jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/parNew/asParNewGeneration.cpp@ee019285a52c (annotated)

src/share/vm/gc_implementation/parNew/asParNewGeneration.cpp@ee019285a52c (annotated)

src/share/vm/gc_implementation/parNew/asParNewGeneration.cpp

Mon, 04 Aug 2014 10:48:10 -0700

author: jmasa
date: Mon, 04 Aug 2014 10:48:10 -0700
changeset 7031: ee019285a52c
parent 6680: 78bbf4d43a14
child 6876: 710a3c8b516e
permissions: -rw-r--r--

8031323: Optionally align objects copied to survivor spaces
Reviewed-by: brutisso, tschatzl

 /*
  * Copyright (c) 2005, 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 "gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.hpp"
 #include "gc_implementation/concurrentMarkSweep/cmsGCAdaptivePolicyCounters.hpp"
 #include "gc_implementation/parNew/asParNewGeneration.hpp"
 #include "gc_implementation/parNew/parNewGeneration.hpp"
 #include "gc_implementation/shared/markSweep.inline.hpp"
 #include "gc_implementation/shared/spaceDecorator.hpp"
 #include "memory/defNewGeneration.inline.hpp"
 #include "memory/referencePolicy.hpp"
 #include "oops/markOop.inline.hpp"
 #include "oops/oop.pcgc.inline.hpp"
 ASParNewGeneration::ASParNewGeneration(ReservedSpace rs,
                                        size_t initial_byte_size,
                                        size_t min_byte_size,
                                        int level) :
   ParNewGeneration(rs, initial_byte_size, level),
   _min_gen_size(min_byte_size) {}
 const char* ASParNewGeneration::name() const {
   return "adaptive size par new generation";
 }
 void ASParNewGeneration::adjust_desired_tenuring_threshold() {
   assert(UseAdaptiveSizePolicy,
     "Should only be used with UseAdaptiveSizePolicy");
 }
 void ASParNewGeneration::resize(size_t eden_size, size_t survivor_size) {
   // Resize the generation if needed. If the generation resize
   // reports false, do not attempt to resize the spaces.
   if (resize_generation(eden_size, survivor_size)) {
     // Then we lay out the spaces inside the generation
     resize_spaces(eden_size, survivor_size);
     space_invariants();
     if (PrintAdaptiveSizePolicy && Verbose) {
       gclog_or_tty->print_cr("Young generation size: "
         "desired eden: " SIZE_FORMAT " survivor: " SIZE_FORMAT
         " used: " SIZE_FORMAT " capacity: " SIZE_FORMAT
         " gen limits: " SIZE_FORMAT " / " SIZE_FORMAT,
         eden_size, survivor_size, used(), capacity(),
         max_gen_size(), min_gen_size());
     }
   }
 }
 size_t ASParNewGeneration::available_to_min_gen() {
   assert(virtual_space()->committed_size() >= min_gen_size(), "Invariant");
   return virtual_space()->committed_size() - min_gen_size();
 }
 // This method assumes that from-space has live data and that
 // any shrinkage of the young gen is limited by location of
 // from-space.
 size_t ASParNewGeneration::available_to_live() const {
 #undef SHRINKS_AT_END_OF_EDEN
 #ifdef SHRINKS_AT_END_OF_EDEN
   size_t delta_in_survivor = 0;
   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
   const size_t space_alignment = heap->intra_heap_alignment();
   const size_t gen_alignment = heap->object_heap_alignment();
   MutableSpace* space_shrinking = NULL;
   if (from_space()->end() > to_space()->end()) {
     space_shrinking = from_space();
   } else {
     space_shrinking = to_space();
   }
   // Include any space that is committed but not included in
   // the survivor spaces.
   assert(((HeapWord*)virtual_space()->high()) >= space_shrinking->end(),
     "Survivor space beyond high end");
   size_t unused_committed = pointer_delta(virtual_space()->high(),
     space_shrinking->end(), sizeof(char));
   if (space_shrinking->is_empty()) {
     // Don't let the space shrink to 0
     assert(space_shrinking->capacity_in_bytes() >= space_alignment,
       "Space is too small");
     delta_in_survivor = space_shrinking->capacity_in_bytes() - space_alignment;
   } else {
     delta_in_survivor = pointer_delta(space_shrinking->end(),
                                       space_shrinking->top(),
                                       sizeof(char));
   }
   size_t delta_in_bytes = unused_committed + delta_in_survivor;
   delta_in_bytes = align_size_down(delta_in_bytes, gen_alignment);
   return delta_in_bytes;
 #else
   // The only space available for shrinking is in to-space if it
   // is above from-space.
   if (to()->bottom() > from()->bottom()) {
     const size_t alignment = os::vm_page_size();
     if (to()->capacity() < alignment) {
       return 0;
     } else {
       return to()->capacity() - alignment;
     }
   } else {
     return 0;
   }
 #endif
 }
 // Return the number of bytes available for resizing down the young
 // generation.  This is the minimum of
 //      input "bytes"
 //      bytes to the minimum young gen size
 //      bytes to the size currently being used + some small extra
 size_t ASParNewGeneration::limit_gen_shrink (size_t bytes) {
   // Allow shrinkage into the current eden but keep eden large enough
   // to maintain the minimum young gen size
   bytes = MIN3(bytes, available_to_min_gen(), available_to_live());
   return align_size_down(bytes, os::vm_page_size());
 }
 // Note that the the alignment used is the OS page size as
 // opposed to an alignment associated with the virtual space
 // (as is done in the ASPSYoungGen/ASPSOldGen)
 bool ASParNewGeneration::resize_generation(size_t eden_size,
                                            size_t survivor_size) {
   const size_t alignment = os::vm_page_size();
   size_t orig_size = virtual_space()->committed_size();
   bool size_changed = false;
   // There used to be this guarantee there.
   // guarantee ((eden_size + 2*survivor_size)  <= _max_gen_size, "incorrect input arguments");
   // Code below forces this requirement.  In addition the desired eden
   // size and disired survivor sizes are desired goals and may
   // exceed the total generation size.
   assert(min_gen_size() <= orig_size && orig_size <= max_gen_size(),
     "just checking");
   // Adjust new generation size
   const size_t eden_plus_survivors =
           align_size_up(eden_size + 2 * survivor_size, alignment);
   size_t desired_size = MAX2(MIN2(eden_plus_survivors, max_gen_size()),
                              min_gen_size());
   assert(desired_size <= max_gen_size(), "just checking");
   if (desired_size > orig_size) {
     // Grow the generation
     size_t change = desired_size - orig_size;
     assert(change % alignment == 0, "just checking");
     if (expand(change)) {
       return false; // Error if we fail to resize!
     }
     size_changed = true;
   } else if (desired_size < orig_size) {
     size_t desired_change = orig_size - desired_size;
     assert(desired_change % alignment == 0, "just checking");
     desired_change = limit_gen_shrink(desired_change);
     if (desired_change > 0) {
       virtual_space()->shrink_by(desired_change);
       reset_survivors_after_shrink();
       size_changed = true;
     }
   } else {
     if (Verbose && PrintGC) {
       if (orig_size == max_gen_size()) {
         gclog_or_tty->print_cr("ASParNew generation size at maximum: "
           SIZE_FORMAT "K", orig_size/K);
       } else if (orig_size == min_gen_size()) {
         gclog_or_tty->print_cr("ASParNew generation size at minium: "
           SIZE_FORMAT "K", orig_size/K);
       }
     }
   }
   if (size_changed) {
     MemRegion cmr((HeapWord*)virtual_space()->low(),
                   (HeapWord*)virtual_space()->high());
     GenCollectedHeap::heap()->barrier_set()->resize_covered_region(cmr);
     if (Verbose && PrintGC) {
       size_t current_size  = virtual_space()->committed_size();
       gclog_or_tty->print_cr("ASParNew generation size changed: "
                              SIZE_FORMAT "K->" SIZE_FORMAT "K",
                              orig_size/K, current_size/K);
     }
   }
   guarantee(eden_plus_survivors <= virtual_space()->committed_size() ||
             virtual_space()->committed_size() == max_gen_size(), "Sanity");
   return true;
 }
 void ASParNewGeneration::reset_survivors_after_shrink() {
   GenCollectedHeap* gch = GenCollectedHeap::heap();
   HeapWord* new_end = (HeapWord*)virtual_space()->high();
   if (from()->end() > to()->end()) {
     assert(new_end >= from()->end(), "Shrinking past from-space");
   } else {
     assert(new_end >= to()->bottom(), "Shrink was too large");
     // Was there a shrink of the survivor space?
     if (new_end < to()->end()) {
       MemRegion mr(to()->bottom(), new_end);
       to()->initialize(mr,
                        SpaceDecorator::DontClear,
                        SpaceDecorator::DontMangle);
     }
   }
 }
 void ASParNewGeneration::resize_spaces(size_t requested_eden_size,
                                        size_t requested_survivor_size) {
   assert(UseAdaptiveSizePolicy, "sanity check");
   assert(requested_eden_size > 0  && requested_survivor_size > 0,
          "just checking");
   CollectedHeap* heap = Universe::heap();
   assert(heap->kind() == CollectedHeap::GenCollectedHeap, "Sanity");
   // We require eden and to space to be empty
   if ((!eden()->is_empty()) || (!to()->is_empty())) {
     return;
   }
   size_t cur_eden_size = eden()->capacity();
   if (PrintAdaptiveSizePolicy && Verbose) {
     gclog_or_tty->print_cr("ASParNew::resize_spaces(requested_eden_size: "
                   SIZE_FORMAT
                   ", requested_survivor_size: " SIZE_FORMAT ")",
                   requested_eden_size, requested_survivor_size);
     gclog_or_tty->print_cr("    eden: [" PTR_FORMAT ".." PTR_FORMAT ") "
                   SIZE_FORMAT,
                   p2i(eden()->bottom()),
                   p2i(eden()->end()),
                   pointer_delta(eden()->end(),
                                 eden()->bottom(),
                                 sizeof(char)));
     gclog_or_tty->print_cr("    from: [" PTR_FORMAT ".." PTR_FORMAT ") "
                   SIZE_FORMAT,
                   p2i(from()->bottom()),
                   p2i(from()->end()),
                   pointer_delta(from()->end(),
                                 from()->bottom(),
                                 sizeof(char)));
     gclog_or_tty->print_cr("      to: [" PTR_FORMAT ".." PTR_FORMAT ") "
                   SIZE_FORMAT,
                   p2i(to()->bottom()),
                   p2i(to()->end()),
                   pointer_delta(  to()->end(),
                                   to()->bottom(),
                                   sizeof(char)));
   }
   // There's nothing to do if the new sizes are the same as the current
   if (requested_survivor_size == to()->capacity() &&
       requested_survivor_size == from()->capacity() &&
       requested_eden_size == eden()->capacity()) {
     if (PrintAdaptiveSizePolicy && Verbose) {
       gclog_or_tty->print_cr("    capacities are the right sizes, returning");
     }
     return;
   }
   char* eden_start = (char*)eden()->bottom();
   char* eden_end   = (char*)eden()->end();
   char* from_start = (char*)from()->bottom();
   char* from_end   = (char*)from()->end();
   char* to_start   = (char*)to()->bottom();
   char* to_end     = (char*)to()->end();
   const size_t alignment = os::vm_page_size();
   const bool maintain_minimum =
     (requested_eden_size + 2 * requested_survivor_size) <= min_gen_size();
   // Check whether from space is below to space
   if (from_start < to_start) {
     // Eden, from, to
     if (PrintAdaptiveSizePolicy && Verbose) {
       gclog_or_tty->print_cr("  Eden, from, to:");
     }
     // Set eden
     // "requested_eden_size" is a goal for the size of eden
     // and may not be attainable.  "eden_size" below is
     // calculated based on the location of from-space and
     // the goal for the size of eden.  from-space is
     // fixed in place because it contains live data.
     // The calculation is done this way to avoid 32bit
     // overflow (i.e., eden_start + requested_eden_size
     // may too large for representation in 32bits).
     size_t eden_size;
     if (maintain_minimum) {
       // Only make eden larger than the requested size if
       // the minimum size of the generation has to be maintained.
       // This could be done in general but policy at a higher
       // level is determining a requested size for eden and that
       // should be honored unless there is a fundamental reason.
       eden_size = pointer_delta(from_start,
                                 eden_start,
                                 sizeof(char));
     } else {
       eden_size = MIN2(requested_eden_size,
                        pointer_delta(from_start, eden_start, sizeof(char)));
     }
     eden_size = align_size_down(eden_size, alignment);
     eden_end = eden_start + eden_size;
     assert(eden_end >= eden_start, "addition overflowed");
     // To may resize into from space as long as it is clear of live data.
     // From space must remain page aligned, though, so we need to do some
     // extra calculations.
     // First calculate an optimal to-space
     to_end   = (char*)virtual_space()->high();
     to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size,
                                     sizeof(char));
     // Does the optimal to-space overlap from-space?
     if (to_start < (char*)from()->end()) {
       // Calculate the minimum offset possible for from_end
       size_t from_size = pointer_delta(from()->top(), from_start, sizeof(char));
       // Should we be in this method if from_space is empty? Why not the set_space method? FIX ME!
       if (from_size == 0) {
         from_size = alignment;
       } else {
         from_size = align_size_up(from_size, alignment);
       }
       from_end = from_start + from_size;
       assert(from_end > from_start, "addition overflow or from_size problem");
       guarantee(from_end <= (char*)from()->end(), "from_end moved to the right");
       // Now update to_start with the new from_end
       to_start = MAX2(from_end, to_start);
     } else {
       // If shrinking, move to-space down to abut the end of from-space
       // so that shrinking will move to-space down.  If not shrinking
       // to-space is moving up to allow for growth on the next expansion.
       if (requested_eden_size <= cur_eden_size) {
         to_start = from_end;
         if (to_start + requested_survivor_size > to_start) {
           to_end = to_start + requested_survivor_size;
         }
       }
       // else leave to_end pointing to the high end of the virtual space.
     }
     guarantee(to_start != to_end, "to space is zero sized");
     if (PrintAdaptiveSizePolicy && Verbose) {
       gclog_or_tty->print_cr("    [eden_start .. eden_end): "
                     "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
                     p2i(eden_start),
                     p2i(eden_end),
                     pointer_delta(eden_end, eden_start, sizeof(char)));
       gclog_or_tty->print_cr("    [from_start .. from_end): "
                     "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
                     p2i(from_start),
                     p2i(from_end),
                     pointer_delta(from_end, from_start, sizeof(char)));
       gclog_or_tty->print_cr("    [  to_start ..   to_end): "
                     "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
                     p2i(to_start),
                     p2i(to_end),
                     pointer_delta(  to_end,   to_start, sizeof(char)));
     }
   } else {
     // Eden, to, from
     if (PrintAdaptiveSizePolicy && Verbose) {
       gclog_or_tty->print_cr("  Eden, to, from:");
     }
     // Calculate the to-space boundaries based on
     // the start of from-space.
     to_end = from_start;
     to_start = (char*)pointer_delta(from_start,
                                     (char*)requested_survivor_size,
                                     sizeof(char));
     // Calculate the ideal eden boundaries.
     // eden_end is already at the bottom of the generation
     assert(eden_start == virtual_space()->low(),
       "Eden is not starting at the low end of the virtual space");
     if (eden_start + requested_eden_size >= eden_start) {
       eden_end = eden_start + requested_eden_size;
     } else {
       eden_end = to_start;
     }
     // Does eden intrude into to-space?  to-space
     // gets priority but eden is not allowed to shrink
     // to 0.
     if (eden_end > to_start) {
       eden_end = to_start;
     }
     // Don't let eden shrink down to 0 or less.
     eden_end = MAX2(eden_end, eden_start + alignment);
     assert(eden_start + alignment >= eden_start, "Overflow");
     size_t eden_size;
     if (maintain_minimum) {
       // Use all the space available.
       eden_end = MAX2(eden_end, to_start);
       eden_size = pointer_delta(eden_end, eden_start, sizeof(char));
       eden_size = MIN2(eden_size, cur_eden_size);
     } else {
       eden_size = pointer_delta(eden_end, eden_start, sizeof(char));
     }
     eden_size = align_size_down(eden_size, alignment);
     assert(maintain_minimum || eden_size <= requested_eden_size,
       "Eden size is too large");
     assert(eden_size >= alignment, "Eden size is too small");
     eden_end = eden_start + eden_size;
     // Move to-space down to eden.
     if (requested_eden_size < cur_eden_size) {
       to_start = eden_end;
       if (to_start + requested_survivor_size > to_start) {
         to_end = MIN2(from_start, to_start + requested_survivor_size);
       } else {
         to_end = from_start;
       }
     }
     // eden_end may have moved so again make sure
     // the to-space and eden don't overlap.
     to_start = MAX2(eden_end, to_start);
     // from-space
     size_t from_used = from()->used();
     if (requested_survivor_size > from_used) {
       if (from_start + requested_survivor_size >= from_start) {
         from_end = from_start + requested_survivor_size;
       }
       if (from_end > virtual_space()->high()) {
         from_end = virtual_space()->high();
       }
     }
     assert(to_start >= eden_end, "to-space should be above eden");
     if (PrintAdaptiveSizePolicy && Verbose) {
       gclog_or_tty->print_cr("    [eden_start .. eden_end): "
                     "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
                     p2i(eden_start),
                     p2i(eden_end),
                     pointer_delta(eden_end, eden_start, sizeof(char)));
       gclog_or_tty->print_cr("    [  to_start ..   to_end): "
                     "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
                     p2i(to_start),
                     p2i(to_end),
                     pointer_delta(  to_end,   to_start, sizeof(char)));
       gclog_or_tty->print_cr("    [from_start .. from_end): "
                     "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
                     p2i(from_start),
                     p2i(from_end),
                     pointer_delta(from_end, from_start, sizeof(char)));
     }
   }
   guarantee((HeapWord*)from_start <= from()->bottom(),
             "from start moved to the right");
   guarantee((HeapWord*)from_end >= from()->top(),
             "from end moved into live data");
   assert(is_object_aligned((intptr_t)eden_start), "checking alignment");
   assert(is_object_aligned((intptr_t)from_start), "checking alignment");
   assert(is_object_aligned((intptr_t)to_start), "checking alignment");
   MemRegion edenMR((HeapWord*)eden_start, (HeapWord*)eden_end);
   MemRegion toMR  ((HeapWord*)to_start,   (HeapWord*)to_end);
   MemRegion fromMR((HeapWord*)from_start, (HeapWord*)from_end);
   // Let's make sure the call to initialize doesn't reset "top"!
   HeapWord* old_from_top = from()->top();
   // For PrintAdaptiveSizePolicy block  below
   size_t old_from = from()->capacity();
   size_t old_to   = to()->capacity();
   // If not clearing the spaces, do some checking to verify that
   // the spaces are already mangled.
   // Must check mangling before the spaces are reshaped.  Otherwise,
   // the bottom or end of one space may have moved into another
   // a failure of the check may not correctly indicate which space
   // is not properly mangled.
   if (ZapUnusedHeapArea) {
     HeapWord* limit = (HeapWord*) virtual_space()->high();
     eden()->check_mangled_unused_area(limit);
     from()->check_mangled_unused_area(limit);
       to()->check_mangled_unused_area(limit);
   }
   // The call to initialize NULL's the next compaction space
   eden()->initialize(edenMR,
                      SpaceDecorator::Clear,
                      SpaceDecorator::DontMangle);
   eden()->set_next_compaction_space(from());
     to()->initialize(toMR  ,
                      SpaceDecorator::Clear,
                      SpaceDecorator::DontMangle);
   from()->initialize(fromMR,
                      SpaceDecorator::DontClear,
                      SpaceDecorator::DontMangle);
   assert(from()->top() == old_from_top, "from top changed!");
   if (PrintAdaptiveSizePolicy) {
     GenCollectedHeap* gch = GenCollectedHeap::heap();
     assert(gch->kind() == CollectedHeap::GenCollectedHeap, "Sanity");
     gclog_or_tty->print("AdaptiveSizePolicy::survivor space sizes: "
                   "collection: %d "
                   "(" SIZE_FORMAT ", " SIZE_FORMAT ") -> "
                   "(" SIZE_FORMAT ", " SIZE_FORMAT ") ",
                   gch->total_collections(),
                   old_from, old_to,
                   from()->capacity(),
                   to()->capacity());
     gclog_or_tty->cr();
   }
 }
 void ASParNewGeneration::compute_new_size() {
   GenCollectedHeap* gch = GenCollectedHeap::heap();
   assert(gch->kind() == CollectedHeap::GenCollectedHeap,
     "not a CMS generational heap");
   CMSAdaptiveSizePolicy* size_policy =
     (CMSAdaptiveSizePolicy*)gch->gen_policy()->size_policy();
   assert(size_policy->is_gc_cms_adaptive_size_policy(),
     "Wrong type of size policy");
   size_t survived = from()->used();
   if (!survivor_overflow()) {
     // Keep running averages on how much survived
     size_policy->avg_survived()->sample(survived);
   } else {
     size_t promoted =
       (size_t) next_gen()->gc_stats()->avg_promoted()->last_sample();
     assert(promoted < gch->capacity(), "Conversion problem?");
     size_t survived_guess = survived + promoted;
     size_policy->avg_survived()->sample(survived_guess);
   }
   size_t survivor_limit = max_survivor_size();
   _tenuring_threshold =
     size_policy->compute_survivor_space_size_and_threshold(
                                                      _survivor_overflow,
                                                      _tenuring_threshold,
                                                      survivor_limit);
   size_policy->avg_young_live()->sample(used());
   size_policy->avg_eden_live()->sample(eden()->used());
   size_policy->compute_eden_space_size(eden()->capacity(), max_gen_size());
   resize(size_policy->calculated_eden_size_in_bytes(),
          size_policy->calculated_survivor_size_in_bytes());
   if (UsePerfData) {
     CMSGCAdaptivePolicyCounters* counters =
       (CMSGCAdaptivePolicyCounters*) gch->collector_policy()->counters();
     assert(counters->kind() ==
            GCPolicyCounters::CMSGCAdaptivePolicyCountersKind,
       "Wrong kind of counters");
     counters->update_tenuring_threshold(_tenuring_threshold);
     counters->update_survivor_overflowed(_survivor_overflow);
     counters->update_young_capacity(capacity());
   }
 }
 #ifndef PRODUCT
 // Changes from PSYoungGen version
 //      value of "alignment"
 void ASParNewGeneration::space_invariants() {
   const size_t alignment = os::vm_page_size();
   // Currently, our eden size cannot shrink to zero
   guarantee(eden()->capacity() >= alignment, "eden too small");
   guarantee(from()->capacity() >= alignment, "from too small");
   guarantee(to()->capacity() >= alignment, "to too small");
   // Relationship of spaces to each other
   char* eden_start = (char*)eden()->bottom();
   char* eden_end   = (char*)eden()->end();
   char* from_start = (char*)from()->bottom();
   char* from_end   = (char*)from()->end();
   char* to_start   = (char*)to()->bottom();
   char* to_end     = (char*)to()->end();
   guarantee(eden_start >= virtual_space()->low(), "eden bottom");
   guarantee(eden_start < eden_end, "eden space consistency");
   guarantee(from_start < from_end, "from space consistency");
   guarantee(to_start < to_end, "to space consistency");
   // Check whether from space is below to space
   if (from_start < to_start) {
     // Eden, from, to
     guarantee(eden_end <= from_start, "eden/from boundary");
     guarantee(from_end <= to_start,   "from/to boundary");
     guarantee(to_end <= virtual_space()->high(), "to end");
   } else {
     // Eden, to, from
     guarantee(eden_end <= to_start, "eden/to boundary");
     guarantee(to_end <= from_start, "to/from boundary");
     guarantee(from_end <= virtual_space()->high(), "from end");
   }
   // More checks that the virtual space is consistent with the spaces
   assert(virtual_space()->committed_size() >=
     (eden()->capacity() +
      to()->capacity() +
      from()->capacity()), "Committed size is inconsistent");
   assert(virtual_space()->committed_size() <= virtual_space()->reserved_size(),
     "Space invariant");
   char* eden_top = (char*)eden()->top();
   char* from_top = (char*)from()->top();
   char* to_top = (char*)to()->top();
   assert(eden_top <= virtual_space()->high(), "eden top");
   assert(from_top <= virtual_space()->high(), "from top");
   assert(to_top <= virtual_space()->high(), "to top");
 }
 #endif

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/parNew/asParNewGeneration.cpp@ee019285a52c (annotated)

src/share/vm/gc_implementation/parNew/asParNewGeneration.cpp