1 /*
2 * Copyright (c) 2017, 2018, 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 #include "precompiled.hpp"
25 #include "code/relocInfo.hpp"
26 #include "code/nmethod.hpp"
27 #include "code/icBuffer.hpp"
28 #include "gc/shared/barrierSet.hpp"
29 #include "gc/shared/barrierSetNMethod.hpp"
30 #include "gc/z/zGlobals.hpp"
31 #include "gc/z/zLock.inline.hpp"
32 #include "gc/z/zNMethod.hpp"
33 #include "gc/z/zNMethodClosure.hpp"
34 #include "gc/z/zNMethodData.hpp"
35 #include "gc/z/zNMethodTable.hpp"
36 #include "gc/z/zOopClosures.inline.hpp"
37 #include "gc/z/zTask.hpp"
38 #include "gc/z/zWorkers.hpp"
39 #include "logging/log.hpp"
40 #include "memory/allocation.inline.hpp"
41 #include "memory/resourceArea.hpp"
42 #include "runtime/atomic.hpp"
43 #include "runtime/orderAccess.hpp"
44 #include "utilities/debug.hpp"
45
46 static ZNMethodData* gc_data(const nmethod* nm) {
47 return nm->gc_data<ZNMethodData>();
48 }
49
50 static void set_gc_data(nmethod* nm, ZNMethodData* data) {
51 return nm->set_gc_data<ZNMethodData>(data);
52 }
53
54 void ZNMethod::attach_gc_data(nmethod* nm) {
55 GrowableArray<oop*> immediate_oops;
56 bool non_immediate_oops = false;
57
58 // Find all oops relocations
59 RelocIterator iter(nm);
60 while (iter.next()) {
61 if (iter.type() != relocInfo::oop_type) {
62 // Not an oop
63 continue;
64 }
65
66 oop_Relocation* r = iter.oop_reloc();
67
68 if (!r->oop_is_immediate()) {
69 // Non-immediate oop found
70 non_immediate_oops = true;
71 continue;
72 }
73
74 if (r->oop_value() != NULL) {
75 // Non-NULL immediate oop found. NULL oops can safely be
76 // ignored since the method will be re-registered if they
77 // are later patched to be non-NULL.
78 immediate_oops.push(r->oop_addr());
79 }
80 }
81
82 // Attach GC data to nmethod
83 ZNMethodData* data = gc_data(nm);
84 if (data == NULL) {
85 data = ZNMethodData::create(nm);
86 set_gc_data(nm, data);
87 }
88
89 // Attach oops in GC data
90 ZNMethodDataOops* const new_oops = ZNMethodDataOops::create(immediate_oops, non_immediate_oops);
91 ZNMethodDataOops* const old_oops = data->swap_oops(new_oops);
92 ZNMethodDataOops::destroy(old_oops);
93 }
94
95 void ZNMethod::detach_gc_data(nmethod* nm) {
96 // Destroy GC data
97 ZNMethodData::destroy(gc_data(nm));
98 set_gc_data(nm, NULL);
99 }
100
101 ZReentrantLock* ZNMethod::lock_for_nmethod(nmethod* nm) {
102 ZNMethodData* const data = gc_data(nm);
103 if (data == NULL) {
104 return NULL;
105 }
106 return data->lock();
107 }
108
109 void ZNMethod::log_register(const nmethod* nm) {
110 LogTarget(Trace, gc, nmethod) log;
111 if (!log.is_enabled()) {
112 return;
113 }
114
115 const ZNMethodDataOops* const oops = gc_data(nm)->oops();
116
117 log.print("Register NMethod: %s.%s (" PTR_FORMAT "), "
118 "Compiler: %s, Oops: %d, ImmediateOops: " SIZE_FORMAT ", NonImmediateOops: %s",
119 nm->method()->method_holder()->external_name(),
120 nm->method()->name()->as_C_string(),
121 p2i(nm),
122 nm->compiler_name(),
123 nm->oops_count() - 1,
124 oops->immediates_count(),
125 oops->has_non_immediates() ? "Yes" : "No");
126
127 LogTarget(Trace, gc, nmethod, oops) log_oops;
128 if (!log_oops.is_enabled()) {
129 return;
130 }
131
132 // Print nmethod oops table
133 oop* const begin = nm->oops_begin();
134 oop* const end = nm->oops_end();
135 for (oop* p = begin; p < end; p++) {
136 log_oops.print(" Oop[" SIZE_FORMAT "] " PTR_FORMAT " (%s)",
137 (p - begin), p2i(*p), (*p)->klass()->external_name());
138 }
139
140 // Print nmethod immediate oops
141 if (oops->immediates_count() > 0) {
142 oop** const begin = oops->immediates_begin();
143 oop** const end = oops->immediates_end();
144 for (oop** p = begin; p < end; p++) {
145 log_oops.print(" ImmediateOop[" SIZE_FORMAT "] " PTR_FORMAT " @ " PTR_FORMAT " (%s)",
146 (p - begin), p2i(**p), p2i(*p), (**p)->klass()->external_name());
147 }
148 }
149 }
150
151 void ZNMethod::log_unregister(const nmethod* nm) {
152 LogTarget(Debug, gc, nmethod) log;
153 if (!log.is_enabled()) {
154 return;
155 }
156
157 log.print("Unregister NMethod: %s.%s (" PTR_FORMAT ")",
158 nm->method()->method_holder()->external_name(),
159 nm->method()->name()->as_C_string(),
160 p2i(nm));
161 }
162
163 void ZNMethod::register_nmethod(nmethod* nm) {
164 ResourceMark rm;
165
166 // Create and attach gc data
167 attach_gc_data(nm);
168
169 log_register(nm);
170
171 ZNMethodTable::register_nmethod(nm);
172
173 // Disarm nmethod entry barrier
174 disarm_nmethod(nm);
175 }
176
177 void ZNMethod::unregister_nmethod(nmethod* nm) {
178 assert(CodeCache_lock->owned_by_self(), "Lock must be held");
179
180 if (Thread::current()->is_Code_cache_sweeper_thread()) {
181 // The sweeper must wait for any ongoing iteration to complete
182 // before it can unregister an nmethod.
183 ZNMethodTable::wait_until_iteration_done();
184 }
185
186 ResourceMark rm;
187
188 log_unregister(nm);
189
190 ZNMethodTable::unregister_nmethod(nm);
191
192 // Destroy and detach gc data
193 detach_gc_data(nm);
194 }
195
196 void ZNMethod::disarm_nmethod(nmethod* nm) {
197 BarrierSetNMethod* const bs = BarrierSet::barrier_set()->barrier_set_nmethod();
198 if (bs != NULL) {
199 bs->disarm(nm);
200 }
201 }
202
203 void ZNMethod::nmethod_oops_do(nmethod* nm, OopClosure* cl) {
204 // Process oops table
205 oop* const begin = nm->oops_begin();
206 oop* const end = nm->oops_end();
207 for (oop* p = begin; p < end; p++) {
208 if (*p != Universe::non_oop_word()) {
209 cl->do_oop(p);
210 }
211 }
212
213 ZNMethodDataOops* const oops = gc_data(nm)->oops();
214
215 // Process immediate oops
216 if (oops->immediates_count() > 0) {
217 oop** const begin = oops->immediates_begin();
218 oop** const end = oops->immediates_end();
219 for (oop** p = begin; p < end; p++) {
220 if (**p != Universe::non_oop_word()) {
221 cl->do_oop(*p);
222 }
223 }
224 }
225
226 // Process non-immediate oops
227 if (oops->has_non_immediates()) {
228 nm->fix_oop_relocations();
229 }
230 }
231
232 class ZNMethodToOopsDo : public ZNMethodClosure {
233 private:
234 OopClosure* _cl;
235
236 public:
237 ZNMethodToOopsDo(OopClosure* cl) :
238 _cl(cl) {}
239
240 void do_nmethod(nmethod* nm) {
241 ZNMethod::nmethod_oops_do(nm, _cl);
242 }
243 };
244
245 void ZNMethod::oops_do_begin() {
246 ZNMethodTable::nmethods_do_begin();
247 }
248
249 void ZNMethod::oops_do_end() {
250 ZNMethodTable::nmethods_do_end();
251 }
252
253 void ZNMethod::oops_do(OopClosure* cl) {
254 ZNMethodToOopsDo nmethod_cl(cl);
255 ZNMethodTable::nmethods_do(&nmethod_cl);
256 }
257
258 class ZNMethodUnlinkClosure : public ZNMethodClosure {
259 private:
260 bool _unloading_occurred;
261 volatile bool _failed;
262
263 void set_failed() {
264 Atomic::store(true, &_failed);
265 }
266
267 public:
268 ZNMethodUnlinkClosure(bool unloading_occurred) :
269 _unloading_occurred(unloading_occurred),
270 _failed(false) {}
271
272 virtual void do_nmethod(nmethod* nm) {
273 if (failed()) {
274 return;
275 }
276
277 if (!nm->is_alive()) {
278 return;
279 }
280
281 ZLocker<ZReentrantLock> locker(ZNMethod::lock_for_nmethod(nm));
282
283 if (nm->is_unloading()) {
284 // Unlinking of the dependencies must happen before the
285 // handshake separating unlink and purge.
286 nm->flush_dependencies(false /* delete_immediately */);
287
288 // We don't need to take the lock when unlinking nmethods from
289 // the Method, because it is only concurrently unlinked by
290 // the entry barrier, which acquires the per nmethod lock.
291 nm->unlink_from_method(false /* acquire_lock */);
292 return;
293 }
294
295 // Heal oops and disarm
296 ZNMethodOopClosure cl;
297 ZNMethod::nmethod_oops_do(nm, &cl);
298 ZNMethod::disarm_nmethod(nm);
299
300 // Clear compiled ICs and exception caches
301 if (!nm->unload_nmethod_caches(_unloading_occurred)) {
302 set_failed();
303 }
304 }
305
306 bool failed() const {
307 return Atomic::load(&_failed);
308 }
309 };
310
311 class ZNMethodUnlinkTask : public ZTask {
312 private:
313 ZNMethodUnlinkClosure _cl;
314 ICRefillVerifier* _verifier;
315
316 public:
317 ZNMethodUnlinkTask(bool unloading_occurred, ICRefillVerifier* verifier) :
318 ZTask("ZNMethodUnlinkTask"),
319 _cl(unloading_occurred),
320 _verifier(verifier) {
321 ZNMethodTable::nmethods_do_begin();
322 }
323
324 ~ZNMethodUnlinkTask() {
325 ZNMethodTable::nmethods_do_end();
326 }
327
328 virtual void work() {
329 ICRefillVerifierMark mark(_verifier);
330 ZNMethodTable::nmethods_do(&_cl);
331 }
332
333 bool success() const {
334 return !_cl.failed();
335 }
336 };
337
338 void ZNMethod::unlink(ZWorkers* workers, bool unloading_occurred) {
339 for (;;) {
340 ICRefillVerifier verifier;
341
342 {
343 ZNMethodUnlinkTask task(unloading_occurred, &verifier);
344 workers->run_concurrent(&task);
345 if (task.success()) {
346 return;
347 }
348 }
349
350 // Cleaning failed because we ran out of transitional IC stubs,
351 // so we have to refill and try again. Refilling requires taking
352 // a safepoint, so we temporarily leave the suspendible thread set.
353 SuspendibleThreadSetLeaver sts;
354 InlineCacheBuffer::refill_ic_stubs();
355 }
356 }
357
358 class ZNMethodPurgeClosure : public ZNMethodClosure {
359 public:
360 virtual void do_nmethod(nmethod* nm) {
361 if (nm->is_alive() && nm->is_unloading()) {
362 nm->make_unloaded();
363 }
364 }
365 };
366
367 class ZNMethodPurgeTask : public ZTask {
368 private:
369 ZNMethodPurgeClosure _cl;
370
371 public:
372 ZNMethodPurgeTask() :
373 ZTask("ZNMethodPurgeTask"),
374 _cl() {
375 ZNMethodTable::nmethods_do_begin();
376 }
377
378 ~ZNMethodPurgeTask() {
379 ZNMethodTable::nmethods_do_end();
380 }
381
382 virtual void work() {
383 ZNMethodTable::nmethods_do(&_cl);
384 }
385 };
386
387 void ZNMethod::purge(ZWorkers* workers) {
388 ZNMethodPurgeTask task;
389 workers->run_concurrent(&task);
390 }