Drive-by improve a hashtable to hashset.

Benoit Hudson · Benoit Hudson · commit d016b24ef34e · 2018-09-26T03:50:21.000-04:00
Also added comments explaining what the hashset is about.
diff --git a/src/runtime/typemanager.cs b/src/runtime/typemanager.cs
@@ -454,7 +454,10 @@ internal static IntPtr AllocateTypeObject(string name)
         /// </summary>
         internal static void InitializeSlots(IntPtr type, Type impl)
         {
-            var seen = new Hashtable(8);
+            // We work from the most-derived class up; make sure to get
+            // the most-derived slot and not to override it with a base
+            // class's slot.
+            var seen = new HashSet<string>();
             Type offsetType = typeof(TypeOffset);
 
             while (impl != null)
@@ -473,7 +476,7 @@ internal static void InitializeSlots(IntPtr type, Type impl)
                         continue;
                     }
 
-                    if (seen[name] != null)
+                    if (seen.Contains(name))
                     {
                         continue;
                     }
@@ -484,7 +487,7 @@ internal static void InitializeSlots(IntPtr type, Type impl)
                     IntPtr slot = Interop.GetThunk(method);
                     Marshal.WriteIntPtr(type, offset, slot);
 
-                    seen[name] = 1;
+                    seen.Add(name);
                 }
 
                 impl = impl.BaseType;

Original file line number	Diff line number	Diff line change
`@@ -454,7 +454,10 @@ internal static IntPtr AllocateTypeObject(string name)`
`454`	`454`	`/// </summary>`
`455`	`455`	`internal static void InitializeSlots(IntPtr type, Type impl)`
`456`	`456`	`{`
`457`		`- var seen = new Hashtable(8);`
	`457`	`+ // We work from the most-derived class up; make sure to get`
	`458`	`+ // the most-derived slot and not to override it with a base`
	`459`	`+ // class's slot.`
	`460`	`+ var seen = new HashSet<string>();`
`458`	`461`	`Type offsetType = typeof(TypeOffset);`
`459`	`462`
`460`	`463`	`while (impl != null)`
`@@ -473,7 +476,7 @@ internal static void InitializeSlots(IntPtr type, Type impl)`
`473`	`476`	`continue;`
`474`	`477`	`}`
`475`	`478`
`476`		`- if (seen[name] != null)`
	`479`	`+ if (seen.Contains(name))`
`477`	`480`	`{`
`478`	`481`	`continue;`
`479`	`482`	`}`
`@@ -484,7 +487,7 @@ internal static void InitializeSlots(IntPtr type, Type impl)`
`484`	`487`	`IntPtr slot = Interop.GetThunk(method);`
`485`	`488`	`Marshal.WriteIntPtr(type, offset, slot);`
`486`	`489`
`487`		`- seen[name] = 1;`
	`490`	`+ seen.Add(name);`
`488`	`491`	`}`
`489`	`492`
`490`	`493`	`impl = impl.BaseType;`