1 /*
2 * Copyright (c) 1997, 2014, 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_implementation/shared/markSweep.hpp"
27 #include "gc_interface/collectedHeap.hpp"
28 #include "gc_interface/collectedHeap.inline.hpp"
29 #include "memory/genCollectedHeap.hpp"
30 #include "memory/resourceArea.hpp"
31 #include "runtime/init.hpp"
32 #include "runtime/interfaceSupport.hpp"
33 #include "runtime/orderAccess.inline.hpp"
34 #include "runtime/threadLocalStorage.hpp"
35 #include "runtime/vframe.hpp"
36 #include "utilities/preserveException.hpp"
37
38 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
39
40 // Implementation of InterfaceSupport
41
42 #ifdef ASSERT
43
44 long InterfaceSupport::_number_of_calls = 0;
45 long InterfaceSupport::_scavenge_alot_counter = 1;
46 long InterfaceSupport::_fullgc_alot_counter = 1;
47 long InterfaceSupport::_fullgc_alot_invocation = 0;
48
49 Histogram* RuntimeHistogram;
50
51 RuntimeHistogramElement::RuntimeHistogramElement(const char* elementName) {
52 static volatile jint RuntimeHistogram_lock = 0;
53 _name = elementName;
54 uintx count = 0;
55
56 while (Atomic::cmpxchg(1, &RuntimeHistogram_lock, 0) != 0) {
57 while (OrderAccess::load_acquire(&RuntimeHistogram_lock) != 0) {
58 count +=1;
59 if ( (WarnOnStalledSpinLock > 0)
60 && (count % WarnOnStalledSpinLock == 0)) {
61 warning("RuntimeHistogram_lock seems to be stalled");
62 }
63 }
64 }
65
66 if (RuntimeHistogram == NULL) {
67 RuntimeHistogram = new Histogram("VM Runtime Call Counts",200);
68 }
69
70 RuntimeHistogram->add_element(this);
71 Atomic::dec(&RuntimeHistogram_lock);
72 }
73
74 void InterfaceSupport::trace(const char* result_type, const char* header) {
75 tty->print_cr("%6d %s", _number_of_calls, header);
76 }
77
78 void InterfaceSupport::gc_alot() {
79 Thread *thread = Thread::current();
80 if (!thread->is_Java_thread()) return; // Avoid concurrent calls
81 // Check for new, not quite initialized thread. A thread in new mode cannot initiate a GC.
82 JavaThread *current_thread = (JavaThread *)thread;
83 if (current_thread->active_handles() == NULL) return;
84
85 // Short-circuit any possible re-entrant gc-a-lot attempt
86 if (thread->skip_gcalot()) return;
87
88 if (is_init_completed()) {
89
90 if (++_fullgc_alot_invocation < FullGCALotStart) {
91 return;
92 }
93
94 // Use this line if you want to block at a specific point,
95 // e.g. one number_of_calls/scavenge/gc before you got into problems
96 if (FullGCALot) _fullgc_alot_counter--;
97
98 // Check if we should force a full gc
99 if (_fullgc_alot_counter == 0) {
100 // Release dummy so objects are forced to move
101 if (!Universe::release_fullgc_alot_dummy()) {
102 warning("FullGCALot: Unable to release more dummies at bottom of heap");
103 }
104 HandleMark hm(thread);
105 Universe::heap()->collect(GCCause::_full_gc_alot);
106 unsigned int invocations = Universe::heap()->total_full_collections();
107 // Compute new interval
108 if (FullGCALotInterval > 1) {
109 _fullgc_alot_counter = 1+(long)((double)FullGCALotInterval*os::random()/(max_jint+1.0));
110 if (PrintGCDetails && Verbose) {
111 tty->print_cr("Full gc no: %u\tInterval: %d", invocations,
112 _fullgc_alot_counter);
113 }
114 } else {
115 _fullgc_alot_counter = 1;
116 }
117 // Print progress message
118 if (invocations % 100 == 0) {
119 if (PrintGCDetails && Verbose) tty->print_cr("Full gc no: %u", invocations);
120 }
121 } else {
122 if (ScavengeALot) _scavenge_alot_counter--;
123 // Check if we should force a scavenge
124 if (_scavenge_alot_counter == 0) {
125 HandleMark hm(thread);
126 Universe::heap()->collect(GCCause::_scavenge_alot);
127 unsigned int invocations = Universe::heap()->total_collections() - Universe::heap()->total_full_collections();
128 // Compute new interval
129 if (ScavengeALotInterval > 1) {
130 _scavenge_alot_counter = 1+(long)((double)ScavengeALotInterval*os::random()/(max_jint+1.0));
131 if (PrintGCDetails && Verbose) {
132 tty->print_cr("Scavenge no: %u\tInterval: %d", invocations,
133 _scavenge_alot_counter);
134 }
135 } else {
136 _scavenge_alot_counter = 1;
137 }
138 // Print progress message
139 if (invocations % 1000 == 0) {
140 if (PrintGCDetails && Verbose) tty->print_cr("Scavenge no: %u", invocations);
141 }
142 }
143 }
144 }
145 }
146
147
148 vframe* vframe_array[50];
149 int walk_stack_counter = 0;
150
151 void InterfaceSupport::walk_stack_from(vframe* start_vf) {
152 // walk
153 int i = 0;
154 for (vframe* f = start_vf; f; f = f->sender() ) {
155 if (i < 50) vframe_array[i++] = f;
156 }
157 }
158
159
160 void InterfaceSupport::walk_stack() {
161 JavaThread* thread = JavaThread::current();
162 walk_stack_counter++;
163 if (!thread->has_last_Java_frame()) return;
164 ResourceMark rm(thread);
165 RegisterMap reg_map(thread);
166 walk_stack_from(thread->last_java_vframe(®_map));
167 }
168
169
170 # ifdef ENABLE_ZAP_DEAD_LOCALS
171
172 static int zap_traversals = 0;
173
174 void InterfaceSupport::zap_dead_locals_old() {
175 JavaThread* thread = JavaThread::current();
176 if (zap_traversals == -1) // edit constant for debugging
177 warning("I am here");
178 int zap_frame_count = 0; // count frames to help debugging
179 for (StackFrameStream sfs(thread); !sfs.is_done(); sfs.next()) {
180 sfs.current()->zap_dead_locals(thread, sfs.register_map());
181 ++zap_frame_count;
182 }
183 ++zap_traversals;
184 }
185
186 # endif
187
188
189 int deoptimizeAllCounter = 0;
190 int zombieAllCounter = 0;
191
192
193 void InterfaceSupport::zombieAll() {
194 if (is_init_completed() && zombieAllCounter > ZombieALotInterval) {
195 zombieAllCounter = 0;
196 VM_ZombieAll op;
197 VMThread::execute(&op);
198 } else {
199 zombieAllCounter++;
200 }
201 }
202
203 void InterfaceSupport::unlinkSymbols() {
204 VM_UnlinkSymbols op;
205 VMThread::execute(&op);
206 }
207
208 void InterfaceSupport::deoptimizeAll() {
209 if (is_init_completed() ) {
210 if (DeoptimizeALot && deoptimizeAllCounter > DeoptimizeALotInterval) {
211 deoptimizeAllCounter = 0;
212 VM_DeoptimizeAll op;
213 VMThread::execute(&op);
214 } else if (DeoptimizeRandom && (deoptimizeAllCounter & 0x1f) == (os::random() & 0x1f)) {
215 VM_DeoptimizeAll op;
216 VMThread::execute(&op);
217 }
218 }
219 deoptimizeAllCounter++;
220 }
221
222
223 void InterfaceSupport::stress_derived_pointers() {
224 #ifdef COMPILER2
225 JavaThread *thread = JavaThread::current();
226 if (!is_init_completed()) return;
227 ResourceMark rm(thread);
228 bool found = false;
229 for (StackFrameStream sfs(thread); !sfs.is_done() && !found; sfs.next()) {
230 CodeBlob* cb = sfs.current()->cb();
231 if (cb != NULL && cb->oop_maps() ) {
232 // Find oopmap for current method
233 OopMap* map = cb->oop_map_for_return_address(sfs.current()->pc());
234 assert(map != NULL, "no oopmap found for pc");
235 found = map->has_derived_pointer();
236 }
237 }
238 if (found) {
239 // $$$ Not sure what to do here.
240 /*
241 Scavenge::invoke(0);
242 */
243 }
244 #endif
245 }
246
247
248 void InterfaceSupport::verify_stack() {
249 JavaThread* thread = JavaThread::current();
250 ResourceMark rm(thread);
251 // disabled because it throws warnings that oop maps should only be accessed
252 // in VM thread or during debugging
253
254 if (!thread->has_pending_exception()) {
255 // verification does not work if there are pending exceptions
256 StackFrameStream sfs(thread);
257 CodeBlob* cb = sfs.current()->cb();
258 // In case of exceptions we might not have a runtime_stub on
259 // top of stack, hence, all callee-saved registers are not going
260 // to be setup correctly, hence, we cannot do stack verify
261 if (cb != NULL && !(cb->is_runtime_stub() || cb->is_uncommon_trap_stub())) return;
262
263 for (; !sfs.is_done(); sfs.next()) {
264 sfs.current()->verify(sfs.register_map());
265 }
266 }
267 }
268
269
270 void InterfaceSupport::verify_last_frame() {
271 JavaThread* thread = JavaThread::current();
272 ResourceMark rm(thread);
273 RegisterMap reg_map(thread);
274 frame fr = thread->last_frame();
275 fr.verify(®_map);
276 }
277
278
279 #endif // ASSERT
280
281
282 void InterfaceSupport_init() {
283 #ifdef ASSERT
284 if (ScavengeALot || FullGCALot) {
285 srand(ScavengeALotInterval * FullGCALotInterval);
286 }
287 #endif
288 }