hotspot/src/share/vm/memory/genCollectedHeap.hpp

rev 611 : Merge

*** 1,10 ****
  #ifdef USE_PRAGMA_IDENT_HDR
  #pragma ident "@(#)genCollectedHeap.hpp 1.106 07/07/22 22:36:34 JVM"
  #endif
  /*
!  * Copyright 2000-2007 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.
--- 1,10 ----
  #ifdef USE_PRAGMA_IDENT_HDR
  #pragma ident "@(#)genCollectedHeap.hpp 1.106 07/07/22 22:36:34 JVM"
  #endif
  /*
!  * Copyright 2000-2008 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.
*** 36,45 ****
--- 36,46 ----
    friend class TenuredGeneration;
    friend class ConcurrentMarkSweepGeneration;
    friend class CMSCollector;
    friend class GenMarkSweep;
    friend class VM_GenCollectForAllocation;
+   friend class VM_GenCollectForPermanentAllocation;
    friend class VM_GenCollectFull;
    friend class VM_GenCollectFullConcurrent;
    friend class VM_GC_HeapInspection;
    friend class VM_HeapDumper;
    friend class HeapInspection;
*** 252,268 ****
--- 253,287 ----
    virtual bool supports_tlab_allocation() const;
    virtual size_t tlab_capacity(Thread* thr) const;
    virtual size_t unsafe_max_tlab_alloc(Thread* thr) const;
    virtual HeapWord* allocate_new_tlab(size_t size);
  
+   // Can a compiler initialize a new object without store barriers?
+   // This permission only extends from the creation of a new object
+   // via a TLAB up to the first subsequent safepoint.
+   virtual bool can_elide_tlab_store_barriers() const {
+     return true;
+   }
+ 
+   // Can a compiler elide a store barrier when it writes
+   // a permanent oop into the heap?  Applies when the compiler
+   // is storing x to the heap, where x->is_perm() is true.
+   virtual bool can_elide_permanent_oop_store_barriers() const {
+     // CMS needs to see all, even intra-generational, ref updates.
+     return !UseConcMarkSweepGC;
+   }
+ 
    // The "requestor" generation is performing some garbage collection
    // action for which it would be useful to have scratch space.  The
    // requestor promises to allocate no more than "max_alloc_words" in any
    // older generation (via promotion say.)   Any blocks of space that can
    // be provided are returned as a list of ScratchBlocks, sorted by
    // decreasing size.
    ScratchBlock* gather_scratch(Generation* requestor, size_t max_alloc_words);
+   // Allow each generation to reset any scratch space that it has
+   // contributed as it needs.
+   void release_scratch();
  
    size_t large_typearray_limit();
  
    // Ensure parsability: override
    virtual void ensure_parsability(bool retire_tlabs);
*** 453,464 ****
    // gens in ascending order; return the new location of obj if successful.
    // Otherwise, try expand-and-allocate for obj in each generation starting at
    // gen; return the new location of obj if successful.  Otherwise, return NULL.
    oop handle_failed_promotion(Generation* gen,
                                oop obj,
!                               size_t obj_size,
!                               oop* ref);
  
  private:
    // Accessor for memory state verification support
    NOT_PRODUCT(
      static size_t skip_header_HeapWords() { return _skip_header_HeapWords; }
--- 472,482 ----
    // gens in ascending order; return the new location of obj if successful.
    // Otherwise, try expand-and-allocate for obj in each generation starting at
    // gen; return the new location of obj if successful.  Otherwise, return NULL.
    oop handle_failed_promotion(Generation* gen,
                                oop obj,
!                               size_t obj_size);
  
  private:
    // Accessor for memory state verification support
    NOT_PRODUCT(
      static size_t skip_header_HeapWords() { return _skip_header_HeapWords; }
*** 483,492 ****
--- 501,513 ----
  
    // In support of ExplicitGCInvokesConcurrent functionality
    bool should_do_concurrent_full_gc(GCCause::Cause cause);
    void collect_mostly_concurrent(GCCause::Cause cause);
  
+   // Save the tops of the spaces in all generations
+   void record_gen_tops_before_GC() PRODUCT_RETURN;
+ 
  protected:
    virtual void gc_prologue(bool full);
    virtual void gc_epilogue(bool full);
    
  public: