Fix GC tests that contain GC.Collect() used in wrong scope

tests/src/GC/API/GC/Finalize.cs

@@ -5,6 +5,7 @@
 // Tests Finalize() and WaitForPendingFinalizers()
 
 using System;
+using System.Runtime.CompilerServices;
 
 public class Test
 {
@@ -28,12 +29,10 @@ public CreateObj()
             obj = new Dummy();
         }
 
+        [MethodImplAttribute(MethodImplOptions.NoInlining)]
         public void RunTest()
         {
             obj = null;
-            GC.Collect();
-
-            GC.WaitForPendingFinalizers();  // makes sure Finalize() is called.
         }
     }
 
@@ -42,6 +41,9 @@ public static int Main()
         CreateObj temp = new CreateObj();
         temp.RunTest();
 
+        GC.Collect();
+        GC.WaitForPendingFinalizers();  // makes sure Finalize() is called.
+        GC.Collect();
 
         if (visited)
         {

tests/src/GC/API/GC/GetTotalMemory.cs

@@ -4,16 +4,35 @@
 
 namespace DefaultNamespace {
     using System;
+    using System.Runtime.CompilerServices;
 
     internal class GetTotalMemory
     {
         // margin of error, since GetTotalMemory is an approximation
         // a discrepancy of more than 50 bytes should be investigated
         public const int padding = 50;
 
-        public static int Main(String [] args )
+        public static bool AllocAndDealloc(int i, int MB, long heapSizeBeforeAlloc)
         {
+            byte[] bary = new byte[i*MB];  //allocate iMB memory
+            bary[0] = 1;
+            bary[i*MB-1] = 1;
+
+            long heapSizeAfterAlloc = GC.GetTotalMemory(false);
+            Console.WriteLine( "HeapSize after allocated {0} MB memory: {1}", i, heapSizeAfterAlloc);
+            if( (heapSizeAfterAlloc - heapSizeBeforeAlloc)+i*padding<= i*MB || (heapSizeAfterAlloc - heapSizeBeforeAlloc) > (i+1)*MB )
+            {
+                Console.WriteLine( "Test Failed" );
+                return false;
+            }
+            bary[0] = 2;
+            bary[i*MB-1] = 2;
+            bary = null;
+            return true;
+        }
 
+        public static int Main(String [] args )
+        {
             int MB = 1024*1024;
             int iRep = 0;
             Console.WriteLine("Test should return with ExitCode 100 ...");
@@ -38,35 +57,25 @@ public static int Main(String [] args )
             // clean up memory before measuring
             GC.Collect();
             GC.WaitForPendingFinalizers();
+            GC.Collect();
 
             long heapSizeBeforeAlloc = GC.GetTotalMemory(false);
 
             Console.WriteLine( "HeapSize before allocating any memory: {0}", heapSizeBeforeAlloc );
 
-            byte[] bary = new byte[1];
             for(int i=1; i<=iRep; i++ )
             {
-                bary = new byte[i*MB];  //allocate iMB memory
-                bary[0] = 1;
-                bary[i*MB-1] = 1;
-
-                long heapSizeAfterAlloc = GC.GetTotalMemory(false);
-                Console.WriteLine( "HeapSize after allocated {0} MB memory: {1}", i, heapSizeAfterAlloc);
-                if( (heapSizeAfterAlloc - heapSizeBeforeAlloc)+i*padding<= i*MB || (heapSizeAfterAlloc - heapSizeBeforeAlloc) > (i+1)*MB )
+                if(!AllocAndDealloc(i, MB, heapSizeBeforeAlloc))
                 {
-                    Console.WriteLine( "Test Failed" );
                     return 1;
                 }
-                bary[0] = 2;
-                bary[i*MB-1] = 2;
-                bary = null;
 
                 GC.Collect();
                 GC.WaitForPendingFinalizers();
+                GC.Collect();
 
                 heapSizeBeforeAlloc = GC.GetTotalMemory(false);
                 Console.WriteLine( "HeapSize after delete all objects: {0}", heapSizeBeforeAlloc );
-
             }
 
             Console.WriteLine( "Test Passed!" );

tests/src/GC/API/GC/KeepAlive.cs

@@ -16,6 +16,7 @@
  */
 
 using System;
+using System.Runtime.CompilerServices;
 
 public class Test
 {
@@ -47,6 +48,7 @@ public class Dummy2
     }
 
 
+    [MethodImplAttribute(MethodImplOptions.NoInlining)]
     public static void RunTest2()
     {
         Dummy2 obj2 = new Dummy2();
@@ -66,6 +68,7 @@ public static void RunTest()
         //for (int i=0; i<5; i++) {
         GC.Collect();
         GC.WaitForPendingFinalizers();
+        GC.Collect();
         //}
 
         GC.KeepAlive(obj);  // will keep obj alive until this point

tests/src/GC/API/GC/KeepAliveNull.cs

@@ -5,6 +5,7 @@
 // Tests KeepAlive()
 
 using System;
+using System.Runtime.CompilerServices;
 
 public class Test
 {
@@ -27,11 +28,19 @@ public CreateObj()
             obj = new Dummy();
         }
 
-        public void RunTest()
+        [MethodImplAttribute(MethodImplOptions.NoInlining)]
+        public void DestroyObj()
         {
             obj = null;     // this will collect the obj even if we have KeepAlive()		
+        }
+
+        public void RunTest()
+        {
+            DestroyObj();
+
             GC.Collect();
             GC.WaitForPendingFinalizers();
+            GC.Collect();
 
             GC.KeepAlive(obj);  // will keep alive 'obj' till this point
         }

tests/src/GC/API/GC/KeepAliveRecur.cs

@@ -28,6 +28,7 @@ public static void foo(Object o)
 
         GC.Collect();
         GC.WaitForPendingFinalizers();
+        GC.Collect();
 
         foo(o);     //Recursive call
 

tests/src/GC/API/GC/SuppressFinalize.cs

@@ -5,6 +5,7 @@
 // Tests SuppressFinalize()
 
 using System;
+using System.Runtime.CompilerServices;
 
 public class Test {
 
@@ -17,16 +18,21 @@ public class Dummy {
 		}
 	}
 
-	public static int Main() {
-
+    [MethodImplAttribute(MethodImplOptions.NoInlining)]
+    public static void RunTest()
+    {
 		Dummy obj1 = new Dummy();
-
 		GC.SuppressFinalize(obj1);	// should not call the Finalizer() for obj1
 		obj1=null;
-
+    }
+
+	public static int Main()
+    {
+        RunTest();
+
 		GC.Collect();
-
 		GC.WaitForPendingFinalizers();   // call all Finalizers.
+		GC.Collect();
 
 		if(Dummy.visited == false) {
 			Console.WriteLine("Test for SuppressFinalize() passed!");

tests/src/GC/API/GCHandle/HandleCopy.cs

@@ -7,6 +7,7 @@
 // Also tests the target of the handle.
 
 using System;
+using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
 public class Test
@@ -37,13 +38,17 @@ public CreateObj()
             copy = handle;
         }
 
-        public bool RunTest()
+        [MethodImplAttribute(MethodImplOptions.NoInlining)]
+        public void DestroyObj()
         {
-            // ensuring that GC happens even with /debug mode
             obj = null;
-            GC.Collect();
+        }    
 
+        public bool RunTest()
+        {
+            GC.Collect();
             GC.WaitForPendingFinalizers();
+            GC.Collect();
 
             bool ans1 = handle.IsAllocated;
             bool ans2 = copy.IsAllocated;

tests/src/GC/API/GCHandle/Normal.cs

@@ -6,6 +6,7 @@
 // should not be collected.
 
 using System;
+using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
 public class Test {
@@ -19,21 +20,27 @@ public class Dummy {
 		}
 	}
 
-	public static int Main() {
-
-		Dummy obj = new Dummy();
+    [MethodImplAttribute(MethodImplOptions.NoInlining)]
+    public static void RunTest()
+    {
+        Dummy obj = new Dummy();
 
 		Console.WriteLine("Allocating a normal handle to object..");
 		GCHandle handle = GCHandle.Alloc(obj,GCHandleType.Normal); // Normal handle
 
 		// ensuring that GC happens even with /debug mode
 		obj=null;
+    }    
+
+
+	public static int Main() {
+        RunTest();
 
 		GC.Collect();
 		GC.WaitForPendingFinalizers();
+		GC.Collect();
 
 		if(Dummy.flag == 0) {
-
 			Console.WriteLine("Test for GCHandleType.Normal passed!");
             return 100;
 		}

tests/src/GC/API/GCHandle/Weak.cs

@@ -6,6 +6,7 @@
 // will be collected.
 
 using System;
+using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
 public class Test
@@ -31,30 +32,24 @@ public CreateObj()
             GCHandle handle = GCHandle.Alloc(obj, GCHandleType.Weak);
         }
 
-        public bool RunTest()
+        [MethodImplAttribute(MethodImplOptions.NoInlining)]
+        public void RunTest()
         {
             // ensuring that GC happens even with /debug mode
             obj = null;
-            GC.Collect();
-
-            GC.WaitForPendingFinalizers();
-
-            if (Dummy.flag == 99)
-            {
-                return true;
-            }
-            else
-            {
-                return false;
-            }
         }
     }
 
     public static int Main()
     {
         CreateObj temp = new CreateObj();
+        temp.RunTest();
+
+        GC.Collect();
+        GC.WaitForPendingFinalizers();
+        GC.Collect();
 
-        if (temp.RunTest())
+        if (Dummy.flag == 99)
         {
             Console.WriteLine("Test for GCHandleType.Weak passed!");
             return 100;

tests/src/GC/API/GCHandleCollector/Usage.cs

@@ -8,6 +8,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
 
 // the class that holds the HandleCollectors
@@ -46,6 +47,7 @@ public class Usage
     private int _numInstances = 100;
     private const int deltaPercent = 10;
 
+
     // ensures GC Collections occur when handle count exceeds maximum
     private bool Case1()
     {
@@ -56,14 +58,16 @@ private bool Case1()
         GC.WaitForPendingFinalizers();
         GC.Collect();
 
-        HandleCollectorTest h;
         int original = GC.CollectionCount(0);
 
+        HandleCollectorTest h;
+
         // create objects and let them go out of scope
         for (int i = 0; i < _numInstances; i++)
             h = new HandleCollectorTest();
 
         h = null;
+
         GC.WaitForPendingFinalizers();
 
         // Collection should not have occurred
@@ -96,7 +100,9 @@ private bool Case2()
         for (int i = 0; i < _numInstances; i++)
         {
             new HandleCollectorTest();
+
             GC.WaitForPendingFinalizers();
+
             handleCount = HandleCollectorTest.Count;
             //Note that the GC should occur when handle count is 101 but it will happen at anytime after a creation and we stick to the previous
             //count to avoid error