1 /*
2 * Copyright (c) 1997, 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 "gc/shared/collectedHeap.hpp"
27 #include "gc/shared/collectedHeap.inline.hpp"
28 #include "gc/shared/genCollectedHeap.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "runtime/atomic.inline.hpp"
31 #include "runtime/init.hpp"
32 #include "runtime/interfaceSupport.hpp"
33 #include "runtime/orderAccess.inline.hpp"
34 #include "runtime/os.inline.hpp"
35 #include "runtime/threadLocalStorage.hpp"
36 #include "runtime/vframe.hpp"
37 #include "utilities/preserveException.hpp"
38
39 // Implementation of InterfaceSupport
40
41 #ifdef ASSERT
42
43 long InterfaceSupport::_number_of_calls = 0;
44 long InterfaceSupport::_scavenge_alot_counter = 1;
45 long InterfaceSupport::_fullgc_alot_counter = 1;
46 long InterfaceSupport::_fullgc_alot_invocation = 0;
47
48 Histogram* RuntimeHistogram;
49
50 RuntimeHistogramElement::RuntimeHistogramElement(const char* elementName) {
51 static volatile jint RuntimeHistogram_lock = 0;
52 _name = elementName;
53 uintx count = 0;
54
55 while (Atomic::cmpxchg(1, &RuntimeHistogram_lock, 0) != 0) {
56 while (OrderAccess::load_acquire(&RuntimeHistogram_lock) != 0) {
57 count +=1;
58 if ( (WarnOnStalledSpinLock > 0)
59 && (count % WarnOnStalledSpinLock == 0)) {
60 warning("RuntimeHistogram_lock seems to be stalled");
61 }
62 }
63 }
64
65 if (RuntimeHistogram == NULL) {
66 RuntimeHistogram = new Histogram("VM Runtime Call Counts",200);
67 }
68
69 RuntimeHistogram->add_element(this);
70 Atomic::dec(&RuntimeHistogram_lock);
71 }
72
73 void InterfaceSupport::trace(const char* result_type, const char* header) {
74 tty->print_cr("%6ld %s", _number_of_calls, header);
75 }
76
77 void InterfaceSupport::gc_alot() {
78 Thread *thread = Thread::current();
79 if (!thread->is_Java_thread()) return; // Avoid concurrent calls
80 // Check for new, not quite initialized thread. A thread in new mode cannot initiate a GC.
81 JavaThread *current_thread = (JavaThread *)thread;
82 if (current_thread->active_handles() == NULL) return;
83
84 // Short-circuit any possible re-entrant gc-a-lot attempt
85 if (thread->skip_gcalot()) return;
86
87 if (Threads::is_vm_complete()) {
88
89 if (++_fullgc_alot_invocation < FullGCALotStart) {
90 return;
91 }
92
93 // Use this line if you want to block at a specific point,
94 // e.g. one number_of_calls/scavenge/gc before you got into problems
95 if (FullGCALot) _fullgc_alot_counter--;
96
97 // Check if we should force a full gc
98 if (_fullgc_alot_counter == 0) {
99 // Release dummy so objects are forced to move
100 if (!Universe::release_fullgc_alot_dummy()) {
101 warning("FullGCALot: Unable to release more dummies at bottom of heap");
102 }
103 HandleMark hm(thread);
104 Universe::heap()->collect(GCCause::_full_gc_alot);
105 unsigned int invocations = Universe::heap()->total_full_collections();
106 // Compute new interval
107 if (FullGCALotInterval > 1) {
108 _fullgc_alot_counter = 1+(long)((double)FullGCALotInterval*os::random()/(max_jint+1.0));
109 log_trace(gc)("Full gc no: %u\tInterval: %ld", invocations, _fullgc_alot_counter);
110 } else {
111 _fullgc_alot_counter = 1;
112 }
113 // Print progress message
114 if (invocations % 100 == 0) {
115 log_trace(gc)("Full gc no: %u", invocations);
116 }
117 } else {
118 if (ScavengeALot) _scavenge_alot_counter--;
119 // Check if we should force a scavenge
120 if (_scavenge_alot_counter == 0) {
121 HandleMark hm(thread);
122 Universe::heap()->collect(GCCause::_scavenge_alot);
123 unsigned int invocations = Universe::heap()->total_collections() - Universe::heap()->total_full_collections();
124 // Compute new interval
125 if (ScavengeALotInterval > 1) {
126 _scavenge_alot_counter = 1+(long)((double)ScavengeALotInterval*os::random()/(max_jint+1.0));
127 log_trace(gc)("Scavenge no: %u\tInterval: %ld", invocations, _scavenge_alot_counter);
128 } else {
129 _scavenge_alot_counter = 1;
130 }
131 // Print progress message
132 if (invocations % 1000 == 0) {
133 log_trace(gc)("Scavenge no: %u", invocations);
134 }
135 }
136 }
137 }
138 }
139
140
141 vframe* vframe_array[50];
142 int walk_stack_counter = 0;
143
144 void InterfaceSupport::walk_stack_from(vframe* start_vf) {
145 // walk
146 int i = 0;
147 for (vframe* f = start_vf; f; f = f->sender() ) {
148 if (i < 50) vframe_array[i++] = f;
149 }
150 }
151
152
153 void InterfaceSupport::walk_stack() {
154 JavaThread* thread = JavaThread::current();
155 walk_stack_counter++;
156 if (!thread->has_last_Java_frame()) return;
157 ResourceMark rm(thread);
158 RegisterMap reg_map(thread);
159 walk_stack_from(thread->last_java_vframe(®_map));
160 }
161
162 // invocation counter for InterfaceSupport::deoptimizeAll/zombieAll functions
163 int deoptimizeAllCounter = 0;
164 int zombieAllCounter = 0;
165
166 void InterfaceSupport::zombieAll() {
167 // This method is called by all threads when a thread make
168 // transition to VM state (for example, runtime calls).
169 // Divide number of calls by number of threads to avoid
170 // dependence of ZombieAll events frequency on number of threads.
171 int value = zombieAllCounter / Threads::number_of_threads();
172 if (is_init_completed() && value > ZombieALotInterval) {
173 zombieAllCounter = 0;
174 VM_ZombieAll op;
175 VMThread::execute(&op);
176 }
177 zombieAllCounter++;
178 }
179
180 void InterfaceSupport::unlinkSymbols() {
181 VM_UnlinkSymbols op;
182 VMThread::execute(&op);
183 }
184
185 void InterfaceSupport::deoptimizeAll() {
186 // This method is called by all threads when a thread make
187 // transition to VM state (for example, runtime calls).
188 // Divide number of calls by number of threads to avoid
189 // dependence of DeoptimizeAll events frequency on number of threads.
190 int value = deoptimizeAllCounter / Threads::number_of_threads();
191 if (is_init_completed()) {
192 if (DeoptimizeALot && value > DeoptimizeALotInterval) {
193 deoptimizeAllCounter = 0;
194 VM_DeoptimizeAll op;
195 VMThread::execute(&op);
196 } else if (DeoptimizeRandom && (value & 0x1F) == (os::random() & 0x1F)) {
197 VM_DeoptimizeAll op;
198 VMThread::execute(&op);
199 }
200 }
201 deoptimizeAllCounter++;
202 }
203
204
205 void InterfaceSupport::stress_derived_pointers() {
206 #ifdef COMPILER2
207 JavaThread *thread = JavaThread::current();
208 if (!is_init_completed()) return;
209 ResourceMark rm(thread);
210 bool found = false;
211 for (StackFrameStream sfs(thread); !sfs.is_done() && !found; sfs.next()) {
212 CodeBlob* cb = sfs.current()->cb();
213 if (cb != NULL && cb->oop_maps() ) {
214 // Find oopmap for current method
215 const ImmutableOopMap* map = cb->oop_map_for_return_address(sfs.current()->pc());
216 assert(map != NULL, "no oopmap found for pc");
217 found = map->has_derived_pointer();
218 }
219 }
220 if (found) {
221 // $$$ Not sure what to do here.
222 /*
223 Scavenge::invoke(0);
224 */
225 }
226 #endif
227 }
228
229
230 void InterfaceSupport::verify_stack() {
231 JavaThread* thread = JavaThread::current();
232 ResourceMark rm(thread);
233 // disabled because it throws warnings that oop maps should only be accessed
234 // in VM thread or during debugging
235
236 if (!thread->has_pending_exception()) {
237 // verification does not work if there are pending exceptions
238 StackFrameStream sfs(thread);
239 CodeBlob* cb = sfs.current()->cb();
240 // In case of exceptions we might not have a runtime_stub on
241 // top of stack, hence, all callee-saved registers are not going
242 // to be setup correctly, hence, we cannot do stack verify
243 if (cb != NULL && !(cb->is_runtime_stub() || cb->is_uncommon_trap_stub())) return;
244
245 for (; !sfs.is_done(); sfs.next()) {
246 sfs.current()->verify(sfs.register_map());
247 }
248 }
249 }
250
251
252 void InterfaceSupport::verify_last_frame() {
253 JavaThread* thread = JavaThread::current();
254 ResourceMark rm(thread);
255 RegisterMap reg_map(thread);
256 frame fr = thread->last_frame();
257 fr.verify(®_map);
258 }
259
260
261 #endif // ASSERT
262
263
264 void InterfaceSupport_init() {
265 #ifdef ASSERT
266 if (ScavengeALot || FullGCALot) {
267 srand(ScavengeALotInterval * FullGCALotInterval);
268 }
269 #endif
270 }