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 if (PrintGCDetails && Verbose) {
110 tty->print_cr("Full gc no: %u\tInterval: %ld", invocations, _fullgc_alot_counter);
111 }
112 } else {
113 _fullgc_alot_counter = 1;
114 }
115 // Print progress message
116 if (invocations % 100 == 0) {
117 if (PrintGCDetails && Verbose) tty->print_cr("Full gc no: %u", invocations);
118 }
119 } else {
120 if (ScavengeALot) _scavenge_alot_counter--;
121 // Check if we should force a scavenge
122 if (_scavenge_alot_counter == 0) {
123 HandleMark hm(thread);
124 Universe::heap()->collect(GCCause::_scavenge_alot);
125 unsigned int invocations = Universe::heap()->total_collections() - Universe::heap()->total_full_collections();
126 // Compute new interval
127 if (ScavengeALotInterval > 1) {
128 _scavenge_alot_counter = 1+(long)((double)ScavengeALotInterval*os::random()/(max_jint+1.0));
129 if (PrintGCDetails && Verbose) {
130 tty->print_cr("Scavenge no: %u\tInterval: %ld", invocations, _scavenge_alot_counter);
131 }
132 } else {
133 _scavenge_alot_counter = 1;
134 }
135 // Print progress message
136 if (invocations % 1000 == 0) {
137 if (PrintGCDetails && Verbose) tty->print_cr("Scavenge no: %u", invocations);
138 }
139 }
140 }
141 }
142 }
143
144
145 vframe* vframe_array[50];
146 int walk_stack_counter = 0;
147
148 void InterfaceSupport::walk_stack_from(vframe* start_vf) {
149 // walk
150 int i = 0;
151 for (vframe* f = start_vf; f; f = f->sender() ) {
152 if (i < 50) vframe_array[i++] = f;
153 }
154 }
155
156
157 void InterfaceSupport::walk_stack() {
158 JavaThread* thread = JavaThread::current();
159 walk_stack_counter++;
160 if (!thread->has_last_Java_frame()) return;
161 ResourceMark rm(thread);
162 RegisterMap reg_map(thread);
163 walk_stack_from(thread->last_java_vframe(®_map));
164 }
165
166 // invocation counter for InterfaceSupport::deoptimizeAll/zombieAll functions
167 int deoptimizeAllCounter = 0;
168 int zombieAllCounter = 0;
169
170 void InterfaceSupport::zombieAll() {
171 // This method is called by all threads when a thread make
172 // transition to VM state (for example, runtime calls).
173 // Divide number of calls by number of threads to avoid
174 // dependence of ZombieAll events frequency on number of threads.
175 int value = zombieAllCounter / Threads::number_of_threads();
176 if (is_init_completed() && value > ZombieALotInterval) {
177 zombieAllCounter = 0;
178 VM_ZombieAll op;
179 VMThread::execute(&op);
180 }
181 zombieAllCounter++;
182 }
183
184 void InterfaceSupport::unlinkSymbols() {
185 VM_UnlinkSymbols op;
186 VMThread::execute(&op);
187 }
188
189 void InterfaceSupport::deoptimizeAll() {
190 // This method is called by all threads when a thread make
191 // transition to VM state (for example, runtime calls).
192 // Divide number of calls by number of threads to avoid
193 // dependence of DeoptimizeAll events frequency on number of threads.
194 int value = deoptimizeAllCounter / Threads::number_of_threads();
195 if (is_init_completed()) {
196 if (DeoptimizeALot && value > DeoptimizeALotInterval) {
197 deoptimizeAllCounter = 0;
198 VM_DeoptimizeAll op;
199 VMThread::execute(&op);
200 } else if (DeoptimizeRandom && (value & 0x1F) == (os::random() & 0x1F)) {
201 VM_DeoptimizeAll op;
202 VMThread::execute(&op);
203 }
204 }
205 deoptimizeAllCounter++;
206 }
207
208
209 void InterfaceSupport::stress_derived_pointers() {
210 #ifdef COMPILER2
211 JavaThread *thread = JavaThread::current();
212 if (!is_init_completed()) return;
213 ResourceMark rm(thread);
214 bool found = false;
215 for (StackFrameStream sfs(thread); !sfs.is_done() && !found; sfs.next()) {
216 CodeBlob* cb = sfs.current()->cb();
217 if (cb != NULL && cb->oop_maps() ) {
218 // Find oopmap for current method
219 const ImmutableOopMap* map = cb->oop_map_for_return_address(sfs.current()->pc());
220 assert(map != NULL, "no oopmap found for pc");
221 found = map->has_derived_pointer();
222 }
223 }
224 if (found) {
225 // $$$ Not sure what to do here.
226 /*
227 Scavenge::invoke(0);
228 */
229 }
230 #endif
231 }
232
233
234 void InterfaceSupport::verify_stack() {
235 JavaThread* thread = JavaThread::current();
236 ResourceMark rm(thread);
237 // disabled because it throws warnings that oop maps should only be accessed
238 // in VM thread or during debugging
239
240 if (!thread->has_pending_exception()) {
241 // verification does not work if there are pending exceptions
242 StackFrameStream sfs(thread);
243 CodeBlob* cb = sfs.current()->cb();
244 // In case of exceptions we might not have a runtime_stub on
245 // top of stack, hence, all callee-saved registers are not going
246 // to be setup correctly, hence, we cannot do stack verify
247 if (cb != NULL && !(cb->is_runtime_stub() || cb->is_uncommon_trap_stub())) return;
248
249 for (; !sfs.is_done(); sfs.next()) {
250 sfs.current()->verify(sfs.register_map());
251 }
252 }
253 }
254
255
256 void InterfaceSupport::verify_last_frame() {
257 JavaThread* thread = JavaThread::current();
258 ResourceMark rm(thread);
259 RegisterMap reg_map(thread);
260 frame fr = thread->last_frame();
261 fr.verify(®_map);
262 }
263
264
265 #endif // ASSERT
266
267
268 void InterfaceSupport_init() {
269 #ifdef ASSERT
270 if (ScavengeALot || FullGCALot) {
271 srand(ScavengeALotInterval * FullGCALotInterval);
272 }
273 #endif
274 }