src/share/vm/memory/compactingPermGenGen.hpp - toolchain/jdk/jdk9_hotspot - Git at Google

 /*
  * Copyright 2003-2006 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.
  *
  */

 // All heaps contains a "permanent generation," containing permanent
 // (reflective) objects.  This is like a regular generation in some ways,
 // but unlike one in others, and so is split apart.

 class PermanentGenerationSpec;

 // This is the "generation" view of a CompactingPermGen.
 class CompactingPermGenGen: public OneContigSpaceCardGeneration {
   friend class VMStructs;
   // Abstractly, this is a subtype that gets access to protected fields.
   friend class CompactingPermGen;

 private:
   // Shared spaces
   PermanentGenerationSpec* _spec;
   size_t _shared_space_size;
   VirtualSpace _ro_vs;
   VirtualSpace _rw_vs;
   VirtualSpace _md_vs;
   VirtualSpace _mc_vs;
   BlockOffsetSharedArray* _ro_bts;
   BlockOffsetSharedArray* _rw_bts;
   OffsetTableContigSpace* _ro_space;
   OffsetTableContigSpace* _rw_space;

   // With shared spaces there is a dicotomy in the use of the
   // _virtual_space of the generation.  There is a portion of the
   // _virtual_space that is used for the unshared part of the
   // permanent generation and a portion that is reserved for the shared part.
   // The _reserved field in the generation represents both the
   // unshared and shared parts of the generation.  The _reserved
   // variable is initialized for only the unshared part but is
   // later extended to include the shared part during initialization
   // if shared spaces are being used.
   // The reserved size for the _virtual_space for CompactingPermGenGen
   // is the size of the space for the permanent generation including the
   // the shared spaces.  This can be seen by the use of MaxPermSize
   // in the allocation of PermanentGenerationSpec.  The space for the
   // shared spaces is committed separately (???).
   // In general at initialization only a part of the
   // space for the unshared part of the permanent generation is
   // committed and more is committed as the permanent generation is
   // grown.  In growing the permanent generation the capacity() and
   // max_capacity() of the generation are used.  For the permanent
   // generation (implemented with a CompactingPermGenGen) the capacity()
   // is taken from the capacity of the space (_the_space variable used for the
   // unshared part of the generation) and the max_capacity() is based
   // on the size of the _reserved variable (which includes the size of the
   // shared spaces) minus the size of the shared spaces.

   // These values are redundant, but are called out separately to avoid
   // going through heap/space/gen pointers for performance.
   static HeapWord* unshared_bottom;
   static HeapWord* unshared_end;
   static HeapWord* shared_bottom;
   static HeapWord* readonly_bottom;
   static HeapWord* readonly_end;
   static HeapWord* readwrite_bottom;
   static HeapWord* readwrite_end;
   static HeapWord* miscdata_bottom;
   static HeapWord* miscdata_end;
   static HeapWord* misccode_bottom;
   static HeapWord* misccode_end;
   static HeapWord* shared_end;

   // List of klassOops whose vtbl entries are used to patch others.
   static void**        _vtbl_list;

   // Performance Counters
   GenerationCounters*  _gen_counters;
   CSpaceCounters*      _space_counters;

   void initialize_performance_counters();

 public:

   enum {
     vtbl_list_size = 16, // number of entries in the shared space vtable list.
     num_virtuals = 100   // number of virtual methods in Klass (or
                          // subclass) objects, or greater.
   };

   enum {
     ro = 0,  // read-only shared space in the heap
     rw = 1,  // read-write shared space in the heap
     md = 2,  // miscellaneous data for initializing tables, etc.
     mc = 3,  // miscellaneous code - vtable replacement.
     n_regions = 4
   };

   CompactingPermGenGen(ReservedSpace rs, ReservedSpace shared_rs,
                        size_t initial_byte_size, int level, GenRemSet* remset,
                        ContiguousSpace* space,
                        PermanentGenerationSpec* perm_spec);

   const char* name() const {
     return "compacting perm gen";
   }

   const char* short_name() const {
     return "Perm";
   }

   // Return the maximum capacity for the object space.  This
   // explicitly does not include the shared spaces.
   size_t max_capacity() const;

   void update_counters();

   void compute_new_size() {
     assert(false, "Should not call this -- handled at PermGen level.");
   }

   bool must_be_youngest() const { return false; }
   bool must_be_oldest() const { return false; }

   OffsetTableContigSpace* ro_space() const { return _ro_space; }
   OffsetTableContigSpace* rw_space() const { return _rw_space; }
   VirtualSpace*           md_space()       { return &_md_vs; }
   VirtualSpace*           mc_space()       { return &_mc_vs; }
   ContiguousSpace* unshared_space() const { return _the_space; }

   static bool inline is_shared(const oopDesc* p) {
     return (HeapWord*)p >= shared_bottom && (HeapWord*)p < shared_end;
   }
   // RedefineClasses note: this tester is used to check residence of
   // the specified oop in the shared readonly space and not whether
   // the oop is readonly.
   static bool inline is_shared_readonly(const oopDesc* p) {
     return (HeapWord*)p >= readonly_bottom && (HeapWord*)p < readonly_end;
   }
   // RedefineClasses note: this tester is used to check residence of
   // the specified oop in the shared readwrite space and not whether
   // the oop is readwrite.
   static bool inline is_shared_readwrite(const oopDesc* p) {
     return (HeapWord*)p >= readwrite_bottom && (HeapWord*)p < readwrite_end;
   }

   bool is_in_unshared(const void* p) const {
     return OneContigSpaceCardGeneration::is_in(p);
   }

   bool is_in_shared(const void* p) const {
    return p >= shared_bottom && p < shared_end;
    }

   inline bool is_in(const void* p) const {
     return is_in_unshared(p) || is_in_shared(p);
   }

   inline PermanentGenerationSpec* spec() const { return _spec; }
   inline void set_spec(PermanentGenerationSpec* spec) { _spec = spec; }

   void pre_adjust_pointers();
   void adjust_pointers();
   void space_iterate(SpaceClosure* blk, bool usedOnly = false);
   void print_on(outputStream* st) const;
   void younger_refs_iterate(OopsInGenClosure* blk);
   void compact();
   void post_compact();
   size_t contiguous_available() const;

   void clear_remembered_set();
   void invalidate_remembered_set();

   inline bool block_is_obj(const HeapWord* addr) const {
     if      (addr < the_space()->top()) return true;
     else if (addr < the_space()->end()) return false;
     else if (addr < ro_space()->top())  return true;
     else if (addr < ro_space()->end())  return false;
     else if (addr < rw_space()->top())  return true;
     else                                return false;
   }


   inline size_t block_size(const HeapWord* addr) const {
     if (addr < the_space()->top()) {
       return oop(addr)->size();
     }
     else if (addr < the_space()->end()) {
       assert(addr == the_space()->top(), "non-block head arg to block_size");
       return the_space()->end() - the_space()->top();
     }

     else if (addr < ro_space()->top()) {
       return oop(addr)->size();
     }
     else if (addr < ro_space()->end()) {
       assert(addr == ro_space()->top(), "non-block head arg to block_size");
       return ro_space()->end() - ro_space()->top();
     }

     else if (addr < rw_space()->top()) {
       return oop(addr)->size();
     }
     else {
       assert(addr == rw_space()->top(), "non-block head arg to block_size");
       return rw_space()->end() - rw_space()->top();
     }
   }

   static void generate_vtable_methods(void** vtbl_list,
                                       void** vtable,
                                       char** md_top, char* md_end,
                                       char** mc_top, char* mc_end);

   void verify(bool allow_dirty);

   // Serialization
   static void initialize_oops() KERNEL_RETURN;
   static void serialize_oops(SerializeOopClosure* soc);
   void serialize_bts(SerializeOopClosure* soc);

   // Initiate dumping of shared file.
   static jint dump_shared(GrowableArray<oop>* class_promote_order, TRAPS);

   // JVM/TI RedefineClasses() support:
   // Remap the shared readonly space to shared readwrite, private if
   // sharing is enabled. Simply returns true if sharing is not enabled
   // or if the remapping has already been done by a prior call.
   static bool remap_shared_readonly_as_readwrite();
 };
	/*
	* Copyright 2003-2006 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.
	*
	*/

	// All heaps contains a "permanent generation," containing permanent
	// (reflective) objects. This is like a regular generation in some ways,
	// but unlike one in others, and so is split apart.

	class PermanentGenerationSpec;

	// This is the "generation" view of a CompactingPermGen.
	class CompactingPermGenGen: public OneContigSpaceCardGeneration {
	friend class VMStructs;
	// Abstractly, this is a subtype that gets access to protected fields.
	friend class CompactingPermGen;

	private:
	// Shared spaces
	PermanentGenerationSpec* _spec;
	size_t _shared_space_size;
	VirtualSpace _ro_vs;
	VirtualSpace _rw_vs;
	VirtualSpace _md_vs;
	VirtualSpace _mc_vs;
	BlockOffsetSharedArray* _ro_bts;
	BlockOffsetSharedArray* _rw_bts;
	OffsetTableContigSpace* _ro_space;
	OffsetTableContigSpace* _rw_space;

	// With shared spaces there is a dicotomy in the use of the
	// _virtual_space of the generation. There is a portion of the
	// _virtual_space that is used for the unshared part of the
	// permanent generation and a portion that is reserved for the shared part.
	// The _reserved field in the generation represents both the
	// unshared and shared parts of the generation. The _reserved
	// variable is initialized for only the unshared part but is
	// later extended to include the shared part during initialization
	// if shared spaces are being used.
	// The reserved size for the _virtual_space for CompactingPermGenGen
	// is the size of the space for the permanent generation including the
	// the shared spaces. This can be seen by the use of MaxPermSize
	// in the allocation of PermanentGenerationSpec. The space for the
	// shared spaces is committed separately (???).
	// In general at initialization only a part of the
	// space for the unshared part of the permanent generation is
	// committed and more is committed as the permanent generation is
	// grown. In growing the permanent generation the capacity() and
	// max_capacity() of the generation are used. For the permanent
	// generation (implemented with a CompactingPermGenGen) the capacity()
	// is taken from the capacity of the space (_the_space variable used for the
	// unshared part of the generation) and the max_capacity() is based
	// on the size of the _reserved variable (which includes the size of the
	// shared spaces) minus the size of the shared spaces.

	// These values are redundant, but are called out separately to avoid
	// going through heap/space/gen pointers for performance.
	static HeapWord* unshared_bottom;
	static HeapWord* unshared_end;
	static HeapWord* shared_bottom;
	static HeapWord* readonly_bottom;
	static HeapWord* readonly_end;
	static HeapWord* readwrite_bottom;
	static HeapWord* readwrite_end;
	static HeapWord* miscdata_bottom;
	static HeapWord* miscdata_end;
	static HeapWord* misccode_bottom;
	static HeapWord* misccode_end;
	static HeapWord* shared_end;

	// List of klassOops whose vtbl entries are used to patch others.
	static void** _vtbl_list;

	// Performance Counters
	GenerationCounters* _gen_counters;
	CSpaceCounters* _space_counters;

	void initialize_performance_counters();

	public:

	enum {
	vtbl_list_size = 16, // number of entries in the shared space vtable list.
	num_virtuals = 100 // number of virtual methods in Klass (or
	// subclass) objects, or greater.
	};

	enum {
	ro = 0, // read-only shared space in the heap
	rw = 1, // read-write shared space in the heap
	md = 2, // miscellaneous data for initializing tables, etc.
	mc = 3, // miscellaneous code - vtable replacement.
	n_regions = 4
	};

	CompactingPermGenGen(ReservedSpace rs, ReservedSpace shared_rs,
	size_t initial_byte_size, int level, GenRemSet* remset,
	ContiguousSpace* space,
	PermanentGenerationSpec* perm_spec);

	const char* name() const {
	return "compacting perm gen";
	}

	const char* short_name() const {
	return "Perm";
	}

	// Return the maximum capacity for the object space. This
	// explicitly does not include the shared spaces.
	size_t max_capacity() const;

	void update_counters();

	void compute_new_size() {
	assert(false, "Should not call this -- handled at PermGen level.");
	}

	bool must_be_youngest() const { return false; }
	bool must_be_oldest() const { return false; }

	OffsetTableContigSpace* ro_space() const { return _ro_space; }
	OffsetTableContigSpace* rw_space() const { return _rw_space; }
	VirtualSpace* md_space() { return &_md_vs; }
	VirtualSpace* mc_space() { return &_mc_vs; }
	ContiguousSpace* unshared_space() const { return _the_space; }

	static bool inline is_shared(const oopDesc* p) {
	return (HeapWord)p >= shared_bottom && (HeapWord)p < shared_end;
	}
	// RedefineClasses note: this tester is used to check residence of
	// the specified oop in the shared readonly space and not whether
	// the oop is readonly.
	static bool inline is_shared_readonly(const oopDesc* p) {
	return (HeapWord)p >= readonly_bottom && (HeapWord)p < readonly_end;
	}
	// RedefineClasses note: this tester is used to check residence of
	// the specified oop in the shared readwrite space and not whether
	// the oop is readwrite.
	static bool inline is_shared_readwrite(const oopDesc* p) {
	return (HeapWord)p >= readwrite_bottom && (HeapWord)p < readwrite_end;
	}

	bool is_in_unshared(const void* p) const {
	return OneContigSpaceCardGeneration::is_in(p);
	}

	bool is_in_shared(const void* p) const {
	return p >= shared_bottom && p < shared_end;
	}

	inline bool is_in(const void* p) const {
	return is_in_unshared(p) \|\| is_in_shared(p);
	}

	inline PermanentGenerationSpec* spec() const { return _spec; }
	inline void set_spec(PermanentGenerationSpec* spec) { _spec = spec; }

	void pre_adjust_pointers();
	void adjust_pointers();
	void space_iterate(SpaceClosure* blk, bool usedOnly = false);
	void print_on(outputStream* st) const;
	void younger_refs_iterate(OopsInGenClosure* blk);
	void compact();
	void post_compact();
	size_t contiguous_available() const;

	void clear_remembered_set();
	void invalidate_remembered_set();

	inline bool block_is_obj(const HeapWord* addr) const {
	if (addr < the_space()->top()) return true;
	else if (addr < the_space()->end()) return false;
	else if (addr < ro_space()->top()) return true;
	else if (addr < ro_space()->end()) return false;
	else if (addr < rw_space()->top()) return true;
	else return false;
	}


	inline size_t block_size(const HeapWord* addr) const {
	if (addr < the_space()->top()) {
	return oop(addr)->size();
	}
	else if (addr < the_space()->end()) {
	assert(addr == the_space()->top(), "non-block head arg to block_size");
	return the_space()->end() - the_space()->top();
	}

	else if (addr < ro_space()->top()) {
	return oop(addr)->size();
	}
	else if (addr < ro_space()->end()) {
	assert(addr == ro_space()->top(), "non-block head arg to block_size");
	return ro_space()->end() - ro_space()->top();
	}

	else if (addr < rw_space()->top()) {
	return oop(addr)->size();
	}
	else {
	assert(addr == rw_space()->top(), "non-block head arg to block_size");
	return rw_space()->end() - rw_space()->top();
	}
	}

	static void generate_vtable_methods(void** vtbl_list,
	void** vtable,
	char** md_top, char* md_end,
	char** mc_top, char* mc_end);

	void verify(bool allow_dirty);

	// Serialization
	static void initialize_oops() KERNEL_RETURN;
	static void serialize_oops(SerializeOopClosure* soc);
	void serialize_bts(SerializeOopClosure* soc);

	// Initiate dumping of shared file.
	static jint dump_shared(GrowableArray<oop>* class_promote_order, TRAPS);

	// JVM/TI RedefineClasses() support:
	// Remap the shared readonly space to shared readwrite, private if
	// sharing is enabled. Simply returns true if sharing is not enabled
	// or if the remapping has already been done by a prior call.
	static bool remap_shared_readonly_as_readwrite();
	};