Added test case for cleaner thread overload

Author: pmconrad

build.xml

@@ -1396,6 +1396,7 @@ cd ..
     </propertyset>
     <junit fork="${test.fork}" forkmode="${test.forkmode}" failureproperty="testfailure" tempdir="${build}">
       <jvmarg if:set="test.jdwp" value="${test.jdwp}" />
+      <jvmarg value="-Xmx64m" />
       <!-- optionally run headless -->
       <syspropertyset refid="headless"/>
       <!-- avoid VM conflicts with JNA protected mode -->

test/com/sun/jna/different_package/CleanerTest.java

@@ -0,0 +1,47 @@
+package com.sun.jna.different_package;
+
+import com.sun.jna.Structure;
+import junit.framework.TestCase;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class CleanerTest extends TestCase {
+    private static final int NUM_THREADS = 16;
+    private static final long ITERATIONS = 100000;
+
+    @Structure.FieldOrder({"bytes"})
+    public static class Dummy extends Structure {
+        public byte[] bytes;
+
+        public Dummy() {}
+
+        public Dummy(byte[] what) { bytes = what; }
+    }
+
+    private static class Allocator implements Runnable {
+        @Override
+        public void run() {
+            for (long i = 0; i < ITERATIONS; ++i) {
+                Dummy d = new Dummy(new byte[1024]);
+                d.write();
+            }
+        }
+    }
+
+    public void testOOM() {
+        List<Thread> threads = new ArrayList<>(NUM_THREADS);
+        for (int i = 0; i < NUM_THREADS; ++i) {
+            Thread t = new Thread(new Allocator());
+            t.start();
+            threads.add(t);
+        }
+        for (Thread t : threads) {
+            while (t.isAlive()) {
+                try {
+                    t.join();
+                } catch (InterruptedException ignore) {}
+            }
+        }
+    }
+}