/* * Copyright 2001-2008 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. * * 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. * */ class PSMarkSweepDecorator; class PSOldGen : public CHeapObj { friend class VMStructs; friend class PSPromotionManager; // Uses the cas_allocate methods friend class ParallelScavengeHeap; friend class AdjoiningGenerations; protected: MemRegion _reserved; // Used for simple containment tests PSVirtualSpace* _virtual_space; // Controls mapping and unmapping of virtual mem ObjectStartArray _start_array; // Keeps track of where objects start in a 512b block MutableSpace* _object_space; // Where all the objects live PSMarkSweepDecorator* _object_mark_sweep; // The mark sweep view of _object_space const char* const _name; // Name of this generation. // Performance Counters PSGenerationCounters* _gen_counters; SpaceCounters* _space_counters; // Sizing information, in bytes, set in constructor const size_t _init_gen_size; const size_t _min_gen_size; const size_t _max_gen_size; // Used when initializing the _name field. static inline const char* select_name(); HeapWord* allocate_noexpand(size_t word_size, bool is_tlab) { // We assume the heap lock is held here. assert(!is_tlab, "Does not support TLAB allocation"); assert_locked_or_safepoint(Heap_lock); HeapWord* res = object_space()->allocate(word_size); if (res != NULL) { _start_array.allocate_block(res); } return res; } // Support for MT garbage collection. CAS allocation is lower overhead than grabbing // and releasing the heap lock, which is held during gc's anyway. This method is not // safe for use at the same time as allocate_noexpand()! HeapWord* cas_allocate_noexpand(size_t word_size) { assert(SafepointSynchronize::is_at_safepoint(), "Must only be called at safepoint") HeapWord* res = object_space()->cas_allocate(word_size); if (res != NULL) { _start_array.allocate_block(res); } return res; } // Support for MT garbage collection. See above comment. HeapWord* cas_allocate(size_t word_size) { HeapWord* res = cas_allocate_noexpand(word_size); return (res == NULL) ? expand_and_cas_allocate(word_size) : res; } HeapWord* expand_and_allocate(size_t word_size, bool is_tlab); HeapWord* expand_and_cas_allocate(size_t word_size); void expand(size_t bytes); bool expand_by(size_t bytes); bool expand_to_reserved(); void shrink(size_t bytes); void post_resize(); public: // Initialize the generation. PSOldGen(ReservedSpace rs, size_t alignment, size_t initial_size, size_t min_size, size_t max_size, const char* perf_data_name, int level); PSOldGen(size_t initial_size, size_t min_size, size_t max_size, const char* perf_data_name, int level); void initialize(ReservedSpace rs, size_t alignment, const char* perf_data_name, int level); void initialize_virtual_space(ReservedSpace rs, size_t alignment); void initialize_work(const char* perf_data_name, int level); MemRegion reserved() const { return _reserved; } virtual size_t max_gen_size() { return _max_gen_size; } size_t min_gen_size() { return _min_gen_size; } size_t init_gen_size() { return _init_gen_size; } // Returns limit on the maximum size of the generation. This // is the same as _max_gen_size for PSOldGen but need not be // for a derived class. virtual size_t gen_size_limit(); bool is_in(const void* p) const { return _virtual_space->contains((void *)p); } bool is_in_reserved(const void* p) const { return reserved().contains(p); } MutableSpace* object_space() const { return _object_space; } PSMarkSweepDecorator* object_mark_sweep() const { return _object_mark_sweep; } ObjectStartArray* start_array() { return &_start_array; } PSVirtualSpace* virtual_space() const { return _virtual_space;} // Has the generation been successfully allocated? bool is_allocated(); // MarkSweep methods virtual void precompact(); void adjust_pointers(); void compact(); // Parallel old virtual void move_and_update(ParCompactionManager* cm); // Size info size_t capacity_in_bytes() const { return object_space()->capacity_in_bytes(); } size_t used_in_bytes() const { return object_space()->used_in_bytes(); } size_t free_in_bytes() const { return object_space()->free_in_bytes(); } size_t capacity_in_words() const { return object_space()->capacity_in_words(); } size_t used_in_words() const { return object_space()->used_in_words(); } size_t free_in_words() const { return object_space()->free_in_words(); } // Includes uncommitted memory size_t contiguous_available() const; bool is_maximal_no_gc() const { return virtual_space()->uncommitted_size() == 0; } // Calculating new sizes void resize(size_t desired_free_space); // Allocation. We report all successful allocations to the size policy // Note that the perm gen does not use this method, and should not! HeapWord* allocate(size_t word_size, bool is_tlab); // Iteration. void oop_iterate(OopClosure* cl) { object_space()->oop_iterate(cl); } void object_iterate(ObjectClosure* cl) { object_space()->object_iterate(cl); } // Debugging - do not use for time critical operations virtual void print() const; virtual void print_on(outputStream* st) const; void print_used_change(size_t prev_used) const; void verify(bool allow_dirty); void verify_object_start_array(); // These should not used virtual void reset_after_change(); // These should not used virtual size_t available_for_expansion(); virtual size_t available_for_contraction(); void space_invariants() PRODUCT_RETURN; // Performace Counter support void update_counters(); // Printing support virtual const char* name() const { return _name; } // Debugging support // Save the tops of all spaces for later use during mangling. void record_spaces_top() PRODUCT_RETURN; void try_to_expand_by(size_t expand_bytes); void try_to_shrink_by(size_t shrink_bytes); };