.cast::<u32>(), 42);
124            __quantum__rt__tuple_update_alias_count(tup1, -1);
125            __quantum__rt__tuple_update_reference_count(tup1, -1);
126        }
127    }
128}
qir_stdlib/tuples.rs

qir_stdlib/
tuples.rs
