add test for https://github.com/GtkSharp/GtkSharp/issues/226

Source/Samples/Sections/Miscellaneous/PixbufSection.cs

@@ -0,0 +1,93 @@
+using System;
+using System.Threading;
+using Gdk;
+using Gtk;
+
+namespace Samples
+{
+
+	[Section (ContentType = typeof(PixbufDemo), Category = Category.Miscellaneous)]
+	class PixbufSection : ListSection
+	{
+
+		public PixbufSection ()
+		{
+			AddItem ($"Press button to run / stop {nameof(PixbufDemo)} :", new PixbufDemo ("Press me"));
+		}
+
+	}
+
+	class PixbufDemo : Button
+	{
+
+		public PixbufDemo (string text) : base (text) { }
+
+		private bool running = false;
+
+		public void DispatchPendingEvents ()
+		{
+			// The loop is limited to 1000 iterations as a workaround for an issue that some users
+			// have experienced. Sometimes EventsPending starts return 'true' for all iterations,
+			// causing the loop to never end.
+
+			int n = 1000;
+			Gdk.Threads.Enter ();
+
+			while (Gtk.Application.EventsPending () && --n > 0) {
+				Gtk.Application.RunIteration (false);
+			}
+
+			Gdk.Threads.Leave ();
+		}
+
+		protected override void OnPressed ()
+		{
+			base.OnPressed ();
+			var count = 0;
+
+			if (running) {
+				running = false;
+
+				return;
+			}
+
+			var startmem = GC.GetTotalMemory (true);
+			var testfile = "Textpic.png";
+
+			using (var writeTestFile = new Pixbuf (typeof(ImageSection).Assembly, "Testpic")) {
+				writeTestFile.Save (testfile, "png");
+			}
+
+			using (var heatup = new Pixbuf (testfile)) {
+				ApplicationOutput.WriteLine ($"{nameof(heatup)}.{nameof(Pixbuf.ByteLength)}\t{heatup.ByteLength:N0}");
+			}
+
+			startmem = GC.GetTotalMemory (true);
+			ApplicationOutput.WriteLine ($"{nameof(GC.GetTotalMemory)} at start: {startmem:N}");
+			running = true;
+
+			var memAllocated = 0UL;
+
+			while (running) {
+
+				using (var source = new Pixbuf (typeof(ImageSection).Assembly, "Testpic")) {
+					memAllocated += source.ByteLength;
+					count++;
+				}
+
+				DispatchPendingEvents ();
+
+				if (!running)
+					break;
+
+			}
+
+			var endmem = GC.GetTotalMemory (true);
+			ApplicationOutput.WriteLine ($"Leak:\t{(endmem - startmem):N0}\t{nameof(memAllocated)}");
+			ApplicationOutput.WriteLine ($"{nameof(GC.GetTotalMemory)} at start: {startmem:N0}\tat end: {endmem:N0}\t{nameof(Pixbuf)} created: {count}");
+
+		}
+
+	}
+
+}