qir_stdlib/
tuples.rs

1// Copyright (c) Microsoft Corporation.
2// Licensed under the MIT License.
3
4use crate::update_counts;
5use std::{
6    mem::{ManuallyDrop, size_of},
7    rc::Rc,
8};
9
10#[allow(clippy::cast_ptr_alignment)]
11#[unsafe(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#[unsafe(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    unsafe {
34        let rc = ManuallyDrop::new(Rc::from_raw(*(raw_tup).wrapping_sub(1)));
35        if force || Rc::weak_count(&rc) > 0 {
36            let mut copy = rc.as_ref().clone();
37            let header = copy.as_mut_ptr().cast::<*const Vec<u8>>();
38            *header = Rc::into_raw(Rc::new(copy));
39            header.wrapping_add(1)
40        } else {
41            let _ = Rc::into_raw(Rc::clone(&rc));
42            raw_tup
43        }
44    }
45}
46
47#[unsafe(no_mangle)]
48pub unsafe extern "C" fn __quantum__rt__tuple_update_reference_count(
49    raw_tup: *mut *const Vec<u8>,
50    update: i32,
51) {
52    unsafe {
53        update_counts(*raw_tup.wrapping_sub(1), update, false);
54    }
55}
56
57#[unsafe(no_mangle)]
58pub unsafe extern "C" fn __quantum__rt__tuple_update_alias_count(
59    raw_tup: *mut *const Vec<u8>,
60    update: i32,
61) {
62    unsafe {
63        update_counts(*raw_tup.wrapping_sub(1), update, true);
64    }
65}
66
67#[cfg(test)]
68mod tests {
69    use super::*;
70
71    #[test]
72    fn test_tuple_create() {
73        let tup = __quantum__rt__tuple_create(size_of::<u32>() as u64);
74        unsafe {
75            *tup.cast::<u32>() = 42;
76            __quantum__rt__tuple_update_reference_count(tup, -1);
77        }
78    }
79
80    #[test]
81    fn test_tuple_update_reference_count() {
82        let tup = __quantum__rt__tuple_create(size_of::<u32>() as u64);
83        unsafe {
84            let rc = ManuallyDrop::new(Rc::from_raw(*tup.cast::<*const Vec<u8>>().wrapping_sub(1)));
85            assert_eq!(Rc::strong_count(&rc), 1);
86            __quantum__rt__tuple_update_reference_count(tup, 2);
87            assert_eq!(Rc::strong_count(&rc), 3);
88            __quantum__rt__tuple_update_reference_count(tup, -2);
89            assert_eq!(Rc::strong_count(&rc), 1);
90            __quantum__rt__tuple_update_reference_count(tup, -1);
91        }
92    }
93
94    #[test]
95    fn test_tuple_update_alias_count() {
96        let tup = __quantum__rt__tuple_create(size_of::<u32>() as u64);
97        unsafe {
98            let rc = ManuallyDrop::new(Rc::from_raw(*tup.cast::<*const Vec<u8>>().wrapping_sub(1)));
99            assert_eq!(Rc::strong_count(&rc), 1);
100            assert_eq!(Rc::weak_count(&rc), 0);
101            __quantum__rt__tuple_update_alias_count(tup, 2);
102            assert_eq!(Rc::weak_count(&rc), 2);
103            __quantum__rt__tuple_update_alias_count(tup, -2);
104            assert_eq!(Rc::weak_count(&rc), 0);
105            __quantum__rt__tuple_update_reference_count(tup, -1);
106        }
107    }
108
109    #[test]
110    fn test_tuple_copy() {
111        let tup1 = __quantum__rt__tuple_create(size_of::<u32>() as u64);
112        unsafe {
113            *tup1.cast::<u32>() = 42;
114            let tup2 = __quantum__rt__tuple_copy(tup1, false);
115            assert_eq!(tup2, tup1);
116            assert_eq!(*tup2.cast::<u32>(), 42);
117            __quantum__rt__tuple_update_reference_count(tup2, -1);
118            assert_eq!(*tup1.cast::<u32>(), 42);
119            let tup3 = __quantum__rt__tuple_copy(tup1, true);
120            assert_ne!(tup3, tup1);
121            assert_eq!(*tup3.cast::<u32>(), 42);
122            __quantum__rt__tuple_update_reference_count(tup3, -1);
123            assert_eq!(*tup1.cast::<u32>(), 42);
124            __quantum__rt__tuple_update_alias_count(tup1, 1);
125            let tup4 = __quantum__rt__tuple_copy(tup1, false);
126            assert_ne!(tup4, tup1);
127            assert_eq!(*tup4.cast::<u32>(), 42);
128            __quantum__rt__tuple_update_reference_count(tup4, -1);
129            assert_eq!(*tup1.cast::<u32>(), 42);
130            __quantum__rt__tuple_update_alias_count(tup1, -1);
131            __quantum__rt__tuple_update_reference_count(tup1, -1);
132        }
133    }
134}
qir_stdlib/tuples.rs

qir_stdlib/
tuples.rs
