src/hotspot/share/gc/parallel/psOldGen.hpp
changeset 47216 71c04702a3d5
parent 33105 294e48b4f704
child 49982 9042ffe5b7fe
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/parallel/psOldGen.hpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,220 @@
+/*
+ * 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
+ * questions.
+ *
+ */
+
+#ifndef SHARE_VM_GC_PARALLEL_PSOLDGEN_HPP
+#define SHARE_VM_GC_PARALLEL_PSOLDGEN_HPP
+
+#include "gc/parallel/mutableSpace.hpp"
+#include "gc/parallel/objectStartArray.hpp"
+#include "gc/parallel/psGenerationCounters.hpp"
+#include "gc/parallel/psVirtualspace.hpp"
+#include "gc/parallel/spaceCounters.hpp"
+#include "runtime/safepoint.hpp"
+
+class PSMarkSweepDecorator;
+
+class PSOldGen : public CHeapObj<mtGC> {
+  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();
+
+#ifdef ASSERT
+  void assert_block_in_covered_region(MemRegion new_memregion) {
+    // Explictly capture current covered_region in a local
+    MemRegion covered_region = this->start_array()->covered_region();
+    assert(covered_region.contains(new_memregion),
+           "new region is not in covered_region [ " PTR_FORMAT ", " PTR_FORMAT " ], "
+           "new region [ " PTR_FORMAT ", " PTR_FORMAT " ], "
+           "object space [ " PTR_FORMAT ", " PTR_FORMAT " ]",
+           p2i(covered_region.start()),
+           p2i(covered_region.end()),
+           p2i(new_memregion.start()),
+           p2i(new_memregion.end()),
+           p2i(this->object_space()->used_region().start()),
+           p2i(this->object_space()->used_region().end()));
+  }
+#endif
+
+  HeapWord* allocate_noexpand(size_t word_size) {
+    // We assume the heap lock is held here.
+    assert_locked_or_safepoint(Heap_lock);
+    HeapWord* res = object_space()->allocate(word_size);
+    if (res != NULL) {
+      DEBUG_ONLY(assert_block_in_covered_region(MemRegion(res, word_size)));
+      _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) {
+      DEBUG_ONLY(assert_block_in_covered_region(MemRegion(res, word_size)));
+      _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);
+  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);
+
+  virtual void initialize(ReservedSpace rs, size_t alignment,
+                  const char* perf_data_name, int level);
+  void initialize_virtual_space(ReservedSpace rs, size_t alignment);
+  virtual void initialize_work(const char* perf_data_name, int level);
+  virtual void initialize_performance_counters(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; }
+
+  // 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();
+
+  // 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);
+
+  // Iteration.
+  void oop_iterate_no_header(OopClosure* cl) { object_space()->oop_iterate_no_header(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();
+  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;
+
+  // Performance 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;
+};
+
+#endif // SHARE_VM_GC_PARALLEL_PSOLDGEN_HPP