8079792: GC directory structure cleanup

Reviewed-by: brutisso, stefank, david

hotspot/src/share/vm/gc/parallel/parMarkBitMap.hpp

@@ -0,0 +1,399 @@
+/*
+ * Copyright (c) 2005, 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_PARMARKBITMAP_HPP
+#define SHARE_VM_GC_PARALLEL_PARMARKBITMAP_HPP
+
+#include "memory/memRegion.hpp"
+#include "oops/oop.hpp"
+#include "utilities/bitMap.hpp"
+
+class ParMarkBitMapClosure;
+class PSVirtualSpace;
+
+class ParMarkBitMap: public CHeapObj<mtGC>
+{
+public:
+  typedef BitMap::idx_t idx_t;
+
+  // Values returned by the iterate() methods.
+  enum IterationStatus { incomplete, complete, full, would_overflow };
+
+  inline ParMarkBitMap();
+  bool initialize(MemRegion covered_region);
+
+  // Atomically mark an object as live.
+  bool mark_obj(HeapWord* addr, size_t size);
+  inline bool mark_obj(oop obj, int size);
+
+  // Return whether the specified begin or end bit is set.
+  inline bool is_obj_beg(idx_t bit) const;
+  inline bool is_obj_end(idx_t bit) const;
+
+  // Traditional interface for testing whether an object is marked or not (these
+  // test only the begin bits).
+  inline bool is_marked(idx_t bit)      const;
+  inline bool is_marked(HeapWord* addr) const;
+  inline bool is_marked(oop obj)        const;
+
+  inline bool is_unmarked(idx_t bit)      const;
+  inline bool is_unmarked(HeapWord* addr) const;
+  inline bool is_unmarked(oop obj)        const;
+
+  // Convert sizes from bits to HeapWords and back.  An object that is n bits
+  // long will be bits_to_words(n) words long.  An object that is m words long
+  // will take up words_to_bits(m) bits in the bitmap.
+  inline static size_t bits_to_words(idx_t bits);
+  inline static idx_t  words_to_bits(size_t words);
+
+  // Return the size in words of an object given a begin bit and an end bit, or
+  // the equivalent beg_addr and end_addr.
+  inline size_t obj_size(idx_t beg_bit, idx_t end_bit) const;
+  inline size_t obj_size(HeapWord* beg_addr, HeapWord* end_addr) const;
+
+  // Return the size in words of the object (a search is done for the end bit).
+  inline size_t obj_size(idx_t beg_bit)  const;
+  inline size_t obj_size(HeapWord* addr) const;
+
+  // Apply live_closure to each live object that lies completely within the
+  // range [live_range_beg, live_range_end).  This is used to iterate over the
+  // compacted region of the heap.  Return values:
+  //
+  // incomplete         The iteration is not complete.  The last object that
+  //                    begins in the range does not end in the range;
+  //                    closure->source() is set to the start of that object.
+  //
+  // complete           The iteration is complete.  All objects in the range
+  //                    were processed and the closure is not full;
+  //                    closure->source() is set one past the end of the range.
+  //
+  // full               The closure is full; closure->source() is set to one
+  //                    past the end of the last object processed.
+  //
+  // would_overflow     The next object in the range would overflow the closure;
+  //                    closure->source() is set to the start of that object.
+  IterationStatus iterate(ParMarkBitMapClosure* live_closure,
+                          idx_t range_beg, idx_t range_end) const;
+  inline IterationStatus iterate(ParMarkBitMapClosure* live_closure,
+                                 HeapWord* range_beg,
+                                 HeapWord* range_end) const;
+
+  // Apply live closure as above and additionally apply dead_closure to all dead
+  // space in the range [range_beg, dead_range_end).  Note that dead_range_end
+  // must be >= range_end.  This is used to iterate over the dense prefix.
+  //
+  // This method assumes that if the first bit in the range (range_beg) is not
+  // marked, then dead space begins at that point and the dead_closure is
+  // applied.  Thus callers must ensure that range_beg is not in the middle of a
+  // live object.
+  IterationStatus iterate(ParMarkBitMapClosure* live_closure,
+                          ParMarkBitMapClosure* dead_closure,
+                          idx_t range_beg, idx_t range_end,
+                          idx_t dead_range_end) const;
+  inline IterationStatus iterate(ParMarkBitMapClosure* live_closure,
+                                 ParMarkBitMapClosure* dead_closure,
+                                 HeapWord* range_beg,
+                                 HeapWord* range_end,
+                                 HeapWord* dead_range_end) const;
+
+  // Return the number of live words in the range [beg_addr, end_obj) due to
+  // objects that start in the range.  If a live object extends onto the range,
+  // the caller must detect and account for any live words due to that object.
+  // If a live object extends beyond the end of the range, only the words within
+  // the range are included in the result. The end of the range must be a live object,
+  // which is the case when updating pointers.  This allows a branch to be removed
+  // from inside the loop.
+  size_t live_words_in_range(HeapWord* beg_addr, oop end_obj) const;
+
+  inline HeapWord* region_start() const;
+  inline HeapWord* region_end() const;
+  inline size_t    region_size() const;
+  inline size_t    size() const;
+
+  size_t reserved_byte_size() const { return _reserved_byte_size; }
+
+  // Convert a heap address to/from a bit index.
+  inline idx_t     addr_to_bit(HeapWord* addr) const;
+  inline HeapWord* bit_to_addr(idx_t bit) const;
+
+  // Return the bit index of the first marked object that begins (or ends,
+  // respectively) in the range [beg, end).  If no object is found, return end.
+  inline idx_t find_obj_beg(idx_t beg, idx_t end) const;
+  inline idx_t find_obj_end(idx_t beg, idx_t end) const;
+
+  inline HeapWord* find_obj_beg(HeapWord* beg, HeapWord* end) const;
+  inline HeapWord* find_obj_end(HeapWord* beg, HeapWord* end) const;
+
+  // Clear a range of bits or the entire bitmap (both begin and end bits are
+  // cleared).
+  inline void clear_range(idx_t beg, idx_t end);
+
+  // Return the number of bits required to represent the specified number of
+  // HeapWords, or the specified region.
+  static inline idx_t bits_required(size_t words);
+  static inline idx_t bits_required(MemRegion covered_region);
+
+  void print_on_error(outputStream* st) const {
+    st->print_cr("Marking Bits: (ParMarkBitMap*) " PTR_FORMAT, p2i(this));
+    _beg_bits.print_on_error(st, " Begin Bits: ");
+    _end_bits.print_on_error(st, " End Bits:   ");
+  }
+
+#ifdef  ASSERT
+  void verify_clear() const;
+  inline void verify_bit(idx_t bit) const;
+  inline void verify_addr(HeapWord* addr) const;
+#endif  // #ifdef ASSERT
+
+private:
+  // Each bit in the bitmap represents one unit of 'object granularity.' Objects
+  // are double-word aligned in 32-bit VMs, but not in 64-bit VMs, so the 32-bit
+  // granularity is 2, 64-bit is 1.
+  static inline size_t obj_granularity() { return size_t(MinObjAlignment); }
+  static inline int obj_granularity_shift() { return LogMinObjAlignment; }
+
+  HeapWord*       _region_start;
+  size_t          _region_size;
+  BitMap          _beg_bits;
+  BitMap          _end_bits;
+  PSVirtualSpace* _virtual_space;
+  size_t          _reserved_byte_size;
+};
+
+inline ParMarkBitMap::ParMarkBitMap():
+  _beg_bits(), _end_bits(), _region_start(NULL), _region_size(0), _virtual_space(NULL), _reserved_byte_size(0)
+{ }
+
+inline void ParMarkBitMap::clear_range(idx_t beg, idx_t end)
+{
+  _beg_bits.clear_range(beg, end);
+  _end_bits.clear_range(beg, end);
+}
+
+inline ParMarkBitMap::idx_t
+ParMarkBitMap::bits_required(size_t words)
+{
+  // Need two bits (one begin bit, one end bit) for each unit of 'object
+  // granularity' in the heap.
+  return words_to_bits(words * 2);
+}
+
+inline ParMarkBitMap::idx_t
+ParMarkBitMap::bits_required(MemRegion covered_region)
+{
+  return bits_required(covered_region.word_size());
+}
+
+inline HeapWord*
+ParMarkBitMap::region_start() const
+{
+  return _region_start;
+}
+
+inline HeapWord*
+ParMarkBitMap::region_end() const
+{
+  return region_start() + region_size();
+}
+
+inline size_t
+ParMarkBitMap::region_size() const
+{
+  return _region_size;
+}
+
+inline size_t
+ParMarkBitMap::size() const
+{
+  return _beg_bits.size();
+}
+
+inline bool ParMarkBitMap::is_obj_beg(idx_t bit) const
+{
+  return _beg_bits.at(bit);
+}
+
+inline bool ParMarkBitMap::is_obj_end(idx_t bit) const
+{
+  return _end_bits.at(bit);
+}
+
+inline bool ParMarkBitMap::is_marked(idx_t bit) const
+{
+  return is_obj_beg(bit);
+}
+
+inline bool ParMarkBitMap::is_marked(HeapWord* addr) const
+{
+  return is_marked(addr_to_bit(addr));
+}
+
+inline bool ParMarkBitMap::is_marked(oop obj) const
+{
+  return is_marked((HeapWord*)obj);
+}
+
+inline bool ParMarkBitMap::is_unmarked(idx_t bit) const
+{
+  return !is_marked(bit);
+}
+
+inline bool ParMarkBitMap::is_unmarked(HeapWord* addr) const
+{
+  return !is_marked(addr);
+}
+
+inline bool ParMarkBitMap::is_unmarked(oop obj) const
+{
+  return !is_marked(obj);
+}
+
+inline size_t
+ParMarkBitMap::bits_to_words(idx_t bits)
+{
+  return bits << obj_granularity_shift();
+}
+
+inline ParMarkBitMap::idx_t
+ParMarkBitMap::words_to_bits(size_t words)
+{
+  return words >> obj_granularity_shift();
+}
+
+inline size_t ParMarkBitMap::obj_size(idx_t beg_bit, idx_t end_bit) const
+{
+  DEBUG_ONLY(verify_bit(beg_bit);)
+  DEBUG_ONLY(verify_bit(end_bit);)
+  return bits_to_words(end_bit - beg_bit + 1);
+}
+
+inline size_t
+ParMarkBitMap::obj_size(HeapWord* beg_addr, HeapWord* end_addr) const
+{
+  DEBUG_ONLY(verify_addr(beg_addr);)
+  DEBUG_ONLY(verify_addr(end_addr);)
+  return pointer_delta(end_addr, beg_addr) + obj_granularity();
+}
+
+inline size_t ParMarkBitMap::obj_size(idx_t beg_bit) const
+{
+  const idx_t end_bit = _end_bits.get_next_one_offset_inline(beg_bit, size());
+  assert(is_marked(beg_bit), "obj not marked");
+  assert(end_bit < size(), "end bit missing");
+  return obj_size(beg_bit, end_bit);
+}
+
+inline size_t ParMarkBitMap::obj_size(HeapWord* addr) const
+{
+  return obj_size(addr_to_bit(addr));
+}
+
+inline ParMarkBitMap::IterationStatus
+ParMarkBitMap::iterate(ParMarkBitMapClosure* live_closure,
+                       HeapWord* range_beg,
+                       HeapWord* range_end) const
+{
+  return iterate(live_closure, addr_to_bit(range_beg), addr_to_bit(range_end));
+}
+
+inline ParMarkBitMap::IterationStatus
+ParMarkBitMap::iterate(ParMarkBitMapClosure* live_closure,
+                       ParMarkBitMapClosure* dead_closure,
+                       HeapWord* range_beg,
+                       HeapWord* range_end,
+                       HeapWord* dead_range_end) const
+{
+  return iterate(live_closure, dead_closure,
+                 addr_to_bit(range_beg), addr_to_bit(range_end),
+                 addr_to_bit(dead_range_end));
+}
+
+inline bool
+ParMarkBitMap::mark_obj(oop obj, int size)
+{
+  return mark_obj((HeapWord*)obj, (size_t)size);
+}
+
+inline BitMap::idx_t
+ParMarkBitMap::addr_to_bit(HeapWord* addr) const
+{
+  DEBUG_ONLY(verify_addr(addr);)
+  return words_to_bits(pointer_delta(addr, region_start()));
+}
+
+inline HeapWord*
+ParMarkBitMap::bit_to_addr(idx_t bit) const
+{
+  DEBUG_ONLY(verify_bit(bit);)
+  return region_start() + bits_to_words(bit);
+}
+
+inline ParMarkBitMap::idx_t
+ParMarkBitMap::find_obj_beg(idx_t beg, idx_t end) const
+{
+  return _beg_bits.get_next_one_offset_inline_aligned_right(beg, end);
+}
+
+inline ParMarkBitMap::idx_t
+ParMarkBitMap::find_obj_end(idx_t beg, idx_t end) const
+{
+  return _end_bits.get_next_one_offset_inline_aligned_right(beg, end);
+}
+
+inline HeapWord*
+ParMarkBitMap::find_obj_beg(HeapWord* beg, HeapWord* end) const
+{
+  const idx_t beg_bit = addr_to_bit(beg);
+  const idx_t end_bit = addr_to_bit(end);
+  const idx_t search_end = BitMap::word_align_up(end_bit);
+  const idx_t res_bit = MIN2(find_obj_beg(beg_bit, search_end), end_bit);
+  return bit_to_addr(res_bit);
+}
+
+inline HeapWord*
+ParMarkBitMap::find_obj_end(HeapWord* beg, HeapWord* end) const
+{
+  const idx_t beg_bit = addr_to_bit(beg);
+  const idx_t end_bit = addr_to_bit(end);
+  const idx_t search_end = BitMap::word_align_up(end_bit);
+  const idx_t res_bit = MIN2(find_obj_end(beg_bit, search_end), end_bit);
+  return bit_to_addr(res_bit);
+}
+
+#ifdef  ASSERT
+inline void ParMarkBitMap::verify_bit(idx_t bit) const {
+  // Allow one past the last valid bit; useful for loop bounds.
+  assert(bit <= _beg_bits.size(), "bit out of range");
+}
+
+inline void ParMarkBitMap::verify_addr(HeapWord* addr) const {
+  // Allow one past the last valid address; useful for loop bounds.
+  assert(addr >= region_start(),
+      err_msg("addr too small, addr: " PTR_FORMAT " region start: " PTR_FORMAT, p2i(addr), p2i(region_start())));
+  assert(addr <= region_end(),
+      err_msg("addr too big, addr: " PTR_FORMAT " region end: " PTR_FORMAT, p2i(addr), p2i(region_end())));
+}
+#endif  // #ifdef ASSERT
+
+#endif // SHARE_VM_GC_PARALLEL_PARMARKBITMAP_HPP