src/share/vm/runtime/sweeper.cpp

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 115     _records[_sweep_index].invocation = _invocations;
 116     _records[_sweep_index].compile_id = nm->compile_id();
 117     _records[_sweep_index].kind = nm->compile_kind();
 118     _records[_sweep_index].state = nm->_state;
 119     _records[_sweep_index].vep = nm->verified_entry_point();
 120     _records[_sweep_index].uep = nm->entry_point();
 121     _records[_sweep_index].line = line;
 122 
 123     _sweep_index = (_sweep_index + 1) % SweeperLogEntries;
 124   }
 125 }
 126 #else
 127 #define SWEEP(nm)
 128 #endif
 129 
 130 
 131 long      NMethodSweeper::_traversals = 0;   // No. of stack traversals performed
 132 nmethod*  NMethodSweeper::_current = NULL;   // Current nmethod
 133 int       NMethodSweeper::_seen = 0 ;        // No. of nmethods we have currently processed in current pass of CodeCache
 134 int       NMethodSweeper::_flushed_count = 0;   // Nof. nmethods flushed in current sweep

 135 int       NMethodSweeper::_zombified_count = 0; // Nof. nmethods made zombie in current sweep
 136 int       NMethodSweeper::_marked_count = 0;    // Nof. nmethods marked for reclaim in current sweep
 137 
 138 volatile int NMethodSweeper::_invocations = 0;   // No. of invocations left until we are completed with this pass
 139 volatile int NMethodSweeper::_sweep_started = 0; // Whether a sweep is in progress.
 140 
 141 jint      NMethodSweeper::_locked_seen = 0;
 142 jint      NMethodSweeper::_not_entrant_seen_on_stack = 0;
 143 bool      NMethodSweeper::_resweep = false;
 144 jint      NMethodSweeper::_flush_token = 0;
 145 jlong     NMethodSweeper::_last_full_flush_time = 0;
 146 int       NMethodSweeper::_highest_marked = 0;
 147 int       NMethodSweeper::_dead_compile_ids = 0;
 148 long      NMethodSweeper::_last_flush_traversal_id = 0;
 149 
 150 int       NMethodSweeper::_number_of_flushes = 0; // Total of full traversals caused by full cache
 151 int       NMethodSweeper::_total_nof_methods_reclaimed = 0;

 152 jlong     NMethodSweeper::_total_time_sweeping = 0;
 153 jlong     NMethodSweeper::_total_time_this_sweep = 0;
 154 jlong     NMethodSweeper::_peak_sweep_time = 0;
 155 jlong     NMethodSweeper::_peak_sweep_fraction_time = 0;
 156 jlong     NMethodSweeper::_total_disconnect_time = 0;
 157 jlong     NMethodSweeper::_peak_disconnect_time = 0;
 158 
 159 class MarkActivationClosure: public CodeBlobClosure {
 160 public:
 161   virtual void do_code_blob(CodeBlob* cb) {
 162     // If we see an activation belonging to a non_entrant nmethod, we mark it.
 163     if (cb->is_nmethod() && ((nmethod*)cb)->is_not_entrant()) {
 164       ((nmethod*)cb)->mark_as_seen_on_stack();
 165     }
 166   }
 167 };
 168 static MarkActivationClosure mark_activation_closure;
 169 
 170 bool NMethodSweeper::sweep_in_progress() {
 171   return (_current != NULL);


 231 #ifdef ASSERT
 232     if (LogSweeper && _records == NULL) {
 233       // Create the ring buffer for the logging code
 234       _records = NEW_C_HEAP_ARRAY(SweeperRecord, SweeperLogEntries, mtGC);
 235       memset(_records, 0, sizeof(SweeperRecord) * SweeperLogEntries);
 236     }
 237 #endif
 238     if (_invocations > 0) {
 239       sweep_code_cache();
 240       _invocations--;
 241     }
 242     _sweep_started = 0;
 243   }
 244 }
 245 
 246 void NMethodSweeper::sweep_code_cache() {
 247 
 248   jlong sweep_start_counter = os::elapsed_counter();
 249 
 250   _flushed_count   = 0;

 251   _zombified_count = 0;
 252   _marked_count    = 0;
 253 
 254   if (PrintMethodFlushing && Verbose) {
 255     tty->print_cr("### Sweep at %d out of %d. Invocations left: %d", _seen, CodeCache::nof_nmethods(), _invocations);
 256   }
 257 
 258   if (!CompileBroker::should_compile_new_jobs()) {
 259     // If we have turned off compilations we might as well do full sweeps
 260     // in order to reach the clean state faster. Otherwise the sleeping compiler
 261     // threads will slow down sweeping. After a few iterations the cache
 262     // will be clean and sweeping stops (_resweep will not be set)
 263     _invocations = 1;
 264   }
 265 
 266   // We want to visit all nmethods after NmethodSweepFraction
 267   // invocations so divide the remaining number of nmethods by the
 268   // remaining number of invocations.  This is only an estimate since
 269   // the number of nmethods changes during the sweep so the final
 270   // stage must iterate until it there are no more nmethods.


 308 
 309   assert(_invocations > 1 || _current == NULL, "must have scanned the whole cache");
 310 
 311   if (!sweep_in_progress() && !_resweep && (_locked_seen || _not_entrant_seen_on_stack)) {
 312     // we've completed a scan without making progress but there were
 313     // nmethods we were unable to process either because they were
 314     // locked or were still on stack.  We don't have to aggresively
 315     // clean them up so just stop scanning.  We could scan once more
 316     // but that complicates the control logic and it's unlikely to
 317     // matter much.
 318     if (PrintMethodFlushing) {
 319       tty->print_cr("### Couldn't make progress on some nmethods so stopping sweep");
 320     }
 321   }
 322 
 323   jlong sweep_end_counter = os::elapsed_counter();
 324   jlong sweep_time = sweep_end_counter - sweep_start_counter;
 325   _total_time_sweeping  += sweep_time;
 326   _total_time_this_sweep += sweep_time;
 327   _peak_sweep_fraction_time = MAX2(sweep_time, _peak_sweep_fraction_time);

 328   _total_nof_methods_reclaimed += _flushed_count;
 329 
 330   EventSweepCodeCache event(UNTIMED);
 331   if (event.should_commit()) {
 332     event.set_starttime(sweep_start_counter);
 333     event.set_endtime(sweep_end_counter);
 334     event.set_sweepIndex(_traversals);
 335     event.set_sweepFractionIndex(NmethodSweepFraction - _invocations + 1);
 336     event.set_sweptCount(swept_count);
 337     event.set_flushedCount(_flushed_count);
 338     event.set_markedCount(_marked_count);
 339     event.set_zombifiedCount(_zombified_count);
 340     event.commit();
 341   }
 342 
 343 #ifdef ASSERT
 344   if(PrintMethodFlushing) {
 345     tty->print_cr("### sweeper:      sweep time(%d): " INT64_FORMAT, _invocations, (jlong)sweep_time);
 346   }
 347 #endif


 408       // Clean-up all inline caches that points to zombie/non-reentrant methods
 409       MutexLocker cl(CompiledIC_lock);
 410       nm->cleanup_inline_caches();
 411       SWEEP(nm);
 412     } else {
 413       _locked_seen++;
 414       SWEEP(nm);
 415     }
 416     return;
 417   }
 418 
 419   if (nm->is_zombie()) {
 420     // If it is first time, we see nmethod then we mark it. Otherwise,
 421     // we reclame it. When we have seen a zombie method twice, we know that
 422     // there are no inline caches that refer to it.
 423     if (nm->is_marked_for_reclamation()) {
 424       assert(!nm->is_locked_by_vm(), "must not flush locked nmethods");
 425       if (PrintMethodFlushing && Verbose) {
 426         tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (marked for reclamation) being flushed", nm->compile_id(), nm);
 427       }

 428       release_nmethod(nm);
 429       _flushed_count++;
 430     } else {
 431       if (PrintMethodFlushing && Verbose) {
 432         tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (zombie) being marked for reclamation", nm->compile_id(), nm);
 433       }
 434       nm->mark_for_reclamation();
 435       _resweep = true;
 436       _marked_count++;
 437       SWEEP(nm);
 438     }
 439   } else if (nm->is_not_entrant()) {
 440     // If there is no current activations of this method on the
 441     // stack we can safely convert it to a zombie method
 442     if (nm->can_not_entrant_be_converted()) {
 443       if (PrintMethodFlushing && Verbose) {
 444         tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (not entrant) being made zombie", nm->compile_id(), nm);
 445       }
 446       nm->make_zombie();
 447       _resweep = true;
 448       _zombified_count++;
 449       SWEEP(nm);
 450     } else {
 451       // Still alive, clean up its inline caches
 452       MutexLocker cl(CompiledIC_lock);
 453       nm->cleanup_inline_caches();
 454       // we coudn't transition this nmethod so don't immediately
 455       // request a rescan.  If this method stays on the stack for a
 456       // long time we don't want to keep rescanning the code cache.
 457       _not_entrant_seen_on_stack++;
 458       SWEEP(nm);
 459     }
 460   } else if (nm->is_unloaded()) {
 461     // Unloaded code, just make it a zombie
 462     if (PrintMethodFlushing && Verbose)
 463       tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (unloaded) being made zombie", nm->compile_id(), nm);
 464 
 465     if (nm->is_osr_method()) {
 466       SWEEP(nm);
 467       // No inline caches will ever point to osr methods, so we can just remove it

 468       release_nmethod(nm);
 469       _flushed_count++;
 470     } else {
 471       nm->make_zombie();
 472       _resweep = true;
 473       _zombified_count++;
 474       SWEEP(nm);
 475     }
 476   } else {
 477     assert(nm->is_alive(), "should be alive");
 478 
 479     if (UseCodeCacheFlushing) {
 480       if (nm->is_speculatively_disconnected() && !nm->is_locked_by_vm() && !nm->is_osr_method() &&
 481           (_traversals > _last_flush_traversal_id + 2) && (nm->compile_id() < _highest_marked)) {
 482         // This method has not been called since the forced cleanup happened
 483         nm->make_not_entrant();
 484       }
 485     }
 486 
 487     // Clean-up all inline caches that points to zombie/non-reentrant methods


 633   }
 634 
 635   if (LogCompilation && (xtty != NULL)) {
 636     stringStream s;
 637     // Dump code cache state into a buffer before locking the tty,
 638     // because log_state() will use locks causing lock conflicts.
 639     CodeCache::log_state(&s);
 640 
 641     ttyLocker ttyl;
 642     xtty->begin_elem("sweeper state='%s' traversals='" INTX_FORMAT "' ", msg, (intx)traversal_count());
 643     if (format != NULL) {
 644       va_list ap;
 645       va_start(ap, format);
 646       xtty->vprint(format, ap);
 647       va_end(ap);
 648     }
 649     xtty->print(s.as_string());
 650     xtty->stamp();
 651     xtty->end_elem();
 652   }











 653 }


 115     _records[_sweep_index].invocation = _invocations;
 116     _records[_sweep_index].compile_id = nm->compile_id();
 117     _records[_sweep_index].kind = nm->compile_kind();
 118     _records[_sweep_index].state = nm->_state;
 119     _records[_sweep_index].vep = nm->verified_entry_point();
 120     _records[_sweep_index].uep = nm->entry_point();
 121     _records[_sweep_index].line = line;
 122 
 123     _sweep_index = (_sweep_index + 1) % SweeperLogEntries;
 124   }
 125 }
 126 #else
 127 #define SWEEP(nm)
 128 #endif
 129 
 130 
 131 long      NMethodSweeper::_traversals = 0;   // No. of stack traversals performed
 132 nmethod*  NMethodSweeper::_current = NULL;   // Current nmethod
 133 int       NMethodSweeper::_seen = 0 ;        // No. of nmethods we have currently processed in current pass of CodeCache
 134 int       NMethodSweeper::_flushed_count = 0;   // Nof. nmethods flushed in current sweep
 135 size_t    NMethodSweeper::_flushed_size = 0;    // Total size of nmethods flushed in current sweep
 136 int       NMethodSweeper::_zombified_count = 0; // Nof. nmethods made zombie in current sweep
 137 int       NMethodSweeper::_marked_count = 0;    // Nof. nmethods marked for reclaim in current sweep
 138 
 139 volatile int NMethodSweeper::_invocations = 0;   // No. of invocations left until we are completed with this pass
 140 volatile int NMethodSweeper::_sweep_started = 0; // Whether a sweep is in progress.
 141 
 142 jint      NMethodSweeper::_locked_seen = 0;
 143 jint      NMethodSweeper::_not_entrant_seen_on_stack = 0;
 144 bool      NMethodSweeper::_resweep = false;
 145 jint      NMethodSweeper::_flush_token = 0;
 146 jlong     NMethodSweeper::_last_full_flush_time = 0;
 147 int       NMethodSweeper::_highest_marked = 0;
 148 int       NMethodSweeper::_dead_compile_ids = 0;
 149 long      NMethodSweeper::_last_flush_traversal_id = 0;
 150 
 151 int       NMethodSweeper::_number_of_flushes = 0; // Total of full traversals caused by full cache
 152 int       NMethodSweeper::_total_nof_methods_reclaimed = 0;
 153 size_t    NMethodSweeper::_total_flushed_size = 0;
 154 jlong     NMethodSweeper::_total_time_sweeping = 0;
 155 jlong     NMethodSweeper::_total_time_this_sweep = 0;
 156 jlong     NMethodSweeper::_peak_sweep_time = 0;
 157 jlong     NMethodSweeper::_peak_sweep_fraction_time = 0;
 158 jlong     NMethodSweeper::_total_disconnect_time = 0;
 159 jlong     NMethodSweeper::_peak_disconnect_time = 0;
 160 
 161 class MarkActivationClosure: public CodeBlobClosure {
 162 public:
 163   virtual void do_code_blob(CodeBlob* cb) {
 164     // If we see an activation belonging to a non_entrant nmethod, we mark it.
 165     if (cb->is_nmethod() && ((nmethod*)cb)->is_not_entrant()) {
 166       ((nmethod*)cb)->mark_as_seen_on_stack();
 167     }
 168   }
 169 };
 170 static MarkActivationClosure mark_activation_closure;
 171 
 172 bool NMethodSweeper::sweep_in_progress() {
 173   return (_current != NULL);


 233 #ifdef ASSERT
 234     if (LogSweeper && _records == NULL) {
 235       // Create the ring buffer for the logging code
 236       _records = NEW_C_HEAP_ARRAY(SweeperRecord, SweeperLogEntries, mtGC);
 237       memset(_records, 0, sizeof(SweeperRecord) * SweeperLogEntries);
 238     }
 239 #endif
 240     if (_invocations > 0) {
 241       sweep_code_cache();
 242       _invocations--;
 243     }
 244     _sweep_started = 0;
 245   }
 246 }
 247 
 248 void NMethodSweeper::sweep_code_cache() {
 249 
 250   jlong sweep_start_counter = os::elapsed_counter();
 251 
 252   _flushed_count   = 0;
 253   _flushed_size    = 0;
 254   _zombified_count = 0;
 255   _marked_count    = 0;
 256 
 257   if (PrintMethodFlushing && Verbose) {
 258     tty->print_cr("### Sweep at %d out of %d. Invocations left: %d", _seen, CodeCache::nof_nmethods(), _invocations);
 259   }
 260 
 261   if (!CompileBroker::should_compile_new_jobs()) {
 262     // If we have turned off compilations we might as well do full sweeps
 263     // in order to reach the clean state faster. Otherwise the sleeping compiler
 264     // threads will slow down sweeping. After a few iterations the cache
 265     // will be clean and sweeping stops (_resweep will not be set)
 266     _invocations = 1;
 267   }
 268 
 269   // We want to visit all nmethods after NmethodSweepFraction
 270   // invocations so divide the remaining number of nmethods by the
 271   // remaining number of invocations.  This is only an estimate since
 272   // the number of nmethods changes during the sweep so the final
 273   // stage must iterate until it there are no more nmethods.


 311 
 312   assert(_invocations > 1 || _current == NULL, "must have scanned the whole cache");
 313 
 314   if (!sweep_in_progress() && !_resweep && (_locked_seen || _not_entrant_seen_on_stack)) {
 315     // we've completed a scan without making progress but there were
 316     // nmethods we were unable to process either because they were
 317     // locked or were still on stack.  We don't have to aggresively
 318     // clean them up so just stop scanning.  We could scan once more
 319     // but that complicates the control logic and it's unlikely to
 320     // matter much.
 321     if (PrintMethodFlushing) {
 322       tty->print_cr("### Couldn't make progress on some nmethods so stopping sweep");
 323     }
 324   }
 325 
 326   jlong sweep_end_counter = os::elapsed_counter();
 327   jlong sweep_time = sweep_end_counter - sweep_start_counter;
 328   _total_time_sweeping  += sweep_time;
 329   _total_time_this_sweep += sweep_time;
 330   _peak_sweep_fraction_time = MAX2(sweep_time, _peak_sweep_fraction_time);
 331   _total_flushed_size += _flushed_size;
 332   _total_nof_methods_reclaimed += _flushed_count;
 333 
 334   EventSweepCodeCache event(UNTIMED);
 335   if (event.should_commit()) {
 336     event.set_starttime(sweep_start_counter);
 337     event.set_endtime(sweep_end_counter);
 338     event.set_sweepIndex(_traversals);
 339     event.set_sweepFractionIndex(NmethodSweepFraction - _invocations + 1);
 340     event.set_sweptCount(swept_count);
 341     event.set_flushedCount(_flushed_count);
 342     event.set_markedCount(_marked_count);
 343     event.set_zombifiedCount(_zombified_count);
 344     event.commit();
 345   }
 346 
 347 #ifdef ASSERT
 348   if(PrintMethodFlushing) {
 349     tty->print_cr("### sweeper:      sweep time(%d): " INT64_FORMAT, _invocations, (jlong)sweep_time);
 350   }
 351 #endif


 412       // Clean-up all inline caches that points to zombie/non-reentrant methods
 413       MutexLocker cl(CompiledIC_lock);
 414       nm->cleanup_inline_caches();
 415       SWEEP(nm);
 416     } else {
 417       _locked_seen++;
 418       SWEEP(nm);
 419     }
 420     return;
 421   }
 422 
 423   if (nm->is_zombie()) {
 424     // If it is first time, we see nmethod then we mark it. Otherwise,
 425     // we reclame it. When we have seen a zombie method twice, we know that
 426     // there are no inline caches that refer to it.
 427     if (nm->is_marked_for_reclamation()) {
 428       assert(!nm->is_locked_by_vm(), "must not flush locked nmethods");
 429       if (PrintMethodFlushing && Verbose) {
 430         tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (marked for reclamation) being flushed", nm->compile_id(), nm);
 431       }
 432       _flushed_size += nm->size();
 433       release_nmethod(nm);
 434       _flushed_count++;
 435     } else {
 436       if (PrintMethodFlushing && Verbose) {
 437         tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (zombie) being marked for reclamation", nm->compile_id(), nm);
 438       }
 439       nm->mark_for_reclamation();
 440       _resweep = true;
 441       _marked_count++;
 442       SWEEP(nm);
 443     }
 444   } else if (nm->is_not_entrant()) {
 445     // If there is no current activations of this method on the
 446     // stack we can safely convert it to a zombie method
 447     if (nm->can_not_entrant_be_converted()) {
 448       if (PrintMethodFlushing && Verbose) {
 449         tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (not entrant) being made zombie", nm->compile_id(), nm);
 450       }
 451       nm->make_zombie();
 452       _resweep = true;
 453       _zombified_count++;
 454       SWEEP(nm);
 455     } else {
 456       // Still alive, clean up its inline caches
 457       MutexLocker cl(CompiledIC_lock);
 458       nm->cleanup_inline_caches();
 459       // we coudn't transition this nmethod so don't immediately
 460       // request a rescan.  If this method stays on the stack for a
 461       // long time we don't want to keep rescanning the code cache.
 462       _not_entrant_seen_on_stack++;
 463       SWEEP(nm);
 464     }
 465   } else if (nm->is_unloaded()) {
 466     // Unloaded code, just make it a zombie
 467     if (PrintMethodFlushing && Verbose)
 468       tty->print_cr("### Nmethod %3d/" PTR_FORMAT " (unloaded) being made zombie", nm->compile_id(), nm);
 469 
 470     if (nm->is_osr_method()) {
 471       SWEEP(nm);
 472       // No inline caches will ever point to osr methods, so we can just remove it
 473       _flushed_size += nm->size();
 474       release_nmethod(nm);
 475       _flushed_count++;
 476     } else {
 477       nm->make_zombie();
 478       _resweep = true;
 479       _zombified_count++;
 480       SWEEP(nm);
 481     }
 482   } else {
 483     assert(nm->is_alive(), "should be alive");
 484 
 485     if (UseCodeCacheFlushing) {
 486       if (nm->is_speculatively_disconnected() && !nm->is_locked_by_vm() && !nm->is_osr_method() &&
 487           (_traversals > _last_flush_traversal_id + 2) && (nm->compile_id() < _highest_marked)) {
 488         // This method has not been called since the forced cleanup happened
 489         nm->make_not_entrant();
 490       }
 491     }
 492 
 493     // Clean-up all inline caches that points to zombie/non-reentrant methods


 639   }
 640 
 641   if (LogCompilation && (xtty != NULL)) {
 642     stringStream s;
 643     // Dump code cache state into a buffer before locking the tty,
 644     // because log_state() will use locks causing lock conflicts.
 645     CodeCache::log_state(&s);
 646 
 647     ttyLocker ttyl;
 648     xtty->begin_elem("sweeper state='%s' traversals='" INTX_FORMAT "' ", msg, (intx)traversal_count());
 649     if (format != NULL) {
 650       va_list ap;
 651       va_start(ap, format);
 652       xtty->vprint(format, ap);
 653       va_end(ap);
 654     }
 655     xtty->print(s.as_string());
 656     xtty->stamp();
 657     xtty->end_elem();
 658   }
 659 }
 660 
 661 void NMethodSweeper::print() {
 662   ttyLocker ttyl;
 663   tty->print_cr("Method flushing statistics:");
 664   tty->print_cr("  Total sweep time: %1.3lfms", (double)_total_time_sweeping/1000);
 665   tty->print_cr("  Peak sweep time: %1.3lfms", (double)_peak_sweep_time/1000);
 666   tty->print_cr("  Peak sweep fraction time: %1.3lfms", (double)_peak_sweep_fraction_time/1000);
 667   tty->print_cr("  Total number of stack traversals: %d", _traversals);
 668   tty->print_cr("  Total number of flushed methods: %d", _total_nof_methods_reclaimed);
 669   tty->print_cr("  Total size of flushed methods: " SIZE_FORMAT "Kb", _total_flushed_size/K);
 670 }