--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/shared/collectorPolicy.hpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,277 @@
+/*
+ * Copyright (c) 2001, 2016, 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
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_GC_SHARED_COLLECTORPOLICY_HPP
+#define SHARE_VM_GC_SHARED_COLLECTORPOLICY_HPP
+
+#include "gc/shared/barrierSet.hpp"
+#include "gc/shared/cardTableRS.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:
+ 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;
+
+ // 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; }
+
+ 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.
+ virtual 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; }
+#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; }
+#else // INCLUDE_ALL_GCS
+ bool is_concurrent_mark_sweep_policy() { return false; }
+#endif // INCLUDE_ALL_GCS
+
+
+ virtual CardTableRS* create_rem_set(MemRegion reserved);
+
+ MetaWord* satisfy_failed_metadata_allocation(ClassLoaderData* loader_data,
+ size_t size,
+ Metaspace::MetadataType mdtype);
+};
+
+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();
+ }
+ }
+
+ bool should_clear() { return _clear_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;
+
+ GCPolicyCounters* _gc_policy_counters;
+
+ // The sizing of the heap is 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();
+
+ 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;
+ }
+
+ // Performance Counter support
+ GCPolicyCounters* counters() { return _gc_policy_counters; }
+
+ // Create the jstat counters for the GC policy.
+ virtual void initialize_gc_policy_counters() = 0;
+
+ 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
+ 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);
+
+ virtual void cleared_all_soft_refs();
+
+};
+
+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