Mercurial > hg > graal-compiler
annotate src/share/vm/services/lowMemoryDetector.cpp @ 2142:8012aa3ccede
4926272: methodOopDesc::method_from_bcp is unsafe
Reviewed-by: coleenp, jrose, kvn, dcubed
author | never |
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date | Thu, 13 Jan 2011 22:15:41 -0800 |
parents | f95d63e2154a |
children | 3582bf76420e |
rev | line source |
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0 | 1 /* |
1972 | 2 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved. |
0 | 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 * | |
1552
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
0 | 22 * |
23 */ | |
24 | |
1972 | 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/lowMemoryDetector.hpp" | |
35 #include "services/management.hpp" | |
0 | 36 |
37 LowMemoryDetectorThread* LowMemoryDetector::_detector_thread = NULL; | |
38 volatile bool LowMemoryDetector::_enabled_for_collected_pools = false; | |
39 volatile jint LowMemoryDetector::_disabled_count = 0; | |
40 | |
41 void LowMemoryDetector::initialize() { | |
42 EXCEPTION_MARK; | |
43 | |
1142 | 44 instanceKlassHandle klass (THREAD, SystemDictionary::Thread_klass()); |
0 | 45 instanceHandle thread_oop = klass->allocate_instance_handle(CHECK); |
46 | |
47 const char thread_name[] = "Low Memory Detector"; | |
48 Handle string = java_lang_String::create_from_str(thread_name, CHECK); | |
49 | |
50 // Initialize thread_oop to put it into the system threadGroup | |
51 Handle thread_group (THREAD, Universe::system_thread_group()); | |
52 JavaValue result(T_VOID); | |
53 JavaCalls::call_special(&result, thread_oop, | |
54 klass, | |
55 vmSymbolHandles::object_initializer_name(), | |
56 vmSymbolHandles::threadgroup_string_void_signature(), | |
57 thread_group, | |
58 string, | |
59 CHECK); | |
60 | |
61 { | |
62 MutexLocker mu(Threads_lock); | |
63 _detector_thread = new LowMemoryDetectorThread(&low_memory_detector_thread_entry); | |
64 | |
65 // At this point it may be possible that no osthread was created for the | |
66 // JavaThread due to lack of memory. We would have to throw an exception | |
67 // in that case. However, since this must work and we do not allow | |
68 // exceptions anyway, check and abort if this fails. | |
69 if (_detector_thread == NULL || _detector_thread->osthread() == NULL) { | |
70 vm_exit_during_initialization("java.lang.OutOfMemoryError", | |
71 "unable to create new native thread"); | |
72 } | |
73 | |
74 java_lang_Thread::set_thread(thread_oop(), _detector_thread); | |
75 java_lang_Thread::set_priority(thread_oop(), NearMaxPriority); | |
76 java_lang_Thread::set_daemon(thread_oop()); | |
77 _detector_thread->set_threadObj(thread_oop()); | |
78 | |
79 Threads::add(_detector_thread); | |
80 Thread::start(_detector_thread); | |
81 } | |
82 } | |
83 | |
84 bool LowMemoryDetector::has_pending_requests() { | |
85 assert(LowMemory_lock->owned_by_self(), "Must own LowMemory_lock"); | |
86 bool has_requests = false; | |
87 int num_memory_pools = MemoryService::num_memory_pools(); | |
88 for (int i = 0; i < num_memory_pools; i++) { | |
89 MemoryPool* pool = MemoryService::get_memory_pool(i); | |
90 SensorInfo* sensor = pool->usage_sensor(); | |
91 if (sensor != NULL) { | |
92 has_requests = has_requests || sensor->has_pending_requests(); | |
93 } | |
94 | |
95 SensorInfo* gc_sensor = pool->gc_usage_sensor(); | |
96 if (gc_sensor != NULL) { | |
97 has_requests = has_requests || gc_sensor->has_pending_requests(); | |
98 } | |
99 } | |
100 return has_requests; | |
101 } | |
102 | |
103 void LowMemoryDetector::low_memory_detector_thread_entry(JavaThread* jt, TRAPS) { | |
104 while (true) { | |
105 bool sensors_changed = false; | |
106 | |
107 { | |
108 // _no_safepoint_check_flag is used here as LowMemory_lock is a | |
109 // special lock and the VMThread may acquire this lock at safepoint. | |
110 // Need state transition ThreadBlockInVM so that this thread | |
111 // will be handled by safepoint correctly when this thread is | |
112 // notified at a safepoint. | |
113 | |
114 // This ThreadBlockInVM object is not also considered to be | |
115 // suspend-equivalent because LowMemoryDetector threads are | |
116 // not visible to external suspension. | |
117 | |
118 ThreadBlockInVM tbivm(jt); | |
119 | |
120 MutexLockerEx ml(LowMemory_lock, Mutex::_no_safepoint_check_flag); | |
121 while (!(sensors_changed = has_pending_requests())) { | |
122 // wait until one of the sensors has pending requests | |
123 LowMemory_lock->wait(Mutex::_no_safepoint_check_flag); | |
124 } | |
125 } | |
126 | |
127 { | |
128 ResourceMark rm(THREAD); | |
129 HandleMark hm(THREAD); | |
130 | |
131 // No need to hold LowMemory_lock to call out to Java | |
132 int num_memory_pools = MemoryService::num_memory_pools(); | |
133 for (int i = 0; i < num_memory_pools; i++) { | |
134 MemoryPool* pool = MemoryService::get_memory_pool(i); | |
135 SensorInfo* sensor = pool->usage_sensor(); | |
136 SensorInfo* gc_sensor = pool->gc_usage_sensor(); | |
137 if (sensor != NULL && sensor->has_pending_requests()) { | |
138 sensor->process_pending_requests(CHECK); | |
139 } | |
140 if (gc_sensor != NULL && gc_sensor->has_pending_requests()) { | |
141 gc_sensor->process_pending_requests(CHECK); | |
142 } | |
143 } | |
144 } | |
145 } | |
146 } | |
147 | |
148 // This method could be called from any Java threads | |
149 // and also VMThread. | |
150 void LowMemoryDetector::detect_low_memory() { | |
151 MutexLockerEx ml(LowMemory_lock, Mutex::_no_safepoint_check_flag); | |
152 | |
153 bool has_pending_requests = false; | |
154 int num_memory_pools = MemoryService::num_memory_pools(); | |
155 for (int i = 0; i < num_memory_pools; i++) { | |
156 MemoryPool* pool = MemoryService::get_memory_pool(i); | |
157 SensorInfo* sensor = pool->usage_sensor(); | |
158 if (sensor != NULL && | |
159 pool->usage_threshold()->is_high_threshold_supported() && | |
160 pool->usage_threshold()->high_threshold() != 0) { | |
161 MemoryUsage usage = pool->get_memory_usage(); | |
162 sensor->set_gauge_sensor_level(usage, | |
163 pool->usage_threshold()); | |
164 has_pending_requests = has_pending_requests || sensor->has_pending_requests(); | |
165 } | |
166 } | |
167 | |
168 if (has_pending_requests) { | |
169 LowMemory_lock->notify_all(); | |
170 } | |
171 } | |
172 | |
173 // This method could be called from any Java threads | |
174 // and also VMThread. | |
175 void LowMemoryDetector::detect_low_memory(MemoryPool* pool) { | |
176 SensorInfo* sensor = pool->usage_sensor(); | |
177 if (sensor == NULL || | |
178 !pool->usage_threshold()->is_high_threshold_supported() || | |
179 pool->usage_threshold()->high_threshold() == 0) { | |
180 return; | |
181 } | |
182 | |
183 { | |
184 MutexLockerEx ml(LowMemory_lock, Mutex::_no_safepoint_check_flag); | |
185 | |
186 MemoryUsage usage = pool->get_memory_usage(); | |
187 sensor->set_gauge_sensor_level(usage, | |
188 pool->usage_threshold()); | |
189 if (sensor->has_pending_requests()) { | |
190 // notify sensor state update | |
191 LowMemory_lock->notify_all(); | |
192 } | |
193 } | |
194 } | |
195 | |
196 // Only called by VMThread at GC time | |
197 void LowMemoryDetector::detect_after_gc_memory(MemoryPool* pool) { | |
198 SensorInfo* sensor = pool->gc_usage_sensor(); | |
199 if (sensor == NULL || | |
200 !pool->gc_usage_threshold()->is_high_threshold_supported() || | |
201 pool->gc_usage_threshold()->high_threshold() == 0) { | |
202 return; | |
203 } | |
204 | |
205 { | |
206 MutexLockerEx ml(LowMemory_lock, Mutex::_no_safepoint_check_flag); | |
207 | |
208 MemoryUsage usage = pool->get_last_collection_usage(); | |
209 sensor->set_counter_sensor_level(usage, pool->gc_usage_threshold()); | |
210 | |
211 if (sensor->has_pending_requests()) { | |
212 // notify sensor state update | |
213 LowMemory_lock->notify_all(); | |
214 } | |
215 } | |
216 } | |
217 | |
218 // recompute enabled flag | |
219 void LowMemoryDetector::recompute_enabled_for_collected_pools() { | |
220 bool enabled = false; | |
221 int num_memory_pools = MemoryService::num_memory_pools(); | |
222 for (int i=0; i<num_memory_pools; i++) { | |
223 MemoryPool* pool = MemoryService::get_memory_pool(i); | |
224 if (pool->is_collected_pool() && is_enabled(pool)) { | |
225 enabled = true; | |
226 break; | |
227 } | |
228 } | |
229 _enabled_for_collected_pools = enabled; | |
230 } | |
231 | |
232 SensorInfo::SensorInfo() { | |
233 _sensor_obj = NULL; | |
234 _sensor_on = false; | |
235 _sensor_count = 0; | |
236 _pending_trigger_count = 0; | |
237 _pending_clear_count = 0; | |
238 } | |
239 | |
240 // When this method is used, the memory usage is monitored | |
241 // as a gauge attribute. Sensor notifications (trigger or | |
242 // clear) is only emitted at the first time it crosses | |
243 // a threshold. | |
244 // | |
245 // High and low thresholds are designed to provide a | |
246 // hysteresis mechanism to avoid repeated triggering | |
247 // of notifications when the attribute value makes small oscillations | |
248 // around the high or low threshold value. | |
249 // | |
250 // The sensor will be triggered if: | |
251 // (1) the usage is crossing above the high threshold and | |
252 // the sensor is currently off and no pending | |
253 // trigger requests; or | |
254 // (2) the usage is crossing above the high threshold and | |
255 // the sensor will be off (i.e. sensor is currently on | |
256 // and has pending clear requests). | |
257 // | |
258 // Subsequent crossings of the high threshold value do not cause | |
259 // any triggers unless the usage becomes less than the low threshold. | |
260 // | |
261 // The sensor will be cleared if: | |
262 // (1) the usage is crossing below the low threshold and | |
263 // the sensor is currently on and no pending | |
264 // clear requests; or | |
265 // (2) the usage is crossing below the low threshold and | |
266 // the sensor will be on (i.e. sensor is currently off | |
267 // and has pending trigger requests). | |
268 // | |
269 // Subsequent crossings of the low threshold value do not cause | |
270 // any clears unless the usage becomes greater than or equal | |
271 // to the high threshold. | |
272 // | |
273 // If the current level is between high and low threhsold, no change. | |
274 // | |
275 void SensorInfo::set_gauge_sensor_level(MemoryUsage usage, ThresholdSupport* high_low_threshold) { | |
276 assert(high_low_threshold->is_high_threshold_supported(), "just checking"); | |
277 | |
278 bool is_over_high = high_low_threshold->is_high_threshold_crossed(usage); | |
279 bool is_below_low = high_low_threshold->is_low_threshold_crossed(usage); | |
280 | |
281 assert(!(is_over_high && is_below_low), "Can't be both true"); | |
282 | |
283 if (is_over_high && | |
284 ((!_sensor_on && _pending_trigger_count == 0) || | |
285 _pending_clear_count > 0)) { | |
286 // low memory detected and need to increment the trigger pending count | |
287 // if the sensor is off or will be off due to _pending_clear_ > 0 | |
288 // Request to trigger the sensor | |
289 _pending_trigger_count++; | |
290 _usage = usage; | |
291 | |
292 if (_pending_clear_count > 0) { | |
293 // non-zero pending clear requests indicates that there are | |
294 // pending requests to clear this sensor. | |
295 // This trigger request needs to clear this clear count | |
296 // since the resulting sensor flag should be on. | |
297 _pending_clear_count = 0; | |
298 } | |
299 } else if (is_below_low && | |
300 ((_sensor_on && _pending_clear_count == 0) || | |
301 (_pending_trigger_count > 0 && _pending_clear_count == 0))) { | |
302 // memory usage returns below the threshold | |
303 // Request to clear the sensor if the sensor is on or will be on due to | |
304 // _pending_trigger_count > 0 and also no clear request | |
305 _pending_clear_count++; | |
306 } | |
307 } | |
308 | |
309 // When this method is used, the memory usage is monitored as a | |
310 // simple counter attribute. The sensor will be triggered | |
311 // whenever the usage is crossing the threshold to keep track | |
312 // of the number of times the VM detects such a condition occurs. | |
313 // | |
314 // High and low thresholds are designed to provide a | |
315 // hysteresis mechanism to avoid repeated triggering | |
316 // of notifications when the attribute value makes small oscillations | |
317 // around the high or low threshold value. | |
318 // | |
319 // The sensor will be triggered if: | |
320 // - the usage is crossing above the high threshold regardless | |
321 // of the current sensor state. | |
322 // | |
323 // The sensor will be cleared if: | |
324 // (1) the usage is crossing below the low threshold and | |
325 // the sensor is currently on; or | |
326 // (2) the usage is crossing below the low threshold and | |
327 // the sensor will be on (i.e. sensor is currently off | |
328 // and has pending trigger requests). | |
329 void SensorInfo::set_counter_sensor_level(MemoryUsage usage, ThresholdSupport* counter_threshold) { | |
330 assert(counter_threshold->is_high_threshold_supported(), "just checking"); | |
331 | |
332 bool is_over_high = counter_threshold->is_high_threshold_crossed(usage); | |
333 bool is_below_low = counter_threshold->is_low_threshold_crossed(usage); | |
334 | |
335 assert(!(is_over_high && is_below_low), "Can't be both true"); | |
336 | |
337 if (is_over_high) { | |
338 _pending_trigger_count++; | |
339 _usage = usage; | |
340 _pending_clear_count = 0; | |
341 } else if (is_below_low && (_sensor_on || _pending_trigger_count > 0)) { | |
342 _pending_clear_count++; | |
343 } | |
344 } | |
345 | |
346 void SensorInfo::oops_do(OopClosure* f) { | |
347 f->do_oop((oop*) &_sensor_obj); | |
348 } | |
349 | |
350 void SensorInfo::process_pending_requests(TRAPS) { | |
351 if (!has_pending_requests()) { | |
352 return; | |
353 } | |
354 | |
355 int pending_count = pending_trigger_count(); | |
356 if (pending_clear_count() > 0) { | |
357 clear(pending_count, CHECK); | |
358 } else { | |
359 trigger(pending_count, CHECK); | |
360 } | |
361 | |
362 } | |
363 | |
364 void SensorInfo::trigger(int count, TRAPS) { | |
365 assert(count <= _pending_trigger_count, "just checking"); | |
366 | |
367 if (_sensor_obj != NULL) { | |
368 klassOop k = Management::sun_management_Sensor_klass(CHECK); | |
369 instanceKlassHandle sensorKlass (THREAD, k); | |
370 Handle sensor_h(THREAD, _sensor_obj); | |
371 Handle usage_h = MemoryService::create_MemoryUsage_obj(_usage, CHECK); | |
372 | |
373 JavaValue result(T_VOID); | |
374 JavaCallArguments args(sensor_h); | |
375 args.push_int((int) count); | |
376 args.push_oop(usage_h); | |
377 | |
378 JavaCalls::call_virtual(&result, | |
379 sensorKlass, | |
380 vmSymbolHandles::trigger_name(), | |
381 vmSymbolHandles::trigger_method_signature(), | |
382 &args, | |
383 CHECK); | |
384 } | |
385 | |
386 { | |
387 // Holds LowMemory_lock and update the sensor state | |
388 MutexLockerEx ml(LowMemory_lock, Mutex::_no_safepoint_check_flag); | |
389 _sensor_on = true; | |
390 _sensor_count += count; | |
391 _pending_trigger_count = _pending_trigger_count - count; | |
392 } | |
393 } | |
394 | |
395 void SensorInfo::clear(int count, TRAPS) { | |
396 if (_sensor_obj != NULL) { | |
397 klassOop k = Management::sun_management_Sensor_klass(CHECK); | |
398 instanceKlassHandle sensorKlass (THREAD, k); | |
399 Handle sensor(THREAD, _sensor_obj); | |
400 | |
401 JavaValue result(T_VOID); | |
402 JavaCallArguments args(sensor); | |
403 args.push_int((int) count); | |
404 JavaCalls::call_virtual(&result, | |
405 sensorKlass, | |
406 vmSymbolHandles::clear_name(), | |
407 vmSymbolHandles::int_void_signature(), | |
408 &args, | |
409 CHECK); | |
410 } | |
411 | |
412 { | |
413 // Holds LowMemory_lock and update the sensor state | |
414 MutexLockerEx ml(LowMemory_lock, Mutex::_no_safepoint_check_flag); | |
415 _sensor_on = false; | |
416 _pending_clear_count = 0; | |
417 _pending_trigger_count = _pending_trigger_count - count; | |
418 } | |
419 } | |
420 | |
421 //-------------------------------------------------------------- | |
422 // Non-product code | |
423 | |
424 #ifndef PRODUCT | |
425 void SensorInfo::print() { | |
426 tty->print_cr("%s count = %ld pending_triggers = %ld pending_clears = %ld", | |
427 (_sensor_on ? "on" : "off"), | |
428 _sensor_count, _pending_trigger_count, _pending_clear_count); | |
429 } | |
430 | |
431 #endif // PRODUCT |