jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/concurrentMarkSweep/cmsOopClosures.hpp@c96030fff130 (annotated)

src/share/vm/gc_implementation/concurrentMarkSweep/cmsOopClosures.hpp@c96030fff130 (annotated)

src/share/vm/gc_implementation/concurrentMarkSweep/cmsOopClosures.hpp

Thu, 20 Nov 2008 16:56:09 -0800

author: ysr
date: Thu, 20 Nov 2008 16:56:09 -0800
changeset 888: c96030fff130
parent 887: 00b023ae2d78
child 1370: 05f89f00a864
child 1424: 148e5441d916
permissions: -rw-r--r--

6684579: SoftReference processing can be made more efficient
Summary: For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not.
Reviewed-by: jmasa

 /*
  * Copyright (c) 2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.com if you need additional information or
  * have any questions.
  *
  */
 /////////////////////////////////////////////////////////////////
 // Closures used by ConcurrentMarkSweepGeneration's collector
 /////////////////////////////////////////////////////////////////
 class ConcurrentMarkSweepGeneration;
 class CMSBitMap;
 class CMSMarkStack;
 class CMSCollector;
 class MarkFromRootsClosure;
 class Par_MarkFromRootsClosure;
 // Decode the oop and call do_oop on it.
 #define DO_OOP_WORK_DEFN \
   void do_oop(oop obj);                                   \
   template <class T> inline void do_oop_work(T* p) {      \
     T heap_oop = oopDesc::load_heap_oop(p);               \
     if (!oopDesc::is_null(heap_oop)) {                    \
       oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);       \
       do_oop(obj);                                        \
     }                                                     \
   }
 class MarkRefsIntoClosure: public OopsInGenClosure {
  private:
   const MemRegion _span;
   CMSBitMap*      _bitMap;
   const bool      _should_do_nmethods;
  protected:
   DO_OOP_WORK_DEFN
  public:
   MarkRefsIntoClosure(MemRegion span, CMSBitMap* bitMap,
                       bool should_do_nmethods);
   virtual void do_oop(oop* p);
   virtual void do_oop(narrowOop* p);
   inline void do_oop_nv(oop* p)       { MarkRefsIntoClosure::do_oop_work(p); }
   inline void do_oop_nv(narrowOop* p) { MarkRefsIntoClosure::do_oop_work(p); }
   bool do_header() { return true; }
   virtual const bool do_nmethods() const {
     return _should_do_nmethods;
   }
   Prefetch::style prefetch_style() {
     return Prefetch::do_read;
   }
 };
 // A variant of the above used in certain kinds of CMS
 // marking verification.
 class MarkRefsIntoVerifyClosure: public OopsInGenClosure {
  private:
   const MemRegion _span;
   CMSBitMap*      _verification_bm;
   CMSBitMap*      _cms_bm;
   const bool      _should_do_nmethods;
  protected:
   DO_OOP_WORK_DEFN
  public:
   MarkRefsIntoVerifyClosure(MemRegion span, CMSBitMap* verification_bm,
                             CMSBitMap* cms_bm, bool should_do_nmethods);
   virtual void do_oop(oop* p);
   virtual void do_oop(narrowOop* p);
   inline void do_oop_nv(oop* p)       { MarkRefsIntoVerifyClosure::do_oop_work(p); }
   inline void do_oop_nv(narrowOop* p) { MarkRefsIntoVerifyClosure::do_oop_work(p); }
   bool do_header() { return true; }
   virtual const bool do_nmethods() const {
     return _should_do_nmethods;
   }
   Prefetch::style prefetch_style() {
     return Prefetch::do_read;
   }
 };
 // The non-parallel version (the parallel version appears further below).
 class PushAndMarkClosure: public OopClosure {
  private:
   CMSCollector* _collector;
   MemRegion     _span;
   CMSBitMap*    _bit_map;
   CMSBitMap*    _mod_union_table;
   CMSMarkStack* _mark_stack;
   CMSMarkStack* _revisit_stack;
   bool          _concurrent_precleaning;
   bool const    _should_remember_klasses;
  protected:
   DO_OOP_WORK_DEFN
  public:
   PushAndMarkClosure(CMSCollector* collector,
                      MemRegion span,
                      ReferenceProcessor* rp,
                      CMSBitMap* bit_map,
                      CMSBitMap* mod_union_table,
                      CMSMarkStack* mark_stack,
                      CMSMarkStack* revisit_stack,
                      bool concurrent_precleaning);
   virtual void do_oop(oop* p);
   virtual void do_oop(narrowOop* p);
   inline void do_oop_nv(oop* p)       { PushAndMarkClosure::do_oop_work(p); }
   inline void do_oop_nv(narrowOop* p) { PushAndMarkClosure::do_oop_work(p); }
   bool do_header() { return true; }
   Prefetch::style prefetch_style() {
     return Prefetch::do_read;
   }
   virtual const bool should_remember_klasses() const {
     return _should_remember_klasses;
   }
   virtual void remember_klass(Klass* k);
 };
 // In the parallel case, the revisit stack, the bit map and the
 // reference processor are currently all shared. Access to
 // these shared mutable structures must use appropriate
 // synchronization (for instance, via CAS). The marking stack
 // used in the non-parallel case above is here replaced with
 // an OopTaskQueue structure to allow efficient work stealing.
 class Par_PushAndMarkClosure: public OopClosure {
  private:
   CMSCollector* _collector;
   MemRegion     _span;
   CMSBitMap*    _bit_map;
   OopTaskQueue* _work_queue;
   CMSMarkStack* _revisit_stack;
   bool const    _should_remember_klasses;
  protected:
   DO_OOP_WORK_DEFN
  public:
   Par_PushAndMarkClosure(CMSCollector* collector,
                          MemRegion span,
                          ReferenceProcessor* rp,
                          CMSBitMap* bit_map,
                          OopTaskQueue* work_queue,
                          CMSMarkStack* revisit_stack);
   virtual void do_oop(oop* p);
   virtual void do_oop(narrowOop* p);
   inline void do_oop_nv(oop* p)       { Par_PushAndMarkClosure::do_oop_work(p); }
   inline void do_oop_nv(narrowOop* p) { Par_PushAndMarkClosure::do_oop_work(p); }
   bool do_header() { return true; }
   Prefetch::style prefetch_style() {
     return Prefetch::do_read;
   }
   virtual const bool should_remember_klasses() const {
     return _should_remember_klasses;
   }
   virtual void remember_klass(Klass* k);
 };
 // The non-parallel version (the parallel version appears further below).
 class MarkRefsIntoAndScanClosure: public OopsInGenClosure {
  private:
   MemRegion          _span;
   CMSBitMap*         _bit_map;
   CMSMarkStack*      _mark_stack;
   PushAndMarkClosure _pushAndMarkClosure;
   CMSCollector*      _collector;
   Mutex*             _freelistLock;
   bool               _yield;
   // Whether closure is being used for concurrent precleaning
   bool               _concurrent_precleaning;
  protected:
   DO_OOP_WORK_DEFN
  public:
   MarkRefsIntoAndScanClosure(MemRegion span,
                              ReferenceProcessor* rp,
                              CMSBitMap* bit_map,
                              CMSBitMap* mod_union_table,
                              CMSMarkStack* mark_stack,
                              CMSMarkStack* revisit_stack,
                              CMSCollector* collector,
                              bool should_yield,
                              bool concurrent_precleaning);
   virtual void do_oop(oop* p);
   virtual void do_oop(narrowOop* p);
   inline void do_oop_nv(oop* p)       { MarkRefsIntoAndScanClosure::do_oop_work(p); }
   inline void do_oop_nv(narrowOop* p) { MarkRefsIntoAndScanClosure::do_oop_work(p); }
   bool do_header() { return true; }
   virtual const bool do_nmethods() const { return true; }
   Prefetch::style prefetch_style() {
     return Prefetch::do_read;
   }
   void set_freelistLock(Mutex* m) {
     _freelistLock = m;
   }
  private:
   inline void do_yield_check();
   void do_yield_work();
   bool take_from_overflow_list();
 };
 // Tn this, the parallel avatar of MarkRefsIntoAndScanClosure, the revisit
 // stack and the bitMap are shared, so access needs to be suitably
 // sycnhronized. An OopTaskQueue structure, supporting efficient
 // workstealing, replaces a CMSMarkStack for storing grey objects.
 class Par_MarkRefsIntoAndScanClosure: public OopsInGenClosure {
  private:
   MemRegion              _span;
   CMSBitMap*             _bit_map;
   OopTaskQueue*          _work_queue;
   const uint             _low_water_mark;
   Par_PushAndMarkClosure _par_pushAndMarkClosure;
  protected:
   DO_OOP_WORK_DEFN
  public:
   Par_MarkRefsIntoAndScanClosure(CMSCollector* collector,
                                  MemRegion span,
                                  ReferenceProcessor* rp,
                                  CMSBitMap* bit_map,
                                  OopTaskQueue* work_queue,
                                  CMSMarkStack*  revisit_stack);
   virtual void do_oop(oop* p);
   virtual void do_oop(narrowOop* p);
   inline void do_oop_nv(oop* p)       { Par_MarkRefsIntoAndScanClosure::do_oop_work(p); }
   inline void do_oop_nv(narrowOop* p) { Par_MarkRefsIntoAndScanClosure::do_oop_work(p); }
   bool do_header() { return true; }
   virtual const bool do_nmethods() const { return true; }
   Prefetch::style prefetch_style() {
     return Prefetch::do_read;
   }
   void trim_queue(uint size);
 };
 // This closure is used during the concurrent marking phase
 // following the first checkpoint. Its use is buried in
 // the closure MarkFromRootsClosure.
 class PushOrMarkClosure: public OopClosure {
  private:
   CMSCollector*   _collector;
   MemRegion       _span;
   CMSBitMap*      _bitMap;
   CMSMarkStack*   _markStack;
   CMSMarkStack*   _revisitStack;
   HeapWord* const _finger;
   MarkFromRootsClosure* const
                   _parent;
   bool const      _should_remember_klasses;
  protected:
   DO_OOP_WORK_DEFN
  public:
   PushOrMarkClosure(CMSCollector* cms_collector,
                     MemRegion span,
                     CMSBitMap* bitMap,
                     CMSMarkStack* markStack,
                     CMSMarkStack* revisitStack,
                     HeapWord* finger,
                     MarkFromRootsClosure* parent);
   virtual void do_oop(oop* p);
   virtual void do_oop(narrowOop* p);
   inline void do_oop_nv(oop* p)       { PushOrMarkClosure::do_oop_work(p); }
   inline void do_oop_nv(narrowOop* p) { PushOrMarkClosure::do_oop_work(p); }
   virtual const bool should_remember_klasses() const {
     return _should_remember_klasses;
   }
   virtual void remember_klass(Klass* k);
   // Deal with a stack overflow condition
   void handle_stack_overflow(HeapWord* lost);
  private:
   inline void do_yield_check();
 };
 // A parallel (MT) version of the above.
 // This closure is used during the concurrent marking phase
 // following the first checkpoint. Its use is buried in
 // the closure Par_MarkFromRootsClosure.
 class Par_PushOrMarkClosure: public OopClosure {
  private:
   CMSCollector*    _collector;
   MemRegion        _whole_span;
   MemRegion        _span;        // local chunk
   CMSBitMap*       _bit_map;
   OopTaskQueue*    _work_queue;
   CMSMarkStack*    _overflow_stack;
   CMSMarkStack*    _revisit_stack;
   HeapWord*  const _finger;
   HeapWord** const _global_finger_addr;
   Par_MarkFromRootsClosure* const
                    _parent;
   bool const       _should_remember_klasses;
  protected:
   DO_OOP_WORK_DEFN
  public:
   Par_PushOrMarkClosure(CMSCollector* cms_collector,
                         MemRegion span,
                         CMSBitMap* bit_map,
                         OopTaskQueue* work_queue,
                         CMSMarkStack* mark_stack,
                         CMSMarkStack* revisit_stack,
                         HeapWord* finger,
                         HeapWord** global_finger_addr,
                         Par_MarkFromRootsClosure* parent);
   virtual void do_oop(oop* p);
   virtual void do_oop(narrowOop* p);
   inline void do_oop_nv(oop* p)       { Par_PushOrMarkClosure::do_oop_work(p); }
   inline void do_oop_nv(narrowOop* p) { Par_PushOrMarkClosure::do_oop_work(p); }
   virtual const bool should_remember_klasses() const {
     return _should_remember_klasses;
   }
   virtual void remember_klass(Klass* k);
   // Deal with a stack overflow condition
   void handle_stack_overflow(HeapWord* lost);
  private:
   inline void do_yield_check();
 };
 // For objects in CMS generation, this closure marks
 // given objects (transitively) as being reachable/live.
 // This is currently used during the (weak) reference object
 // processing phase of the CMS final checkpoint step, as
 // well as during the concurrent precleaning of the discovered
 // reference lists.
 class CMSKeepAliveClosure: public OopClosure {
  private:
   CMSCollector* _collector;
   const MemRegion _span;
   CMSMarkStack* _mark_stack;
   CMSBitMap*    _bit_map;
   bool          _concurrent_precleaning;
  protected:
   DO_OOP_WORK_DEFN
  public:
   CMSKeepAliveClosure(CMSCollector* collector, MemRegion span,
                       CMSBitMap* bit_map, CMSMarkStack* mark_stack,
                       bool cpc):
     _collector(collector),
     _span(span),
     _bit_map(bit_map),
     _mark_stack(mark_stack),
     _concurrent_precleaning(cpc) {
     assert(!_span.is_empty(), "Empty span could spell trouble");
   }
   bool    concurrent_precleaning() const { return _concurrent_precleaning; }
   virtual void do_oop(oop* p);
   virtual void do_oop(narrowOop* p);
   inline void do_oop_nv(oop* p)       { CMSKeepAliveClosure::do_oop_work(p); }
   inline void do_oop_nv(narrowOop* p) { CMSKeepAliveClosure::do_oop_work(p); }
 };
 class CMSInnerParMarkAndPushClosure: public OopClosure {
  private:
   CMSCollector* _collector;
   MemRegion     _span;
   OopTaskQueue* _work_queue;
   CMSBitMap*    _bit_map;
  protected:
   DO_OOP_WORK_DEFN
  public:
   CMSInnerParMarkAndPushClosure(CMSCollector* collector,
                                 MemRegion span, CMSBitMap* bit_map,
                                 OopTaskQueue* work_queue):
     _collector(collector),
     _span(span),
     _bit_map(bit_map),
     _work_queue(work_queue) { }
   virtual void do_oop(oop* p);
   virtual void do_oop(narrowOop* p);
   inline void do_oop_nv(oop* p)       { CMSInnerParMarkAndPushClosure::do_oop_work(p); }
   inline void do_oop_nv(narrowOop* p) { CMSInnerParMarkAndPushClosure::do_oop_work(p); }
 };
 // A parallel (MT) version of the above, used when
 // reference processing is parallel; the only difference
 // is in the do_oop method.
 class CMSParKeepAliveClosure: public OopClosure {
  private:
   CMSCollector* _collector;
   MemRegion     _span;
   OopTaskQueue* _work_queue;
   CMSBitMap*    _bit_map;
   CMSInnerParMarkAndPushClosure
                 _mark_and_push;
   const uint    _low_water_mark;
   void trim_queue(uint max);
  protected:
   DO_OOP_WORK_DEFN
  public:
   CMSParKeepAliveClosure(CMSCollector* collector, MemRegion span,
                          CMSBitMap* bit_map, OopTaskQueue* work_queue);
   virtual void do_oop(oop* p);
   virtual void do_oop(narrowOop* p);
   inline void do_oop_nv(oop* p)       { CMSParKeepAliveClosure::do_oop_work(p); }
   inline void do_oop_nv(narrowOop* p) { CMSParKeepAliveClosure::do_oop_work(p); }
 };

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/concurrentMarkSweep/cmsOopClosures.hpp@c96030fff130 (annotated)

src/share/vm/gc_implementation/concurrentMarkSweep/cmsOopClosures.hpp