Fix GC.KeepAlive test case

BruceForstall · BruceForstall · commit d087b29b9f68 · 2018-01-11T16:22:55.000-08:00
In the test, as written, a GC could sneak in between the GC.KeepAlive()
call and the subsequent line that checks whether the finalizer
has run, especially in GC stress modes. Simply move the GC.KeepAlive()
call down.
diff --git a/tests/src/CoreMangLib/cti/system/gc/gckeepalive.cs b/tests/src/CoreMangLib/cti/system/gc/gckeepalive.cs
@@ -44,13 +44,13 @@ public bool PosTest1()
             GC.WaitForPendingFinalizers();
             GC.Collect();
 
-            GC.KeepAlive(tc);
             if (TestClass.m_TestInt != 1)
             {
                 TestLibrary.TestFramework.LogError("001.1", "Calling KeepAlive can not prevent an object to be GCed");
                 TestLibrary.TestFramework.LogInformation("WARNING [LOCAL VARIABLE] TestClass.m_TestInt = " + TestClass.m_TestInt);
                 retVal = false;
             }
+            GC.KeepAlive(tc);
         }
         catch (Exception e)
         {

Original file line number	Diff line number	Diff line change
`@@ -44,13 +44,13 @@ public bool PosTest1()`
`44`	`44`	`GC.WaitForPendingFinalizers();`
`45`	`45`	`GC.Collect();`
`46`	`46`
`47`		`- GC.KeepAlive(tc);`
`48`	`47`	`if (TestClass.m_TestInt != 1)`
`49`	`48`	`{`
`50`	`49`	`TestLibrary.TestFramework.LogError("001.1", "Calling KeepAlive can not prevent an object to be GCed");`
`51`	`50`	`TestLibrary.TestFramework.LogInformation("WARNING [LOCAL VARIABLE] TestClass.m_TestInt = " + TestClass.m_TestInt);`
`52`	`51`	`retVal = false;`
`53`	`52`	`}`
	`53`	`+ GC.KeepAlive(tc);`
`54`	`54`	`}`
`55`	`55`	`catch (Exception e)`
`56`	`56`	`{`