1 /*
2 * Copyright (c) 1997, 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 "gc/shared/collectedHeap.hpp"
27 #include "gc/shared/collectedHeap.inline.hpp"
28 #include "logging/log.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "memory/universe.hpp"
31 #include "runtime/atomic.hpp"
32 #include "runtime/frame.inline.hpp"
33 #include "runtime/handles.inline.hpp"
34 #include "runtime/init.hpp"
35 #include "runtime/interfaceSupport.inline.hpp"
36 #include "runtime/orderAccess.hpp"
37 #include "runtime/os.inline.hpp"
38 #include "runtime/thread.inline.hpp"
39 #include "runtime/safepointVerifiers.hpp"
40 #include "runtime/vframe.hpp"
41 #include "runtime/vmThread.hpp"
42 #include "utilities/preserveException.hpp"
43
44 // Implementation of InterfaceSupport
45
46 #ifdef ASSERT
47 VMEntryWrapper::VMEntryWrapper() {
48 if (VerifyLastFrame) {
49 InterfaceSupport::verify_last_frame();
50 }
51 }
52
53 VMEntryWrapper::~VMEntryWrapper() {
54 InterfaceSupport::check_gc_alot();
55 if (WalkStackALot) {
56 InterfaceSupport::walk_stack();
57 }
58 #ifdef COMPILER2
59 // This option is not used by Compiler 1
60 if (StressDerivedPointers) {
61 InterfaceSupport::stress_derived_pointers();
62 }
63 #endif
64 if (DeoptimizeALot || DeoptimizeRandom) {
65 InterfaceSupport::deoptimizeAll();
66 }
67 if (ZombieALot) {
68 InterfaceSupport::zombieAll();
69 }
70 // do verification AFTER potential deoptimization
71 if (VerifyStack) {
72 InterfaceSupport::verify_stack();
73 }
74 }
75
76 VMNativeEntryWrapper::VMNativeEntryWrapper() {
77 if (GCALotAtAllSafepoints) InterfaceSupport::check_gc_alot();
78 }
79
80 VMNativeEntryWrapper::~VMNativeEntryWrapper() {
81 if (GCALotAtAllSafepoints) InterfaceSupport::check_gc_alot();
82 }
83
84 long InterfaceSupport::_number_of_calls = 0;
85 long InterfaceSupport::_scavenge_alot_counter = 1;
86 long InterfaceSupport::_fullgc_alot_counter = 1;
87 long InterfaceSupport::_fullgc_alot_invocation = 0;
88
89 Histogram* RuntimeHistogram;
90
91 RuntimeHistogramElement::RuntimeHistogramElement(const char* elementName) {
92 static volatile int RuntimeHistogram_lock = 0;
93 _name = elementName;
94 uintx count = 0;
95
96 while (Atomic::cmpxchg(1, &RuntimeHistogram_lock, 0) != 0) {
97 while (OrderAccess::load_acquire(&RuntimeHistogram_lock) != 0) {
98 count +=1;
99 if ( (WarnOnStalledSpinLock > 0)
100 && (count % WarnOnStalledSpinLock == 0)) {
101 warning("RuntimeHistogram_lock seems to be stalled");
102 }
103 }
104 }
105
106 if (RuntimeHistogram == NULL) {
107 RuntimeHistogram = new Histogram("VM Runtime Call Counts",200);
108 }
109
110 RuntimeHistogram->add_element(this);
111 Atomic::dec(&RuntimeHistogram_lock);
112 }
113
114 void InterfaceSupport::gc_alot() {
115 Thread *thread = Thread::current();
116 if (!thread->is_Java_thread()) return; // Avoid concurrent calls
117 // Check for new, not quite initialized thread. A thread in new mode cannot initiate a GC.
118 JavaThread *current_thread = (JavaThread *)thread;
119 if (current_thread->active_handles() == NULL) return;
120
121 // Short-circuit any possible re-entrant gc-a-lot attempt
122 if (thread->skip_gcalot()) return;
123
124 if (Threads::is_vm_complete()) {
125
126 if (++_fullgc_alot_invocation < FullGCALotStart) {
127 return;
128 }
129
130 // Use this line if you want to block at a specific point,
131 // e.g. one number_of_calls/scavenge/gc before you got into problems
132 if (FullGCALot) _fullgc_alot_counter--;
133
134 // Check if we should force a full gc
135 if (_fullgc_alot_counter == 0) {
136 // Release dummy so objects are forced to move
137 if (!Universe::release_fullgc_alot_dummy()) {
138 warning("FullGCALot: Unable to release more dummies at bottom of heap");
139 }
140 HandleMark hm(thread);
141 Universe::heap()->collect(GCCause::_full_gc_alot);
142 unsigned int invocations = Universe::heap()->total_full_collections();
143 // Compute new interval
144 if (FullGCALotInterval > 1) {
145 _fullgc_alot_counter = 1+(long)((double)FullGCALotInterval*os::random()/(max_jint+1.0));
146 log_trace(gc)("Full gc no: %u\tInterval: %ld", invocations, _fullgc_alot_counter);
147 } else {
148 _fullgc_alot_counter = 1;
149 }
150 // Print progress message
151 if (invocations % 100 == 0) {
152 log_trace(gc)("Full gc no: %u", invocations);
153 }
154 } else {
155 if (ScavengeALot) _scavenge_alot_counter--;
156 // Check if we should force a scavenge
157 if (_scavenge_alot_counter == 0) {
158 HandleMark hm(thread);
159 Universe::heap()->collect(GCCause::_scavenge_alot);
160 unsigned int invocations = Universe::heap()->total_collections() - Universe::heap()->total_full_collections();
161 // Compute new interval
162 if (ScavengeALotInterval > 1) {
163 _scavenge_alot_counter = 1+(long)((double)ScavengeALotInterval*os::random()/(max_jint+1.0));
164 log_trace(gc)("Scavenge no: %u\tInterval: %ld", invocations, _scavenge_alot_counter);
165 } else {
166 _scavenge_alot_counter = 1;
167 }
168 // Print progress message
169 if (invocations % 1000 == 0) {
170 log_trace(gc)("Scavenge no: %u", invocations);
171 }
172 }
173 }
174 }
175 }
176
177
178 vframe* vframe_array[50];
179 int walk_stack_counter = 0;
180
181 void InterfaceSupport::walk_stack_from(vframe* start_vf) {
182 // walk
183 int i = 0;
184 for (vframe* f = start_vf; f; f = f->sender() ) {
185 if (i < 50) vframe_array[i++] = f;
186 }
187 }
188
189
190 void InterfaceSupport::walk_stack() {
191 JavaThread* thread = JavaThread::current();
192 walk_stack_counter++;
193 if (!thread->has_last_Java_frame()) return;
194 ResourceMark rm(thread);
195 RegisterMap reg_map(thread);
196 walk_stack_from(thread->last_java_vframe(®_map));
197 }
198
199 // invocation counter for InterfaceSupport::deoptimizeAll/zombieAll functions
200 int deoptimizeAllCounter = 0;
201 int zombieAllCounter = 0;
202
203 void InterfaceSupport::zombieAll() {
204 // This method is called by all threads when a thread make
205 // transition to VM state (for example, runtime calls).
206 // Divide number of calls by number of threads to avoid
207 // dependence of ZombieAll events frequency on number of threads.
208 int value = zombieAllCounter / Threads::number_of_threads();
209 if (is_init_completed() && value > ZombieALotInterval) {
210 zombieAllCounter = 0;
211 VM_ZombieAll op;
212 VMThread::execute(&op);
213 }
214 zombieAllCounter++;
215 }
216
217 void InterfaceSupport::deoptimizeAll() {
218 // This method is called by all threads when a thread make
219 // transition to VM state (for example, runtime calls).
220 // Divide number of calls by number of threads to avoid
221 // dependence of DeoptimizeAll events frequency on number of threads.
222 int value = deoptimizeAllCounter / Threads::number_of_threads();
223 if (is_init_completed()) {
224 if (DeoptimizeALot && value > DeoptimizeALotInterval) {
225 deoptimizeAllCounter = 0;
226 VM_DeoptimizeAll op;
227 VMThread::execute(&op);
228 } else if (DeoptimizeRandom && (value & 0x1F) == (os::random() & 0x1F)) {
229 VM_DeoptimizeAll op;
230 VMThread::execute(&op);
231 }
232 }
233 deoptimizeAllCounter++;
234 }
235
236
237 void InterfaceSupport::stress_derived_pointers() {
238 #ifdef COMPILER2
239 JavaThread *thread = JavaThread::current();
240 if (!is_init_completed()) return;
241 ResourceMark rm(thread);
242 bool found = false;
243 for (StackFrameStream sfs(thread); !sfs.is_done() && !found; sfs.next()) {
244 CodeBlob* cb = sfs.current()->cb();
245 if (cb != NULL && cb->oop_maps() ) {
246 // Find oopmap for current method
247 const ImmutableOopMap* map = cb->oop_map_for_return_address(sfs.current()->pc());
248 assert(map != NULL, "no oopmap found for pc");
249 found = map->has_derived_pointer();
250 }
251 }
252 if (found) {
253 // $$$ Not sure what to do here.
254 /*
255 Scavenge::invoke(0);
256 */
257 }
258 #endif
259 }
260
261
262 void InterfaceSupport::verify_stack() {
263 JavaThread* thread = JavaThread::current();
264 ResourceMark rm(thread);
265 // disabled because it throws warnings that oop maps should only be accessed
266 // in VM thread or during debugging
267
268 if (!thread->has_pending_exception()) {
269 // verification does not work if there are pending exceptions
270 StackFrameStream sfs(thread);
271 CodeBlob* cb = sfs.current()->cb();
272 // In case of exceptions we might not have a runtime_stub on
273 // top of stack, hence, all callee-saved registers are not going
274 // to be setup correctly, hence, we cannot do stack verify
275 if (cb != NULL && !(cb->is_runtime_stub() || cb->is_uncommon_trap_stub())) return;
276
277 for (; !sfs.is_done(); sfs.next()) {
278 sfs.current()->verify(sfs.register_map());
279 }
280 }
281 }
282
283
284 void InterfaceSupport::verify_last_frame() {
285 JavaThread* thread = JavaThread::current();
286 ResourceMark rm(thread);
287 RegisterMap reg_map(thread);
288 frame fr = thread->last_frame();
289 fr.verify(®_map);
290 }
291
292
293 #endif // ASSERT
294
295
296 void InterfaceSupport_init() {
297 #ifdef ASSERT
298 if (ScavengeALot || FullGCALot) {
299 srand(ScavengeALotInterval * FullGCALotInterval);
300 }
301 #endif
302 }