8057827: notify an obj when allocation context stats are available

Reviewed-by: mikael, jmasa, tschatzl

src/share/vm/gc_implementation/g1/g1AllocationContext.hpp

@@ -46,6 +46,7 @@ public:
   inline void clear() { }
   inline void update(bool full_gc) { }
   inline void update_at_remark() { }
+  inline bool available() { return false; }
 };
 
 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1ALLOCATIONCONTEXT_HPP

src/share/vm/memory/universe.cpp

@@ -126,6 +126,8 @@ oop Universe::_null_ptr_exception_instance            = NULL;
 oop Universe::_arithmetic_exception_instance          = NULL;
 oop Universe::_virtual_machine_error_instance         = NULL;
 oop Universe::_vm_exception                           = NULL;
+oop Universe::_allocation_context_notification_obj    = NULL;
+
 Method* Universe::_throw_illegal_access_error         = NULL;
 Array<int>* Universe::_the_empty_int_array            = NULL;
 Array<u2>* Universe::_the_empty_short_array           = NULL;
@@ -195,6 +197,7 @@ void Universe::oops_do(OopClosure* f, bool do_all) {
   f->do_oop((oop*)&_main_thread_group);
   f->do_oop((oop*)&_system_thread_group);
   f->do_oop((oop*)&_vm_exception);
+  f->do_oop((oop*)&_allocation_context_notification_obj);
   debug_only(f->do_oop((oop*)&_fullgc_alot_dummy_array);)
 }
 

src/share/vm/memory/universe.hpp

@@ -178,6 +178,8 @@ class Universe: AllStatic {
   // the vm thread.
   static oop          _vm_exception;
 
+  static oop          _allocation_context_notification_obj;
+
   // The particular choice of collected heap.
   static CollectedHeap* _collectedHeap;
 
@@ -307,6 +309,10 @@ class Universe: AllStatic {
   static oop          arithmetic_exception_instance() { return _arithmetic_exception_instance; }
   static oop          virtual_machine_error_instance() { return _virtual_machine_error_instance; }
   static oop          vm_exception()                  { return _vm_exception; }
+
+  static inline oop   allocation_context_notification_obj();
+  static inline void  set_allocation_context_notification_obj(oop obj);
+
   static Method*      throw_illegal_access_error()    { return _throw_illegal_access_error; }
 
   static Array<int>*       the_empty_int_array()    { return _the_empty_int_array; }

src/share/vm/memory/universe.inline.hpp

@@ -41,4 +41,12 @@ inline bool Universe::field_type_should_be_aligned(BasicType type) {
   return type == T_DOUBLE || type == T_LONG;
 }
 
+inline oop Universe::allocation_context_notification_obj() {
+  return _allocation_context_notification_obj;
+}
+
+inline void Universe::set_allocation_context_notification_obj(oop obj) {
+  _allocation_context_notification_obj = obj;
+}
+
 #endif // SHARE_VM_MEMORY_UNIVERSE_INLINE_HPP

src/share/vm/runtime/serviceThread.cpp

@@ -28,6 +28,7 @@
 #include "runtime/serviceThread.hpp"
 #include "runtime/mutexLocker.hpp"
 #include "prims/jvmtiImpl.hpp"
+#include "services/allocationContextService.hpp"
 #include "services/gcNotifier.hpp"
 #include "services/diagnosticArgument.hpp"
 #include "services/diagnosticFramework.hpp"
@@ -86,6 +87,7 @@ void ServiceThread::service_thread_entry(JavaThread* jt, TRAPS) {
     bool has_jvmti_events = false;
     bool has_gc_notification_event = false;
     bool has_dcmd_notification_event = false;
+    bool acs_notify = false;
     JvmtiDeferredEvent jvmti_event;
     {
       // Need state transition ThreadBlockInVM so that this thread
@@ -102,7 +104,8 @@ void ServiceThread::service_thread_entry(JavaThread* jt, TRAPS) {
       while (!(sensors_changed = LowMemoryDetector::has_pending_requests()) &&
              !(has_jvmti_events = JvmtiDeferredEventQueue::has_events()) &&
               !(has_gc_notification_event = GCNotifier::has_event()) &&
-              !(has_dcmd_notification_event = DCmdFactory::has_pending_jmx_notification())) {
+              !(has_dcmd_notification_event = DCmdFactory::has_pending_jmx_notification()) &&
+             !(acs_notify = AllocationContextService::should_notify())) {
         // wait until one of the sensors has pending requests, or there is a
         // pending JVMTI event or JMX GC notification to post
         Service_lock->wait(Mutex::_no_safepoint_check_flag);
@@ -128,6 +131,10 @@ void ServiceThread::service_thread_entry(JavaThread* jt, TRAPS) {
     if(has_dcmd_notification_event) {
       DCmdFactory::send_notification(CHECK);
     }
+
+    if (acs_notify) {
+      AllocationContextService::notify(CHECK);
+    }
   }
 }
 

src/share/vm/services/allocationContextService.hpp

+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_SERVICES_ALLOCATION_CONTEXT_SERVICE_HPP
+#define SHARE_VM_SERVICES_ALLOCATION_CONTEXT_SERVICE_HPP
+
+#include "utilities/exceptions.hpp"
+
+class AllocationContextService: public AllStatic {
+public:
+  static inline bool should_notify();
+  static inline void notify(TRAPS);
+};
+
+bool AllocationContextService::should_notify() { return false; }
+void AllocationContextService::notify(TRAPS) { }
+
+#endif // SHARE_VM_SERVICES_ALLOCATION_CONTEXT_SERVICE_HPP