1 /*
2 * Copyright (c) 1997, 2013, 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 "code/codeCache.hpp"
27 #include "code/compiledIC.hpp"
28 #include "code/icBuffer.hpp"
29 #include "code/nmethod.hpp"
30 #include "compiler/compileBroker.hpp"
31 #include "memory/resourceArea.hpp"
32 #include "oops/method.hpp"
33 #include "runtime/atomic.hpp"
34 #include "runtime/compilationPolicy.hpp"
35 #include "runtime/mutexLocker.hpp"
36 #include "runtime/os.hpp"
37 #include "runtime/sweeper.hpp"
38 #include "runtime/vm_operations.hpp"
39 #include "trace/tracing.hpp"
40 #include "utilities/events.hpp"
41 #include "utilities/ticks.inline.hpp"
42 #include "utilities/xmlstream.hpp"
43
44 #ifdef ASSERT
45
46 #define SWEEP(nm) record_sweep(nm, __LINE__)
47 // Sweeper logging code
48 class SweeperRecord {
49 public:
50 int traversal;
51 int invocation;
52 int compile_id;
53 long traversal_mark;
54 int state;
55 const char* kind;
56 address vep;
57 address uep;
58 int line;
59
60 void print() {
61 tty->print_cr("traversal = %d invocation = %d compile_id = %d %s uep = " PTR_FORMAT " vep = "
62 PTR_FORMAT " state = %d traversal_mark %d line = %d",
63 traversal,
64 invocation,
65 compile_id,
66 kind == NULL ? "" : kind,
67 uep,
68 vep,
69 state,
70 traversal_mark,
71 line);
72 }
73 };
74
75 static int _sweep_index = 0;
76 static SweeperRecord* _records = NULL;
77
78 void NMethodSweeper::report_events(int id, address entry) {
79 if (_records != NULL) {
80 for (int i = _sweep_index; i < SweeperLogEntries; i++) {
81 if (_records[i].uep == entry ||
82 _records[i].vep == entry ||
83 _records[i].compile_id == id) {
84 _records[i].print();
85 }
86 }
87 for (int i = 0; i < _sweep_index; i++) {
88 if (_records[i].uep == entry ||
89 _records[i].vep == entry ||
90 _records[i].compile_id == id) {
91 _records[i].print();
92 }
93 }
94 }
95 }
96
97 void NMethodSweeper::report_events() {
98 if (_records != NULL) {
99 for (int i = _sweep_index; i < SweeperLogEntries; i++) {
100 // skip empty records
101 if (_records[i].vep == NULL) continue;
102 _records[i].print();
103 }
104 for (int i = 0; i < _sweep_index; i++) {
105 // skip empty records
106 if (_records[i].vep == NULL) continue;
107 _records[i].print();
108 }
109 }
110 }
111
112 void NMethodSweeper::record_sweep(nmethod* nm, int line) {
113 if (_records != NULL) {
114 _records[_sweep_index].traversal = _traversals;
115 _records[_sweep_index].traversal_mark = nm->_stack_traversal_mark;
116 _records[_sweep_index].invocation = _sweep_fractions_left;
117 _records[_sweep_index].compile_id = nm->compile_id();
118 _records[_sweep_index].kind = nm->compile_kind();
119 _records[_sweep_index].state = nm->_state;
120 _records[_sweep_index].vep = nm->verified_entry_point();
121 _records[_sweep_index].uep = nm->entry_point();
122 _records[_sweep_index].line = line;
123 _sweep_index = (_sweep_index + 1) % SweeperLogEntries;
124 }
125 }
126 #else
127 #define SWEEP(nm)
128 #endif
129
130 nmethod* NMethodSweeper::_current = NULL; // Current nmethod
131 long NMethodSweeper::_traversals = 0; // Stack scan count, also sweep ID.
132 long NMethodSweeper::_time_counter = 0; // Virtual time used to periodically invoke sweeper
133 long NMethodSweeper::_last_sweep = 0; // Value of _time_counter when the last sweep happened
134 int NMethodSweeper::_seen = 0; // Nof. nmethod we have currently processed in current pass of CodeCache
135 int NMethodSweeper::_flushed_count = 0; // Nof. nmethods flushed in current sweep
136 int NMethodSweeper::_zombified_count = 0; // Nof. nmethods made zombie in current sweep
137 int NMethodSweeper::_marked_for_reclamation_count = 0; // Nof. nmethods marked for reclaim in current sweep
138
139 volatile bool NMethodSweeper::_should_sweep = true; // Indicates if we should invoke the sweeper
140 volatile int NMethodSweeper::_sweep_fractions_left = 0; // Nof. invocations left until we are completed with this pass
141 volatile int NMethodSweeper::_sweep_started = 0; // Flag to control conc sweeper
142 volatile int NMethodSweeper::_bytes_changed = 0; // Counts the total nmethod size if the nmethod changed from:
143 // 1) alive -> not_entrant
144 // 2) not_entrant -> zombie
145 // 3) zombie -> marked_for_reclamation
146
147 int NMethodSweeper::_total_nof_methods_reclaimed = 0; // Accumulated nof methods flushed
148 Tickspan NMethodSweeper::_total_time_sweeping; // Accumulated time sweeping
149 Tickspan NMethodSweeper::_total_time_this_sweep; // Total time this sweep
150 Tickspan NMethodSweeper::_peak_sweep_time; // Peak time for a full sweep
151 Tickspan NMethodSweeper::_peak_sweep_fraction_time; // Peak time sweeping one fraction
152 int NMethodSweeper::_hotness_counter_reset_val = 0;
153
154
155 class MarkActivationClosure: public CodeBlobClosure {
156 public:
157 virtual void do_code_blob(CodeBlob* cb) {
158 if (cb->is_nmethod()) {
159 nmethod* nm = (nmethod*)cb;
160 nm->set_hotness_counter(NMethodSweeper::hotness_counter_reset_val());
161 // If we see an activation belonging to a non_entrant nmethod, we mark it.
162 if (nm->is_not_entrant()) {
163 nm->mark_as_seen_on_stack();
164 }
165 }
166 }
167 };
168 static MarkActivationClosure mark_activation_closure;
169
170 class SetHotnessClosure: public CodeBlobClosure {
171 public:
172 virtual void do_code_blob(CodeBlob* cb) {
173 if (cb->is_nmethod()) {
174 nmethod* nm = (nmethod*)cb;
175 nm->set_hotness_counter(NMethodSweeper::hotness_counter_reset_val());
176 }
177 }
178 };
179 static SetHotnessClosure set_hotness_closure;
180
181
182 int NMethodSweeper::hotness_counter_reset_val() {
183 if (_hotness_counter_reset_val == 0) {
184 _hotness_counter_reset_val = (ReservedCodeCacheSize < M) ? 1 : (ReservedCodeCacheSize / M) * 2;
185 }
186 return _hotness_counter_reset_val;
187 }
188 bool NMethodSweeper::sweep_in_progress() {
189 return (_current != NULL);
190 }
191
192 // Scans the stacks of all Java threads and marks activations of not-entrant methods.
193 // No need to synchronize access, since 'mark_active_nmethods' is always executed at a
194 // safepoint.
195 void NMethodSweeper::mark_active_nmethods() {
196 assert(SafepointSynchronize::is_at_safepoint(), "must be executed at a safepoint");
197 // If we do not want to reclaim not-entrant or zombie methods there is no need
198 // to scan stacks
199 if (!MethodFlushing) {
200 return;
201 }
202
203 // Increase time so that we can estimate when to invoke the sweeper again.
204 _time_counter++;
205
206 // Check for restart
207 assert(CodeCache::find_blob_unsafe(_current) == _current, "Sweeper nmethod cached state invalid");
208 if (!sweep_in_progress()) {
209 _seen = 0;
210 _sweep_fractions_left = NmethodSweepFraction;
211 _current = CodeCache::first_nmethod();
212 _traversals += 1;
213 _total_time_this_sweep = Tickspan();
214
215 if (PrintMethodFlushing) {
216 tty->print_cr("### Sweep: stack traversal %d", _traversals);
217 }
218 Threads::nmethods_do(&mark_activation_closure);
219
220 } else {
221 // Only set hotness counter
222 Threads::nmethods_do(&set_hotness_closure);
223 }
224
225 OrderAccess::storestore();
226 }
227 /**
228 * This function invokes the sweeper if at least one of the three conditions is met:
229 * (1) The code cache is getting full
230 * (2) There are sufficient state changes in/since the last sweep.
231 * (3) We have not been sweeping for 'some time'
232 */
233 void NMethodSweeper::possibly_sweep() {
234 assert(JavaThread::current()->thread_state() == _thread_in_vm, "must run in vm mode");
235 if (!MethodFlushing || !sweep_in_progress()) {
236 return;
237 }
238
239 // If there was no state change while nmethod sweeping, 'should_sweep' will be false.
240 // This is one of the two places where should_sweep can be set to true. The general
241 // idea is as follows: If there is enough free space in the code cache, there is no
242 // need to invoke the sweeper. The following formula (which determines whether to invoke
243 // the sweeper or not) depends on the assumption that for larger ReservedCodeCacheSizes
244 // we need less frequent sweeps than for smaller ReservedCodecCacheSizes. Furthermore,
245 // the formula considers how much space in the code cache is currently used. Here are
246 // some examples that will (hopefully) help in understanding.
247 //
248 // Small ReservedCodeCacheSizes: (e.g., < 16M) We invoke the sweeper every time, since
249 // the result of the division is 0. This
250 // keeps the used code cache size small
251 // (important for embedded Java)
252 // Large ReservedCodeCacheSize : (e.g., 256M + code cache is 10% full). The formula
253 // computes: (256 / 16) - 1 = 15
254 // As a result, we invoke the sweeper after
255 // 15 invocations of 'mark_active_nmethods.
256 // Large ReservedCodeCacheSize: (e.g., 256M + code Cache is 90% full). The formula
257 // computes: (256 / 16) - 10 = 6.
258 if (!_should_sweep) {
259 int time_since_last_sweep = _time_counter - _last_sweep;
260 double wait_until_next_sweep = (ReservedCodeCacheSize / (16 * M)) - time_since_last_sweep -
261 CodeCache::reverse_free_ratio();
262
263 if ((wait_until_next_sweep <= 0.0) || !CompileBroker::should_compile_new_jobs()) {
264 _should_sweep = true;
265 }
266 }
267
268 if (_should_sweep && _sweep_fractions_left > 0) {
269 // Only one thread at a time will sweep
270 jint old = Atomic::cmpxchg( 1, &_sweep_started, 0 );
271 if (old != 0) {
272 return;
273 }
274 #ifdef ASSERT
275 if (LogSweeper && _records == NULL) {
276 // Create the ring buffer for the logging code
277 _records = NEW_C_HEAP_ARRAY(SweeperRecord, SweeperLogEntries, mtGC);
278 memset(_records, 0, sizeof(SweeperRecord) * SweeperLogEntries);
279 }
280 #endif
281
282 if (_sweep_fractions_left > 0) {
283 sweep_code_cache();
284 _sweep_fractions_left--;
285 }
286
287 // We are done with sweeping the code cache once.
288 if (_sweep_fractions_left == 0) {
289 _last_sweep = _time_counter;
290 // Reset flag; temporarily disables sweeper
291 _should_sweep = false;
292 // If there was enough state change, 'possibly_enable_sweeper()'
293 // sets '_should_sweep' to true
294 possibly_enable_sweeper();
295 // Reset _bytes_changed only if there was enough state change. _bytes_changed
296 // can further increase by calls to 'report_state_change'.
297 if (_should_sweep) {
298 _bytes_changed = 0;
299 }
300 }
301 _sweep_started = 0;
302 }
303 }
304
305 void NMethodSweeper::sweep_code_cache() {
306 Ticks sweep_start_counter = Ticks::now();
307
308 _flushed_count = 0;
309 _zombified_count = 0;
310 _marked_for_reclamation_count = 0;
311
312 if (PrintMethodFlushing && Verbose) {
313 tty->print_cr("### Sweep at %d out of %d. Invocations left: %d", _seen, CodeCache::nof_nmethods(), _sweep_fractions_left);
314 }
315
316 if (!CompileBroker::should_compile_new_jobs()) {
317 // If we have turned off compilations we might as well do full sweeps
318 // in order to reach the clean state faster. Otherwise the sleeping compiler
319 // threads will slow down sweeping.
320 _sweep_fractions_left = 1;
321 }
322
323 // We want to visit all nmethods after NmethodSweepFraction
324 // invocations so divide the remaining number of nmethods by the
325 // remaining number of invocations. This is only an estimate since
326 // the number of nmethods changes during the sweep so the final
327 // stage must iterate until it there are no more nmethods.
328 int todo = (CodeCache::nof_nmethods() - _seen) / _sweep_fractions_left;
329 int swept_count = 0;
330
331
332 assert(!SafepointSynchronize::is_at_safepoint(), "should not be in safepoint when we get here");
333 assert(!CodeCache_lock->owned_by_self(), "just checking");
334
335 int freed_memory = 0;
336 {
337 MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
338
339 // The last invocation iterates until there are no more nmethods
340 for (int i = 0; (i < todo || _sweep_fractions_left == 1) && _current != NULL; i++) {
341 swept_count++;
342 if (SafepointSynchronize::is_synchronizing()) { // Safepoint request
343 if (PrintMethodFlushing && Verbose) {
344 tty->print_cr("### Sweep at %d out of %d, invocation: %d, yielding to safepoint", _seen, CodeCache::nof_nmethods(), _sweep_fractions_left);
345 }
346 MutexUnlockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
347
348 assert(Thread::current()->is_Java_thread(), "should be java thread");
349 JavaThread* thread = (JavaThread*)Thread::current();
350 ThreadBlockInVM tbivm(thread);
351 thread->java_suspend_self();
352 }
353 // Since we will give up the CodeCache_lock, always skip ahead
354 // to the next nmethod. Other blobs can be deleted by other
355 // threads but nmethods are only reclaimed by the sweeper.
356 nmethod* next = CodeCache::next_nmethod(_current);
357
358 // Now ready to process nmethod and give up CodeCache_lock
359 {
360 MutexUnlockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
361 freed_memory += process_nmethod(_current);
362 }
363 _seen++;
364 _current = next;
365 }
366 }
367
368 assert(_sweep_fractions_left > 1 || _current == NULL, "must have scanned the whole cache");
369
370 const Ticks sweep_end_counter = Ticks::now();
371 const Tickspan sweep_time = sweep_end_counter - sweep_start_counter;
372 _total_time_sweeping += sweep_time;
373 _total_time_this_sweep += sweep_time;
374 _peak_sweep_fraction_time = MAX2(sweep_time, _peak_sweep_fraction_time);
375 _total_nof_methods_reclaimed += _flushed_count;
376
377 EventSweepCodeCache event(UNTIMED);
378 if (event.should_commit()) {
379 event.set_starttime(sweep_start_counter);
380 event.set_endtime(sweep_end_counter);
381 event.set_sweepIndex(_traversals);
382 event.set_sweepFractionIndex(NmethodSweepFraction - _sweep_fractions_left + 1);
383 event.set_sweptCount(swept_count);
384 event.set_flushedCount(_flushed_count);
385 event.set_markedCount(_marked_for_reclamation_count);
386 event.set_zombifiedCount(_zombified_count);
387 event.commit();
388 }
389
390 #ifdef ASSERT
391 if(PrintMethodFlushing) {
392 tty->print_cr("### sweeper: sweep time(%d): "
393 INT64_FORMAT, _sweep_fractions_left, (jlong)sweep_time.value());
394 }
395 #endif
396
397 if (_sweep_fractions_left == 1) {
398 _peak_sweep_time = MAX2(_peak_sweep_time, _total_time_this_sweep);
399 log_sweep("finished");
400 }
401
402 // Sweeper is the only case where memory is released, check here if it
403 // is time to restart the compiler. Only checking if there is a certain
404 // amount of free memory in the code cache might lead to re-enabling
405 // compilation although no memory has been released. For example, there are
406 // cases when compilation was disabled although there is 4MB (or more) free
407 // memory in the code cache. The reason is code cache fragmentation. Therefore,
408 // it only makes sense to re-enable compilation if we have actually freed memory.
409 // Note that typically several kB are released for sweeping 16MB of the code
410 // cache. As a result, 'freed_memory' > 0 to restart the compiler.
411 if (!CompileBroker::should_compile_new_jobs() && (freed_memory > 0)) {
412 CompileBroker::set_should_compile_new_jobs(CompileBroker::run_compilation);
413 log_sweep("restart_compiler");
414 }
415 }
416
417 /**
418 * This function updates the sweeper statistics that keep track of nmethods
419 * state changes. If there is 'enough' state change, the sweeper is invoked
420 * as soon as possible. There can be data races on _bytes_changed. The data
421 * races are benign, since it does not matter if we loose a couple of bytes.
422 * In the worst case we call the sweeper a little later. Also, we are guaranteed
423 * to invoke the sweeper if the code cache gets full.
424 */
425 void NMethodSweeper::report_state_change(nmethod* nm) {
426 _bytes_changed += nm->total_size();
427 possibly_enable_sweeper();
428 }
429
430 /**
431 * Function determines if there was 'enough' state change in the code cache to invoke
432 * the sweeper again. Currently, we determine 'enough' as more than 1% state change in
433 * the code cache since the last sweep.
434 */
435 void NMethodSweeper::possibly_enable_sweeper() {
436 double percent_changed = ((double)_bytes_changed / (double)ReservedCodeCacheSize) * 100;
437 if (percent_changed > 1.0) {
438 _should_sweep = true;
439 }
440 }
441
442 class NMethodMarker: public StackObj {
443 private:
444 CompilerThread* _thread;
445 public:
446 NMethodMarker(nmethod* nm) {
447 _thread = CompilerThread::current();
448 if (!nm->is_zombie() && !nm->is_unloaded()) {
449 // Only expose live nmethods for scanning
450 _thread->set_scanned_nmethod(nm);
451 }
452 }
453 ~NMethodMarker() {
454 _thread->set_scanned_nmethod(NULL);
455 }
456 };
457
458 void NMethodSweeper::release_nmethod(nmethod *nm) {
459 // Clean up any CompiledICHolders
460 {
461 ResourceMark rm;
462 MutexLocker ml_patch(CompiledIC_lock);
463 RelocIterator iter(nm);
464 while (iter.next()) {
465 if (iter.type() == relocInfo::virtual_call_type) {
466 CompiledIC::cleanup_call_site(iter.virtual_call_reloc());
467 }
468 }
469 }
470
471 MutexLockerEx mu(CodeCache_lock, Mutex::_no_safepoint_check_flag);
472 nm->flush();
473 }
474
475 int NMethodSweeper::process_nmethod(nmethod *nm) {
476 assert(!CodeCache_lock->owned_by_self(), "just checking");
477
478 int freed_memory = 0;
479 // Make sure this nmethod doesn't get unloaded during the scan,
480 // since safepoints may happen during acquired below locks.
481 NMethodMarker nmm(nm);
482 SWEEP(nm);
483
484 // Skip methods that are currently referenced by the VM
485 if (nm->is_locked_by_vm()) {
486 // But still remember to clean-up inline caches for alive nmethods
487 if (nm->is_alive()) {
488 // Clean inline caches that point to zombie/non-entrant methods
489 MutexLocker cl(CompiledIC_lock);
490 nm->cleanup_inline_caches();
491 SWEEP(nm);
492 }
493 return freed_memory;
494 }
495
496 if (nm->is_zombie()) {
497 // If it is the first time we see nmethod then we mark it. Otherwise,
498 // we reclaim it. When we have seen a zombie method twice, we know that
499 // there are no inline caches that refer to it.
500 if (nm->is_marked_for_reclamation()) {
501 assert(!nm->is_locked_by_vm(), "must not flush locked nmethods");
502 if (PrintMethodFlushing && Verbose) {
503 tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (marked for reclamation) being flushed", nm->compile_id(), nm);
504 }
505 freed_memory = nm->total_size();
506 release_nmethod(nm);
507 _flushed_count++;
508 } else {
509 if (PrintMethodFlushing && Verbose) {
510 tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (zombie) being marked for reclamation", nm->compile_id(), nm);
511 }
512 nm->mark_for_reclamation();
513 // Keep track of code cache state change
514 _bytes_changed += nm->total_size();
515 _marked_for_reclamation_count++;
516 SWEEP(nm);
517 }
518 } else if (nm->is_not_entrant()) {
519 // If there are no current activations of this method on the
520 // stack we can safely convert it to a zombie method
521 if (nm->can_not_entrant_be_converted()) {
522 if (PrintMethodFlushing && Verbose) {
523 tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (not entrant) being made zombie", nm->compile_id(), nm);
524 }
525 // Code cache state change is tracked in make_zombie()
526 nm->make_zombie();
527 _zombified_count++;
528 SWEEP(nm);
529 } else {
530 // Still alive, clean up its inline caches
531 MutexLocker cl(CompiledIC_lock);
532 nm->cleanup_inline_caches();
533 SWEEP(nm);
534 }
535 } else if (nm->is_unloaded()) {
536 // Unloaded code, just make it a zombie
537 if (PrintMethodFlushing && Verbose) {
538 tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (unloaded) being made zombie", nm->compile_id(), nm);
539 }
540 if (nm->is_osr_method()) {
541 SWEEP(nm);
542 // No inline caches will ever point to osr methods, so we can just remove it
543 freed_memory = nm->total_size();
544 release_nmethod(nm);
545 _flushed_count++;
546 } else {
547 // Code cache state change is tracked in make_zombie()
548 nm->make_zombie();
549 _zombified_count++;
550 SWEEP(nm);
551 }
552 } else {
553 if (UseCodeCacheFlushing) {
554 if (!nm->is_locked_by_vm() && !nm->is_osr_method() && !nm->is_native_method()) {
555 // Do not make native methods and OSR-methods not-entrant
556 nm->dec_hotness_counter();
557 // Get the initial value of the hotness counter. This value depends on the
558 // ReservedCodeCacheSize
559 int reset_val = hotness_counter_reset_val();
560 int time_since_reset = reset_val - nm->hotness_counter();
561 double threshold = -reset_val + (CodeCache::reverse_free_ratio() * NmethodSweepActivity);
562 // The less free space in the code cache we have - the bigger reverse_free_ratio() is.
563 // I.e., 'threshold' increases with lower available space in the code cache and a higher
564 // NmethodSweepActivity. If the current hotness counter - which decreases from its initial
565 // value until it is reset by stack walking - is smaller than the computed threshold, the
566 // corresponding nmethod is considered for removal.
567 if ((NmethodSweepActivity > 0) && (nm->hotness_counter() < threshold) && (time_since_reset > 10)) {
568 // A method is marked as not-entrant if the method is
569 // 1) 'old enough': nm->hotness_counter() < threshold
570 // 2) The method was in_use for a minimum amount of time: (time_since_reset > 10)
571 // The second condition is necessary if we are dealing with very small code cache
572 // sizes (e.g., <10m) and the code cache size is too small to hold all hot methods.
573 // The second condition ensures that methods are not immediately made not-entrant
574 // after compilation.
575 nm->make_not_entrant();
576 // Code cache state change is tracked in make_not_entrant()
577 if (PrintMethodFlushing && Verbose) {
578 tty->print_cr("### Nmethod %d/" PTR_FORMAT "made not-entrant: hotness counter %d/%d threshold %f",
579 nm->compile_id(), nm, nm->hotness_counter(), reset_val, threshold);
580 }
581 }
582 }
583 }
584 // Clean-up all inline caches that point to zombie/non-reentrant methods
585 MutexLocker cl(CompiledIC_lock);
586 nm->cleanup_inline_caches();
587 SWEEP(nm);
588 }
589 return freed_memory;
590 }
591
592 // Print out some state information about the current sweep and the
593 // state of the code cache if it's requested.
594 void NMethodSweeper::log_sweep(const char* msg, const char* format, ...) {
595 if (PrintMethodFlushing) {
596 stringStream s;
597 // Dump code cache state into a buffer before locking the tty,
598 // because log_state() will use locks causing lock conflicts.
599 CodeCache::log_state(&s);
600
601 ttyLocker ttyl;
602 tty->print("### sweeper: %s ", msg);
603 if (format != NULL) {
604 va_list ap;
605 va_start(ap, format);
606 tty->vprint(format, ap);
607 va_end(ap);
608 }
609 tty->print_cr(s.as_string());
610 }
611
612 if (LogCompilation && (xtty != NULL)) {
613 stringStream s;
614 // Dump code cache state into a buffer before locking the tty,
615 // because log_state() will use locks causing lock conflicts.
616 CodeCache::log_state(&s);
617
618 ttyLocker ttyl;
619 xtty->begin_elem("sweeper state='%s' traversals='" INTX_FORMAT "' ", msg, (intx)traversal_count());
620 if (format != NULL) {
621 va_list ap;
622 va_start(ap, format);
623 xtty->vprint(format, ap);
624 va_end(ap);
625 }
626 xtty->print(s.as_string());
627 xtty->stamp();
628 xtty->end_elem();
629 }
630 }