| /* |
| * Copyright (c) 2001, 2015, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
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| * |
| */ |
| |
| #ifndef SHARE_VM_GC_SHARED_COLLECTORPOLICY_HPP |
| #define SHARE_VM_GC_SHARED_COLLECTORPOLICY_HPP |
| |
| #include "gc/shared/barrierSet.hpp" |
| #include "gc/shared/genRemSet.hpp" |
| #include "gc/shared/generationSpec.hpp" |
| #include "memory/allocation.hpp" |
| #include "utilities/macros.hpp" |
| |
| // 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 AdaptiveSizePolicy; |
| #if INCLUDE_ALL_GCS |
| class ConcurrentMarkSweepPolicy; |
| class G1CollectorPolicy; |
| #endif // INCLUDE_ALL_GCS |
| |
| class GCPolicyCounters; |
| class MarkSweepPolicy; |
| |
| class CollectorPolicy : public CHeapObj<mtGC> { |
| protected: |
| GCPolicyCounters* _gc_policy_counters; |
| |
| virtual void initialize_alignments() = 0; |
| virtual void initialize_flags(); |
| virtual void initialize_size_info(); |
| |
| DEBUG_ONLY(virtual void assert_flags();) |
| DEBUG_ONLY(virtual void assert_size_info();) |
| |
| size_t _initial_heap_byte_size; |
| size_t _max_heap_byte_size; |
| size_t _min_heap_byte_size; |
| |
| size_t _space_alignment; |
| size_t _heap_alignment; |
| |
| // Needed to keep information if MaxHeapSize was set on the command line |
| // when the flag value is aligned etc by ergonomics. |
| bool _max_heap_size_cmdline; |
| |
| // The sizing of the heap is controlled by a sizing policy. |
| AdaptiveSizePolicy* _size_policy; |
| |
| // Set to true when policy wants soft refs cleared. |
| // Reset to false by gc after it clears all soft refs. |
| bool _should_clear_all_soft_refs; |
| |
| // Set to true by the GC if the just-completed gc cleared all |
| // softrefs. This is set to true whenever a gc clears all softrefs, and |
| // set to false each time gc returns to the mutator. For example, in the |
| // ParallelScavengeHeap case the latter would be done toward the end of |
| // mem_allocate() where it returns op.result() |
| bool _all_soft_refs_clear; |
| |
| CollectorPolicy(); |
| |
| public: |
| virtual void initialize_all() { |
| initialize_alignments(); |
| initialize_flags(); |
| initialize_size_info(); |
| } |
| |
| // Return maximum heap alignment that may be imposed by the policy. |
| static size_t compute_heap_alignment(); |
| |
| size_t space_alignment() { return _space_alignment; } |
| size_t heap_alignment() { return _heap_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; } |
| |
| AdaptiveSizePolicy* size_policy() { return _size_policy; } |
| bool should_clear_all_soft_refs() { return _should_clear_all_soft_refs; } |
| void set_should_clear_all_soft_refs(bool v) { _should_clear_all_soft_refs = v; } |
| // Returns the current value of _should_clear_all_soft_refs. |
| // _should_clear_all_soft_refs is set to false as a side effect. |
| bool use_should_clear_all_soft_refs(bool v); |
| bool all_soft_refs_clear() { return _all_soft_refs_clear; } |
| void set_all_soft_refs_clear(bool v) { _all_soft_refs_clear = v; } |
| |
| // Called by the GC after Soft Refs have been cleared to indicate |
| // that the request in _should_clear_all_soft_refs has been fulfilled. |
| void cleared_all_soft_refs(); |
| |
| // Identification methods. |
| virtual GenCollectorPolicy* as_generation_policy() { return NULL; } |
| virtual MarkSweepPolicy* as_mark_sweep_policy() { return NULL; } |
| #if INCLUDE_ALL_GCS |
| virtual ConcurrentMarkSweepPolicy* as_concurrent_mark_sweep_policy() { return NULL; } |
| virtual G1CollectorPolicy* as_g1_policy() { return NULL; } |
| #endif // INCLUDE_ALL_GCS |
| // Note that these are not virtual. |
| bool is_generation_policy() { return as_generation_policy() != NULL; } |
| bool is_mark_sweep_policy() { return as_mark_sweep_policy() != NULL; } |
| #if INCLUDE_ALL_GCS |
| bool is_concurrent_mark_sweep_policy() { return as_concurrent_mark_sweep_policy() != NULL; } |
| bool is_g1_policy() { return as_g1_policy() != NULL; } |
| #else // INCLUDE_ALL_GCS |
| bool is_concurrent_mark_sweep_policy() { return false; } |
| bool is_g1_policy() { return false; } |
| #endif // INCLUDE_ALL_GCS |
| |
| |
| virtual GenRemSet* create_rem_set(MemRegion reserved); |
| |
| // 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; |
| // This method controls how a collector handles a metadata allocation |
| // failure. |
| virtual MetaWord* satisfy_failed_metadata_allocation(ClassLoaderData* loader_data, |
| size_t size, |
| Metaspace::MetadataType mdtype); |
| |
| // Performance 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(); |
| } |
| |
| // Do any updates required to global flags that are due to heap initialization |
| // changes |
| virtual void post_heap_initialize() = 0; |
| }; |
| |
| class ClearedAllSoftRefs : public StackObj { |
| bool _clear_all_soft_refs; |
| CollectorPolicy* _collector_policy; |
| public: |
| ClearedAllSoftRefs(bool clear_all_soft_refs, |
| CollectorPolicy* collector_policy) : |
| _clear_all_soft_refs(clear_all_soft_refs), |
| _collector_policy(collector_policy) {} |
| |
| ~ClearedAllSoftRefs() { |
| if (_clear_all_soft_refs) { |
| _collector_policy->cleared_all_soft_refs(); |
| } |
| } |
| }; |
| |
| class GenCollectorPolicy : public CollectorPolicy { |
| friend class TestGenCollectorPolicy; |
| friend class VMStructs; |
| protected: |
| size_t _min_young_size; |
| size_t _initial_young_size; |
| size_t _max_young_size; |
| size_t _min_old_size; |
| size_t _initial_old_size; |
| size_t _max_old_size; |
| |
| // _gen_alignment and _space_alignment will have the same value most of the |
| // time. When using large pages they can differ. |
| size_t _gen_alignment; |
| |
| GenerationSpec* _young_gen_spec; |
| GenerationSpec* _old_gen_spec; |
| |
| // 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(); |
| |
| DEBUG_ONLY(void assert_flags();) |
| DEBUG_ONLY(void assert_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(); |
| |
| // Scale the base_size by NewRatio according to |
| // result = base_size / (NewRatio + 1) |
| // and align by min_alignment() |
| size_t scale_by_NewRatio_aligned(size_t base_size); |
| |
| // Bound the value by the given maximum minus the min_alignment. |
| size_t bound_minus_alignment(size_t desired_size, size_t maximum_size); |
| |
| public: |
| GenCollectorPolicy(); |
| |
| // Accessors |
| size_t min_young_size() { return _min_young_size; } |
| size_t initial_young_size() { return _initial_young_size; } |
| size_t max_young_size() { return _max_young_size; } |
| size_t gen_alignment() { return _gen_alignment; } |
| size_t min_old_size() { return _min_old_size; } |
| size_t initial_old_size() { return _initial_old_size; } |
| size_t max_old_size() { return _max_old_size; } |
| |
| GenerationSpec* young_gen_spec() const { |
| assert(_young_gen_spec != NULL, "_young_gen_spec should have been initialized"); |
| return _young_gen_spec; |
| } |
| |
| GenerationSpec* old_gen_spec() const { |
| assert(_old_gen_spec != NULL, "_old_gen_spec should have been initialized"); |
| return _old_gen_spec; |
| } |
| |
| virtual GenCollectorPolicy* as_generation_policy() { return this; } |
| |
| virtual void initialize_generations() { }; |
| |
| virtual void initialize_all() { |
| CollectorPolicy::initialize_all(); |
| initialize_generations(); |
| } |
| |
| size_t young_gen_size_lower_bound(); |
| |
| size_t old_gen_size_lower_bound(); |
| |
| 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); |
| |
| // Adaptive size policy |
| virtual void initialize_size_policy(size_t init_eden_size, |
| size_t init_promo_size, |
| size_t init_survivor_size); |
| |
| virtual void post_heap_initialize() { |
| assert(_max_young_size == MaxNewSize, "Should be taken care of by initialize_size_info"); |
| } |
| }; |
| |
| class MarkSweepPolicy : public GenCollectorPolicy { |
| protected: |
| void initialize_alignments(); |
| void initialize_generations(); |
| |
| public: |
| MarkSweepPolicy() {} |
| |
| MarkSweepPolicy* as_mark_sweep_policy() { return this; } |
| |
| void initialize_gc_policy_counters(); |
| }; |
| |
| #endif // SHARE_VM_GC_SHARED_COLLECTORPOLICY_HPP |