8066780: Split CardGeneration out to its own file

Reviewed-by: kbarrett, tschatzl

hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp

@@ -30,8 +30,8 @@
 #include "gc_implementation/shared/gcStats.hpp"
 #include "gc_implementation/shared/gcWhen.hpp"
 #include "gc_implementation/shared/generationCounters.hpp"
+#include "memory/cardGeneration.hpp"
 #include "memory/freeBlockDictionary.hpp"
-#include "memory/generation.hpp"
 #include "memory/iterator.hpp"
 #include "runtime/mutexLocker.hpp"
 #include "runtime/virtualspace.hpp"

hotspot/src/share/vm/memory/cardGeneration.cpp

@@ -0,0 +1,271 @@
+/*
+ * Copyright (c) 2014, 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.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "memory/blockOffsetTable.inline.hpp"
+#include "memory/gcLocker.hpp"
+#include "memory/generationSpec.hpp"
+#include "memory/genOopClosures.inline.hpp"
+#include "memory/genRemSet.hpp"
+#include "memory/iterator.hpp"
+#include "memory/memRegion.hpp"
+#include "memory/space.inline.hpp"
+#include "runtime/java.hpp"
+
+CardGeneration::CardGeneration(ReservedSpace rs, size_t initial_byte_size,
+                               int level,
+                               GenRemSet* remset) :
+  Generation(rs, initial_byte_size, level), _rs(remset),
+  _shrink_factor(0), _min_heap_delta_bytes(), _capacity_at_prologue(),
+  _used_at_prologue()
+{
+  HeapWord* start = (HeapWord*)rs.base();
+  size_t reserved_byte_size = rs.size();
+  assert((uintptr_t(start) & 3) == 0, "bad alignment");
+  assert((reserved_byte_size & 3) == 0, "bad alignment");
+  MemRegion reserved_mr(start, heap_word_size(reserved_byte_size));
+  _bts = new BlockOffsetSharedArray(reserved_mr,
+                                    heap_word_size(initial_byte_size));
+  MemRegion committed_mr(start, heap_word_size(initial_byte_size));
+  _rs->resize_covered_region(committed_mr);
+  if (_bts == NULL)
+    vm_exit_during_initialization("Could not allocate a BlockOffsetArray");
+
+  // Verify that the start and end of this generation is the start of a card.
+  // If this wasn't true, a single card could span more than on generation,
+  // which would cause problems when we commit/uncommit memory, and when we
+  // clear and dirty cards.
+  guarantee(_rs->is_aligned(reserved_mr.start()), "generation must be card aligned");
+  if (reserved_mr.end() != Universe::heap()->reserved_region().end()) {
+    // Don't check at the very end of the heap as we'll assert that we're probing off
+    // the end if we try.
+    guarantee(_rs->is_aligned(reserved_mr.end()), "generation must be card aligned");
+  }
+  _min_heap_delta_bytes = MinHeapDeltaBytes;
+  _capacity_at_prologue = initial_byte_size;
+  _used_at_prologue = 0;
+}
+
+bool CardGeneration::expand(size_t bytes, size_t expand_bytes) {
+  assert_locked_or_safepoint(Heap_lock);
+  if (bytes == 0) {
+    return true;  // That's what grow_by(0) would return
+  }
+  size_t aligned_bytes  = ReservedSpace::page_align_size_up(bytes);
+  if (aligned_bytes == 0){
+    // The alignment caused the number of bytes to wrap.  An expand_by(0) will
+    // return true with the implication that an expansion was done when it
+    // was not.  A call to expand implies a best effort to expand by "bytes"
+    // but not a guarantee.  Align down to give a best effort.  This is likely
+    // the most that the generation can expand since it has some capacity to
+    // start with.
+    aligned_bytes = ReservedSpace::page_align_size_down(bytes);
+  }
+  size_t aligned_expand_bytes = ReservedSpace::page_align_size_up(expand_bytes);
+  bool success = false;
+  if (aligned_expand_bytes > aligned_bytes) {
+    success = grow_by(aligned_expand_bytes);
+  }
+  if (!success) {
+    success = grow_by(aligned_bytes);
+  }
+  if (!success) {
+    success = grow_to_reserved();
+  }
+  if (PrintGC && Verbose) {
+    if (success && GC_locker::is_active_and_needs_gc()) {
+      gclog_or_tty->print_cr("Garbage collection disabled, expanded heap instead");
+    }
+  }
+
+  return success;
+}
+
+// No young generation references, clear this generation's cards.
+void CardGeneration::clear_remembered_set() {
+  _rs->clear(reserved());
+}
+
+// Objects in this generation may have moved, invalidate this
+// generation's cards.
+void CardGeneration::invalidate_remembered_set() {
+  _rs->invalidate(used_region());
+}
+
+void CardGeneration::compute_new_size() {
+  assert(_shrink_factor <= 100, "invalid shrink factor");
+  size_t current_shrink_factor = _shrink_factor;
+  _shrink_factor = 0;
+
+  // We don't have floating point command-line arguments
+  // Note:  argument processing ensures that MinHeapFreeRatio < 100.
+  const double minimum_free_percentage = MinHeapFreeRatio / 100.0;
+  const double maximum_used_percentage = 1.0 - minimum_free_percentage;
+
+  // Compute some numbers about the state of the heap.
+  const size_t used_after_gc = used();
+  const size_t capacity_after_gc = capacity();
+
+  const double min_tmp = used_after_gc / maximum_used_percentage;
+  size_t minimum_desired_capacity = (size_t)MIN2(min_tmp, double(max_uintx));
+  // Don't shrink less than the initial generation size
+  minimum_desired_capacity = MAX2(minimum_desired_capacity,
+                                  spec()->init_size());
+  assert(used_after_gc <= minimum_desired_capacity, "sanity check");
+
+  if (PrintGC && Verbose) {
+    const size_t free_after_gc = free();
+    const double free_percentage = ((double)free_after_gc) / capacity_after_gc;
+    gclog_or_tty->print_cr("TenuredGeneration::compute_new_size: ");
+    gclog_or_tty->print_cr("  "
+                  "  minimum_free_percentage: %6.2f"
+                  "  maximum_used_percentage: %6.2f",
+                  minimum_free_percentage,
+                  maximum_used_percentage);
+    gclog_or_tty->print_cr("  "
+                  "   free_after_gc   : %6.1fK"
+                  "   used_after_gc   : %6.1fK"
+                  "   capacity_after_gc   : %6.1fK",
+                  free_after_gc / (double) K,
+                  used_after_gc / (double) K,
+                  capacity_after_gc / (double) K);
+    gclog_or_tty->print_cr("  "
+                  "   free_percentage: %6.2f",
+                  free_percentage);
+  }
+
+  if (capacity_after_gc < minimum_desired_capacity) {
+    // If we have less free space than we want then expand
+    size_t expand_bytes = minimum_desired_capacity - capacity_after_gc;
+    // Don't expand unless it's significant
+    if (expand_bytes >= _min_heap_delta_bytes) {
+      expand(expand_bytes, 0); // safe if expansion fails
+    }
+    if (PrintGC && Verbose) {
+      gclog_or_tty->print_cr("    expanding:"
+                    "  minimum_desired_capacity: %6.1fK"
+                    "  expand_bytes: %6.1fK"
+                    "  _min_heap_delta_bytes: %6.1fK",
+                    minimum_desired_capacity / (double) K,
+                    expand_bytes / (double) K,
+                    _min_heap_delta_bytes / (double) K);
+    }
+    return;
+  }
+
+  // No expansion, now see if we want to shrink
+  size_t shrink_bytes = 0;
+  // We would never want to shrink more than this
+  size_t max_shrink_bytes = capacity_after_gc - minimum_desired_capacity;
+
+  if (MaxHeapFreeRatio < 100) {
+    const double maximum_free_percentage = MaxHeapFreeRatio / 100.0;
+    const double minimum_used_percentage = 1.0 - maximum_free_percentage;
+    const double max_tmp = used_after_gc / minimum_used_percentage;
+    size_t maximum_desired_capacity = (size_t)MIN2(max_tmp, double(max_uintx));
+    maximum_desired_capacity = MAX2(maximum_desired_capacity,
+                                    spec()->init_size());
+    if (PrintGC && Verbose) {
+      gclog_or_tty->print_cr("  "
+                             "  maximum_free_percentage: %6.2f"
+                             "  minimum_used_percentage: %6.2f",
+                             maximum_free_percentage,
+                             minimum_used_percentage);
+      gclog_or_tty->print_cr("  "
+                             "  _capacity_at_prologue: %6.1fK"
+                             "  minimum_desired_capacity: %6.1fK"
+                             "  maximum_desired_capacity: %6.1fK",
+                             _capacity_at_prologue / (double) K,
+                             minimum_desired_capacity / (double) K,
+                             maximum_desired_capacity / (double) K);
+    }
+    assert(minimum_desired_capacity <= maximum_desired_capacity,
+           "sanity check");
+
+    if (capacity_after_gc > maximum_desired_capacity) {
+      // Capacity too large, compute shrinking size
+      shrink_bytes = capacity_after_gc - maximum_desired_capacity;
+      // We don't want shrink all the way back to initSize if people call
+      // System.gc(), because some programs do that between "phases" and then
+      // we'd just have to grow the heap up again for the next phase.  So we
+      // damp the shrinking: 0% on the first call, 10% on the second call, 40%
+      // on the third call, and 100% by the fourth call.  But if we recompute
+      // size without shrinking, it goes back to 0%.
+      shrink_bytes = shrink_bytes / 100 * current_shrink_factor;
+      assert(shrink_bytes <= max_shrink_bytes, "invalid shrink size");
+      if (current_shrink_factor == 0) {
+        _shrink_factor = 10;
+      } else {
+        _shrink_factor = MIN2(current_shrink_factor * 4, (size_t) 100);
+      }
+      if (PrintGC && Verbose) {
+        gclog_or_tty->print_cr("  "
+                      "  shrinking:"
+                      "  initSize: %.1fK"
+                      "  maximum_desired_capacity: %.1fK",
+                      spec()->init_size() / (double) K,
+                      maximum_desired_capacity / (double) K);
+        gclog_or_tty->print_cr("  "
+                      "  shrink_bytes: %.1fK"
+                      "  current_shrink_factor: " SIZE_FORMAT
+                      "  new shrink factor: " SIZE_FORMAT
+                      "  _min_heap_delta_bytes: %.1fK",
+                      shrink_bytes / (double) K,
+                      current_shrink_factor,
+                      _shrink_factor,
+                      _min_heap_delta_bytes / (double) K);
+      }
+    }
+  }
+
+  if (capacity_after_gc > _capacity_at_prologue) {
+    // We might have expanded for promotions, in which case we might want to
+    // take back that expansion if there's room after GC.  That keeps us from
+    // stretching the heap with promotions when there's plenty of room.
+    size_t expansion_for_promotion = capacity_after_gc - _capacity_at_prologue;
+    expansion_for_promotion = MIN2(expansion_for_promotion, max_shrink_bytes);
+    // We have two shrinking computations, take the largest
+    shrink_bytes = MAX2(shrink_bytes, expansion_for_promotion);
+    assert(shrink_bytes <= max_shrink_bytes, "invalid shrink size");
+    if (PrintGC && Verbose) {
+      gclog_or_tty->print_cr("  "
+                             "  aggressive shrinking:"
+                             "  _capacity_at_prologue: %.1fK"
+                             "  capacity_after_gc: %.1fK"
+                             "  expansion_for_promotion: %.1fK"
+                             "  shrink_bytes: %.1fK",
+                             capacity_after_gc / (double) K,
+                             _capacity_at_prologue / (double) K,
+                             expansion_for_promotion / (double) K,
+                             shrink_bytes / (double) K);
+    }
+  }
+  // Don't shrink unless it's significant
+  if (shrink_bytes >= _min_heap_delta_bytes) {
+    shrink(shrink_bytes);
+  }
+}
+
+// Currently nothing to do.
+void CardGeneration::prepare_for_verify() {}

hotspot/src/share/vm/memory/cardGeneration.hpp

@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2014, 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_MEMORY_CARDGENERATION_HPP
+#define SHARE_VM_MEMORY_CARDGENERATION_HPP
+
+// Class CardGeneration is a generation that is covered by a card table,
+// and uses a card-size block-offset array to implement block_start.
+
+#include "memory/generation.hpp"
+
+class BlockOffsetSharedArray;
+
+class CardGeneration: public Generation {
+  friend class VMStructs;
+ protected:
+  // This is shared with other generations.
+  GenRemSet* _rs;
+  // This is local to this generation.
+  BlockOffsetSharedArray* _bts;
+
+  // current shrinking effect: this damps shrinking when the heap gets empty.
+  size_t _shrink_factor;
+
+  size_t _min_heap_delta_bytes;   // Minimum amount to expand.
+
+  // Some statistics from before gc started.
+  // These are gathered in the gc_prologue (and should_collect)
+  // to control growing/shrinking policy in spite of promotions.
+  size_t _capacity_at_prologue;
+  size_t _used_at_prologue;
+
+  CardGeneration(ReservedSpace rs, size_t initial_byte_size, int level,
+                 GenRemSet* remset);
+
+ public:
+
+  // Attempt to expand the generation by "bytes".  Expand by at a
+  // minimum "expand_bytes".  Return true if some amount (not
+  // necessarily the full "bytes") was done.
+  virtual bool expand(size_t bytes, size_t expand_bytes);
+
+  // Shrink generation with specified size
+  virtual void shrink(size_t bytes) = 0;
+
+  virtual void compute_new_size();
+
+  virtual void clear_remembered_set();
+
+  virtual void invalidate_remembered_set();
+
+  virtual void prepare_for_verify();
+
+  // Grow generation with specified size (returns false if unable to grow)
+  virtual bool grow_by(size_t bytes) = 0;
+  // Grow generation to reserved size.
+  virtual bool grow_to_reserved() = 0;
+};
+
+#endif // SHARE_VM_MEMORY_CARDGENERATION_HPP

hotspot/src/share/vm/memory/generation.cpp

@@ -361,244 +361,3 @@ void Generation::compact() {
     sp = sp->next_compaction_space();
   }
 }
-
-CardGeneration::CardGeneration(ReservedSpace rs, size_t initial_byte_size,
-                               int level,
-                               GenRemSet* remset) :
-  Generation(rs, initial_byte_size, level), _rs(remset),
-  _shrink_factor(0), _min_heap_delta_bytes(), _capacity_at_prologue(),
-  _used_at_prologue()
-{
-  HeapWord* start = (HeapWord*)rs.base();
-  size_t reserved_byte_size = rs.size();
-  assert((uintptr_t(start) & 3) == 0, "bad alignment");
-  assert((reserved_byte_size & 3) == 0, "bad alignment");
-  MemRegion reserved_mr(start, heap_word_size(reserved_byte_size));
-  _bts = new BlockOffsetSharedArray(reserved_mr,
-                                    heap_word_size(initial_byte_size));
-  MemRegion committed_mr(start, heap_word_size(initial_byte_size));
-  _rs->resize_covered_region(committed_mr);
-  if (_bts == NULL)
-    vm_exit_during_initialization("Could not allocate a BlockOffsetArray");
-
-  // Verify that the start and end of this generation is the start of a card.
-  // If this wasn't true, a single card could span more than on generation,
-  // which would cause problems when we commit/uncommit memory, and when we
-  // clear and dirty cards.
-  guarantee(_rs->is_aligned(reserved_mr.start()), "generation must be card aligned");
-  if (reserved_mr.end() != Universe::heap()->reserved_region().end()) {
-    // Don't check at the very end of the heap as we'll assert that we're probing off
-    // the end if we try.
-    guarantee(_rs->is_aligned(reserved_mr.end()), "generation must be card aligned");
-  }
-  _min_heap_delta_bytes = MinHeapDeltaBytes;
-  _capacity_at_prologue = initial_byte_size;
-  _used_at_prologue = 0;
-}
-
-bool CardGeneration::expand(size_t bytes, size_t expand_bytes) {
-  assert_locked_or_safepoint(Heap_lock);
-  if (bytes == 0) {
-    return true;  // That's what grow_by(0) would return
-  }
-  size_t aligned_bytes  = ReservedSpace::page_align_size_up(bytes);
-  if (aligned_bytes == 0){
-    // The alignment caused the number of bytes to wrap.  An expand_by(0) will
-    // return true with the implication that an expansion was done when it
-    // was not.  A call to expand implies a best effort to expand by "bytes"
-    // but not a guarantee.  Align down to give a best effort.  This is likely
-    // the most that the generation can expand since it has some capacity to
-    // start with.
-    aligned_bytes = ReservedSpace::page_align_size_down(bytes);
-  }
-  size_t aligned_expand_bytes = ReservedSpace::page_align_size_up(expand_bytes);
-  bool success = false;
-  if (aligned_expand_bytes > aligned_bytes) {
-    success = grow_by(aligned_expand_bytes);
-  }
-  if (!success) {
-    success = grow_by(aligned_bytes);
-  }
-  if (!success) {
-    success = grow_to_reserved();
-  }
-  if (PrintGC && Verbose) {
-    if (success && GC_locker::is_active_and_needs_gc()) {
-      gclog_or_tty->print_cr("Garbage collection disabled, expanded heap instead");
-    }
-  }
-
-  return success;
-}
-
-
-// No young generation references, clear this generation's cards.
-void CardGeneration::clear_remembered_set() {
-  _rs->clear(reserved());
-}
-
-
-// Objects in this generation may have moved, invalidate this
-// generation's cards.
-void CardGeneration::invalidate_remembered_set() {
-  _rs->invalidate(used_region());
-}
-
-
-void CardGeneration::compute_new_size() {
-  assert(_shrink_factor <= 100, "invalid shrink factor");
-  size_t current_shrink_factor = _shrink_factor;
-  _shrink_factor = 0;
-
-  // We don't have floating point command-line arguments
-  // Note:  argument processing ensures that MinHeapFreeRatio < 100.
-  const double minimum_free_percentage = MinHeapFreeRatio / 100.0;
-  const double maximum_used_percentage = 1.0 - minimum_free_percentage;
-
-  // Compute some numbers about the state of the heap.
-  const size_t used_after_gc = used();
-  const size_t capacity_after_gc = capacity();
-
-  const double min_tmp = used_after_gc / maximum_used_percentage;
-  size_t minimum_desired_capacity = (size_t)MIN2(min_tmp, double(max_uintx));
-  // Don't shrink less than the initial generation size
-  minimum_desired_capacity = MAX2(minimum_desired_capacity,
-                                  spec()->init_size());
-  assert(used_after_gc <= minimum_desired_capacity, "sanity check");
-
-  if (PrintGC && Verbose) {
-    const size_t free_after_gc = free();
-    const double free_percentage = ((double)free_after_gc) / capacity_after_gc;
-    gclog_or_tty->print_cr("TenuredGeneration::compute_new_size: ");
-    gclog_or_tty->print_cr("  "
-                  "  minimum_free_percentage: %6.2f"
-                  "  maximum_used_percentage: %6.2f",
-                  minimum_free_percentage,
-                  maximum_used_percentage);
-    gclog_or_tty->print_cr("  "
-                  "   free_after_gc   : %6.1fK"
-                  "   used_after_gc   : %6.1fK"
-                  "   capacity_after_gc   : %6.1fK",
-                  free_after_gc / (double) K,
-                  used_after_gc / (double) K,
-                  capacity_after_gc / (double) K);
-    gclog_or_tty->print_cr("  "
-                  "   free_percentage: %6.2f",
-                  free_percentage);
-  }
-
-  if (capacity_after_gc < minimum_desired_capacity) {
-    // If we have less free space than we want then expand
-    size_t expand_bytes = minimum_desired_capacity - capacity_after_gc;
-    // Don't expand unless it's significant
-    if (expand_bytes >= _min_heap_delta_bytes) {
-      expand(expand_bytes, 0); // safe if expansion fails
-    }
-    if (PrintGC && Verbose) {
-      gclog_or_tty->print_cr("    expanding:"
-                    "  minimum_desired_capacity: %6.1fK"
-                    "  expand_bytes: %6.1fK"
-                    "  _min_heap_delta_bytes: %6.1fK",
-                    minimum_desired_capacity / (double) K,
-                    expand_bytes / (double) K,
-                    _min_heap_delta_bytes / (double) K);
-    }
-    return;
-  }
-
-  // No expansion, now see if we want to shrink
-  size_t shrink_bytes = 0;
-  // We would never want to shrink more than this
-  size_t max_shrink_bytes = capacity_after_gc - minimum_desired_capacity;
-
-  if (MaxHeapFreeRatio < 100) {
-    const double maximum_free_percentage = MaxHeapFreeRatio / 100.0;
-    const double minimum_used_percentage = 1.0 - maximum_free_percentage;
-    const double max_tmp = used_after_gc / minimum_used_percentage;
-    size_t maximum_desired_capacity = (size_t)MIN2(max_tmp, double(max_uintx));
-    maximum_desired_capacity = MAX2(maximum_desired_capacity,
-                                    spec()->init_size());
-    if (PrintGC && Verbose) {
-      gclog_or_tty->print_cr("  "
-                             "  maximum_free_percentage: %6.2f"
-                             "  minimum_used_percentage: %6.2f",
-                             maximum_free_percentage,
-                             minimum_used_percentage);
-      gclog_or_tty->print_cr("  "
-                             "  _capacity_at_prologue: %6.1fK"
-                             "  minimum_desired_capacity: %6.1fK"
-                             "  maximum_desired_capacity: %6.1fK",
-                             _capacity_at_prologue / (double) K,
-                             minimum_desired_capacity / (double) K,
-                             maximum_desired_capacity / (double) K);
-    }
-    assert(minimum_desired_capacity <= maximum_desired_capacity,
-           "sanity check");
-
-    if (capacity_after_gc > maximum_desired_capacity) {
-      // Capacity too large, compute shrinking size
-      shrink_bytes = capacity_after_gc - maximum_desired_capacity;
-      // We don't want shrink all the way back to initSize if people call
-      // System.gc(), because some programs do that between "phases" and then
-      // we'd just have to grow the heap up again for the next phase.  So we
-      // damp the shrinking: 0% on the first call, 10% on the second call, 40%
-      // on the third call, and 100% by the fourth call.  But if we recompute
-      // size without shrinking, it goes back to 0%.
-      shrink_bytes = shrink_bytes / 100 * current_shrink_factor;
-      assert(shrink_bytes <= max_shrink_bytes, "invalid shrink size");
-      if (current_shrink_factor == 0) {
-        _shrink_factor = 10;
-      } else {
-        _shrink_factor = MIN2(current_shrink_factor * 4, (size_t) 100);
-      }
-      if (PrintGC && Verbose) {
-        gclog_or_tty->print_cr("  "
-                      "  shrinking:"
-                      "  initSize: %.1fK"
-                      "  maximum_desired_capacity: %.1fK",
-                      spec()->init_size() / (double) K,
-                      maximum_desired_capacity / (double) K);
-        gclog_or_tty->print_cr("  "
-                      "  shrink_bytes: %.1fK"
-                      "  current_shrink_factor: " SIZE_FORMAT
-                      "  new shrink factor: " SIZE_FORMAT
-                      "  _min_heap_delta_bytes: %.1fK",
-                      shrink_bytes / (double) K,
-                      current_shrink_factor,
-                      _shrink_factor,
-                      _min_heap_delta_bytes / (double) K);
-      }
-    }
-  }
-
-  if (capacity_after_gc > _capacity_at_prologue) {
-    // We might have expanded for promotions, in which case we might want to
-    // take back that expansion if there's room after GC.  That keeps us from
-    // stretching the heap with promotions when there's plenty of room.
-    size_t expansion_for_promotion = capacity_after_gc - _capacity_at_prologue;
-    expansion_for_promotion = MIN2(expansion_for_promotion, max_shrink_bytes);
-    // We have two shrinking computations, take the largest
-    shrink_bytes = MAX2(shrink_bytes, expansion_for_promotion);
-    assert(shrink_bytes <= max_shrink_bytes, "invalid shrink size");
-    if (PrintGC && Verbose) {
-      gclog_or_tty->print_cr("  "
-                             "  aggressive shrinking:"
-                             "  _capacity_at_prologue: %.1fK"
-                             "  capacity_after_gc: %.1fK"
-                             "  expansion_for_promotion: %.1fK"
-                             "  shrink_bytes: %.1fK",
-                             capacity_after_gc / (double) K,
-                             _capacity_at_prologue / (double) K,
-                             expansion_for_promotion / (double) K,
-                             shrink_bytes / (double) K);
-    }
-  }
-  // Don't shrink unless it's significant
-  if (shrink_bytes >= _min_heap_delta_bytes) {
-    shrink(shrink_bytes);
-  }
-}
-
-// Currently nothing to do.
-void CardGeneration::prepare_for_verify() {}
-

hotspot/src/share/vm/memory/generation.hpp

@@ -584,57 +584,4 @@ public:
   virtual CollectorCounters* counters() { return _gc_counters; }
 };
 
-// Class CardGeneration is a generation that is covered by a card table,
-// and uses a card-size block-offset array to implement block_start.
-
-// class BlockOffsetArray;
-// class BlockOffsetArrayContigSpace;
-class BlockOffsetSharedArray;
-
-class CardGeneration: public Generation {
-  friend class VMStructs;
- protected:
-  // This is shared with other generations.
-  GenRemSet* _rs;
-  // This is local to this generation.
-  BlockOffsetSharedArray* _bts;
-
-  // current shrinking effect: this damps shrinking when the heap gets empty.
-  size_t _shrink_factor;
-
-  size_t _min_heap_delta_bytes;   // Minimum amount to expand.
-
-  // Some statistics from before gc started.
-  // These are gathered in the gc_prologue (and should_collect)
-  // to control growing/shrinking policy in spite of promotions.
-  size_t _capacity_at_prologue;
-  size_t _used_at_prologue;
-
-  CardGeneration(ReservedSpace rs, size_t initial_byte_size, int level,
-                 GenRemSet* remset);
-
- public:
-
-  // Attempt to expand the generation by "bytes".  Expand by at a
-  // minimum "expand_bytes".  Return true if some amount (not
-  // necessarily the full "bytes") was done.
-  virtual bool expand(size_t bytes, size_t expand_bytes);
-
-  // Shrink generation with specified size (returns false if unable to shrink)
-  virtual void shrink(size_t bytes) = 0;
-
-  virtual void compute_new_size();
-
-  virtual void clear_remembered_set();
-
-  virtual void invalidate_remembered_set();
-
-  virtual void prepare_for_verify();
-
-  // Grow generation with specified size (returns false if unable to grow)
-  virtual bool grow_by(size_t bytes) = 0;
-  // Grow generation to reserved size.
-  virtual bool grow_to_reserved() = 0;
-};
-
 #endif // SHARE_VM_MEMORY_GENERATION_HPP

hotspot/src/share/vm/memory/tenuredGeneration.hpp

@@ -28,7 +28,7 @@
 #include "gc_implementation/shared/cSpaceCounters.hpp"
 #include "gc_implementation/shared/gcStats.hpp"
 #include "gc_implementation/shared/generationCounters.hpp"
-#include "memory/generation.hpp"
+#include "memory/cardGeneration.hpp"
 #include "utilities/macros.hpp"
 
 // TenuredGeneration models the heap containing old (promoted/tenured) objects