File: WrappedSemaphore.swift

package info (click to toggle)
swiftlang 6.0.3-2
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid, trixie
  • size: 2,519,992 kB
  • sloc: cpp: 9,107,863; ansic: 2,040,022; asm: 1,135,751; python: 296,500; objc: 82,456; f90: 60,502; lisp: 34,951; pascal: 19,946; sh: 18,133; perl: 7,482; ml: 4,937; javascript: 4,117; makefile: 3,840; awk: 3,535; xml: 914; fortran: 619; cs: 573; ruby: 573
file content (63 lines) | stat: -rw-r--r-- 2,071 bytes parent folder | download
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
//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2024 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
//
//===----------------------------------------------------------------------===//

import Dispatch
import LSPTestSupport
import XCTest

/// Wrapper around `DispatchSemaphore` so that Swift Concurrency doesn't complain about the usage of semaphores in the
/// tests.
///
/// This should only be used for tests that test priority escalation and thus cannot await a `Task` (which would cause
/// priority elevations).
public struct WrappedSemaphore: Sendable {
  private let name: String
  private let semaphore = DispatchSemaphore(value: 0)

  public init(name: String) {
    self.name = name
  }

  public func signal(value: Int = 1) {
    for _ in 0..<value {
      semaphore.signal()
    }
  }

  private func wait(timeout: DispatchTime) -> DispatchTimeoutResult {
    semaphore.wait(timeout: timeout)
  }

  /// Wait for a signal and throw an error if the semaphore is not signaled within `timeout`.
  public func waitOrThrow(timeout: DispatchTime = DispatchTime.now() + .seconds(Int(defaultTimeout))) throws {
    struct TimeoutError: Error, CustomStringConvertible {
      let name: String
      var description: String { "\(name) timed out" }
    }
    switch self.wait(timeout: timeout) {
    case .success:
      break
    case .timedOut:
      throw TimeoutError(name: name)
    }
  }

  /// Wait for a signal and emit an XCTFail if the semaphore is not signaled within `timeout`.
  public func waitOrXCTFail(timeout: DispatchTime = DispatchTime.now() + .seconds(Int(defaultTimeout))) {
    switch self.wait(timeout: timeout) {
    case .success:
      break
    case .timedOut:
      XCTFail("\(name) timed out")
    }
  }
}