jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/parallelScavenge/psScavenge.hpp@47bdfb3d010f (annotated)

src/share/vm/gc_implementation/parallelScavenge/psScavenge.hpp@47bdfb3d010f (annotated)

src/share/vm/gc_implementation/parallelScavenge/psScavenge.hpp

Thu, 30 May 2013 10:58:16 +0200

author: stefank
date: Thu, 30 May 2013 10:58:16 +0200
changeset 5202: 47bdfb3d010f
parent 4129: 22b8d3d181d9
child 5237: f2110083203d
permissions: -rw-r--r--

8015486: PSScavenge::is_obj_in_young is unnecessarily slow with UseCompressedOops
Summary: Compare compressed oops to a compressed young gen boundary instead of uncompressing the oops before doing the young gen boundary check.
Reviewed-by: brutisso, jmasa

 /*
  * Copyright (c) 2002, 2012, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_HPP
 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_HPP
 #include "gc_implementation/parallelScavenge/cardTableExtension.hpp"
 #include "gc_implementation/parallelScavenge/psVirtualspace.hpp"
 #include "gc_implementation/shared/collectorCounters.hpp"
 #include "memory/allocation.hpp"
 #include "oops/oop.hpp"
 #include "utilities/stack.hpp"
 class GCTaskManager;
 class GCTaskQueue;
 class OopStack;
 class ReferenceProcessor;
 class ParallelScavengeHeap;
 class PSIsAliveClosure;
 class PSRefProcTaskExecutor;
 class PSScavenge: AllStatic {
   friend class PSIsAliveClosure;
   friend class PSKeepAliveClosure;
   friend class PSPromotionManager;
  enum ScavengeSkippedCause {
    not_skipped = 0,
    to_space_not_empty,
    promoted_too_large,
    full_follows_scavenge
  };
   // Saved value of to_space->top(), used to prevent objects in to_space from
   // being rescanned.
   static HeapWord* _to_space_top_before_gc;
   // Number of consecutive attempts to scavenge that were skipped
   static int                _consecutive_skipped_scavenges;
  protected:
   // Flags/counters
   static ReferenceProcessor*  _ref_processor;        // Reference processor for scavenging.
   static PSIsAliveClosure     _is_alive_closure;     // Closure used for reference processing
   static CardTableExtension*  _card_table;           // We cache the card table for fast access.
   static bool                 _survivor_overflow;    // Overflow this collection
   static uint                 _tenuring_threshold;   // tenuring threshold for next scavenge
   static elapsedTimer         _accumulated_time;     // total time spent on scavenge
   // The lowest address possible for the young_gen.
   // This is used to decide if an oop should be scavenged,
   // cards should be marked, etc.
   static HeapWord*            _young_generation_boundary;
   // Used to optimize compressed oops young gen boundary checking.
   static uintptr_t            _young_generation_boundary_compressed;
   static Stack<markOop, mtGC> _preserved_mark_stack; // List of marks to be restored after failed promotion
   static Stack<oop, mtGC>     _preserved_oop_stack;  // List of oops that need their mark restored.
   static CollectorCounters*   _counters;             // collector performance counters
   static bool                 _promotion_failed;
   static void clean_up_failed_promotion();
   static bool should_attempt_scavenge();
   static HeapWord* to_space_top_before_gc() { return _to_space_top_before_gc; }
   static inline void save_to_space_top_before_gc();
   // Private accessors
   static CardTableExtension* const card_table()       { assert(_card_table != NULL, "Sanity"); return _card_table; }
  public:
   // Accessors
   static uint             tenuring_threshold()  { return _tenuring_threshold; }
   static elapsedTimer*    accumulated_time()    { return &_accumulated_time; }
   static bool             promotion_failed()    { return _promotion_failed; }
   static int              consecutive_skipped_scavenges()
     { return _consecutive_skipped_scavenges; }
   // Performance Counters
   static CollectorCounters* counters()           { return _counters; }
   // Used by scavenge_contents && psMarkSweep
   static ReferenceProcessor* const reference_processor() {
     assert(_ref_processor != NULL, "Sanity");
     return _ref_processor;
   }
   // Used to add tasks
   static GCTaskManager* const gc_task_manager();
   // The promotion managers tell us if they encountered overflow
   static void set_survivor_overflow(bool state) {
     _survivor_overflow = state;
   }
   // Adaptive size policy support.  When the young generation/old generation
   // boundary moves, _young_generation_boundary must be reset
   static void set_young_generation_boundary(HeapWord* v) {
     _young_generation_boundary = v;
     if (UseCompressedOops) {
       _young_generation_boundary_compressed = (uintptr_t)oopDesc::encode_heap_oop((oop)v);
     }
   }
   // Called by parallelScavengeHeap to init the tenuring threshold
   static void initialize();
   // Scavenge entry point.  This may invoke a full gc; return true if so.
   static bool invoke();
   // Return true if a collection was done; false otherwise.
   static bool invoke_no_policy();
   // If an attempt to promote fails, this method is invoked
   static void oop_promotion_failed(oop obj, markOop obj_mark);
   template <class T> static inline bool should_scavenge(T* p);
   // These call should_scavenge() above and, if it returns true, also check that
   // the object was not newly copied into to_space.  The version with the bool
   // argument is a convenience wrapper that fetches the to_space pointer from
   // the heap and calls the other version (if the arg is true).
   template <class T> static inline bool should_scavenge(T* p, MutableSpace* to_space);
   template <class T> static inline bool should_scavenge(T* p, bool check_to_space);
   template <class T, bool promote_immediately>
     inline static void copy_and_push_safe_barrier(PSPromotionManager* pm, T* p);
   static void copy_and_push_safe_barrier_from_klass(PSPromotionManager* pm, oop* p);
   // Is an object in the young generation
   // This assumes that the 'o' is in the heap,
   // so it only checks one side of the complete predicate.
   inline static bool is_obj_in_young(oop o) {
     return (HeapWord*)o >= _young_generation_boundary;
   }
   inline static bool is_obj_in_young(narrowOop o) {
     return (uintptr_t)o >= _young_generation_boundary_compressed;
   }
   inline static bool is_obj_in_young(HeapWord* o) {
     return o >= _young_generation_boundary;
   }
 };
 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_HPP

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src/share/vm/gc_implementation/parallelScavenge/psScavenge.hpp@47bdfb3d010f (annotated)

src/share/vm/gc_implementation/parallelScavenge/psScavenge.hpp