317 
 318   // Fill in TLABs
 319   heap->accumulate_statistics_all_tlabs();
 320   heap->ensure_parsability(true);  // retire TLABs
 321 
 322   if (VerifyBeforeGC && heap->total_collections() >= VerifyGCStartAt) {
 323     HandleMark hm;  // Discard invalid handles created during verification
 324     Universe::verify(" VerifyBeforeGC:");
 325   }
 326 
 327   {
 328     ResourceMark rm;
 329     HandleMark hm;
 330 
 331     gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps);
 332     TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
 333     GCTraceTime t1(GCCauseString("GC", gc_cause), PrintGC, !PrintGCDetails, NULL);
 334     TraceCollectorStats tcs(counters());
 335     TraceMemoryManagerStats tms(false /* not full GC */,gc_cause);
 336 
 337     if (TraceGen0Time) accumulated_time()->start();
 338 
 339     // Let the size policy know we're starting
 340     size_policy->minor_collection_begin();
 341 
 342     // Verify the object start arrays.
 343     if (VerifyObjectStartArray &&
 344         VerifyBeforeGC) {
 345       old_gen->verify_object_start_array();
 346     }
 347 
 348     // Verify no unmarked old->young roots
 349     if (VerifyRememberedSets) {
 350       CardTableExtension::verify_all_young_refs_imprecise();
 351     }
 352 
 353     if (!ScavengeWithObjectsInToSpace) {
 354       assert(young_gen->to_space()->is_empty(),
 355              "Attempt to scavenge with live objects in to_space");
 356       young_gen->to_space()->clear(SpaceDecorator::Mangle);
 357     } else if (ZapUnusedHeapArea) {

 641     {
 642       GCTraceTime tm("Prune Scavenge Root Methods", false, false, &_gc_timer);
 643 
 644       CodeCache::prune_scavenge_root_nmethods();
 645     }
 646 
 647     // Re-verify object start arrays
 648     if (VerifyObjectStartArray &&
 649         VerifyAfterGC) {
 650       old_gen->verify_object_start_array();
 651     }
 652 
 653     // Verify all old -> young cards are now precise
 654     if (VerifyRememberedSets) {
 655       // Precise verification will give false positives. Until this is fixed,
 656       // use imprecise verification.
 657       // CardTableExtension::verify_all_young_refs_precise();
 658       CardTableExtension::verify_all_young_refs_imprecise();
 659     }
 660 
 661     if (TraceGen0Time) accumulated_time()->stop();
 662 
 663     if (PrintGC) {
 664       if (PrintGCDetails) {
 665         // Don't print a GC timestamp here.  This is after the GC so
 666         // would be confusing.
 667         young_gen->print_used_change(young_gen_used_before);
 668       }
 669       heap->print_heap_change(prev_used);
 670     }
 671 
 672     // Track memory usage and detect low memory
 673     MemoryService::track_memory_usage();
 674     heap->update_counters();
 675 
 676     gc_task_manager()->release_idle_workers();
 677   }
 678 
 679   if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) {
 680     HandleMark hm;  // Discard invalid handles created during verification
 681     Universe::verify(" VerifyAfterGC:");

 317 
 318   // Fill in TLABs
 319   heap->accumulate_statistics_all_tlabs();
 320   heap->ensure_parsability(true);  // retire TLABs
 321 
 322   if (VerifyBeforeGC && heap->total_collections() >= VerifyGCStartAt) {
 323     HandleMark hm;  // Discard invalid handles created during verification
 324     Universe::verify(" VerifyBeforeGC:");
 325   }
 326 
 327   {
 328     ResourceMark rm;
 329     HandleMark hm;
 330 
 331     gclog_or_tty->date_stamp(PrintGC && PrintGCDateStamps);
 332     TraceCPUTime tcpu(PrintGCDetails, true, gclog_or_tty);
 333     GCTraceTime t1(GCCauseString("GC", gc_cause), PrintGC, !PrintGCDetails, NULL);
 334     TraceCollectorStats tcs(counters());
 335     TraceMemoryManagerStats tms(false /* not full GC */,gc_cause);
 336 
 337     if (TraceYoungGenTime) accumulated_time()->start();
 338 
 339     // Let the size policy know we're starting
 340     size_policy->minor_collection_begin();
 341 
 342     // Verify the object start arrays.
 343     if (VerifyObjectStartArray &&
 344         VerifyBeforeGC) {
 345       old_gen->verify_object_start_array();
 346     }
 347 
 348     // Verify no unmarked old->young roots
 349     if (VerifyRememberedSets) {
 350       CardTableExtension::verify_all_young_refs_imprecise();
 351     }
 352 
 353     if (!ScavengeWithObjectsInToSpace) {
 354       assert(young_gen->to_space()->is_empty(),
 355              "Attempt to scavenge with live objects in to_space");
 356       young_gen->to_space()->clear(SpaceDecorator::Mangle);
 357     } else if (ZapUnusedHeapArea) {

 641     {
 642       GCTraceTime tm("Prune Scavenge Root Methods", false, false, &_gc_timer);
 643 
 644       CodeCache::prune_scavenge_root_nmethods();
 645     }
 646 
 647     // Re-verify object start arrays
 648     if (VerifyObjectStartArray &&
 649         VerifyAfterGC) {
 650       old_gen->verify_object_start_array();
 651     }
 652 
 653     // Verify all old -> young cards are now precise
 654     if (VerifyRememberedSets) {
 655       // Precise verification will give false positives. Until this is fixed,
 656       // use imprecise verification.
 657       // CardTableExtension::verify_all_young_refs_precise();
 658       CardTableExtension::verify_all_young_refs_imprecise();
 659     }
 660 
 661     if (TraceYoungGenTime) accumulated_time()->stop();
 662 
 663     if (PrintGC) {
 664       if (PrintGCDetails) {
 665         // Don't print a GC timestamp here.  This is after the GC so
 666         // would be confusing.
 667         young_gen->print_used_change(young_gen_used_before);
 668       }
 669       heap->print_heap_change(prev_used);
 670     }
 671 
 672     // Track memory usage and detect low memory
 673     MemoryService::track_memory_usage();
 674     heap->update_counters();
 675 
 676     gc_task_manager()->release_idle_workers();
 677   }
 678 
 679   if (VerifyAfterGC && heap->total_collections() >= VerifyGCStartAt) {
 680     HandleMark hm;  // Discard invalid handles created during verification
 681     Universe::verify(" VerifyAfterGC:");