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/atomic.inline.hpp"
32 #include "runtime/init.hpp"
33 #include "runtime/interfaceSupport.hpp"
34 #include "runtime/orderAccess.inline.hpp"
35 #include "runtime/threadLocalStorage.hpp"
36 #include "runtime/vframe.hpp"
37 #include "utilities/preserveException.hpp"
38
39 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
40
41 // Implementation of InterfaceSupport
42
43 #ifdef ASSERT
44
45 long InterfaceSupport::_number_of_calls = 0;
46 long InterfaceSupport::_scavenge_alot_counter = 1;
47 long InterfaceSupport::_fullgc_alot_counter = 1;
48 long InterfaceSupport::_fullgc_alot_invocation = 0;
49
50 Histogram* RuntimeHistogram;
51
52 RuntimeHistogramElement::RuntimeHistogramElement(const char* elementName) {
53 static volatile jint RuntimeHistogram_lock = 0;
54 _name = elementName;
55 uintx count = 0;
56
57 while (Atomic::cmpxchg(1, &RuntimeHistogram_lock, 0) != 0) {
58 while (OrderAccess::load_acquire(&RuntimeHistogram_lock) != 0) {
59 count +=1;
60 if ( (WarnOnStalledSpinLock > 0)
61 && (count % WarnOnStalledSpinLock == 0)) {
62 warning("RuntimeHistogram_lock seems to be stalled");
63 }
64 }
65 }
66
67 if (RuntimeHistogram == NULL) {
68 RuntimeHistogram = new Histogram("VM Runtime Call Counts",200);
69 }
70
71 RuntimeHistogram->add_element(this);
72 Atomic::dec(&RuntimeHistogram_lock);
73 }
74
75 void InterfaceSupport::trace(const char* result_type, const char* header) {
76 tty->print_cr("%6d %s", _number_of_calls, header);
77 }
78
79 void InterfaceSupport::gc_alot() {
80 Thread *thread = Thread::current();
81 if (!thread->is_Java_thread()) return; // Avoid concurrent calls
82 // Check for new, not quite initialized thread. A thread in new mode cannot initiate a GC.
83 JavaThread *current_thread = (JavaThread *)thread;
84 if (current_thread->active_handles() == NULL) return;
85
86 // Short-circuit any possible re-entrant gc-a-lot attempt
87 if (thread->skip_gcalot()) return;
88
89 if (is_init_completed()) {
90
91 if (++_fullgc_alot_invocation < FullGCALotStart) {
92 return;
93 }
94
95 // Use this line if you want to block at a specific point,
96 // e.g. one number_of_calls/scavenge/gc before you got into problems
97 if (FullGCALot) _fullgc_alot_counter--;
98
99 // Check if we should force a full gc
100 if (_fullgc_alot_counter == 0) {
101 // Release dummy so objects are forced to move
102 if (!Universe::release_fullgc_alot_dummy()) {
103 warning("FullGCALot: Unable to release more dummies at bottom of heap");
104 }
105 HandleMark hm(thread);
106 Universe::heap()->collect(GCCause::_full_gc_alot);
107 unsigned int invocations = Universe::heap()->total_full_collections();
108 // Compute new interval
109 if (FullGCALotInterval > 1) {
110 _fullgc_alot_counter = 1+(long)((double)FullGCALotInterval*os::random()/(max_jint+1.0));
111 if (PrintGCDetails && Verbose) {
112 tty->print_cr("Full gc no: %u\tInterval: %d", invocations,
113 _fullgc_alot_counter);
114 }
115 } else {
116 _fullgc_alot_counter = 1;
117 }
118 // Print progress message
119 if (invocations % 100 == 0) {
120 if (PrintGCDetails && Verbose) tty->print_cr("Full gc no: %u", invocations);
121 }
122 } else {
123 if (ScavengeALot) _scavenge_alot_counter--;
124 // Check if we should force a scavenge
125 if (_scavenge_alot_counter == 0) {
126 HandleMark hm(thread);
127 Universe::heap()->collect(GCCause::_scavenge_alot);
128 unsigned int invocations = Universe::heap()->total_collections() - Universe::heap()->total_full_collections();
129 // Compute new interval
130 if (ScavengeALotInterval > 1) {
131 _scavenge_alot_counter = 1+(long)((double)ScavengeALotInterval*os::random()/(max_jint+1.0));
132 if (PrintGCDetails && Verbose) {
133 tty->print_cr("Scavenge no: %u\tInterval: %d", invocations,
134 _scavenge_alot_counter);
135 }
136 } else {
137 _scavenge_alot_counter = 1;
138 }
139 // Print progress message
140 if (invocations % 1000 == 0) {
141 if (PrintGCDetails && Verbose) tty->print_cr("Scavenge no: %u", invocations);
142 }
143 }
144 }
145 }
146 }
147
148
149 vframe* vframe_array[50];
150 int walk_stack_counter = 0;
151
152 void InterfaceSupport::walk_stack_from(vframe* start_vf) {
153 // walk
154 int i = 0;
155 for (vframe* f = start_vf; f; f = f->sender() ) {
156 if (i < 50) vframe_array[i++] = f;
157 }
158 }
159
160
161 void InterfaceSupport::walk_stack() {
162 JavaThread* thread = JavaThread::current();
163 walk_stack_counter++;
164 if (!thread->has_last_Java_frame()) return;
165 ResourceMark rm(thread);
166 RegisterMap reg_map(thread);
167 walk_stack_from(thread->last_java_vframe(®_map));
168 }
169
170
171 # ifdef ENABLE_ZAP_DEAD_LOCALS
172
173 static int zap_traversals = 0;
174
175 void InterfaceSupport::zap_dead_locals_old() {
176 JavaThread* thread = JavaThread::current();
177 if (zap_traversals == -1) // edit constant for debugging
178 warning("I am here");
179 int zap_frame_count = 0; // count frames to help debugging
180 for (StackFrameStream sfs(thread); !sfs.is_done(); sfs.next()) {
181 sfs.current()->zap_dead_locals(thread, sfs.register_map());
182 ++zap_frame_count;
183 }
184 ++zap_traversals;
185 }
186
187 # endif
188
189
190 int deoptimizeAllCounter = 0;
191 int zombieAllCounter = 0;
192
193
194 void InterfaceSupport::zombieAll() {
195 if (is_init_completed() && zombieAllCounter > ZombieALotInterval) {
196 zombieAllCounter = 0;
197 VM_ZombieAll op;
198 VMThread::execute(&op);
199 } else {
200 zombieAllCounter++;
201 }
202 }
203
204 void InterfaceSupport::unlinkSymbols() {
205 VM_UnlinkSymbols op;
206 VMThread::execute(&op);
207 }
208
209 void InterfaceSupport::deoptimizeAll() {
210 if (is_init_completed() ) {
211 if (DeoptimizeALot && deoptimizeAllCounter > DeoptimizeALotInterval) {
212 deoptimizeAllCounter = 0;
213 VM_DeoptimizeAll op;
214 VMThread::execute(&op);
215 } else if (DeoptimizeRandom && (deoptimizeAllCounter & 0x1f) == (os::random() & 0x1f)) {
216 VM_DeoptimizeAll op;
217 VMThread::execute(&op);
218 }
219 }
220 deoptimizeAllCounter++;
221 }
222
223
224 void InterfaceSupport::stress_derived_pointers() {
225 #ifdef COMPILER2
226 JavaThread *thread = JavaThread::current();
227 if (!is_init_completed()) return;
228 ResourceMark rm(thread);
229 bool found = false;
230 for (StackFrameStream sfs(thread); !sfs.is_done() && !found; sfs.next()) {
231 CodeBlob* cb = sfs.current()->cb();
232 if (cb != NULL && cb->oop_maps() ) {
233 // Find oopmap for current method
234 OopMap* map = cb->oop_map_for_return_address(sfs.current()->pc());
235 assert(map != NULL, "no oopmap found for pc");
236 found = map->has_derived_pointer();
237 }
238 }
239 if (found) {
240 // $$$ Not sure what to do here.
241 /*
242 Scavenge::invoke(0);
243 */
244 }
245 #endif
246 }
247
248
249 void InterfaceSupport::verify_stack() {
250 JavaThread* thread = JavaThread::current();
251 ResourceMark rm(thread);
252 // disabled because it throws warnings that oop maps should only be accessed
253 // in VM thread or during debugging
254
255 if (!thread->has_pending_exception()) {
256 // verification does not work if there are pending exceptions
257 StackFrameStream sfs(thread);
258 CodeBlob* cb = sfs.current()->cb();
259 // In case of exceptions we might not have a runtime_stub on
260 // top of stack, hence, all callee-saved registers are not going
261 // to be setup correctly, hence, we cannot do stack verify
262 if (cb != NULL && !(cb->is_runtime_stub() || cb->is_uncommon_trap_stub())) return;
263
264 for (; !sfs.is_done(); sfs.next()) {
265 sfs.current()->verify(sfs.register_map());
266 }
267 }
268 }
269
270
271 void InterfaceSupport::verify_last_frame() {
272 JavaThread* thread = JavaThread::current();
273 ResourceMark rm(thread);
274 RegisterMap reg_map(thread);
275 frame fr = thread->last_frame();
276 fr.verify(®_map);
277 }
278
279
280 #endif // ASSERT
281
282
283 void InterfaceSupport_init() {
284 #ifdef ASSERT
285 if (ScavengeALot || FullGCALot) {
286 srand(ScavengeALotInterval * FullGCALotInterval);
287 }
288 #endif
289 }