fix issue #17

Chronos.xcodeproj/project.pbxproj

@@ -7,6 +7,9 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		1323B0DA1E43AF1C00901259 /* Stopwatch.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1323B0D91E43AF1C00901259 /* Stopwatch.swift */; };
+		1323B0DB1E43AF1C00901259 /* Stopwatch.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1323B0D91E43AF1C00901259 /* Stopwatch.swift */; };
+		1323B0DC1E43AF1C00901259 /* Stopwatch.swift in Sources */ = {isa = PBXBuildFile; fileRef = 1323B0D91E43AF1C00901259 /* Stopwatch.swift */; };
 		6422C4A61AD38BBC00D480E8 /* Timer.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6422C4A51AD38BBC00D480E8 /* Timer.swift */; };
 		6422C4A71AD38C6F00D480E8 /* Timer.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6422C4A51AD38BBC00D480E8 /* Timer.swift */; };
 		6422C4A81AD38C6F00D480E8 /* Timer.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6422C4A51AD38BBC00D480E8 /* Timer.swift */; };
@@ -101,6 +104,7 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+		1323B0D91E43AF1C00901259 /* Stopwatch.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Stopwatch.swift; sourceTree = "<group>"; };
 		6422C4A51AD38BBC00D480E8 /* Timer.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Timer.swift; sourceTree = "<group>"; };
 		644FA4141ADE19560007B808 /* TimerInternal.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = TimerInternal.swift; sourceTree = "<group>"; };
 		644FA4161ADE19760007B808 /* VariableTimer.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = VariableTimer.swift; sourceTree = "<group>"; };
@@ -168,6 +172,14 @@
 /* End PBXFrameworksBuildPhase section */
 
 /* Begin PBXGroup section */
+		1323B0DD1E43AF3B00901259 /* Utils */ = {
+			isa = PBXGroup;
+			children = (
+				1323B0D91E43AF1C00901259 /* Stopwatch.swift */,
+			);
+			name = Utils;
+			sourceTree = "<group>";
+		};
 		64B3CE121ACDDA2800145E36 = {
 			isa = PBXGroup;
 			children = (
@@ -217,6 +229,7 @@
 			children = (
 				644FA4221ADE19A50007B808 /* DispatchTimerTests.swift */,
 				64502B951ADE19C50008443B /* VariableTimerTests.swift */,
+				1323B0DD1E43AF3B00901259 /* Utils */,
 				64B3CE2C1ACDDA2800145E36 /* Supporting Files */,
 			);
 			path = ChronosTests;
@@ -502,6 +515,7 @@
 				644FA4191ADE197C0007B808 /* VariableTimer.swift in Sources */,
 				644FA41E1ADE19810007B808 /* TimerInternal.swift in Sources */,
 				64B8678C1ACFCE070020EDDA /* DispatchTimer.swift in Sources */,
+				1323B0DA1E43AF1C00901259 /* Stopwatch.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -528,6 +542,7 @@
 				64C8842E1C0268A1005DB548 /* RepeatingTimer.swift in Sources */,
 				64C8842F1C0268A1005DB548 /* DispatchTimer.swift in Sources */,
 				64C884301C0268A1005DB548 /* VariableTimer.swift in Sources */,
+				1323B0DC1E43AF1C00901259 /* Stopwatch.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -554,6 +569,7 @@
 				644FA41A1ADE197C0007B808 /* VariableTimer.swift in Sources */,
 				644FA41C1ADE19800007B808 /* TimerInternal.swift in Sources */,
 				64B0D0F71AD0E58A0020EFE1 /* DispatchTimer.swift in Sources */,
+				1323B0DB1E43AF1C00901259 /* Stopwatch.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

Chronos/DispatchTimer.swift

@@ -56,8 +56,6 @@ open class DispatchTimer : NSObject, RepeatingTimer {
     fileprivate var leeway: UInt64 {
         return UInt64(0.05 * interval) * NSEC_PER_SEC;
     }
-    private let timebaseNumer: Double
-    private let timebaseDenom: Double
 
     // MARK: Properties
 
@@ -133,12 +131,6 @@ open class DispatchTimer : NSObject, RepeatingTimer {
       self.queue      = queue
       self.interval   = interval
       self.closure    = closure
-
-      //set timebase info
-      var info = mach_timebase_info(numer: 0, denom: 0)
-      mach_timebase_info(&info)
-      self.timebaseNumer = Double(info.numer)
-      self.timebaseDenom = Double(info.denom)
 
       super.init()
 
@@ -163,7 +155,7 @@ open class DispatchTimer : NSObject, RepeatingTimer {
         validate()
         if OSAtomicCompareAndSwap32Barrier(State.paused, State.running, &running) {
           timer.scheduleRepeating(deadline: startTime(interval, now: now),
-                                  interval:.nanoseconds(Int((interval * self.timebaseNumer) / self.timebaseDenom)))
+                                  interval: interval)
           timer.resume()
         }
     }

Chronos/TimerInternal.swift

@@ -25,7 +25,7 @@ internal struct State {
 // Mark:- Constants and Functions
 
 internal func startTime(_ interval: Double, now: Bool) -> DispatchTime {
-    return DispatchTime.now() + Double(now ? 0 : Int64(interval * Double(NSEC_PER_SEC))) / Double(NSEC_PER_SEC)
+    return DispatchTime.now() + Double(now ? 0 : interval)
 }
 
 

ChronosTests/DispatchTimerTests.swift

@@ -163,4 +163,64 @@ class DispatchTimerTests : XCTestCase {
 
         XCTAssertFalse(dispatchTimer.isValid)
     }
+
+    func testTimeInterval() {
+        var stopwatch = Stopwatch()
+        stopwatch.start()
+
+        let exp = expectation(description: "\(#function)\(#line)")
+
+        var records = [Double]()
+
+        let timeout = 22.2
+        let interval = 5.5
+
+        let dispatchTimer = DispatchTimer(interval: interval) { (timer: RepeatingTimer, invocations: Int) in
+            stopwatch.stop()
+            records += [floor(stopwatch.seconds)]
+
+            if invocations == Int(floor(timeout/interval))-1 {
+                exp.fulfill()
+            }
+        }
+
+        dispatchTimer.start(false)
+
+        waitForExpectations (timeout: timeout) { _ in
+            XCTAssertTrue(records.count == Int(timeout/interval))
+            for i in 0..<Int(floor(timeout/interval)) {
+                XCTAssertTrue(records[i] == floor(interval*Double(i + 1)))
+            }
+        }
+    }
+
+    func testTimeIntervalStartingNow() {
+        var stopwatch = Stopwatch()
+        stopwatch.start()
+
+        let exp = expectation(description: "\(#function)\(#line)")
+
+        var records = [Double]()
+
+        let timeout = 22.2
+        let interval = 5.5
+
+        let dispatchTimer = DispatchTimer(interval: interval) { (timer: RepeatingTimer, invocations: Int) in
+            stopwatch.stop()
+            records += [floor(stopwatch.seconds)]
+
+            if invocations == Int(floor(timeout/interval)) {
+                exp.fulfill()
+            }
+        }
+
+        dispatchTimer.start(true)
+
+        waitForExpectations (timeout: timeout) { _ in
+            XCTAssertTrue(records.count == Int(timeout/interval)+1)
+            for i in 0...Int(floor(timeout/interval)) {
+                XCTAssertTrue(records[i] == floor(interval*Double(i)))
+            }
+        }
+    }
 }

ChronosTests/Stopwatch.swift

@@ -0,0 +1,43 @@
+//
+//  Stopwatch.swift
+//  Chronos
+//
+//  Created by ggiampietro on 2/2/17.
+//  Copyright © 2017 com.comyarzaheri. All rights reserved.
+//
+
+import Foundation
+
+struct Stopwatch {
+    var startTime: UInt64 = 0
+    var stopTime: UInt64 = 0
+    let numer: UInt64
+    let denom: UInt64
+
+    init() {
+        var info = mach_timebase_info(numer: 0, denom: 0)
+        mach_timebase_info(&info)
+        numer = UInt64(info.numer)
+        denom = UInt64(info.denom)
+    }
+
+    mutating func start() {
+        startTime = mach_absolute_time()
+    }
+
+    mutating func stop() {
+        stopTime = mach_absolute_time()
+    }
+
+    var nanoseconds: UInt64 {
+        return ((stopTime - startTime) * numer) / denom
+    }
+
+    var milliseconds: Double {
+        return Double(nanoseconds) / 1_000_000
+    }
+
+    var seconds: Double {
+        return Double(nanoseconds) / 1_000_000_000
+    }
+}