Remove legacy SimpleVersionScheme (#806)

Author: tli2

cs/src/core/Utilities/SimpleVersionScheme.cs

@@ -13,12 +13,12 @@ internal class SimpleVersionSchemeTest
         [Category("FasterLog")]
         public void SimpleTest()
         {
-            var tested = new SimpleVersionScheme();
+            var tested = new EpochProtectedVersionScheme(new LightEpoch());
             var protectedVal = 0;
             var v = tested.Enter();
 
-            Assert.AreEqual(1, v);
-            tested.TryAdvanceVersion((_, _) => protectedVal = 1);
+            Assert.AreEqual(1, v.Version);
+            tested.TryAdvanceVersionWithCriticalSection((_, _) => protectedVal = 1);
             Thread.Sleep(10);
             // because of ongoing protection, nothing should happen yet
             tested.Leave();
@@ -27,37 +27,37 @@ public void SimpleTest()
 
             // Next thread sees new version
             v = tested.Enter();
-            Assert.AreEqual(v, 2);
+            Assert.AreEqual(v.Version, 2);
             tested.Leave();
         }
 
         [Test]
         [Category("FasterLog")]
         public void SingleThreadTest()
         {
-            var tested = new SimpleVersionScheme();
+            var tested = new EpochProtectedVersionScheme(new LightEpoch());
             var protectedVal = 0;
 
             var v = tested.Enter();
-            Assert.AreEqual(1, v);
+            Assert.AreEqual(1, v.Version);
             tested.Leave();
 
-            tested.TryAdvanceVersion((_, _) => protectedVal = 1);
+            tested.TryAdvanceVersionWithCriticalSection((_, _) => protectedVal = 1);
             Assert.AreEqual(1, protectedVal);
 
-            tested.TryAdvanceVersion((_, _) => protectedVal = 2, 4);
+            tested.TryAdvanceVersionWithCriticalSection((_, _) => protectedVal = 2, 4);
             Assert.AreEqual(2, protectedVal);
 
             v = tested.Enter();
-            Assert.AreEqual(4, v);
+            Assert.AreEqual(4, v.Version);
             tested.Leave();
         }
 
         [Test]
         [Category("FasterLog")]
         public void LargeConcurrentTest()
         {
-            var tested = new SimpleVersionScheme();
+            var tested = new EpochProtectedVersionScheme(new LightEpoch());
             var protectedVal = 1L;
             var termination = new ManualResetEventSlim();
 
@@ -71,7 +71,7 @@ public void LargeConcurrentTest()
                     while (!termination.IsSet)
                     {
                         var v = tested.Enter();
-                        Assert.AreEqual(v, Interlocked.Read(ref protectedVal));
+                        Assert.AreEqual(v.Version, Interlocked.Read(ref protectedVal));
                         tested.Leave();
                     }
                 });
@@ -81,7 +81,7 @@ public void LargeConcurrentTest()
 
             for (var i = 0; i < 1000; i++)
             {
-                tested.TryAdvanceVersion((vOld, vNew) =>
+                tested.TryAdvanceVersionWithCriticalSection((vOld, vNew) =>
                 {
                     Assert.AreEqual(vOld, Interlocked.Read(ref protectedVal));
                     // Flip sign to simulate critical section processing

cs/test/SimpleVersionSchemeTest.cs

@@ -19,15 +19,15 @@ public class SimulatedFlakyDevice : StorageDeviceBase
         private ErrorSimulationOptions options;
         private ThreadLocal<Random> random;
         private List<long> permanentlyFailedRangesStart, permanentlyFailedRangesEnd;
-        private SimpleVersionScheme versionScheme;
+        private EpochProtectedVersionScheme versionScheme;
 
         public SimulatedFlakyDevice(IDevice underlying, ErrorSimulationOptions options) : base(underlying.FileName, underlying.SectorSize, underlying.Capacity)
         {
             this.underlying = underlying;
             this.options = options;
             permanentlyFailedRangesStart = new List<long>();
             permanentlyFailedRangesEnd = new List<long>();
-            versionScheme = new SimpleVersionScheme();
+            versionScheme = new EpochProtectedVersionScheme(new LightEpoch());
             random = new ThreadLocal<Random>(() => new Random());
         }
 
@@ -73,7 +73,7 @@ public override void WriteAsync(IntPtr sourceAddress, int segmentId, ulong desti
             else if (random.Value.NextDouble() < options.writePermanentErrorRate)
             {
                 callback(42, numBytesToWrite, context);
-                versionScheme.TryAdvanceVersion((_, _) =>
+                versionScheme.TryAdvanceVersionWithCriticalSection((_, _) =>
                 {
                     var index = permanentlyFailedRangesStart.BinarySearch(logicalDestStart);
                     if (index >= 0)
@@ -129,7 +129,7 @@ public override void ReadAsync(int segmentId, ulong sourceAddress, IntPtr destin
             {
                 callback(42, readLength, context);
 
-                versionScheme.TryAdvanceVersion((_, _) =>
+                versionScheme.TryAdvanceVersionWithCriticalSection((_, _) =>
                 {
                     var index = permanentlyFailedRangesStart.BinarySearch(logicalSrcStart);
                     if (index >= 0)