Remove GC.GetTotalMemory from gc.collect (IronLanguages#2103)

Author: slozier

src/core/IronPython.Modules/gc.cs

@@ -44,13 +44,11 @@ public static object isenabled() {
             return ScriptingRuntimeHelpers.True;
         }
 
-        public static int collect(CodeContext context, int generation) {
-            return context.LanguageContext.Collect(generation);
-        }
+        public static void collect(CodeContext context, int generation)
+            => context.LanguageContext.Collect(generation);
 
-        public static int collect(CodeContext context) {
-            return collect(context, GC.MaxGeneration);
-        }
+        public static void collect(CodeContext context)
+            => collect(context, GC.MaxGeneration);
 
         public static void set_debug(object? o) {
             throw PythonOps.NotImplementedError("gc.set_debug isn't implemented");

src/core/IronPython/Runtime/PythonContext.cs

@@ -3232,15 +3232,11 @@ public override IList<string> GetCallSignatures(object obj) {
         /// Performs a GC collection including the possibility of freeing weak data structures held onto by the Python runtime.
         /// </summary>
         /// <param name="generation"></param>
-        [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Reliability", "CA2001:AvoidCallingProblematicMethods", MessageId = "System.GC.Collect")]
-        internal int Collect(int generation) {
+        internal void Collect(int generation) {
             if (generation > GC.MaxGeneration || generation < 0) {
                 throw PythonOps.ValueError("invalid generation {0}", generation);
             }
 
-            // now let the CLR do it's normal collection
-            long start = GC.GetTotalMemory(false);
-
             for (int i = 0; i < 2; i++) {
                 GC.Collect(generation);
                 GC.WaitForPendingFinalizers();
@@ -3251,8 +3247,6 @@ internal int Collect(int generation) {
                     FunctionCode.CleanFunctionCodes(this, true);
                 }
             }
-
-            return (int)Math.Max(start - GC.GetTotalMemory(false), 0);
         }
 
         public DynamicDelegateCreator DelegateCreator {

tests/suite/modules/system_related/test_gc.py

@@ -138,7 +138,7 @@ def test_isenabled(self):
 
     def test_collect(self):
         if is_cli:
-            i = gc.collect() # returns # of bytes collected, could be anything
+            self.assertIsNone(gc.collect()) # returns None, we don't track collected objects
         else:
             for debug in debug_list:
                 gc.set_debug(debug)