[Wisp] Fix dead loop when killing threads waiting for objectmonitor.

Summary: Threads waiting for objectmonitor will skip calling
WispTask::park when async exception is pending, so mannualy
clear exception before WispThread::park

Test Plan: jtreg test/jdk/com/alibaba/rcm/TestDeadLoopKillObjectMonitor.java

Reviewed-by: yulei

Issue:
dragonwell-project#146

src/hotspot/share/runtime/coroutine.cpp

@@ -735,6 +735,15 @@ void WispThread::park(long millis, const ObjectWaiter* ow) {
   JavaThread* jt = ((WispThread*) ow->_thread)->thread();
   assert(jt == Thread::current(), "current");
 
+  assert (!jt->has_pending_exception(), "should not have any pending exception");
+  if (jt->has_async_exception_condition()) {
+    assert(UseWisp2 && Wisp2ThreadStop, "pre-condition");
+    assert(jt->has_aync_thread_death_exception(), "must be wisp_thread_death_exception");
+    // JavaCalls will be skipped if current thread has a pending exception
+    // mannually clear all async exceptions before calling into java
+    jt->clear_aync_thread_death_exception();
+  }
+
   if (ow->_timeout > 0) {
     millis = ow->_timeout;
     assert(!ow->_using_wisp_park, "invariant");
@@ -821,6 +830,14 @@ void WispThread::unpark(int task_id, bool using_wisp_park, bool proxy_unpark, Pa
     return;
   }
 
+  if (jt->has_async_exception_condition()) {
+    assert(UseWisp2 && Wisp2ThreadStop, "pre-condition");
+    assert(jt->has_aync_thread_death_exception(), "must be wisp_thread_death_exception");
+    // JavaCalls will be skipped if current thread has a pending exception
+    // mannually clear all async exceptions before calling into java
+    jt->clear_aync_thread_death_exception();
+  }
+
   wisp_thread->_unpark_status = WispThread::_wisp_unpark_begin;
   JavaValue result(T_VOID);
   JavaCallArguments args;

src/hotspot/share/runtime/thread.cpp

@@ -1652,6 +1652,21 @@ JavaThread* JavaThread::active() {
   }
 }
 
+bool JavaThread::has_aync_thread_death_exception() {
+  assert(EnableCoroutine && Wisp2ThreadStop, "pre-condition");
+  return _pending_async_exception == Universe::wisp_thread_death_exception();
+}
+
+void JavaThread::clear_aync_thread_death_exception() {
+  assert(UseWisp2 && Wisp2ThreadStop, "pre-condition");
+  if (_pending_async_exception != NULL
+      && _pending_async_exception == Universe::wisp_thread_death_exception()) {
+    _pending_async_exception = NULL;
+    set_async_exception_condition(_no_async_condition);
+    clear_suspend_flag(_has_async_exception);
+  }
+}
+
 bool JavaThread::is_lock_owned(address adr) const {
   if (Thread::is_lock_owned(adr)) return true;
 

src/hotspot/share/runtime/thread.hpp

@@ -1643,6 +1643,9 @@ class JavaThread: public Thread {
   bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
   inline void set_done_attaching_via_jni();
 
+  bool has_aync_thread_death_exception();
+  void clear_aync_thread_death_exception();
+
   // Stack dump assistance:
   // Track the class we want to initialize but for which we have to wait
   // on its init_lock() because it is already being initialized.

test/jdk/com/alibaba/rcm/TestDeadLoopKillObjectMonitor.java

@@ -0,0 +1,74 @@
+/*
+ * @test
+ * @library /test/lib
+ * @build TestDeadLoopKillObjectMonitor RcmUtils
+ * @summary test RCM TestKillThreads
+ * @modules java.base/com.alibaba.wisp.engine:+open
+ * @modules java.base/com.alibaba.rcm.internal:+open
+ * @run main/othervm -XX:+UnlockExperimentalVMOptions -XX:+UseWisp2 -XX:+Wisp2ThreadStop -XX:ActiveProcessorCount=1 TestDeadLoopKillObjectMonitor
+ */
+
+import com.alibaba.rcm.Constraint;
+import com.alibaba.rcm.ResourceContainer;
+import com.alibaba.rcm.ResourceType;
+import com.alibaba.rcm.internal.RCMUnsafe;
+import com.alibaba.wisp.engine.WispResourceContainerFactory;
+
+import java.lang.reflect.Field;
+import java.util.Collections;
+import java.util.concurrent.CountDownLatch;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+
+public class TestDeadLoopKillObjectMonitor {
+
+    private static Object obj = new Object();
+
+    public static void main(String[] args) throws Exception {
+        ResourceContainer container = RcmUtils.createContainer(Collections.singletonList(
+                ResourceType.CPU_PERCENT.newConstraint(100)));
+
+        CountDownLatch latch = new CountDownLatch(1);
+        Thread t1 = new Thread(new Runnable() {
+            @Override
+            public void run() {
+                synchronized (obj) {
+                    try {
+                        Thread.sleep(1000);
+                        Thread t2 =  new Thread(new Runnable() {
+                            @Override
+                            public void run() {
+                                latch.countDown();
+                            }
+                        });
+                        t2.setDaemon(true);
+                        t2.start();
+                    } catch (Exception e) {
+                        e.printStackTrace();
+                    }
+                }
+            }
+        });
+        t1.setDaemon(true);
+        t1.start();
+
+        Thread.sleep(100);
+        container.run(() -> {
+        Thread t = new Thread(new Runnable() {
+            @Override
+            public void run() {
+                while (true)
+                synchronized (obj) {
+                    System.out.println("rr");
+                }
+            }
+        });
+        t.start();
+        });
+
+        Thread.sleep(100);
+        RCMUnsafe.killThreads(container);
+    }
+
+}