Correction to Atomic tests

Author: hlovatt

Concurrency Utilities.xcodeproj/project.pbxproj

@@ -31,6 +31,7 @@
 7678E28F1F5D1B2500FE6D0B /* Concurrency_UtilitiesTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Concurrency_UtilitiesTests.swift; sourceTree = "<group>"; };
 7678E2911F5D1B2500FE6D0B /* Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = Info.plist; sourceTree = "<group>"; };
 7678E29B1F5D1DE500FE6D0B /* Atomic.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Atomic.swift; sourceTree = "<group>"; };
+7678E29D1F5D2CD500FE6D0B /* README.md */ = {isa = PBXFileReference; lastKnownFileType = net.daringfireball.markdown; path = README.md; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -55,6 +56,7 @@
 7678E2771F5D1B2500FE6D0B = {
 isa = PBXGroup;
 children = (
+7678E29D1F5D2CD500FE6D0B /* README.md */,
 7678E2831F5D1B2500FE6D0B /* Concurrency Utilities */,
 7678E28E1F5D1B2500FE6D0B /* Concurrency UtilitiesTests */,
 7678E2821F5D1B2500FE6D0B /* Products */,

Concurrency UtilitiesTests/Concurrency_UtilitiesTests.swift

@@ -10,28 +10,34 @@ import XCTest
 @testable import Concurrency_Utilities
 
 class Concurrency_UtilitiesTests: XCTestCase {
- func testGetSetUpdate() {
- var test = Atomic((0, 0))
- var error = Atomic(false)
- for i in 0 ..< 10 {
+ func testAtomicGetSetUpdate() {
+ let test = Atomic((0, 0)) // Test that two parts of tuple always have same value.
+ let error = Atomic(false)
+ let group = DispatchGroup()
+ for i in 1 ... 10 {
+ group.enter()
  DispatchQueue.global().async {
+ defer { group.leave() }
  test.value = (i, i)
  }
+ group.enter()
  DispatchQueue.global().async {
  test.update {
- ($0.0 + 1, $0.1 + 1)
+ defer { group.leave() }
+ return ($0.0 + 1, $0.1 + 1)
  }
  }
+ group.enter()
  DispatchQueue.global().async {
  error.update {
- guard !$0 else {
- return true
- }
+ defer { group.leave() }
+ guard !$0 else { return true } // Don't over-write an existing error.
  let t = test.value
- return t.0 != t.1
+ return t.0 != t.1 // Test two parts of tuple have same value.
  }
  }
  }
+ group.wait()
  XCTAssertFalse(error.value)
  }