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
|
//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift Atomics open source project
//
// Copyright (c) 2014 - 2020 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
/// A type that tracks the number of live instances.
///
/// To be useful in more contexts, `LifetimeTracked` conforms to various
/// protocols in trivial ways.
///
/// `LifetimeTracked` is useful to check for leaks in algorithms and data
/// structures. `StdlibUnittest` harness automatically checks that after each
/// test has done executing, no `LifetimeTracked` instances exist.
public final class LifetimeTracked {
public init(_ value: Int, identity: Int = 0) {
LifetimeTracked.instances += 1
LifetimeTracked._nextSerialNumber += 1
serialNumber = LifetimeTracked._nextSerialNumber
self.value = value
self.identity = identity
}
deinit {
assert(serialNumber > 0, "double destruction!")
LifetimeTracked.instances -= 1
serialNumber = -serialNumber
}
public static var instances: Int = 0
internal static var _nextSerialNumber = 0
public let value: Int
public var identity: Int
public var serialNumber: Int = 0
}
extension LifetimeTracked : Equatable {
public static func == (x: LifetimeTracked, y: LifetimeTracked) -> Bool {
return x.value == y.value
}
}
extension LifetimeTracked : Hashable {
public var hashValue: Int {
return value
}
public func hash(into hasher: inout Hasher) {
hasher.combine(value)
}
}
extension LifetimeTracked : Strideable {
public func distance(to other: LifetimeTracked) -> Int {
return self.value.distance(to: other.value)
}
public func advanced(by n: Int) -> LifetimeTracked {
return LifetimeTracked(self.value.advanced(by: n))
}
}
extension LifetimeTracked : CustomStringConvertible {
public var description: String {
assert(serialNumber > 0, "dead Tracked!")
return value.description
}
}
public func < (x: LifetimeTracked, y: LifetimeTracked) -> Bool {
return x.value < y.value
}
|
