1 /*
   2  * Copyright (c) 2011, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/systemDictionary.hpp"
  27 #include "classfile/vmSymbols.hpp"
  28 #include "oops/oop.inline.hpp"
  29 #include "runtime/interfaceSupport.hpp"
  30 #include "runtime/java.hpp"
  31 #include "runtime/javaCalls.hpp"
  32 #include "runtime/mutex.hpp"
  33 #include "runtime/mutexLocker.hpp"
  34 #include "services/gcNotifier.hpp"
  35 #include "services/management.hpp"
  36 #include "services/memoryService.hpp"
  37 #include "memoryManager.hpp"
  38 #include "memory/oopFactory.hpp"
  39 
  40 GCNotificationRequest *GCNotifier::first_request = NULL;
  41 GCNotificationRequest *GCNotifier::last_request = NULL;
  42 
  43 void GCNotifier::pushNotification(GCMemoryManager *mgr, const char *action, const char *cause) {
  44   // Make a copy of the last GC statistics
  45   // GC may occur between now and the creation of the notification
  46   int num_pools = MemoryService::num_memory_pools();
  47   // stat is deallocated inside GCNotificationRequest
  48   GCStatInfo* stat = new(ResourceObj::C_HEAP, mtGC) GCStatInfo(num_pools);
  49   mgr->get_last_gc_stat(stat);
  50   GCNotificationRequest *request = new GCNotificationRequest(os::javaTimeMillis(),mgr,action,cause,stat);
  51   addRequest(request);
  52  }
  53 
  54 void GCNotifier::addRequest(GCNotificationRequest *request) {
  55   MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
  56   if(first_request == NULL) {
  57     first_request = request;
  58   } else {
  59     last_request->next = request;
  60   }
  61   last_request = request;
  62   Service_lock->notify_all();
  63 }
  64 
  65 GCNotificationRequest *GCNotifier::getRequest() {
  66   MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
  67   GCNotificationRequest *request = first_request;
  68   if(first_request != NULL) {
  69     first_request = first_request->next;
  70   }
  71   return request;
  72 }
  73 
  74 bool GCNotifier::has_event() {
  75   return first_request != NULL;
  76 }
  77 
  78 static Handle getGcInfoBuilder(GCMemoryManager *gcManager,TRAPS) {
  79 
  80   Klass* k = Management::com_sun_management_internal_GarbageCollectorExtImpl_klass(CHECK_NH);
  81   instanceKlassHandle gcMBeanKlass (THREAD, k);
  82 
  83   instanceOop i = gcManager->get_memory_manager_instance(THREAD);
  84   instanceHandle ih(THREAD, i);
  85 
  86   JavaValue result(T_OBJECT);
  87   JavaCallArguments args(ih);
  88 
  89   JavaCalls::call_virtual(&result,
  90                           gcMBeanKlass,
  91                           vmSymbols::getGcInfoBuilder_name(),
  92                           vmSymbols::getGcInfoBuilder_signature(),
  93                           &args,
  94                           CHECK_NH);
  95   return Handle(THREAD,(oop)result.get_jobject());
  96 }
  97 
  98 static Handle createGcInfo(GCMemoryManager *gcManager, GCStatInfo *gcStatInfo,TRAPS) {
  99 
 100   // Fill the arrays of MemoryUsage objects with before and after GC
 101   // per pool memory usage
 102 
 103   Klass* mu_klass = Management::java_lang_management_MemoryUsage_klass(CHECK_NH);
 104   instanceKlassHandle mu_kh(THREAD, mu_klass);
 105 
 106   // The array allocations below should use a handle containing mu_klass
 107   // as the first allocation could trigger a GC, causing the actual
 108   // klass oop to move, and leaving mu_klass pointing to the old
 109   // location.
 110   objArrayOop bu = oopFactory::new_objArray(mu_kh(), MemoryService::num_memory_pools(), CHECK_NH);
 111   objArrayHandle usage_before_gc_ah(THREAD, bu);
 112   objArrayOop au = oopFactory::new_objArray(mu_kh(), MemoryService::num_memory_pools(), CHECK_NH);
 113   objArrayHandle usage_after_gc_ah(THREAD, au);
 114 
 115   for (int i = 0; i < MemoryService::num_memory_pools(); i++) {
 116     Handle before_usage = MemoryService::create_MemoryUsage_obj(gcStatInfo->before_gc_usage_for_pool(i), CHECK_NH);
 117     Handle after_usage;
 118 
 119     MemoryUsage u = gcStatInfo->after_gc_usage_for_pool(i);
 120     if (u.max_size() == 0 && u.used() > 0) {
 121       // If max size == 0, this pool is a survivor space.
 122       // Set max size = -1 since the pools will be swapped after GC.
 123       MemoryUsage usage(u.init_size(), u.used(), u.committed(), (size_t)-1);
 124       after_usage = MemoryService::create_MemoryUsage_obj(usage, CHECK_NH);
 125     } else {
 126         after_usage = MemoryService::create_MemoryUsage_obj(u, CHECK_NH);
 127     }
 128     usage_before_gc_ah->obj_at_put(i, before_usage());
 129     usage_after_gc_ah->obj_at_put(i, after_usage());
 130   }
 131 
 132   // Current implementation only has 1 attribute (number of GC threads)
 133   // The type is 'I'
 134   objArrayOop extra_args_array = oopFactory::new_objArray(SystemDictionary::Integer_klass(), 1, CHECK_NH);
 135   objArrayHandle extra_array (THREAD, extra_args_array);
 136   Klass* itKlass = SystemDictionary::Integer_klass();
 137   instanceKlassHandle intK(THREAD, itKlass);
 138 
 139   instanceHandle extra_arg_val = intK->allocate_instance_handle(CHECK_NH);
 140 
 141   {
 142     JavaValue res(T_VOID);
 143     JavaCallArguments argsInt;
 144     argsInt.push_oop(extra_arg_val);
 145     argsInt.push_int(gcManager->num_gc_threads());
 146 
 147     JavaCalls::call_special(&res,
 148                             intK,
 149                             vmSymbols::object_initializer_name(),
 150                             vmSymbols::int_void_signature(),
 151                             &argsInt,
 152                             CHECK_NH);
 153   }
 154   extra_array->obj_at_put(0,extra_arg_val());
 155 
 156   Klass* gcInfoklass = Management::com_sun_management_GcInfo_klass(CHECK_NH);
 157   instanceKlassHandle ik(THREAD, gcInfoklass);
 158 
 159   Handle gcInfo_instance = ik->allocate_instance_handle(CHECK_NH);
 160 
 161   JavaValue constructor_result(T_VOID);
 162   JavaCallArguments constructor_args(16);
 163   constructor_args.push_oop(gcInfo_instance);
 164   constructor_args.push_oop(getGcInfoBuilder(gcManager,THREAD));
 165   constructor_args.push_long(gcStatInfo->gc_index());
 166   constructor_args.push_long(Management::ticks_to_ms(gcStatInfo->start_time()));
 167   constructor_args.push_long(Management::ticks_to_ms(gcStatInfo->end_time()));
 168   constructor_args.push_oop(usage_before_gc_ah);
 169   constructor_args.push_oop(usage_after_gc_ah);
 170   constructor_args.push_oop(extra_array);
 171 
 172   JavaCalls::call_special(&constructor_result,
 173                           ik,
 174                           vmSymbols::object_initializer_name(),
 175                           vmSymbols::com_sun_management_GcInfo_constructor_signature(),
 176                           &constructor_args,
 177                           CHECK_NH);
 178 
 179   return Handle(gcInfo_instance());
 180 }
 181 
 182 void GCNotifier::sendNotification(TRAPS) {
 183   GCNotifier::sendNotificationInternal(THREAD);
 184   // Clearing pending exception to avoid premature termination of
 185   // the service thread
 186   if (HAS_PENDING_EXCEPTION) {
 187     CLEAR_PENDING_EXCEPTION;
 188   }
 189 }
 190 
 191 class NotificationMark : public StackObj {
 192   // This class is used in GCNotifier::sendNotificationInternal to ensure that
 193   // the GCNotificationRequest object is properly cleaned up, whatever path
 194   // is used to exit the method.
 195   GCNotificationRequest* _request;
 196 public:
 197   NotificationMark(GCNotificationRequest* r) {
 198     _request = r;
 199   }
 200   ~NotificationMark() {
 201     assert(_request != NULL, "Sanity check");
 202     delete _request;
 203   }
 204 };
 205 
 206 void GCNotifier::sendNotificationInternal(TRAPS) {
 207   ResourceMark rm(THREAD);
 208   HandleMark hm(THREAD);
 209   GCNotificationRequest *request = getRequest();
 210   if (request != NULL) {
 211     NotificationMark nm(request);
 212     Handle objGcInfo = createGcInfo(request->gcManager, request->gcStatInfo, CHECK);
 213 
 214     Handle objName = java_lang_String::create_from_str(request->gcManager->name(), CHECK);
 215     Handle objAction = java_lang_String::create_from_str(request->gcAction, CHECK);
 216     Handle objCause = java_lang_String::create_from_str(request->gcCause, CHECK);
 217     Klass* k = Management::com_sun_management_internal_GarbageCollectorExtImpl_klass(CHECK);
 218 
 219     instanceKlassHandle gc_mbean_klass(THREAD, k);
 220 
 221     instanceOop gc_mbean = request->gcManager->get_memory_manager_instance(THREAD);
 222     instanceHandle gc_mbean_h(THREAD, gc_mbean);
 223     if (!gc_mbean_h->is_a(k)) {
 224       THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
 225                 "This GCMemoryManager doesn't have a GarbageCollectorMXBean");
 226     }
 227 
 228     JavaValue result(T_VOID);
 229     JavaCallArguments args(gc_mbean_h);
 230     args.push_long(request->timestamp);
 231     args.push_oop(objName);
 232     args.push_oop(objAction);
 233     args.push_oop(objCause);
 234     args.push_oop(objGcInfo);
 235 
 236     JavaCalls::call_virtual(&result,
 237                             gc_mbean_klass,
 238                             vmSymbols::createGCNotification_name(),
 239                             vmSymbols::createGCNotification_signature(),
 240                             &args,
 241                             CHECK);
 242   }
 243 }
 244