--- old/test/hotspot/jtreg/serviceability/jvmti/HeapMonitor/libHeapMonitor.c	2018-03-28 08:20:31.037177885 -0700
+++ new/test/hotspot/jtreg/serviceability/jvmti/HeapMonitor/libHeapMonitor.c	2018-03-28 08:20:30.717179056 -0700
@@ -566,6 +566,7 @@
   (*jvmti)->SetHeapSamplingRate(jvmti, value);
 }
 
+// TODO: should be removed, no tests using it.
 JNIEXPORT void JNICALL
 Java_MyPackage_HeapMonitor_setGarbageHistory(JNIEnv* env, jclass cls, jint value) {
   event_storage_set_garbage_history(&global_event_storage, value);
@@ -642,6 +643,32 @@
   return TRUE;
 }
 
+JNIEXPORT jboolean JNICALL
+Java_MyPackage_HeapMonitorIllegalArgumentTest_testIllegalArgument(JNIEnv *env,
+                                                                  jclass cls) {
+  if (check_error((*jvmti)->SetHeapSamplingRate(jvmti, 0),
+                  "Sampling rate 0 failed\n")){
+    return FALSE;
+  }
+
+  if (check_error((*jvmti)->SetHeapSamplingRate(jvmti, 1024),
+                  "Sampling rate 1024 failed\n")){
+    return FALSE;
+  }
+
+  if (!check_error((*jvmti)->SetHeapSamplingRate(jvmti, -1),
+                   "Sampling rate -1 passed\n")){
+    return FALSE;
+  }
+
+  if (!check_error((*jvmti)->SetHeapSamplingRate(jvmti, -1024),
+                   "Sampling rate -1024 passed\n")){
+    return FALSE;
+  }
+
+  return TRUE;
+}
+
 JNIEXPORT jdouble JNICALL
 Java_MyPackage_HeapMonitorStatRateTest_getAverageRate(JNIEnv *env, jclass cls) {
   return event_storage_get_average_rate(&global_event_storage);
@@ -713,12 +740,12 @@
 
   find_threads_in_array(&thread_data, global_event_storage.live_objects,
                         global_event_storage.live_object_count);
-  find_threads_in_array(&thread_data,
-                        global_event_storage.garbage_collected_objects,
-                        global_event_storage.garbage_history_size);
 
   free(thread_data.threads);
   pthread_mutex_unlock(&global_event_storage.storage_mutex);
+  fprintf(stderr, "Obtained %d - %d\n",
+          thread_data.num_threads,
+          num_threads);
   return thread_data.num_threads == num_threads;
 }