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
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
//! Implementation of frontend-feature related methods and functions
//! See the Structs in the [obdd-module][super] for most of the implementations
use crate::datatypes::Term;
use super::BddNode;
impl super::Bdd {
/// Instantiate a new [roBDD][super::Bdd] structure.
/// Constants for the [`⊤`][crate::datatypes::Term::TOP] and [`⊥`][crate::datatypes::Term::BOT] concepts are prepared in that step too.
/// # Attention
/// Constants for [`⊤`][crate::datatypes::Term::TOP] and [`⊥`][crate::datatypes::Term::BOT] concepts are not sent, as they are considered to be existing in every [Bdd][super::Bdd] structure.
pub fn with_sender(sender: crossbeam_channel::Sender<BddNode>) -> Self {
// TODO nicer handling of the initialisation though overhead is not an issue here
let mut result = Self::new();
result.set_sender(sender);
result
}
/// Instantiate a new [roBDD][super::Bdd] structure.
/// Constants for the [`⊤`][crate::datatypes::Term::TOP] and [`⊥`][crate::datatypes::Term::BOT] concepts are prepared in that step too.
/// # Attention
/// Note that mixing manipulating operations and utilising the communication channel for a receiving [roBDD][super::Bdd] may end up in inconsistent data.
/// So far, only manipulate the [roBDD][super::Bdd] if no further [recv][Self::recv] will be called.
pub fn with_receiver(receiver: crossbeam_channel::Receiver<BddNode>) -> Self {
// TODO nicer handling of the initialisation though overhead is not an issue here
let mut result = Self::new();
result.set_receiver(receiver);
result
}
/// Instantiate a new [roBDD][super::Bdd] structure.
/// Constants for the [`⊤`][crate::datatypes::Term::TOP] and [`⊥`][crate::datatypes::Term::BOT] concepts are prepared in that step too.
/// # Attention
/// - Constants for [`⊤`][crate::datatypes::Term::TOP] and [`⊥`][crate::datatypes::Term::BOT] concepts are not sent, as they are considered to be existing in every [Bdd][super::Bdd] structure.
/// - Mixing manipulating operations and utilising the communication channel for a receiving [roBDD][super::Bdd] may end up in inconsistent data.
/// So far, only manipulate the [roBDD][super::Bdd] if no further [recv][Self::recv] will be called.
pub fn with_sender_receiver(
sender: crossbeam_channel::Sender<BddNode>,
receiver: crossbeam_channel::Receiver<BddNode>,
) -> Self {
let mut result = Self::new();
result.set_receiver(receiver);
result.set_sender(sender);
result
}
/// Updates the currently used [sender][crossbeam_channel::Sender]
pub fn set_sender(&mut self, sender: crossbeam_channel::Sender<BddNode>) {
self.sender = Some(sender);
}
/// Updates the currently used [receiver][crossbeam_channel::Receiver]
pub fn set_receiver(&mut self, receiver: crossbeam_channel::Receiver<BddNode>) {
self.receiver = Some(receiver);
}
/// Receives all information till the looked for [`Term`][crate::datatypes::Term] is either found or all data is read.
/// Note that the values are read, consumed, and added to the [Bdd][super::Bdd].
/// # Returns
/// - [`true`] if the [term][crate::datatypes::Term] is found (either in the [Bdd][super::Bdd] or in the channel.
/// - [`false`] if neither the [Bdd][super::Bdd] nor the channel contains the [term][crate::datatypes::Term].
pub fn recv(&mut self, term: Term) -> bool {
if term.value() < self.nodes.len() {
true
} else if let Some(recv) = &self.receiver {
loop {
match recv.try_recv() {
Ok(node) => {
let new_term = Term(self.nodes.len());
self.nodes.push(node);
self.cache.insert(node, new_term);
if let Some(send) = &self.sender {
match send.send(node) {
Ok(_) => log::trace!("Sent {node} to the channel."),
Err(e) => {
log::error!(
"Error {e} occurred when sending {node} to {:?}",
send
)
}
}
}
if new_term == term {
return true;
}
}
Err(_) => return false,
}
}
} else {
false
}
}
}
#[cfg(test)]
mod test {
use super::super::*;
#[test]
fn get_bdd_updates() {
let (send, recv) = crossbeam_channel::unbounded();
let mut bdd = Bdd::with_sender(send);
let solving = std::thread::spawn(move || {
let v1 = bdd.variable(Var(0));
let v2 = bdd.variable(Var(1));
assert_eq!(v1, Term(2));
assert_eq!(v2, Term(3));
let t1 = bdd.and(v1, v2);
let nt1 = bdd.not(t1);
let ft = bdd.or(v1, nt1);
assert_eq!(ft, Term::TOP);
let v3 = bdd.variable(Var(2));
let nv3 = bdd.not(v3);
assert_eq!(bdd.and(v3, nv3), Term::BOT);
let conj = bdd.and(v1, v2);
assert_eq!(bdd.restrict(conj, Var(0), false), Term::BOT);
assert_eq!(bdd.restrict(conj, Var(0), true), v2);
let a = bdd.and(v3, v2);
let b = bdd.or(v2, v1);
let con1 = bdd.and(a, conj);
let end = bdd.or(con1, b);
log::debug!("Restrict test: restrict({},{},false)", end, Var(1));
let x = bdd.restrict(end, Var(1), false);
assert_eq!(x, Term(2));
});
let updates: Vec<BddNode> = recv.iter().collect();
assert_eq!(
updates,
vec![
BddNode::new(Var(0), Term(0), Term(1)),
BddNode::new(Var(1), Term(0), Term(1)),
BddNode::new(Var(0), Term(0), Term(3)),
BddNode::new(Var(1), Term(1), Term(0)),
BddNode::new(Var(0), Term(1), Term(5)),
BddNode::new(Var(2), Term(0), Term(1)),
BddNode::new(Var(2), Term(1), Term(0)),
BddNode::new(Var(1), Term(0), Term(7)),
BddNode::new(Var(0), Term(3), Term(1)),
BddNode::new(Var(0), Term(0), Term(9)),
]
);
solving.join().expect("Both threads should terminate");
}
#[test]
fn recv_send() {
let (send1, recv1) = crossbeam_channel::unbounded();
let (send2, recv2) = crossbeam_channel::unbounded();
let mut bdd1 = Bdd::with_sender(send1);
let mut bddm = Bdd::with_sender_receiver(send2, recv1);
let mut bddl = Bdd::with_receiver(recv2);
let solving = std::thread::spawn(move || {
let v1 = bdd1.variable(Var(0));
let v2 = bdd1.variable(Var(1));
assert_eq!(v1, Term(2));
assert_eq!(v2, Term(3));
let t1 = bdd1.and(v1, v2);
let nt1 = bdd1.not(t1);
let ft = bdd1.or(v1, nt1);
assert_eq!(ft, Term::TOP);
let v3 = bdd1.variable(Var(2));
let nv3 = bdd1.not(v3);
assert_eq!(bdd1.and(v3, nv3), Term::BOT);
let conj = bdd1.and(v1, v2);
assert_eq!(bdd1.restrict(conj, Var(0), false), Term::BOT);
assert_eq!(bdd1.restrict(conj, Var(0), true), v2);
let a = bdd1.and(v3, v2);
let b = bdd1.or(v2, v1);
let con1 = bdd1.and(a, conj);
let end = bdd1.or(con1, b);
log::debug!("Restrict test: restrict({},{},false)", end, Var(1));
let x = bdd1.restrict(end, Var(1), false);
assert_eq!(x, Term(2));
});
// allow the worker to fill the channels
std::thread::sleep(std::time::Duration::from_millis(10));
// both are initialised, no updates so far
assert_eq!(bddm.nodes, bddl.nodes);
// receiving a truth constant should work without changing the bdd
assert!(bddm.recv(Term::TOP));
assert_eq!(bddm.nodes, bddl.nodes);
// receiving some element works for middle -> last, but not last -> middle
assert!(bddm.recv(Term(2)));
assert!(bddl.recv(Term(2)));
assert_eq!(bddl.nodes.len(), 3);
assert!(!bddl.recv(Term(5)));
// get all elements into middle bdd1
assert!(!bddm.recv(Term(usize::MAX)));
assert_eq!(
bddm.nodes,
vec![
BddNode::bot_node(),
BddNode::top_node(),
BddNode::new(Var(0), Term(0), Term(1)),
BddNode::new(Var(1), Term(0), Term(1)),
BddNode::new(Var(0), Term(0), Term(3)),
BddNode::new(Var(1), Term(1), Term(0)),
BddNode::new(Var(0), Term(1), Term(5)),
BddNode::new(Var(2), Term(0), Term(1)),
BddNode::new(Var(2), Term(1), Term(0)),
BddNode::new(Var(1), Term(0), Term(7)),
BddNode::new(Var(0), Term(3), Term(1)),
BddNode::new(Var(0), Term(0), Term(9)),
]
);
// last bdd is still in the previous state
assert_eq!(
bddl.nodes,
vec![
BddNode::bot_node(),
BddNode::top_node(),
BddNode::new(Var(0), Term(0), Term(1)),
]
);
// and now catch up till 10
assert!(bddl.recv(Term(10)));
assert_eq!(
bddl.nodes,
vec![
BddNode::bot_node(),
BddNode::top_node(),
BddNode::new(Var(0), Term(0), Term(1)),
BddNode::new(Var(1), Term(0), Term(1)),
BddNode::new(Var(0), Term(0), Term(3)),
BddNode::new(Var(1), Term(1), Term(0)),
BddNode::new(Var(0), Term(1), Term(5)),
BddNode::new(Var(2), Term(0), Term(1)),
BddNode::new(Var(2), Term(1), Term(0)),
BddNode::new(Var(1), Term(0), Term(7)),
BddNode::new(Var(0), Term(3), Term(1)),
]
);
solving.join().expect("Both threads should terminate");
// asking for 10 again works too
assert!(bddl.recv(Term(10)));
// fully catch up with the last bdd
assert!(bddl.recv(Term(11)));
assert_eq!(bddl.nodes, bddm.nodes);
}
}