Update TestHandleCollector() test (#68285)

* Update TestHandleCollector() test Initialize local member in HandleCollector since it was the only one not initialized. Update test to wait for pending finalizers since that is when the HandleCollector API will trigger the GC. Co-authored-by: Elinor Fung <[email protected]>
dotnet · Apr 20, 2022 · c78bf2f · c78bf2f
1 parent 6ec5931
commit c78bf2f
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Showing 2 changed files with 13 additions and 3 deletions.
diff --git a/...ries/System.Runtime.InteropServices/src/System/Runtime/InteropServices/HandleCollector.cs b/...ries/System.Runtime.InteropServices/src/System/Runtime/InteropServices/HandleCollector.cs
@@ -40,6 +40,7 @@ public HandleCollector(string? name, int initialThreshold, int maximumThreshold)
             MaximumThreshold = maximumThreshold;
             _threshold = initialThreshold;
             _handleCount = 0;
+            _gcGeneration = 0;
         }
 
         public int Count => _handleCount;

diff --git a/....Runtime.InteropServices.UnitTests/System/Runtime/InteropServices/HandleCollectorTests.cs b/....Runtime.InteropServices.UnitTests/System/Runtime/InteropServices/HandleCollectorTests.cs
@@ -122,26 +122,35 @@ public static void Add_Overflows_ThrowsInvalidOperationException()
         public static void TestHandleCollector()
         {
             (int gen0, int gen1, int gen2) initialGcState = (GC.CollectionCount(0), GC.CollectionCount(1), GC.CollectionCount(2));
+            int initSum = initialGcState.gen0 + initialGcState.gen1 + initialGcState.gen2;
 
             HandleCollector lowLimitCollector = new HandleCollector("LowLimit.Collector", LowLimitSize);
             for (int i = 0; i < LowLimitSize + 1; ++i)
             {
                 HandleLimitTester hlt = new HandleLimitTester(lowLimitCollector);
             }
 
-            (int gen0, int gen1, int gen2) postLowLimitState = (GC.CollectionCount(0),GC.CollectionCount(1), GC.CollectionCount(2));
+            // HandleLimitTester does the decrement on the HandleCollector during finalization, so we wait for pending finalizers.
+            GC.WaitForPendingFinalizers();
 
-            Assert.True(initialGcState.gen0 + initialGcState.gen1 + initialGcState.gen2 < postLowLimitState.gen0 + postLowLimitState.gen1 + postLowLimitState.gen2, "Low limit handle did not trigger a GC");
+            (int gen0, int gen1, int gen2) postLowLimitState = (GC.CollectionCount(0), GC.CollectionCount(1), GC.CollectionCount(2));
+            int postLowLimitSum = postLowLimitState.gen0 + postLowLimitState.gen1 + postLowLimitState.gen2;
+
+            Assert.True(initSum < postLowLimitSum, $"Low limit handle did not trigger a GC: {initSum} < {postLowLimitSum}");
 
             HandleCollector highLimitCollector = new HandleCollector("HighLimit.Collector", HighLimitSize);
             for (int i = 0; i < HighLimitSize + 10; ++i)
             {
                 HandleLimitTester hlt = new HandleLimitTester(highLimitCollector);
             }
 
+            // HandleLimitTester does the decrement on the HandleCollector during finalization, so we wait for pending finalizers.
+            GC.WaitForPendingFinalizers();
+
             (int gen0, int gen1, int gen2) postHighLimitState = (GC.CollectionCount(0), GC.CollectionCount(1), GC.CollectionCount(2));
+            int postHighLimitSum = postHighLimitState.gen0 + postHighLimitState.gen1 + postHighLimitState.gen2;
 
-            Assert.True(postLowLimitState.gen0 + postLowLimitState.gen1 + postLowLimitState.gen2 < postHighLimitState.gen0 + postHighLimitState.gen1 + postHighLimitState.gen2, "High limit handle did not trigger a GC");
+            Assert.True(postLowLimitSum < postHighLimitSum, $"High limit handle did not trigger a GC: {postLowLimitSum} < {postHighLimitSum}");
         }
 
         private sealed class HandleLimitTester