1/*
2 * Copyright (c) 2011, 2019, 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/objArrayOop.inline.hpp"
29#include "oops/oop.inline.hpp"
30#include "runtime/handles.inline.hpp"
31#include "runtime/java.hpp"
32#include "runtime/javaCalls.hpp"
33#include "runtime/mutex.hpp"
34#include "runtime/mutexLocker.hpp"
35#include "services/gcNotifier.hpp"
36#include "services/management.hpp"
37#include "services/memoryService.hpp"
38#include "memoryManager.hpp"
39#include "memory/oopFactory.hpp"
40#include "memory/resourceArea.hpp"
41
42GCNotificationRequest *GCNotifier::first_request = NULL;
43GCNotificationRequest *GCNotifier::last_request = NULL;
44
45void GCNotifier::pushNotification(GCMemoryManager *mgr, const char *action, const char *cause) {
46 // Make a copy of the last GC statistics
47 // GC may occur between now and the creation of the notification
48 int num_pools = MemoryService::num_memory_pools();
49 // stat is deallocated inside GCNotificationRequest
50 GCStatInfo* stat = new(ResourceObj::C_HEAP, mtGC) GCStatInfo(num_pools);
51 mgr->get_last_gc_stat(stat);
52 GCNotificationRequest *request = new GCNotificationRequest(os::javaTimeMillis(),mgr,action,cause,stat);
53 addRequest(request);
54 }
55
56void GCNotifier::addRequest(GCNotificationRequest *request) {
57 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
58 if(first_request == NULL) {
59 first_request = request;
60 } else {
61 last_request->next = request;
62 }
63 last_request = request;
64 Service_lock->notify_all();
65}
66
67GCNotificationRequest *GCNotifier::getRequest() {
68 MutexLocker ml(Service_lock, Mutex::_no_safepoint_check_flag);
69 GCNotificationRequest *request = first_request;
70 if(first_request != NULL) {
71 first_request = first_request->next;
72 }
73 return request;
74}
75
76bool GCNotifier::has_event() {
77 return first_request != NULL;
78}
79
80static Handle getGcInfoBuilder(GCMemoryManager *gcManager,TRAPS) {
81
82 Klass* gcMBeanKlass = Management::com_sun_management_internal_GarbageCollectorExtImpl_klass(CHECK_NH);
83
84 instanceOop i = gcManager->get_memory_manager_instance(THREAD);
85 instanceHandle ih(THREAD, i);
86
87 JavaValue result(T_OBJECT);
88 JavaCallArguments args(ih);
89
90 JavaCalls::call_virtual(&result,
91 gcMBeanKlass,
92 vmSymbols::getGcInfoBuilder_name(),
93 vmSymbols::getGcInfoBuilder_signature(),
94 &args,
95 CHECK_NH);
96 return Handle(THREAD,(oop)result.get_jobject());
97}
98
99static Handle createGcInfo(GCMemoryManager *gcManager, GCStatInfo *gcStatInfo,TRAPS) {
100
101 // Fill the arrays of MemoryUsage objects with before and after GC
102 // per pool memory usage
103
104 InstanceKlass* mu_klass = Management::java_lang_management_MemoryUsage_klass(CHECK_NH);
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_klass, MemoryService::num_memory_pools(), CHECK_NH);
111 objArrayHandle usage_before_gc_ah(THREAD, bu);
112 objArrayOop au = oopFactory::new_objArray(mu_klass, 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
137 JavaCallArguments argsInt;
138 argsInt.push_int(gcManager->num_gc_threads());
139 Handle extra_arg_val = JavaCalls::construct_new_instance(
140 SystemDictionary::Integer_klass(),
141 vmSymbols::int_void_signature(),
142 &argsInt,
143 CHECK_NH);
144
145 extra_array->obj_at_put(0,extra_arg_val());
146
147 InstanceKlass* gcInfoklass = Management::com_sun_management_GcInfo_klass(CHECK_NH);
148
149 JavaCallArguments constructor_args(16);
150 constructor_args.push_oop(getGcInfoBuilder(gcManager,THREAD));
151 constructor_args.push_long(gcStatInfo->gc_index());
152 constructor_args.push_long(Management::ticks_to_ms(gcStatInfo->start_time()));
153 constructor_args.push_long(Management::ticks_to_ms(gcStatInfo->end_time()));
154 constructor_args.push_oop(usage_before_gc_ah);
155 constructor_args.push_oop(usage_after_gc_ah);
156 constructor_args.push_oop(extra_array);
157
158 return JavaCalls::construct_new_instance(
159 gcInfoklass,
160 vmSymbols::com_sun_management_GcInfo_constructor_signature(),
161 &constructor_args,
162 CHECK_NH);
163}
164
165void GCNotifier::sendNotification(TRAPS) {
166 GCNotifier::sendNotificationInternal(THREAD);
167 // Clearing pending exception to avoid premature termination of
168 // the service thread
169 if (HAS_PENDING_EXCEPTION) {
170 CLEAR_PENDING_EXCEPTION;
171 }
172}
173
174class NotificationMark : public StackObj {
175 // This class is used in GCNotifier::sendNotificationInternal to ensure that
176 // the GCNotificationRequest object is properly cleaned up, whatever path
177 // is used to exit the method.
178 GCNotificationRequest* _request;
179public:
180 NotificationMark(GCNotificationRequest* r) {
181 _request = r;
182 }
183 ~NotificationMark() {
184 assert(_request != NULL, "Sanity check");
185 delete _request;
186 }
187};
188
189void GCNotifier::sendNotificationInternal(TRAPS) {
190 ResourceMark rm(THREAD);
191 HandleMark hm(THREAD);
192 GCNotificationRequest *request = getRequest();
193 if (request != NULL) {
194 NotificationMark nm(request);
195 Handle objGcInfo = createGcInfo(request->gcManager, request->gcStatInfo, CHECK);
196
197 Handle objName = java_lang_String::create_from_str(request->gcManager->name(), CHECK);
198 Handle objAction = java_lang_String::create_from_str(request->gcAction, CHECK);
199 Handle objCause = java_lang_String::create_from_str(request->gcCause, CHECK);
200 InstanceKlass* gc_mbean_klass = Management::com_sun_management_internal_GarbageCollectorExtImpl_klass(CHECK);
201
202 instanceOop gc_mbean = request->gcManager->get_memory_manager_instance(THREAD);
203 instanceHandle gc_mbean_h(THREAD, gc_mbean);
204 if (!gc_mbean_h->is_a(gc_mbean_klass)) {
205 THROW_MSG(vmSymbols::java_lang_IllegalArgumentException(),
206 "This GCMemoryManager doesn't have a GarbageCollectorMXBean");
207 }
208
209 JavaValue result(T_VOID);
210 JavaCallArguments args(gc_mbean_h);
211 args.push_long(request->timestamp);
212 args.push_oop(objName);
213 args.push_oop(objAction);
214 args.push_oop(objCause);
215 args.push_oop(objGcInfo);
216
217 JavaCalls::call_virtual(&result,
218 gc_mbean_klass,
219 vmSymbols::createGCNotification_name(),
220 vmSymbols::createGCNotification_signature(),
221 &args,
222 CHECK);
223 }
224}
225
226