some benchmarks might be using parameters that have locking finalizers

so we need to dispose them after we are done running the benchmarks

see #1383 and dotnet/runtime#314 for more

src/BenchmarkDotNet/Parameters/ParameterInstance.cs

@@ -8,7 +8,7 @@
 
 namespace BenchmarkDotNet.Parameters
 {
-    public class ParameterInstance
+    public class ParameterInstance : IDisposable
     {
         public const string NullParameterTextRepresentation = "?";
 
@@ -24,6 +24,8 @@ public ParameterInstance(ParameterDefinition definition, object value, SummarySt
             maxParameterColumnWidth = summaryStyle?.MaxParameterColumnWidth ?? SummaryStyle.DefaultMaxParameterColumnWidth;
         }
 
+        public void Dispose() => (Value as IDisposable)?.Dispose();
+
         public string Name => Definition.Name;
         public bool IsStatic => Definition.IsStatic;
         public bool IsArgument => Definition.IsArgument;

src/BenchmarkDotNet/Parameters/ParameterInstances.cs

@@ -1,10 +1,11 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Linq;
 using BenchmarkDotNet.Extensions;
 
 namespace BenchmarkDotNet.Parameters
 {
-    public class ParameterInstances
+    public class ParameterInstances : IDisposable
     {
         public IReadOnlyList<ParameterInstance> Items { get; }
         public int Count => Items.Count;
@@ -18,6 +19,14 @@ public ParameterInstances(IReadOnlyList<ParameterInstance> items)
             Items = items;
         }
 
+        public void Dispose()
+        {
+            foreach (var parameterInstance in Items)
+            {
+                parameterInstance.Dispose();
+            }
+        }
+
         public string FolderInfo => string.Join("_", Items.Select(p => $"{p.Name}-{p.ToDisplayText()}")).AsValidFileName();
 
         public string DisplayInfo =>  Items.Any() ? "[" + string.Join(", ", Items.Select(p => $"{p.Name}={p.ToDisplayText()}")) + "]" : "";

src/BenchmarkDotNet/Running/BenchmarkCase.cs

@@ -6,7 +6,7 @@
 
 namespace BenchmarkDotNet.Running
 {
-    public class BenchmarkCase : IComparable<BenchmarkCase>
+    public class BenchmarkCase : IComparable<BenchmarkCase>, IDisposable
     {
         public Descriptor Descriptor { get; }
         public Job Job { get; }
@@ -26,6 +26,8 @@ private BenchmarkCase(Descriptor descriptor, Job job, ParameterInstances paramet
             Config = config;
         }
 
+        public void Dispose() => Parameters.Dispose();
+
         public int CompareTo(BenchmarkCase other) => string.Compare(FolderInfo, other.FolderInfo, StringComparison.Ordinal);
 
         public bool HasParameters => Parameters != null && Parameters.Items.Any();

src/BenchmarkDotNet/Running/BenchmarkRunInfo.cs

@@ -3,7 +3,7 @@
 
 namespace BenchmarkDotNet.Running
 {
-    public class BenchmarkRunInfo
+    public class BenchmarkRunInfo : IDisposable
     {
         public BenchmarkRunInfo(BenchmarkCase[] benchmarksCase, Type type, ImmutableConfig config)
         {
@@ -12,6 +12,14 @@ public BenchmarkRunInfo(BenchmarkCase[] benchmarksCase, Type type, ImmutableConf
             Config = config;
         }
 
+        public void Dispose()
+        {
+            foreach (var benchmarkCase in BenchmarksCases)
+            {
+                benchmarkCase.Dispose();
+            }
+        }
+
         public BenchmarkCase[] BenchmarksCases { get; }
         public Type Type { get; }
         public ImmutableConfig Config { get; }

src/BenchmarkDotNet/Running/BenchmarkRunnerClean.cs

@@ -107,6 +107,14 @@ internal static Summary[] Run(BenchmarkRunInfo[] benchmarkRunInfos)
                 }
                 finally
                 {
+                    // some benchmarks might be using parameters that have locking finalizers
+                    // so we need to dispose them after we are done running the benchmarks
+                    // see https://github.com/dotnet/BenchmarkDotNet/issues/1383 and https://github.com/dotnet/runtime/issues/314 for more
+                    foreach (var benchmarkInfo in benchmarkRunInfos)
+                    {
+                        benchmarkInfo.Dispose();
+                    }
+
                     compositeLogger.WriteLineHeader("// * Artifacts cleanup *");
                     Cleanup(new HashSet<string>(artifactsToCleanup.Distinct()));
                     compositeLogger.Flush();