hotspot/src/share/vm/memory/collectorPolicy.hpp - platform/libcore - Git at Google

 /*
  * Copyright 2001-2006 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.
  *
  */

 // This class (or more correctly, subtypes of this class)
 // are used to define global garbage collector attributes.
 // This includes initialization of generations and any other
 // shared resources they may need.
 //
 // In general, all flag adjustment and validation should be
 // done in initialize_flags(), which is called prior to
 // initialize_size_info().
 //
 // This class is not fully developed yet. As more collector(s)
 // are added, it is expected that we will come across further
 // behavior that requires global attention. The correct place
 // to deal with those issues is this class.

 // Forward declarations.
 class GenCollectorPolicy;
 class TwoGenerationCollectorPolicy;
 #ifndef SERIALGC
 class ConcurrentMarkSweepPolicy;
 #endif // SERIALGC
 class AdaptiveSizePolicy;
 class GCPolicyCounters;
 class PermanentGenerationSpec;
 class MarkSweepPolicy;

 class CollectorPolicy : public CHeapObj {
  protected:
   PermanentGenerationSpec *_permanent_generation;
   GCPolicyCounters* _gc_policy_counters;

   // Requires that the concrete subclass sets the alignment constraints
   // before calling.
   virtual void initialize_flags();
   virtual void initialize_size_info() = 0;
   // Initialize "_permanent_generation" to a spec for the given kind of
   // Perm Gen.
   void initialize_perm_generation(PermGen::Name pgnm);

   size_t _initial_heap_byte_size;
   size_t _max_heap_byte_size;
   size_t _min_heap_byte_size;

   size_t _min_alignment;
   size_t _max_alignment;

   CollectorPolicy() :
     _min_alignment(1),
     _max_alignment(1),
     _initial_heap_byte_size(0),
     _max_heap_byte_size(0),
     _min_heap_byte_size(0)
   {}

  public:
   void set_min_alignment(size_t align)         { _min_alignment = align; }
   size_t min_alignment()                       { return _min_alignment; }
   void set_max_alignment(size_t align)         { _max_alignment = align; }
   size_t max_alignment()                       { return _max_alignment; }

   size_t initial_heap_byte_size() { return _initial_heap_byte_size; }
   size_t max_heap_byte_size()     { return _max_heap_byte_size; }
   size_t min_heap_byte_size()     { return _min_heap_byte_size; }

   enum Name {
     CollectorPolicyKind,
     TwoGenerationCollectorPolicyKind,
     TrainPolicyKind,
     ConcurrentMarkSweepPolicyKind,
     ASConcurrentMarkSweepPolicyKind
   };

   // Identification methods.
   virtual GenCollectorPolicy*           as_generation_policy()          { return NULL; }
   virtual TwoGenerationCollectorPolicy* as_two_generation_policy()        { return NULL; }
   virtual MarkSweepPolicy*              as_mark_sweep_policy()            { return NULL; }
 #ifndef SERIALGC
   virtual ConcurrentMarkSweepPolicy*    as_concurrent_mark_sweep_policy() { return NULL; }
 #endif // SERIALGC
   // Note that these are not virtual.
   bool is_generation_policy()            { return as_generation_policy() != NULL; }
   bool is_two_generation_policy()        { return as_two_generation_policy() != NULL; }
   bool is_mark_sweep_policy()            { return as_mark_sweep_policy() != NULL; }
 #ifndef SERIALGC
   bool is_concurrent_mark_sweep_policy() { return as_concurrent_mark_sweep_policy() != NULL; }
 #else  // SERIALGC
   bool is_concurrent_mark_sweep_policy() { return false; }
 #endif // SERIALGC

   virtual PermanentGenerationSpec *permanent_generation() {
     assert(_permanent_generation != NULL, "Sanity check");
     return _permanent_generation;
   }

   virtual BarrierSet::Name barrier_set_name() = 0;
   virtual GenRemSet::Name  rem_set_name() = 0;

   // Create the remembered set (to cover the given reserved region,
   // allowing breaking up into at most "max_covered_regions").
   virtual GenRemSet* create_rem_set(MemRegion reserved,
                                     int max_covered_regions);

   // This method controls how a collector satisfies a request
   // for a block of memory.  "gc_time_limit_was_exceeded" will
   // be set to true if the adaptive size policy determine that
   // an excessive amount of time is being spent doing collections
   // and caused a NULL to be returned.  If a NULL is not returned,
   // "gc_time_limit_was_exceeded" has an undefined meaning.
   virtual HeapWord* mem_allocate_work(size_t size,
                                       bool is_tlab,
                                       bool* gc_overhead_limit_was_exceeded) = 0;

   // This method controls how a collector handles one or more
   // of its generations being fully allocated.
   virtual HeapWord *satisfy_failed_allocation(size_t size, bool is_tlab) = 0;
   // Performace Counter support
   GCPolicyCounters* counters()     { return _gc_policy_counters; }

   // Create the jstat counters for the GC policy.  By default, policy's
   // don't have associated counters, and we complain if this is invoked.
   virtual void initialize_gc_policy_counters() {
     ShouldNotReachHere();
   }

   virtual CollectorPolicy::Name kind() {
     return CollectorPolicy::CollectorPolicyKind;
   }

   // Returns true if a collector has eden space with soft end.
   virtual bool has_soft_ended_eden() {
     return false;
   }

 };

 class GenCollectorPolicy : public CollectorPolicy {
  protected:
   size_t _min_gen0_size;
   size_t _initial_gen0_size;
   size_t _max_gen0_size;

   GenerationSpec **_generations;

   // The sizing of the different generations in the heap are controlled
   // by a sizing policy.
   AdaptiveSizePolicy* _size_policy;

   // Return true if an allocation should be attempted in the older
   // generation if it fails in the younger generation.  Return
   // false, otherwise.
   virtual bool should_try_older_generation_allocation(size_t word_size) const;

   void initialize_flags();
   void initialize_size_info();

   // Try to allocate space by expanding the heap.
   virtual HeapWord* expand_heap_and_allocate(size_t size, bool is_tlab);

   // compute max heap alignment
   size_t compute_max_alignment();


  public:
   virtual int number_of_generations() = 0;

   virtual GenerationSpec **generations()       {
     assert(_generations != NULL, "Sanity check");
     return _generations;
   }

   virtual GenCollectorPolicy* as_generation_policy() { return this; }

   virtual void initialize_generations() = 0;

   virtual void initialize_all() {
     initialize_flags();
     initialize_size_info();
     initialize_generations();
   }

   HeapWord* mem_allocate_work(size_t size,
                               bool is_tlab,
                               bool* gc_overhead_limit_was_exceeded);

   HeapWord *satisfy_failed_allocation(size_t size, bool is_tlab);

   // The size that defines a "large array".
   virtual size_t large_typearray_limit();

   // Adaptive size policy
   AdaptiveSizePolicy* size_policy() { return _size_policy; }
   virtual void initialize_size_policy(size_t init_eden_size,
                                       size_t init_promo_size,
                                       size_t init_survivor_size);

 };


 // All of hotspot's current collectors are subtypes of this
 // class. Currently, these collectors all use the same gen[0],
 // but have different gen[1] types. If we add another subtype
 // of CollectorPolicy, this class should be broken out into
 // its own file.

 class TwoGenerationCollectorPolicy : public GenCollectorPolicy {
  protected:
   size_t _min_gen1_size;
   size_t _initial_gen1_size;
   size_t _max_gen1_size;

   void initialize_flags();
   void initialize_size_info();
   void initialize_generations()                { ShouldNotReachHere(); }

  public:
   // Inherited methods
   TwoGenerationCollectorPolicy* as_two_generation_policy() { return this; }

   int number_of_generations()                  { return 2; }
   BarrierSet::Name barrier_set_name()          { return BarrierSet::CardTableModRef; }
   GenRemSet::Name rem_set_name()               { return GenRemSet::CardTable; }

   virtual CollectorPolicy::Name kind() {
     return CollectorPolicy::TwoGenerationCollectorPolicyKind;
   }
 };

 class MarkSweepPolicy : public TwoGenerationCollectorPolicy {
  protected:
   void initialize_generations();

  public:
   MarkSweepPolicy();

   MarkSweepPolicy* as_mark_sweep_policy() { return this; }

   void initialize_gc_policy_counters();
 };
	/*
	* Copyright 2001-2006 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.
	*
	*/

	// This class (or more correctly, subtypes of this class)
	// are used to define global garbage collector attributes.
	// This includes initialization of generations and any other
	// shared resources they may need.
	//
	// In general, all flag adjustment and validation should be
	// done in initialize_flags(), which is called prior to
	// initialize_size_info().
	//
	// This class is not fully developed yet. As more collector(s)
	// are added, it is expected that we will come across further
	// behavior that requires global attention. The correct place
	// to deal with those issues is this class.

	// Forward declarations.
	class GenCollectorPolicy;
	class TwoGenerationCollectorPolicy;
	#ifndef SERIALGC
	class ConcurrentMarkSweepPolicy;
	#endif // SERIALGC
	class AdaptiveSizePolicy;
	class GCPolicyCounters;
	class PermanentGenerationSpec;
	class MarkSweepPolicy;

	class CollectorPolicy : public CHeapObj {
	protected:
	PermanentGenerationSpec *_permanent_generation;
	GCPolicyCounters* _gc_policy_counters;

	// Requires that the concrete subclass sets the alignment constraints
	// before calling.
	virtual void initialize_flags();
	virtual void initialize_size_info() = 0;
	// Initialize "_permanent_generation" to a spec for the given kind of
	// Perm Gen.
	void initialize_perm_generation(PermGen::Name pgnm);

	size_t _initial_heap_byte_size;
	size_t _max_heap_byte_size;
	size_t _min_heap_byte_size;

	size_t _min_alignment;
	size_t _max_alignment;

	CollectorPolicy() :
	_min_alignment(1),
	_max_alignment(1),
	_initial_heap_byte_size(0),
	_max_heap_byte_size(0),
	_min_heap_byte_size(0)
	{}

	public:
	void set_min_alignment(size_t align) { _min_alignment = align; }
	size_t min_alignment() { return _min_alignment; }
	void set_max_alignment(size_t align) { _max_alignment = align; }
	size_t max_alignment() { return _max_alignment; }

	size_t initial_heap_byte_size() { return _initial_heap_byte_size; }
	size_t max_heap_byte_size() { return _max_heap_byte_size; }
	size_t min_heap_byte_size() { return _min_heap_byte_size; }

	enum Name {
	CollectorPolicyKind,
	TwoGenerationCollectorPolicyKind,
	TrainPolicyKind,
	ConcurrentMarkSweepPolicyKind,
	ASConcurrentMarkSweepPolicyKind
	};

	// Identification methods.
	virtual GenCollectorPolicy* as_generation_policy() { return NULL; }
	virtual TwoGenerationCollectorPolicy* as_two_generation_policy() { return NULL; }
	virtual MarkSweepPolicy* as_mark_sweep_policy() { return NULL; }
	#ifndef SERIALGC
	virtual ConcurrentMarkSweepPolicy* as_concurrent_mark_sweep_policy() { return NULL; }
	#endif // SERIALGC
	// Note that these are not virtual.
	bool is_generation_policy() { return as_generation_policy() != NULL; }
	bool is_two_generation_policy() { return as_two_generation_policy() != NULL; }
	bool is_mark_sweep_policy() { return as_mark_sweep_policy() != NULL; }
	#ifndef SERIALGC
	bool is_concurrent_mark_sweep_policy() { return as_concurrent_mark_sweep_policy() != NULL; }
	#else // SERIALGC
	bool is_concurrent_mark_sweep_policy() { return false; }
	#endif // SERIALGC

	virtual PermanentGenerationSpec *permanent_generation() {
	assert(_permanent_generation != NULL, "Sanity check");
	return _permanent_generation;
	}

	virtual BarrierSet::Name barrier_set_name() = 0;
	virtual GenRemSet::Name rem_set_name() = 0;

	// Create the remembered set (to cover the given reserved region,
	// allowing breaking up into at most "max_covered_regions").
	virtual GenRemSet* create_rem_set(MemRegion reserved,
	int max_covered_regions);

	// This method controls how a collector satisfies a request
	// for a block of memory. "gc_time_limit_was_exceeded" will
	// be set to true if the adaptive size policy determine that
	// an excessive amount of time is being spent doing collections
	// and caused a NULL to be returned. If a NULL is not returned,
	// "gc_time_limit_was_exceeded" has an undefined meaning.
	virtual HeapWord* mem_allocate_work(size_t size,
	bool is_tlab,
	bool* gc_overhead_limit_was_exceeded) = 0;

	// This method controls how a collector handles one or more
	// of its generations being fully allocated.
	virtual HeapWord *satisfy_failed_allocation(size_t size, bool is_tlab) = 0;
	// Performace Counter support
	GCPolicyCounters* counters() { return _gc_policy_counters; }

	// Create the jstat counters for the GC policy. By default, policy's
	// don't have associated counters, and we complain if this is invoked.
	virtual void initialize_gc_policy_counters() {
	ShouldNotReachHere();
	}

	virtual CollectorPolicy::Name kind() {
	return CollectorPolicy::CollectorPolicyKind;
	}

	// Returns true if a collector has eden space with soft end.
	virtual bool has_soft_ended_eden() {
	return false;
	}

	};

	class GenCollectorPolicy : public CollectorPolicy {
	protected:
	size_t _min_gen0_size;
	size_t _initial_gen0_size;
	size_t _max_gen0_size;

	GenerationSpec **_generations;

	// The sizing of the different generations in the heap are controlled
	// by a sizing policy.
	AdaptiveSizePolicy* _size_policy;

	// Return true if an allocation should be attempted in the older
	// generation if it fails in the younger generation. Return
	// false, otherwise.
	virtual bool should_try_older_generation_allocation(size_t word_size) const;

	void initialize_flags();
	void initialize_size_info();

	// Try to allocate space by expanding the heap.
	virtual HeapWord* expand_heap_and_allocate(size_t size, bool is_tlab);

	// compute max heap alignment
	size_t compute_max_alignment();


	public:
	virtual int number_of_generations() = 0;

	virtual GenerationSpec **generations() {
	assert(_generations != NULL, "Sanity check");
	return _generations;
	}

	virtual GenCollectorPolicy* as_generation_policy() { return this; }

	virtual void initialize_generations() = 0;

	virtual void initialize_all() {
	initialize_flags();
	initialize_size_info();
	initialize_generations();
	}

	HeapWord* mem_allocate_work(size_t size,
	bool is_tlab,
	bool* gc_overhead_limit_was_exceeded);

	HeapWord *satisfy_failed_allocation(size_t size, bool is_tlab);

	// The size that defines a "large array".
	virtual size_t large_typearray_limit();

	// Adaptive size policy
	AdaptiveSizePolicy* size_policy() { return _size_policy; }
	virtual void initialize_size_policy(size_t init_eden_size,
	size_t init_promo_size,
	size_t init_survivor_size);

	};


	// All of hotspot's current collectors are subtypes of this
	// class. Currently, these collectors all use the same gen[0],
	// but have different gen[1] types. If we add another subtype
	// of CollectorPolicy, this class should be broken out into
	// its own file.

	class TwoGenerationCollectorPolicy : public GenCollectorPolicy {
	protected:
	size_t _min_gen1_size;
	size_t _initial_gen1_size;
	size_t _max_gen1_size;

	void initialize_flags();
	void initialize_size_info();
	void initialize_generations() { ShouldNotReachHere(); }

	public:
	// Inherited methods
	TwoGenerationCollectorPolicy* as_two_generation_policy() { return this; }

	int number_of_generations() { return 2; }
	BarrierSet::Name barrier_set_name() { return BarrierSet::CardTableModRef; }
	GenRemSet::Name rem_set_name() { return GenRemSet::CardTable; }

	virtual CollectorPolicy::Name kind() {
	return CollectorPolicy::TwoGenerationCollectorPolicyKind;
	}
	};

	class MarkSweepPolicy : public TwoGenerationCollectorPolicy {
	protected:
	void initialize_generations();

	public:
	MarkSweepPolicy();

	MarkSweepPolicy* as_mark_sweep_policy() { return this; }

	void initialize_gc_policy_counters();
	};