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
use parking_lot::{RwLock, RwLockReadGuard, RwLockWriteGuard};
use std::{
mem,
ops::{Deref, DerefMut},
sync::Arc,
};
use crate::maps::Map;
pub(crate) struct MapLockError;
#[derive(Debug)]
pub(crate) struct MapLock {
inner: Arc<RwLock<Map>>,
}
impl MapLock {
pub(crate) fn new(map: Map) -> MapLock {
MapLock {
inner: Arc::new(RwLock::new(map)),
}
}
pub(crate) fn try_read(&self) -> Result<MapRef, MapLockError> {
let lock: Option<RwLockReadGuard<'static, Map>> =
unsafe { mem::transmute(self.inner.try_read()) };
lock.map(|guard| MapRef {
_lock: self.inner.clone(),
guard,
})
.ok_or(MapLockError)
}
pub(crate) fn try_write(&self) -> Result<MapRefMut, MapLockError> {
let lock: Option<RwLockWriteGuard<'static, Map>> =
unsafe { mem::transmute(self.inner.try_write()) };
lock.map(|guard| MapRefMut {
_lock: self.inner.clone(),
guard,
})
.ok_or(MapLockError)
}
}
pub struct MapRef {
_lock: Arc<RwLock<Map>>,
guard: RwLockReadGuard<'static, Map>,
}
pub struct MapRefMut {
_lock: Arc<RwLock<Map>>,
guard: RwLockWriteGuard<'static, Map>,
}
impl Deref for MapRef {
type Target = Map;
fn deref(&self) -> &Map {
&*self.guard
}
}
impl Deref for MapRefMut {
type Target = Map;
fn deref(&self) -> &Map {
&*self.guard
}
}
impl DerefMut for MapRefMut {
fn deref_mut(&mut self) -> &mut Map {
&mut *self.guard
}
}