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/vframe.hpp"
36 #include "utilities/preserveException.hpp"
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("%6ld %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 (Threads::is_vm_complete()) {
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: %ld", invocations, _fullgc_alot_counter);
110 }
111 } else {
112 _fullgc_alot_counter = 1;
113 }
114 // Print progress message
115 if (invocations % 100 == 0) {
116 if (PrintGCDetails && Verbose) tty->print_cr("Full gc no: %u", invocations);
117 }
118 } else {
119 if (ScavengeALot) _scavenge_alot_counter--;
120 // Check if we should force a scavenge
121 if (_scavenge_alot_counter == 0) {
122 HandleMark hm(thread);
123 Universe::heap()->collect(GCCause::_scavenge_alot);
124 unsigned int invocations = Universe::heap()->total_collections() - Universe::heap()->total_full_collections();
125 // Compute new interval
126 if (ScavengeALotInterval > 1) {
127 _scavenge_alot_counter = 1+(long)((double)ScavengeALotInterval*os::random()/(max_jint+1.0));
128 if (PrintGCDetails && Verbose) {
129 tty->print_cr("Scavenge no: %u\tInterval: %ld", invocations, _scavenge_alot_counter);
130 }
131 } else {
132 _scavenge_alot_counter = 1;
133 }
134 // Print progress message
135 if (invocations % 1000 == 0) {
136 if (PrintGCDetails && Verbose) tty->print_cr("Scavenge no: %u", invocations);
137 }
138 }
139 }
140 }
141 }
142
143
144 vframe* vframe_array[50];
145 int walk_stack_counter = 0;
146
147 void InterfaceSupport::walk_stack_from(vframe* start_vf) {
148 // walk
149 int i = 0;
150 for (vframe* f = start_vf; f; f = f->sender() ) {
151 if (i < 50) vframe_array[i++] = f;
152 }
153 }
154
155
156 void InterfaceSupport::walk_stack() {
157 JavaThread* thread = JavaThread::current();
158 walk_stack_counter++;
159 if (!thread->has_last_Java_frame()) return;
160 ResourceMark rm(thread);
161 RegisterMap reg_map(thread);
162 walk_stack_from(thread->last_java_vframe(®_map));
163 }
164
165 // invocation counter for InterfaceSupport::deoptimizeAll/zombieAll functions
166 int deoptimizeAllCounter = 0;
167 int zombieAllCounter = 0;
168
169 void InterfaceSupport::zombieAll() {
170 // This method is called by all threads when a thread make
171 // transition to VM state (for example, runtime calls).
172 // Divide number of calls by number of threads to avoid
173 // dependence of ZombieAll events frequency on number of threads.
174 int value = zombieAllCounter / Threads::number_of_threads();
175 if (is_init_completed() && value > ZombieALotInterval) {
176 zombieAllCounter = 0;
177 VM_ZombieAll op;
178 VMThread::execute(&op);
179 }
180 zombieAllCounter++;
181 }
182
183 void InterfaceSupport::unlinkSymbols() {
184 VM_UnlinkSymbols op;
185 VMThread::execute(&op);
186 }
187
188 void InterfaceSupport::deoptimizeAll() {
189 // This method is called by all threads when a thread make
190 // transition to VM state (for example, runtime calls).
191 // Divide number of calls by number of threads to avoid
192 // dependence of DeoptimizeAll events frequency on number of threads.
193 int value = deoptimizeAllCounter / Threads::number_of_threads();
194 if (is_init_completed()) {
195 if (DeoptimizeALot && value > DeoptimizeALotInterval) {
196 deoptimizeAllCounter = 0;
197 VM_DeoptimizeAll op;
198 VMThread::execute(&op);
199 } else if (DeoptimizeRandom && (value & 0x1F) == (os::random() & 0x1F)) {
200 VM_DeoptimizeAll op;
201 VMThread::execute(&op);
202 }
203 }
204 deoptimizeAllCounter++;
205 }
206
207
208 void InterfaceSupport::stress_derived_pointers() {
209 #ifdef COMPILER2
210 JavaThread *thread = JavaThread::current();
211 if (!is_init_completed()) return;
212 ResourceMark rm(thread);
213 bool found = false;
214 for (StackFrameStream sfs(thread); !sfs.is_done() && !found; sfs.next()) {
215 CodeBlob* cb = sfs.current()->cb();
216 if (cb != NULL && cb->oop_maps() ) {
217 // Find oopmap for current method
218 const ImmutableOopMap* map = cb->oop_map_for_return_address(sfs.current()->pc());
219 assert(map != NULL, "no oopmap found for pc");
220 found = map->has_derived_pointer();
221 }
222 }
223 if (found) {
224 // $$$ Not sure what to do here.
225 /*
226 Scavenge::invoke(0);
227 */
228 }
229 #endif
230 }
231
232
233 void InterfaceSupport::verify_stack() {
234 JavaThread* thread = JavaThread::current();
235 ResourceMark rm(thread);
236 // disabled because it throws warnings that oop maps should only be accessed
237 // in VM thread or during debugging
238
239 if (!thread->has_pending_exception()) {
240 // verification does not work if there are pending exceptions
241 StackFrameStream sfs(thread);
242 CodeBlob* cb = sfs.current()->cb();
243 // In case of exceptions we might not have a runtime_stub on
244 // top of stack, hence, all callee-saved registers are not going
245 // to be setup correctly, hence, we cannot do stack verify
246 if (cb != NULL && !(cb->is_runtime_stub() || cb->is_uncommon_trap_stub())) return;
247
248 for (; !sfs.is_done(); sfs.next()) {
249 sfs.current()->verify(sfs.register_map());
250 }
251 }
252 }
253
254
255 void InterfaceSupport::verify_last_frame() {
256 JavaThread* thread = JavaThread::current();
257 ResourceMark rm(thread);
258 RegisterMap reg_map(thread);
259 frame fr = thread->last_frame();
260 fr.verify(®_map);
261 }
262
263
264 #endif // ASSERT
265
266
267 void InterfaceSupport_init() {
268 #ifdef ASSERT
269 if (ScavengeALot || FullGCALot) {
270 srand(ScavengeALotInterval * FullGCALotInterval);
271 }
272 #endif
273 }