1 /*
2 * Copyright (c) 2011, 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 "runtime/interfaceSupport.hpp"
27 #include "runtime/javaCalls.hpp"
28 #include "runtime/serviceThread.hpp"
29 #include "runtime/mutexLocker.hpp"
30 #include "prims/jvmtiImpl.hpp"
31 #include "services/gcNotifier.hpp"
32
33 ServiceThread* ServiceThread::_instance = NULL;
34
35 void ServiceThread::initialize() {
36 EXCEPTION_MARK;
37
38 instanceKlassHandle klass (THREAD, SystemDictionary::Thread_klass());
39 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
40
41 const char* name = JDK_Version::is_gte_jdk17x_version() ?
42 "Service Thread" : "Low Memory Detector";
43
44 Handle string = java_lang_String::create_from_str(name, CHECK);
45
46 // Initialize thread_oop to put it into the system threadGroup
47 Handle thread_group (THREAD, Universe::system_thread_group());
48 JavaValue result(T_VOID);
49 JavaCalls::call_special(&result, thread_oop,
50 klass,
51 vmSymbols::object_initializer_name(),
66 vm_exit_during_initialization("java.lang.OutOfMemoryError",
67 "unable to create new native thread");
68 }
69
70 java_lang_Thread::set_thread(thread_oop(), thread);
71 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
72 java_lang_Thread::set_daemon(thread_oop());
73 thread->set_threadObj(thread_oop());
74 _instance = thread;
75
76 Threads::add(thread);
77 Thread::start(thread);
78 }
79 }
80
81 void ServiceThread::service_thread_entry(JavaThread* jt, TRAPS) {
82 while (true) {
83 bool sensors_changed = false;
84 bool has_jvmti_events = false;
85 bool has_gc_notification_event = false;
86 JvmtiDeferredEvent jvmti_event;
87 {
88 // Need state transition ThreadBlockInVM so that this thread
89 // will be handled by safepoint correctly when this thread is
90 // notified at a safepoint.
91
92 // This ThreadBlockInVM object is not also considered to be
93 // suspend-equivalent because ServiceThread is not visible to
94 // external suspension.
95
96 ThreadBlockInVM tbivm(jt);
97
98 MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
99 while (!(sensors_changed = LowMemoryDetector::has_pending_requests()) &&
100 !(has_jvmti_events = JvmtiDeferredEventQueue::has_events()) &&
101 !(has_gc_notification_event = GCNotifier::has_event())) {
102 // wait until one of the sensors has pending requests, or there is a
103 // pending JVMTI event or JMX GC notification to post
104 Service_lock->wait(Mutex::_no_safepoint_check_flag);
105 }
106
107 if (has_jvmti_events) {
108 jvmti_event = JvmtiDeferredEventQueue::dequeue();
109 }
110 }
111
112 if (has_jvmti_events) {
113 jvmti_event.post();
114 }
115
116 if (sensors_changed) {
117 LowMemoryDetector::process_sensor_changes(jt);
118 }
119
120 if(has_gc_notification_event) {
121 GCNotifier::sendNotification(CHECK);
122 }
123 }
124 }
125
126 bool ServiceThread::is_service_thread(Thread* thread) {
127 return thread == _instance;
128 }
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1 /*
2 * Copyright (c) 2012, 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 "runtime/interfaceSupport.hpp"
27 #include "runtime/javaCalls.hpp"
28 #include "runtime/serviceThread.hpp"
29 #include "runtime/mutexLocker.hpp"
30 #include "prims/jvmtiImpl.hpp"
31 #include "services/gcNotifier.hpp"
32 #include "services/diagnosticArgument.hpp"
33 #include "services/diagnosticFramework.hpp"
34
35 ServiceThread* ServiceThread::_instance = NULL;
36
37 void ServiceThread::initialize() {
38 EXCEPTION_MARK;
39
40 instanceKlassHandle klass (THREAD, SystemDictionary::Thread_klass());
41 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK);
42
43 const char* name = JDK_Version::is_gte_jdk17x_version() ?
44 "Service Thread" : "Low Memory Detector";
45
46 Handle string = java_lang_String::create_from_str(name, CHECK);
47
48 // Initialize thread_oop to put it into the system threadGroup
49 Handle thread_group (THREAD, Universe::system_thread_group());
50 JavaValue result(T_VOID);
51 JavaCalls::call_special(&result, thread_oop,
52 klass,
53 vmSymbols::object_initializer_name(),
68 vm_exit_during_initialization("java.lang.OutOfMemoryError",
69 "unable to create new native thread");
70 }
71
72 java_lang_Thread::set_thread(thread_oop(), thread);
73 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority);
74 java_lang_Thread::set_daemon(thread_oop());
75 thread->set_threadObj(thread_oop());
76 _instance = thread;
77
78 Threads::add(thread);
79 Thread::start(thread);
80 }
81 }
82
83 void ServiceThread::service_thread_entry(JavaThread* jt, TRAPS) {
84 while (true) {
85 bool sensors_changed = false;
86 bool has_jvmti_events = false;
87 bool has_gc_notification_event = false;
88 bool has_dcmd_notification_event = false;
89 JvmtiDeferredEvent jvmti_event;
90 {
91 // Need state transition ThreadBlockInVM so that this thread
92 // will be handled by safepoint correctly when this thread is
93 // notified at a safepoint.
94
95 // This ThreadBlockInVM object is not also considered to be
96 // suspend-equivalent because ServiceThread is not visible to
97 // external suspension.
98
99 ThreadBlockInVM tbivm(jt);
100
101 MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag);
102 while (!(sensors_changed = LowMemoryDetector::has_pending_requests()) &&
103 !(has_jvmti_events = JvmtiDeferredEventQueue::has_events()) &&
104 !(has_gc_notification_event = GCNotifier::has_event()) &&
105 !(has_dcmd_notification_event = DCmdFactory::has_pending_jmx_notification())) {
106 // wait until one of the sensors has pending requests, or there is a
107 // pending JVMTI event or JMX GC notification to post
108 Service_lock->wait(Mutex::_no_safepoint_check_flag);
109 }
110
111 if (has_jvmti_events) {
112 jvmti_event = JvmtiDeferredEventQueue::dequeue();
113 }
114 }
115
116 if (has_jvmti_events) {
117 jvmti_event.post();
118 }
119
120 if (sensors_changed) {
121 LowMemoryDetector::process_sensor_changes(jt);
122 }
123
124 if(has_gc_notification_event) {
125 GCNotifier::sendNotification(CHECK);
126 }
127
128 if(has_dcmd_notification_event) {
129 DCmdFactory::send_notification(CHECK);
130 }
131 }
132 }
133
134 bool ServiceThread::is_service_thread(Thread* thread) {
135 return thread == _instance;
136 }
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