1 /*
2 * Copyright (c) 1997, 2010, 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/threadLocalStorage.hpp"
34 #include "runtime/vframe.hpp"
35 #include "utilities/preserveException.hpp"
36
37
38 // Implementation of InterfaceSupport
39
40 #ifdef ASSERT
41
42 long InterfaceSupport::_number_of_calls = 0;
43 long InterfaceSupport::_scavenge_alot_counter = 1;
44 long InterfaceSupport::_fullgc_alot_counter = 1;
45 long InterfaceSupport::_fullgc_alot_invocation = 0;
46
47 Histogram* RuntimeHistogram;
48
49 RuntimeHistogramElement::RuntimeHistogramElement(const char* elementName) {
50 static volatile jint RuntimeHistogram_lock = 0;
51 _name = elementName;
52 uintx count = 0;
53
54 while (Atomic::cmpxchg(1, &RuntimeHistogram_lock, 0) != 0) {
55 while (OrderAccess::load_acquire(&RuntimeHistogram_lock) != 0) {
56 count +=1;
57 if ( (WarnOnStalledSpinLock > 0)
58 && (count % WarnOnStalledSpinLock == 0)) {
59 warning("RuntimeHistogram_lock seems to be stalled");
60 }
61 }
62 }
63
64 if (RuntimeHistogram == NULL) {
65 RuntimeHistogram = new Histogram("VM Runtime Call Counts",200);
66 }
67
68 RuntimeHistogram->add_element(this);
69 Atomic::dec(&RuntimeHistogram_lock);
70 }
71
72 void InterfaceSupport::trace(const char* result_type, const char* header) {
73 tty->print_cr("%6d %s", _number_of_calls, header);
74 }
75
76 void InterfaceSupport::gc_alot() {
77 Thread *thread = Thread::current();
78 if (!thread->is_Java_thread()) return; // Avoid concurrent calls
79 // Check for new, not quite initialized thread. A thread in new mode cannot initiate a GC.
80 JavaThread *current_thread = (JavaThread *)thread;
81 if (current_thread->active_handles() == NULL) return;
82
83 // Short-circuit any possible re-entrant gc-a-lot attempt
84 if (thread->skip_gcalot()) return;
85
86 if (is_init_completed()) {
87
88 if (++_fullgc_alot_invocation < FullGCALotStart) {
89 return;
90 }
91
92 // Use this line if you want to block at a specific point,
93 // e.g. one number_of_calls/scavenge/gc before you got into problems
94 if (FullGCALot) _fullgc_alot_counter--;
95
96 // Check if we should force a full gc
97 if (_fullgc_alot_counter == 0) {
98 // Release dummy so objects are forced to move
99 if (!Universe::release_fullgc_alot_dummy()) {
100 warning("FullGCALot: Unable to release more dummies at bottom of heap");
101 }
102 HandleMark hm(thread);
103 Universe::heap()->collect(GCCause::_full_gc_alot);
104 unsigned int invocations = Universe::heap()->total_full_collections();
105 // Compute new interval
106 if (FullGCALotInterval > 1) {
107 _fullgc_alot_counter = 1+(long)((double)FullGCALotInterval*os::random()/(max_jint+1.0));
108 if (PrintGCDetails && Verbose) {
109 tty->print_cr("Full gc no: %u\tInterval: %d", invocations,
110 _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: %d", invocations,
131 _scavenge_alot_counter);
132 }
133 } else {
134 _scavenge_alot_counter = 1;
135 }
136 // Print progress message
137 if (invocations % 1000 == 0) {
138 if (PrintGCDetails && Verbose) tty->print_cr("Scavenge no: %u", invocations);
139 }
140 }
141 }
142 }
143 }
144
145
146 vframe* vframe_array[50];
147 int walk_stack_counter = 0;
148
149 void InterfaceSupport::walk_stack_from(vframe* start_vf) {
150 // walk
151 int i = 0;
152 for (vframe* f = start_vf; f; f = f->sender() ) {
153 if (i < 50) vframe_array[i++] = f;
154 }
155 }
156
157
158 void InterfaceSupport::walk_stack() {
159 JavaThread* thread = JavaThread::current();
160 walk_stack_counter++;
161 if (!thread->has_last_Java_frame()) return;
162 ResourceMark rm(thread);
163 RegisterMap reg_map(thread);
164 walk_stack_from(thread->last_java_vframe(®_map));
165 }
166
167
168 # ifdef ENABLE_ZAP_DEAD_LOCALS
169
170 static int zap_traversals = 0;
171
172 void InterfaceSupport::zap_dead_locals_old() {
173 JavaThread* thread = JavaThread::current();
174 if (zap_traversals == -1) // edit constant for debugging
175 warning("I am here");
176 int zap_frame_count = 0; // count frames to help debugging
177 for (StackFrameStream sfs(thread); !sfs.is_done(); sfs.next()) {
178 sfs.current()->zap_dead_locals(thread, sfs.register_map());
179 ++zap_frame_count;
180 }
181 ++zap_traversals;
182 }
183
184 # endif
185
186
187 int deoptimizeAllCounter = 0;
188 int zombieAllCounter = 0;
189
190
191 void InterfaceSupport::zombieAll() {
192 if (is_init_completed() && zombieAllCounter > ZombieALotInterval) {
193 zombieAllCounter = 0;
194 VM_ZombieAll op;
195 VMThread::execute(&op);
196 } else {
197 zombieAllCounter++;
198 }
199 }
200
201 void InterfaceSupport::deoptimizeAll() {
202 if (is_init_completed() ) {
203 if (DeoptimizeALot && deoptimizeAllCounter > DeoptimizeALotInterval) {
204 deoptimizeAllCounter = 0;
205 VM_DeoptimizeAll op;
206 VMThread::execute(&op);
207 } else if (DeoptimizeRandom && (deoptimizeAllCounter & 0x1f) == (os::random() & 0x1f)) {
208 VM_DeoptimizeAll op;
209 VMThread::execute(&op);
210 }
211 }
212 deoptimizeAllCounter++;
213 }
214
215
216 void InterfaceSupport::stress_derived_pointers() {
217 #ifdef COMPILER2
218 JavaThread *thread = JavaThread::current();
219 if (!is_init_completed()) return;
220 ResourceMark rm(thread);
221 bool found = false;
222 for (StackFrameStream sfs(thread); !sfs.is_done() && !found; sfs.next()) {
223 CodeBlob* cb = sfs.current()->cb();
224 if (cb != NULL && cb->oop_maps() ) {
225 // Find oopmap for current method
226 OopMap* map = cb->oop_map_for_return_address(sfs.current()->pc());
227 assert(map != NULL, "no oopmap found for pc");
228 found = map->has_derived_pointer();
229 }
230 }
231 if (found) {
232 // $$$ Not sure what to do here.
233 /*
234 Scavenge::invoke(0);
235 */
236 }
237 #endif
238 }
239
240
241 void InterfaceSupport::verify_stack() {
242 JavaThread* thread = JavaThread::current();
243 ResourceMark rm(thread);
244 // disabled because it throws warnings that oop maps should only be accessed
245 // in VM thread or during debugging
246
247 if (!thread->has_pending_exception()) {
248 // verification does not work if there are pending exceptions
249 StackFrameStream sfs(thread);
250 CodeBlob* cb = sfs.current()->cb();
251 // In case of exceptions we might not have a runtime_stub on
252 // top of stack, hence, all callee-saved registers are not going
253 // to be setup correctly, hence, we cannot do stack verify
254 if (cb != NULL && !(cb->is_runtime_stub() || cb->is_uncommon_trap_stub())) return;
255
256 for (; !sfs.is_done(); sfs.next()) {
257 sfs.current()->verify(sfs.register_map());
258 }
259 }
260 }
261
262
263 void InterfaceSupport::verify_last_frame() {
264 JavaThread* thread = JavaThread::current();
265 ResourceMark rm(thread);
266 RegisterMap reg_map(thread);
267 frame fr = thread->last_frame();
268 fr.verify(®_map);
269 }
270
271
272 #endif // ASSERT
273
274
275 void InterfaceSupport_init() {
276 #ifdef ASSERT
277 if (ScavengeALot || FullGCALot) {
278 srand(ScavengeALotInterval * FullGCALotInterval);
279 }
280 #endif
281 }