[debugger-agent] Regression test for #42625

Check that we can suspend I/O blocked threadpool workers in coop GC mode.

3 files changed, 68 insertions, 2 deletions

diff --git a/mcs/class/Mono.Debugger.Soft/Makefile b/mcs/class/Mono.Debugger.Soft/Makefile
index d92fb61f8a9..1f20c1f89c6 100644
--- a/mcs/class/Mono.Debugger.Soft/Makefile
+++ b/mcs/class/Mono.Debugger.Soft/Makefile
@@ -15,10 +15,13 @@ VALID_TEST_PROFILE := $(filter net_4_x, $(PROFILE))
 # The test exe is not profile specific, and compiling a 2.0 will make the 4.5 tests fail
 ifdef VALID_TEST_PROFILE
 
+TEST_HELPERS_SOURCES = \
+	../test-helpers/NetworkHelpers.cs
+
 test-local: dtest-app.exe dtest-excfilter.exe
 
-dtest-app.exe: Test/dtest-app.cs
-	$(CSCOMPILE) -r:$(topdir)/class/lib/$(PROFILE)/System.Core.dll -r:$(topdir)/class/lib/$(PROFILE)/System.dll -out:$@ -unsafe $(PLATFORM_DEBUG_FLAGS) -optimize- Test/dtest-app.cs
+dtest-app.exe: Test/dtest-app.cs $(TEST_HELPERS_SOURCES)
+	$(CSCOMPILE) -r:$(topdir)/class/lib/$(PROFILE)/System.Core.dll -r:$(topdir)/class/lib/$(PROFILE)/System.dll -out:$@ -unsafe $(PLATFORM_DEBUG_FLAGS) -optimize- Test/dtest-app.cs $(TEST_HELPERS_SOURCES)
 
 dtest-excfilter.exe: Test/dtest-excfilter.il
 	MONO_PATH=$(topdir)/class/lib/$(PROFILE) $(INTERNAL_ILASM) -out:$@ /exe /debug Test/dtest-excfilter.il
diff --git a/mcs/class/Mono.Debugger.Soft/Test/dtest-app.cs b/mcs/class/Mono.Debugger.Soft/Test/dtest-app.cs
index 4b9d569b1ad..6587c37c0b5 100644
--- a/mcs/class/Mono.Debugger.Soft/Test/dtest-app.cs
+++ b/mcs/class/Mono.Debugger.Soft/Test/dtest-app.cs
@@ -9,8 +9,11 @@ using System.Reflection;
 using System.Reflection.Emit;
 using System.Diagnostics;
 using System.Threading;
+using System.Threading.Tasks;
 using System.Collections.Generic;
 using System.Linq;
+using System.Net.Sockets;
+using MonoTests.Helpers;
 
 public class TestsBase
 {
@@ -311,6 +314,10 @@ public class Tests : TestsBase, ITest2
 			wait_one ();
 			return 0;
 		}
+		if (args.Length >0 && args [0] == "threadpool-io") {
+			threadpool_io ();
+			return 0;
+		}
 		breakpoints ();
 		single_stepping ();
 		arguments ();
@@ -1541,6 +1548,46 @@ public class Tests : TestsBase, ITest2
 	public override string virtual_method () {
 		return "V2";
 	}
+
+	[MethodImplAttribute (MethodImplOptions.NoInlining)]
+	public static void threadpool_bp () { }
+
+	[MethodImplAttribute (MethodImplOptions.NoInlining)]
+	public static void threadpool_io () {
+		// Start a threadpool task that blocks on I/O.
+		// Regression test for #42625
+		const int nbytes = 16;
+		var bsOut = new byte[nbytes];
+		for (int i = 0; i < nbytes; i++) {
+			bsOut[i] = (byte)i;
+		}
+		var endPoint = NetworkHelpers.LocalEphemeralEndPoint ();
+		var l = new TcpListener (endPoint);
+		l.Start ();
+		Task<byte[]> t = Task.Run (async () => {
+			var c = new TcpClient ();
+			await c.ConnectAsync (endPoint.Address, endPoint.Port);
+			var streamIn = c.GetStream ();
+			var bs = new byte[nbytes];
+			int nread = 0;
+			while (nread < nbytes) {
+				nread += await streamIn.ReadAsync (bs, nread, nbytes);
+			}
+			streamIn.Close ();
+			return bs;
+			});
+		var s = l.AcceptTcpClient ();
+		l.Stop ();
+		// write bytes in two groups so that the task blocks on the ReadAsync
+		var streamOut = s.GetStream ();
+		var nbytesFirst = nbytes / 2;
+		var nbytesRest = nbytes - nbytesFirst;
+		streamOut.Write (bsOut, 0, nbytesFirst);
+		threadpool_bp ();
+		streamOut.Write (bsOut, nbytesFirst, nbytesRest);
+		streamOut.Close ();
+		var bsIn = t.Result;
+	}
 }
 
 class TypeLoadClass {
diff --git a/mcs/class/Mono.Debugger.Soft/Test/dtest.cs b/mcs/class/Mono.Debugger.Soft/Test/dtest.cs
index c0af12cb38a..88ed411da35 100644
--- a/mcs/class/Mono.Debugger.Soft/Test/dtest.cs
+++ b/mcs/class/Mono.Debugger.Soft/Test/dtest.cs
@@ -4035,6 +4035,22 @@ public class DebuggerTests
 		// Make sure we are still in the cctor
 		Assert.AreEqual (".cctor", e.Thread.GetFrames ()[0].Location.Method.Name);
 	}
+
+	[Test]
+	public void ThreadpoolIOsinglestep () {
+		TearDown ();
+		Start ("dtest-app.exe", "threadpool-io");
+		// This is a regression test for #42625.  It tests the
+		// interaction (particularly in coop GC) of the
+		// threadpool I/O mechanism and the soft debugger.
+		Event e = run_until ("threadpool_io");
+		// run until we sent the task half the bytes it
+		// expects, so that it blocks waiting for the rest.
+		e = run_until ("threadpool_bp");
+		var req = create_step (e);
+		e = step_out (); // leave threadpool_bp
+		e = step_out (); // leave threadpool_io
+	}
 }
 
 }