sim-lib-numbers-tensor 0.2.0

Uniform n-dimensional tensor value, constructors, and specialization hooks for SIM numbers.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140

use std::any::Any;
use std::sync::atomic::{AtomicUsize, Ordering};
use std::sync::{Arc, OnceLock};

use sim_kernel::{DefaultFactory, Error, Factory, Result, Symbol, Value};

use crate::{Tensor, TensorLocation, TensorStorage, build_tensor_value};

use super::{number, test_cx};

struct TestResidentStorage {
    dtype: Symbol,
    host: Arc<dyn TensorStorage>,
    readbacks: Arc<AtomicUsize>,
    fail: bool,
    materialized: OnceLock<Result<Arc<dyn TensorStorage>>>,
}

impl TensorStorage for TestResidentStorage {
    fn dtype(&self) -> &Symbol {
        &self.dtype
    }

    fn len(&self) -> usize {
        self.host.len()
    }

    fn location(&self) -> TensorLocation {
        TensorLocation::Resident {
            site: Symbol::qualified("test", "site"),
            allocation: Symbol::qualified("test", "allocation"),
        }
    }

    fn cell(&self, index: usize) -> Result<Value> {
        self.materialize()?.cell(index)
    }

    fn materialize(&self) -> Result<Arc<dyn TensorStorage>> {
        self.materialized
            .get_or_init(|| {
                self.readbacks.fetch_add(1, Ordering::SeqCst);
                if self.fail {
                    Err(Error::Eval("test tensor readback failed".to_owned()))
                } else {
                    Ok(self.host.clone())
                }
            })
            .clone()
    }

    fn as_any(&self) -> &dyn Any {
        self
    }
}

fn resident_tensor(fail: bool) -> (Tensor, Vec<Value>, Arc<AtomicUsize>) {
    let dtype = Symbol::qualified("numbers", "i64");
    let cells = vec![number("i64", "3"), number("i64", "5")];
    let host = Tensor::new_exact(vec![2], dtype.clone(), cells.clone()).unwrap();
    let readbacks = Arc::new(AtomicUsize::new(0));
    let storage = Arc::new(TestResidentStorage {
        dtype: dtype.clone(),
        host: host.storage().clone(),
        readbacks: readbacks.clone(),
        fail,
        materialized: OnceLock::new(),
    });
    (
        Tensor::from_storage(vec![2], dtype, storage).unwrap(),
        cells,
        readbacks,
    )
}

#[test]
fn tensor_observation_propagates_and_caches_storage_failure() {
    let (tensor, _, readbacks) = resident_tensor(true);
    assert!(tensor.cell(0).unwrap_err().to_string().contains("readback"));
    assert!(tensor.cells().unwrap_err().to_string().contains("readback"));
    assert_eq!(readbacks.load(Ordering::SeqCst), 1);
}

#[test]
fn tensor_materialization_is_idempotent_and_preserves_aliases() {
    let (tensor, source, readbacks) = resident_tensor(false);
    let clone = tensor.clone();
    assert!(Arc::ptr_eq(tensor.storage(), clone.storage()));

    let first_storage = tensor.materialize().unwrap();
    let second_storage = tensor.materialize().unwrap();
    assert!(Arc::ptr_eq(&first_storage, &second_storage));

    let first_cells = tensor.cells().unwrap();
    let second_cells = tensor.cells().unwrap();
    assert!(Arc::ptr_eq(&first_cells, &second_cells));
    assert_eq!(first_cells[0], source[0]);
    assert_eq!(first_cells[1], source[1]);
    assert_eq!(readbacks.load(Ordering::SeqCst), 1);

    let mut cx = test_cx();
    let value = DefaultFactory.opaque(Arc::new(tensor)).unwrap();
    sim_citizen::check_value_fixture(&mut cx, value).unwrap();
    assert_eq!(readbacks.load(Ordering::SeqCst), 1);
}

#[test]
fn zero_sized_tensor_keeps_shape_dtype_and_empty_observation() {
    let dtype = Symbol::qualified("numbers", "i64");
    let tensor = Tensor::new_exact(vec![2, 0, 4], dtype.clone(), Vec::new()).unwrap();
    assert_eq!(tensor.shape(), &[2, 0, 4]);
    assert_eq!(tensor.dtype(), &dtype);
    assert!(tensor.is_empty());
    assert!(tensor.cells().unwrap().is_empty());
    assert!(Tensor::coordinates(tensor.shape()).is_empty());

    let mut cx = test_cx();
    let value = build_tensor_value(&mut cx, vec![0], Some(dtype), Vec::new()).unwrap();
    sim_citizen::check_value_fixture(&mut cx, value).unwrap();
}

#[test]
fn concurrent_tensor_observation_performs_one_readback() {
    let (tensor, _, readbacks) = resident_tensor(false);
    let tensor = Arc::new(tensor);
    let observations = (0..8)
        .map(|_| {
            let tensor = tensor.clone();
            std::thread::spawn(move || tensor.cells().unwrap())
        })
        .collect::<Vec<_>>()
        .into_iter()
        .map(|thread| thread.join().unwrap())
        .collect::<Vec<_>>();

    for cells in observations.iter().skip(1) {
        assert!(Arc::ptr_eq(&observations[0], cells));
    }
    assert_eq!(readbacks.load(Ordering::SeqCst), 1);
}