8318757: VM_ThreadDump asserts in interleaved ObjectMonitor::deflate_…

…monitor calls

8319896: Remove monitor deflation from final audit
8320515: assert(monitor->object_peek() != nullptr) failed: Owned monitors should not have a dead object
8325437: Safepoint polling in monitor deflation can cause massive logs

Reviewed-by: stefank, adinn
Backport-of: 87be6b69fe985eee01fc3344f9153d774db792c1

make/test/JtregNativeHotspot.gmk

@@ -867,7 +867,7 @@ BUILD_HOTSPOT_JTREG_EXECUTABLES_LIBS_exesigtest := -ljvm
 
 ifeq ($(call isTargetOs, windows), true)
   BUILD_HOTSPOT_JTREG_EXECUTABLES_CFLAGS_exeFPRegs := -MT
-  BUILD_HOTSPOT_JTREG_EXCLUDE += exesigtest.c libterminatedThread.c libTestJNI.c libCompleteExit.c libTestPsig.c libnativeStack.c exeGetCreatedJavaVMs.c
+  BUILD_HOTSPOT_JTREG_EXCLUDE += exesigtest.c libterminatedThread.c libTestJNI.c libCompleteExit.c libMonitorWithDeadObjectTest.c libTestPsig.c libnativeStack.c exeGetCreatedJavaVMs.c
   BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libatExit := jvm.lib
   BUILD_HOTSPOT_JTREG_EXECUTABLES_LIBS_exedaemonDestroy := jvm.lib
 else
@@ -1508,6 +1508,7 @@ else
   BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libterminatedThread += -lpthread
   BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libatExit += -ljvm
   BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libCompleteExit += -lpthread
+  BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libMonitorWithDeadObjectTest += -lpthread
   BUILD_HOTSPOT_JTREG_LIBRARIES_LIBS_libnativeStack += -lpthread
   BUILD_HOTSPOT_JTREG_EXECUTABLES_LIBS_exeGetCreatedJavaVMs := -ljvm -lpthread
 endif

src/hotspot/share/prims/jvmtiEnvBase.cpp

@@ -988,7 +988,7 @@ JvmtiEnvBase::get_owned_monitors(JavaThread *calling_thread, JavaThread* java_th
 
   // Get off stack monitors. (e.g. acquired via jni MonitorEnter).
   JvmtiMonitorClosure jmc(calling_thread, owned_monitors_list, this);
-  ObjectSynchronizer::monitors_iterate(&jmc, java_thread);
+  ObjectSynchronizer::owned_monitors_iterate(&jmc, java_thread);
   err = jmc.error();
 
   return err;
@@ -1015,7 +1015,7 @@ JvmtiEnvBase::get_owned_monitors(JavaThread* calling_thread, JavaThread* java_th
 
   // Get off stack monitors. (e.g. acquired via jni MonitorEnter).
   JvmtiMonitorClosure jmc(calling_thread, owned_monitors_list, this);
-  ObjectSynchronizer::monitors_iterate(&jmc, java_thread);
+  ObjectSynchronizer::owned_monitors_iterate(&jmc, java_thread);
   err = jmc.error();
 
   return err;
@@ -2178,6 +2178,13 @@ JvmtiMonitorClosure::do_monitor(ObjectMonitor* mon) {
   }
   // Filter out on stack monitors collected during stack walk.
   oop obj = mon->object();
+
+  if (obj == nullptr) {
+    // This can happen if JNI code drops all references to the
+    // owning object.
+    return;
+  }
+
   bool found = false;
   for (int j = 0; j < _owned_monitors_list->length(); j++) {
     jobject jobj = ((jvmtiMonitorStackDepthInfo*)_owned_monitors_list->at(j))->monitor;

src/hotspot/share/prims/whitebox.cpp

@@ -1833,7 +1833,7 @@ WB_END
 
 WB_ENTRY(jboolean, WB_DeflateIdleMonitors(JNIEnv* env, jobject wb))
   log_info(monitorinflation)("WhiteBox initiated DeflateIdleMonitors");
-  return ObjectSynchronizer::request_deflate_idle_monitors();
+  return ObjectSynchronizer::request_deflate_idle_monitors_from_wb();
 WB_END
 
 WB_ENTRY(void, WB_ForceSafepoint(JNIEnv* env, jobject wb))

src/hotspot/share/runtime/monitorDeflationThread.cpp

@@ -94,6 +94,6 @@ void MonitorDeflationThread::monitor_deflation_thread_entry(JavaThread* jt, TRAP
       }
     }
 
-    (void)ObjectSynchronizer::deflate_idle_monitors(/* ObjectMonitorsHashtable is not needed here */ nullptr);
+    (void)ObjectSynchronizer::deflate_idle_monitors();
   }
 }

src/hotspot/share/runtime/objectMonitor.cpp

@@ -509,16 +509,6 @@ bool ObjectMonitor::deflate_monitor() {
     return false;
   }
 
-  if (ObjectSynchronizer::is_final_audit() && owner_is_DEFLATER_MARKER()) {
-    // The final audit can see an already deflated ObjectMonitor on the
-    // in-use list because MonitorList::unlink_deflated() might have
-    // blocked for the final safepoint before unlinking all the deflated
-    // monitors.
-    assert(contentions() < 0, "must be negative: contentions=%d", contentions());
-    // Already returned 'true' when it was originally deflated.
-    return false;
-  }
-
   const oop obj = object_peek();
 
   if (obj == nullptr) {