duke@435: /*
xdono@772:  * Copyright 2003-2008 Sun Microsystems, Inc.  All Rights Reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
duke@435:  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435:  * CA 95054 USA or visit www.sun.com if you need additional information or
duke@435:  * have any questions.
duke@435:  *
duke@435:  */
duke@435: 
duke@435: // All heaps contains a "permanent generation," containing permanent
duke@435: // (reflective) objects.  This is like a regular generation in some ways,
duke@435: // but unlike one in others, and so is split apart.
duke@435: 
duke@435: class PermanentGenerationSpec;
duke@435: 
duke@435: // This is the "generation" view of a CompactingPermGen.
ysr@1486: // NOTE: the shared spaces used for CDS are here handled in
ysr@1486: // a somewhat awkward and potentially buggy fashion, see CR 6801625.
ysr@1486: // This infelicity should be fixed, see CR 6897789.
duke@435: class CompactingPermGenGen: public OneContigSpaceCardGeneration {
duke@435:   friend class VMStructs;
duke@435:   // Abstractly, this is a subtype that gets access to protected fields.
duke@435:   friend class CompactingPermGen;
duke@435: 
duke@435: private:
duke@435:   // Shared spaces
duke@435:   PermanentGenerationSpec* _spec;
duke@435:   size_t _shared_space_size;
duke@435:   VirtualSpace _ro_vs;
duke@435:   VirtualSpace _rw_vs;
duke@435:   VirtualSpace _md_vs;
duke@435:   VirtualSpace _mc_vs;
duke@435:   BlockOffsetSharedArray* _ro_bts;
duke@435:   BlockOffsetSharedArray* _rw_bts;
duke@435:   OffsetTableContigSpace* _ro_space;
duke@435:   OffsetTableContigSpace* _rw_space;
duke@435: 
ysr@1486:   // With shared spaces there is a dichotomy in the use of the
duke@435:   // _virtual_space of the generation.  There is a portion of the
duke@435:   // _virtual_space that is used for the unshared part of the
duke@435:   // permanent generation and a portion that is reserved for the shared part.
duke@435:   // The _reserved field in the generation represents both the
duke@435:   // unshared and shared parts of the generation.  The _reserved
duke@435:   // variable is initialized for only the unshared part but is
duke@435:   // later extended to include the shared part during initialization
duke@435:   // if shared spaces are being used.
duke@435:   // The reserved size for the _virtual_space for CompactingPermGenGen
duke@435:   // is the size of the space for the permanent generation including the
duke@435:   // the shared spaces.  This can be seen by the use of MaxPermSize
duke@435:   // in the allocation of PermanentGenerationSpec.  The space for the
duke@435:   // shared spaces is committed separately (???).
duke@435:   // In general at initialization only a part of the
duke@435:   // space for the unshared part of the permanent generation is
duke@435:   // committed and more is committed as the permanent generation is
duke@435:   // grown.  In growing the permanent generation the capacity() and
duke@435:   // max_capacity() of the generation are used.  For the permanent
duke@435:   // generation (implemented with a CompactingPermGenGen) the capacity()
duke@435:   // is taken from the capacity of the space (_the_space variable used for the
duke@435:   // unshared part of the generation) and the max_capacity() is based
duke@435:   // on the size of the _reserved variable (which includes the size of the
duke@435:   // shared spaces) minus the size of the shared spaces.
duke@435: 
duke@435:   // These values are redundant, but are called out separately to avoid
duke@435:   // going through heap/space/gen pointers for performance.
duke@435:   static HeapWord* unshared_bottom;
duke@435:   static HeapWord* unshared_end;
duke@435:   static HeapWord* shared_bottom;
duke@435:   static HeapWord* readonly_bottom;
duke@435:   static HeapWord* readonly_end;
duke@435:   static HeapWord* readwrite_bottom;
duke@435:   static HeapWord* readwrite_end;
duke@435:   static HeapWord* miscdata_bottom;
duke@435:   static HeapWord* miscdata_end;
duke@435:   static HeapWord* misccode_bottom;
duke@435:   static HeapWord* misccode_end;
duke@435:   static HeapWord* shared_end;
duke@435: 
duke@435:   // List of klassOops whose vtbl entries are used to patch others.
duke@435:   static void**        _vtbl_list;
duke@435: 
duke@435:   // Performance Counters
duke@435:   GenerationCounters*  _gen_counters;
duke@435:   CSpaceCounters*      _space_counters;
duke@435: 
duke@435:   void initialize_performance_counters();
duke@435: 
duke@435: public:
duke@435: 
duke@435:   enum {
duke@435:     vtbl_list_size = 16, // number of entries in the shared space vtable list.
acorn@843:     num_virtuals = 200   // number of virtual methods in Klass (or
duke@435:                          // subclass) objects, or greater.
duke@435:   };
duke@435: 
duke@435:   enum {
duke@435:     ro = 0,  // read-only shared space in the heap
duke@435:     rw = 1,  // read-write shared space in the heap
duke@435:     md = 2,  // miscellaneous data for initializing tables, etc.
duke@435:     mc = 3,  // miscellaneous code - vtable replacement.
duke@435:     n_regions = 4
duke@435:   };
duke@435: 
duke@435:   CompactingPermGenGen(ReservedSpace rs, ReservedSpace shared_rs,
duke@435:                        size_t initial_byte_size, int level, GenRemSet* remset,
duke@435:                        ContiguousSpace* space,
duke@435:                        PermanentGenerationSpec* perm_spec);
duke@435: 
duke@435:   const char* name() const {
duke@435:     return "compacting perm gen";
duke@435:   }
duke@435: 
duke@435:   const char* short_name() const {
duke@435:     return "Perm";
duke@435:   }
duke@435: 
duke@435:   // Return the maximum capacity for the object space.  This
duke@435:   // explicitly does not include the shared spaces.
duke@435:   size_t max_capacity() const;
duke@435: 
duke@435:   void update_counters();
duke@435: 
duke@435:   void compute_new_size() {
duke@435:     assert(false, "Should not call this -- handled at PermGen level.");
duke@435:   }
duke@435: 
duke@435:   bool must_be_youngest() const { return false; }
duke@435:   bool must_be_oldest() const { return false; }
duke@435: 
duke@435:   OffsetTableContigSpace* ro_space() const { return _ro_space; }
duke@435:   OffsetTableContigSpace* rw_space() const { return _rw_space; }
duke@435:   VirtualSpace*           md_space()       { return &_md_vs; }
duke@435:   VirtualSpace*           mc_space()       { return &_mc_vs; }
duke@435:   ContiguousSpace* unshared_space() const { return _the_space; }
duke@435: 
duke@435:   static bool inline is_shared(const oopDesc* p) {
duke@435:     return (HeapWord*)p >= shared_bottom && (HeapWord*)p < shared_end;
duke@435:   }
duke@435:   // RedefineClasses note: this tester is used to check residence of
duke@435:   // the specified oop in the shared readonly space and not whether
duke@435:   // the oop is readonly.
duke@435:   static bool inline is_shared_readonly(const oopDesc* p) {
duke@435:     return (HeapWord*)p >= readonly_bottom && (HeapWord*)p < readonly_end;
duke@435:   }
duke@435:   // RedefineClasses note: this tester is used to check residence of
duke@435:   // the specified oop in the shared readwrite space and not whether
duke@435:   // the oop is readwrite.
duke@435:   static bool inline is_shared_readwrite(const oopDesc* p) {
duke@435:     return (HeapWord*)p >= readwrite_bottom && (HeapWord*)p < readwrite_end;
duke@435:   }
duke@435: 
duke@435:   bool is_in_unshared(const void* p) const {
duke@435:     return OneContigSpaceCardGeneration::is_in(p);
duke@435:   }
duke@435: 
duke@435:   bool is_in_shared(const void* p) const {
duke@435:    return p >= shared_bottom && p < shared_end;
duke@435:    }
duke@435: 
duke@435:   inline bool is_in(const void* p) const {
duke@435:     return is_in_unshared(p) || is_in_shared(p);
duke@435:   }
duke@435: 
duke@435:   inline PermanentGenerationSpec* spec() const { return _spec; }
duke@435:   inline void set_spec(PermanentGenerationSpec* spec) { _spec = spec; }
duke@435: 
duke@435:   void pre_adjust_pointers();
duke@435:   void adjust_pointers();
duke@435:   void space_iterate(SpaceClosure* blk, bool usedOnly = false);
duke@435:   void print_on(outputStream* st) const;
duke@435:   void younger_refs_iterate(OopsInGenClosure* blk);
duke@435:   void compact();
duke@435:   void post_compact();
duke@435:   size_t contiguous_available() const;
duke@435: 
duke@435:   void clear_remembered_set();
duke@435:   void invalidate_remembered_set();
duke@435: 
duke@435:   inline bool block_is_obj(const HeapWord* addr) const {
duke@435:     if      (addr < the_space()->top()) return true;
duke@435:     else if (addr < the_space()->end()) return false;
duke@435:     else if (addr < ro_space()->top())  return true;
duke@435:     else if (addr < ro_space()->end())  return false;
duke@435:     else if (addr < rw_space()->top())  return true;
duke@435:     else                                return false;
duke@435:   }
duke@435: 
duke@435: 
duke@435:   inline size_t block_size(const HeapWord* addr) const {
duke@435:     if (addr < the_space()->top()) {
duke@435:       return oop(addr)->size();
duke@435:     }
duke@435:     else if (addr < the_space()->end()) {
duke@435:       assert(addr == the_space()->top(), "non-block head arg to block_size");
duke@435:       return the_space()->end() - the_space()->top();
duke@435:     }
duke@435: 
duke@435:     else if (addr < ro_space()->top()) {
duke@435:       return oop(addr)->size();
duke@435:     }
duke@435:     else if (addr < ro_space()->end()) {
duke@435:       assert(addr == ro_space()->top(), "non-block head arg to block_size");
duke@435:       return ro_space()->end() - ro_space()->top();
duke@435:     }
duke@435: 
duke@435:     else if (addr < rw_space()->top()) {
duke@435:       return oop(addr)->size();
duke@435:     }
duke@435:     else {
duke@435:       assert(addr == rw_space()->top(), "non-block head arg to block_size");
duke@435:       return rw_space()->end() - rw_space()->top();
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   static void generate_vtable_methods(void** vtbl_list,
duke@435:                                       void** vtable,
duke@435:                                       char** md_top, char* md_end,
duke@435:                                       char** mc_top, char* mc_end);
duke@435: 
duke@435:   void verify(bool allow_dirty);
duke@435: 
duke@435:   // Serialization
duke@435:   static void initialize_oops() KERNEL_RETURN;
duke@435:   static void serialize_oops(SerializeOopClosure* soc);
duke@435:   void serialize_bts(SerializeOopClosure* soc);
duke@435: 
duke@435:   // Initiate dumping of shared file.
duke@435:   static jint dump_shared(GrowableArray<oop>* class_promote_order, TRAPS);
duke@435: 
duke@435:   // JVM/TI RedefineClasses() support:
duke@435:   // Remap the shared readonly space to shared readwrite, private if
duke@435:   // sharing is enabled. Simply returns true if sharing is not enabled
duke@435:   // or if the remapping has already been done by a prior call.
duke@435:   static bool remap_shared_readonly_as_readwrite();
duke@435: };