duke@435: /*
drchase@6680:  * Copyright (c) 2005, 2014, Oracle and/or its affiliates. All rights reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
stefank@2314: #include "precompiled.hpp"
stefank@2314: #include "gc_implementation/concurrentMarkSweep/cmsAdaptiveSizePolicy.hpp"
stefank@2314: #include "gc_implementation/concurrentMarkSweep/cmsGCAdaptivePolicyCounters.hpp"
stefank@2314: #include "gc_implementation/parNew/asParNewGeneration.hpp"
stefank@2314: #include "gc_implementation/parNew/parNewGeneration.hpp"
stefank@2314: #include "gc_implementation/shared/markSweep.inline.hpp"
stefank@2314: #include "gc_implementation/shared/spaceDecorator.hpp"
stefank@2314: #include "memory/defNewGeneration.inline.hpp"
stefank@2314: #include "memory/referencePolicy.hpp"
stefank@2314: #include "oops/markOop.inline.hpp"
stefank@2314: #include "oops/oop.pcgc.inline.hpp"
duke@435: 
duke@435: ASParNewGeneration::ASParNewGeneration(ReservedSpace rs,
duke@435:                                        size_t initial_byte_size,
duke@435:                                        size_t min_byte_size,
duke@435:                                        int level) :
duke@435:   ParNewGeneration(rs, initial_byte_size, level),
duke@435:   _min_gen_size(min_byte_size) {}
duke@435: 
duke@435: const char* ASParNewGeneration::name() const {
duke@435:   return "adaptive size par new generation";
duke@435: }
duke@435: 
duke@435: void ASParNewGeneration::adjust_desired_tenuring_threshold() {
duke@435:   assert(UseAdaptiveSizePolicy,
duke@435:     "Should only be used with UseAdaptiveSizePolicy");
duke@435: }
duke@435: 
duke@435: void ASParNewGeneration::resize(size_t eden_size, size_t survivor_size) {
duke@435:   // Resize the generation if needed. If the generation resize
duke@435:   // reports false, do not attempt to resize the spaces.
duke@435:   if (resize_generation(eden_size, survivor_size)) {
duke@435:     // Then we lay out the spaces inside the generation
duke@435:     resize_spaces(eden_size, survivor_size);
duke@435: 
duke@435:     space_invariants();
duke@435: 
duke@435:     if (PrintAdaptiveSizePolicy && Verbose) {
duke@435:       gclog_or_tty->print_cr("Young generation size: "
duke@435:         "desired eden: " SIZE_FORMAT " survivor: " SIZE_FORMAT
duke@435:         " used: " SIZE_FORMAT " capacity: " SIZE_FORMAT
duke@435:         " gen limits: " SIZE_FORMAT " / " SIZE_FORMAT,
duke@435:         eden_size, survivor_size, used(), capacity(),
duke@435:         max_gen_size(), min_gen_size());
duke@435:     }
duke@435:   }
duke@435: }
duke@435: 
duke@435: size_t ASParNewGeneration::available_to_min_gen() {
duke@435:   assert(virtual_space()->committed_size() >= min_gen_size(), "Invariant");
duke@435:   return virtual_space()->committed_size() - min_gen_size();
duke@435: }
duke@435: 
duke@435: // This method assumes that from-space has live data and that
duke@435: // any shrinkage of the young gen is limited by location of
duke@435: // from-space.
duke@435: size_t ASParNewGeneration::available_to_live() const {
duke@435: #undef SHRINKS_AT_END_OF_EDEN
duke@435: #ifdef SHRINKS_AT_END_OF_EDEN
duke@435:   size_t delta_in_survivor = 0;
duke@435:   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
jmasa@448:   const size_t space_alignment = heap->intra_heap_alignment();
jmasa@448:   const size_t gen_alignment = heap->object_heap_alignment();
duke@435: 
duke@435:   MutableSpace* space_shrinking = NULL;
duke@435:   if (from_space()->end() > to_space()->end()) {
duke@435:     space_shrinking = from_space();
duke@435:   } else {
duke@435:     space_shrinking = to_space();
duke@435:   }
duke@435: 
duke@435:   // Include any space that is committed but not included in
duke@435:   // the survivor spaces.
duke@435:   assert(((HeapWord*)virtual_space()->high()) >= space_shrinking->end(),
duke@435:     "Survivor space beyond high end");
duke@435:   size_t unused_committed = pointer_delta(virtual_space()->high(),
duke@435:     space_shrinking->end(), sizeof(char));
duke@435: 
duke@435:   if (space_shrinking->is_empty()) {
duke@435:     // Don't let the space shrink to 0
duke@435:     assert(space_shrinking->capacity_in_bytes() >= space_alignment,
duke@435:       "Space is too small");
duke@435:     delta_in_survivor = space_shrinking->capacity_in_bytes() - space_alignment;
duke@435:   } else {
duke@435:     delta_in_survivor = pointer_delta(space_shrinking->end(),
duke@435:                                       space_shrinking->top(),
duke@435:                                       sizeof(char));
duke@435:   }
duke@435: 
duke@435:   size_t delta_in_bytes = unused_committed + delta_in_survivor;
duke@435:   delta_in_bytes = align_size_down(delta_in_bytes, gen_alignment);
duke@435:   return delta_in_bytes;
duke@435: #else
duke@435:   // The only space available for shrinking is in to-space if it
duke@435:   // is above from-space.
duke@435:   if (to()->bottom() > from()->bottom()) {
duke@435:     const size_t alignment = os::vm_page_size();
duke@435:     if (to()->capacity() < alignment) {
duke@435:       return 0;
duke@435:     } else {
duke@435:       return to()->capacity() - alignment;
duke@435:     }
duke@435:   } else {
duke@435:     return 0;
duke@435:   }
duke@435: #endif
duke@435: }
duke@435: 
duke@435: // Return the number of bytes available for resizing down the young
duke@435: // generation.  This is the minimum of
duke@435: //      input "bytes"
duke@435: //      bytes to the minimum young gen size
duke@435: //      bytes to the size currently being used + some small extra
duke@435: size_t ASParNewGeneration::limit_gen_shrink (size_t bytes) {
duke@435:   // Allow shrinkage into the current eden but keep eden large enough
duke@435:   // to maintain the minimum young gen size
duke@435:   bytes = MIN3(bytes, available_to_min_gen(), available_to_live());
duke@435:   return align_size_down(bytes, os::vm_page_size());
duke@435: }
duke@435: 
duke@435: // Note that the the alignment used is the OS page size as
duke@435: // opposed to an alignment associated with the virtual space
duke@435: // (as is done in the ASPSYoungGen/ASPSOldGen)
duke@435: bool ASParNewGeneration::resize_generation(size_t eden_size,
duke@435:                                            size_t survivor_size) {
duke@435:   const size_t alignment = os::vm_page_size();
duke@435:   size_t orig_size = virtual_space()->committed_size();
duke@435:   bool size_changed = false;
duke@435: 
duke@435:   // There used to be this guarantee there.
duke@435:   // guarantee ((eden_size + 2*survivor_size)  <= _max_gen_size, "incorrect input arguments");
duke@435:   // Code below forces this requirement.  In addition the desired eden
duke@435:   // size and disired survivor sizes are desired goals and may
duke@435:   // exceed the total generation size.
duke@435: 
duke@435:   assert(min_gen_size() <= orig_size && orig_size <= max_gen_size(),
duke@435:     "just checking");
duke@435: 
duke@435:   // Adjust new generation size
duke@435:   const size_t eden_plus_survivors =
duke@435:           align_size_up(eden_size + 2 * survivor_size, alignment);
duke@435:   size_t desired_size = MAX2(MIN2(eden_plus_survivors, max_gen_size()),
duke@435:                              min_gen_size());
duke@435:   assert(desired_size <= max_gen_size(), "just checking");
duke@435: 
duke@435:   if (desired_size > orig_size) {
duke@435:     // Grow the generation
duke@435:     size_t change = desired_size - orig_size;
duke@435:     assert(change % alignment == 0, "just checking");
jmasa@698:     if (expand(change)) {
duke@435:       return false; // Error if we fail to resize!
duke@435:     }
duke@435:     size_changed = true;
duke@435:   } else if (desired_size < orig_size) {
duke@435:     size_t desired_change = orig_size - desired_size;
duke@435:     assert(desired_change % alignment == 0, "just checking");
duke@435: 
duke@435:     desired_change = limit_gen_shrink(desired_change);
duke@435: 
duke@435:     if (desired_change > 0) {
duke@435:       virtual_space()->shrink_by(desired_change);
duke@435:       reset_survivors_after_shrink();
duke@435: 
duke@435:       size_changed = true;
duke@435:     }
duke@435:   } else {
duke@435:     if (Verbose && PrintGC) {
duke@435:       if (orig_size == max_gen_size()) {
duke@435:         gclog_or_tty->print_cr("ASParNew generation size at maximum: "
duke@435:           SIZE_FORMAT "K", orig_size/K);
duke@435:       } else if (orig_size == min_gen_size()) {
duke@435:         gclog_or_tty->print_cr("ASParNew generation size at minium: "
duke@435:           SIZE_FORMAT "K", orig_size/K);
duke@435:       }
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   if (size_changed) {
duke@435:     MemRegion cmr((HeapWord*)virtual_space()->low(),
duke@435:                   (HeapWord*)virtual_space()->high());
duke@435:     GenCollectedHeap::heap()->barrier_set()->resize_covered_region(cmr);
duke@435: 
duke@435:     if (Verbose && PrintGC) {
duke@435:       size_t current_size  = virtual_space()->committed_size();
duke@435:       gclog_or_tty->print_cr("ASParNew generation size changed: "
duke@435:                              SIZE_FORMAT "K->" SIZE_FORMAT "K",
duke@435:                              orig_size/K, current_size/K);
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   guarantee(eden_plus_survivors <= virtual_space()->committed_size() ||
duke@435:             virtual_space()->committed_size() == max_gen_size(), "Sanity");
duke@435: 
duke@435:   return true;
duke@435: }
duke@435: 
duke@435: void ASParNewGeneration::reset_survivors_after_shrink() {
duke@435: 
duke@435:   GenCollectedHeap* gch = GenCollectedHeap::heap();
duke@435:   HeapWord* new_end = (HeapWord*)virtual_space()->high();
duke@435: 
duke@435:   if (from()->end() > to()->end()) {
duke@435:     assert(new_end >= from()->end(), "Shrinking past from-space");
duke@435:   } else {
duke@435:     assert(new_end >= to()->bottom(), "Shrink was too large");
duke@435:     // Was there a shrink of the survivor space?
duke@435:     if (new_end < to()->end()) {
duke@435:       MemRegion mr(to()->bottom(), new_end);
jmasa@698:       to()->initialize(mr,
jmasa@698:                        SpaceDecorator::DontClear,
jmasa@698:                        SpaceDecorator::DontMangle);
duke@435:     }
duke@435:   }
duke@435: }
duke@435: void ASParNewGeneration::resize_spaces(size_t requested_eden_size,
duke@435:                                        size_t requested_survivor_size) {
duke@435:   assert(UseAdaptiveSizePolicy, "sanity check");
duke@435:   assert(requested_eden_size > 0  && requested_survivor_size > 0,
duke@435:          "just checking");
duke@435:   CollectedHeap* heap = Universe::heap();
duke@435:   assert(heap->kind() == CollectedHeap::GenCollectedHeap, "Sanity");
duke@435: 
duke@435: 
duke@435:   // We require eden and to space to be empty
duke@435:   if ((!eden()->is_empty()) || (!to()->is_empty())) {
duke@435:     return;
duke@435:   }
duke@435: 
duke@435:   size_t cur_eden_size = eden()->capacity();
duke@435: 
duke@435:   if (PrintAdaptiveSizePolicy && Verbose) {
duke@435:     gclog_or_tty->print_cr("ASParNew::resize_spaces(requested_eden_size: "
duke@435:                   SIZE_FORMAT
duke@435:                   ", requested_survivor_size: " SIZE_FORMAT ")",
duke@435:                   requested_eden_size, requested_survivor_size);
duke@435:     gclog_or_tty->print_cr("    eden: [" PTR_FORMAT ".." PTR_FORMAT ") "
duke@435:                   SIZE_FORMAT,
drchase@6680:                   p2i(eden()->bottom()),
drchase@6680:                   p2i(eden()->end()),
duke@435:                   pointer_delta(eden()->end(),
duke@435:                                 eden()->bottom(),
duke@435:                                 sizeof(char)));
duke@435:     gclog_or_tty->print_cr("    from: [" PTR_FORMAT ".." PTR_FORMAT ") "
duke@435:                   SIZE_FORMAT,
drchase@6680:                   p2i(from()->bottom()),
drchase@6680:                   p2i(from()->end()),
duke@435:                   pointer_delta(from()->end(),
duke@435:                                 from()->bottom(),
duke@435:                                 sizeof(char)));
duke@435:     gclog_or_tty->print_cr("      to: [" PTR_FORMAT ".." PTR_FORMAT ") "
duke@435:                   SIZE_FORMAT,
drchase@6680:                   p2i(to()->bottom()),
drchase@6680:                   p2i(to()->end()),
duke@435:                   pointer_delta(  to()->end(),
duke@435:                                   to()->bottom(),
duke@435:                                   sizeof(char)));
duke@435:   }
duke@435: 
duke@435:   // There's nothing to do if the new sizes are the same as the current
duke@435:   if (requested_survivor_size == to()->capacity() &&
duke@435:       requested_survivor_size == from()->capacity() &&
duke@435:       requested_eden_size == eden()->capacity()) {
duke@435:     if (PrintAdaptiveSizePolicy && Verbose) {
duke@435:       gclog_or_tty->print_cr("    capacities are the right sizes, returning");
duke@435:     }
duke@435:     return;
duke@435:   }
duke@435: 
duke@435:   char* eden_start = (char*)eden()->bottom();
duke@435:   char* eden_end   = (char*)eden()->end();
duke@435:   char* from_start = (char*)from()->bottom();
duke@435:   char* from_end   = (char*)from()->end();
duke@435:   char* to_start   = (char*)to()->bottom();
duke@435:   char* to_end     = (char*)to()->end();
duke@435: 
duke@435:   const size_t alignment = os::vm_page_size();
duke@435:   const bool maintain_minimum =
duke@435:     (requested_eden_size + 2 * requested_survivor_size) <= min_gen_size();
duke@435: 
duke@435:   // Check whether from space is below to space
duke@435:   if (from_start < to_start) {
duke@435:     // Eden, from, to
duke@435:     if (PrintAdaptiveSizePolicy && Verbose) {
duke@435:       gclog_or_tty->print_cr("  Eden, from, to:");
duke@435:     }
duke@435: 
duke@435:     // Set eden
duke@435:     // "requested_eden_size" is a goal for the size of eden
duke@435:     // and may not be attainable.  "eden_size" below is
duke@435:     // calculated based on the location of from-space and
duke@435:     // the goal for the size of eden.  from-space is
duke@435:     // fixed in place because it contains live data.
duke@435:     // The calculation is done this way to avoid 32bit
duke@435:     // overflow (i.e., eden_start + requested_eden_size
duke@435:     // may too large for representation in 32bits).
duke@435:     size_t eden_size;
duke@435:     if (maintain_minimum) {
duke@435:       // Only make eden larger than the requested size if
duke@435:       // the minimum size of the generation has to be maintained.
duke@435:       // This could be done in general but policy at a higher
duke@435:       // level is determining a requested size for eden and that
duke@435:       // should be honored unless there is a fundamental reason.
duke@435:       eden_size = pointer_delta(from_start,
duke@435:                                 eden_start,
duke@435:                                 sizeof(char));
duke@435:     } else {
duke@435:       eden_size = MIN2(requested_eden_size,
duke@435:                        pointer_delta(from_start, eden_start, sizeof(char)));
duke@435:     }
duke@435: 
duke@435:     eden_size = align_size_down(eden_size, alignment);
duke@435:     eden_end = eden_start + eden_size;
jcoomes@1844:     assert(eden_end >= eden_start, "addition overflowed");
duke@435: 
duke@435:     // To may resize into from space as long as it is clear of live data.
duke@435:     // From space must remain page aligned, though, so we need to do some
duke@435:     // extra calculations.
duke@435: 
duke@435:     // First calculate an optimal to-space
duke@435:     to_end   = (char*)virtual_space()->high();
duke@435:     to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size,
duke@435:                                     sizeof(char));
duke@435: 
duke@435:     // Does the optimal to-space overlap from-space?
duke@435:     if (to_start < (char*)from()->end()) {
duke@435:       // Calculate the minimum offset possible for from_end
duke@435:       size_t from_size = pointer_delta(from()->top(), from_start, sizeof(char));
duke@435: 
duke@435:       // Should we be in this method if from_space is empty? Why not the set_space method? FIX ME!
duke@435:       if (from_size == 0) {
duke@435:         from_size = alignment;
duke@435:       } else {
duke@435:         from_size = align_size_up(from_size, alignment);
duke@435:       }
duke@435: 
duke@435:       from_end = from_start + from_size;
duke@435:       assert(from_end > from_start, "addition overflow or from_size problem");
duke@435: 
duke@435:       guarantee(from_end <= (char*)from()->end(), "from_end moved to the right");
duke@435: 
duke@435:       // Now update to_start with the new from_end
duke@435:       to_start = MAX2(from_end, to_start);
duke@435:     } else {
duke@435:       // If shrinking, move to-space down to abut the end of from-space
duke@435:       // so that shrinking will move to-space down.  If not shrinking
duke@435:       // to-space is moving up to allow for growth on the next expansion.
duke@435:       if (requested_eden_size <= cur_eden_size) {
duke@435:         to_start = from_end;
duke@435:         if (to_start + requested_survivor_size > to_start) {
duke@435:           to_end = to_start + requested_survivor_size;
duke@435:         }
duke@435:       }
duke@435:       // else leave to_end pointing to the high end of the virtual space.
duke@435:     }
duke@435: 
duke@435:     guarantee(to_start != to_end, "to space is zero sized");
duke@435: 
duke@435:     if (PrintAdaptiveSizePolicy && Verbose) {
duke@435:       gclog_or_tty->print_cr("    [eden_start .. eden_end): "
duke@435:                     "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
drchase@6680:                     p2i(eden_start),
drchase@6680:                     p2i(eden_end),
duke@435:                     pointer_delta(eden_end, eden_start, sizeof(char)));
duke@435:       gclog_or_tty->print_cr("    [from_start .. from_end): "
duke@435:                     "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
drchase@6680:                     p2i(from_start),
drchase@6680:                     p2i(from_end),
duke@435:                     pointer_delta(from_end, from_start, sizeof(char)));
duke@435:       gclog_or_tty->print_cr("    [  to_start ..   to_end): "
duke@435:                     "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
drchase@6680:                     p2i(to_start),
drchase@6680:                     p2i(to_end),
duke@435:                     pointer_delta(  to_end,   to_start, sizeof(char)));
duke@435:     }
duke@435:   } else {
duke@435:     // Eden, to, from
duke@435:     if (PrintAdaptiveSizePolicy && Verbose) {
duke@435:       gclog_or_tty->print_cr("  Eden, to, from:");
duke@435:     }
duke@435: 
duke@435:     // Calculate the to-space boundaries based on
duke@435:     // the start of from-space.
duke@435:     to_end = from_start;
duke@435:     to_start = (char*)pointer_delta(from_start,
duke@435:                                     (char*)requested_survivor_size,
duke@435:                                     sizeof(char));
duke@435:     // Calculate the ideal eden boundaries.
duke@435:     // eden_end is already at the bottom of the generation
duke@435:     assert(eden_start == virtual_space()->low(),
duke@435:       "Eden is not starting at the low end of the virtual space");
duke@435:     if (eden_start + requested_eden_size >= eden_start) {
duke@435:       eden_end = eden_start + requested_eden_size;
duke@435:     } else {
duke@435:       eden_end = to_start;
duke@435:     }
duke@435: 
duke@435:     // Does eden intrude into to-space?  to-space
duke@435:     // gets priority but eden is not allowed to shrink
duke@435:     // to 0.
duke@435:     if (eden_end > to_start) {
duke@435:       eden_end = to_start;
duke@435:     }
duke@435: 
duke@435:     // Don't let eden shrink down to 0 or less.
duke@435:     eden_end = MAX2(eden_end, eden_start + alignment);
duke@435:     assert(eden_start + alignment >= eden_start, "Overflow");
duke@435: 
duke@435:     size_t eden_size;
duke@435:     if (maintain_minimum) {
duke@435:       // Use all the space available.
duke@435:       eden_end = MAX2(eden_end, to_start);
duke@435:       eden_size = pointer_delta(eden_end, eden_start, sizeof(char));
duke@435:       eden_size = MIN2(eden_size, cur_eden_size);
duke@435:     } else {
duke@435:       eden_size = pointer_delta(eden_end, eden_start, sizeof(char));
duke@435:     }
duke@435:     eden_size = align_size_down(eden_size, alignment);
duke@435:     assert(maintain_minimum || eden_size <= requested_eden_size,
duke@435:       "Eden size is too large");
duke@435:     assert(eden_size >= alignment, "Eden size is too small");
duke@435:     eden_end = eden_start + eden_size;
duke@435: 
duke@435:     // Move to-space down to eden.
duke@435:     if (requested_eden_size < cur_eden_size) {
duke@435:       to_start = eden_end;
duke@435:       if (to_start + requested_survivor_size > to_start) {
duke@435:         to_end = MIN2(from_start, to_start + requested_survivor_size);
duke@435:       } else {
duke@435:         to_end = from_start;
duke@435:       }
duke@435:     }
duke@435: 
duke@435:     // eden_end may have moved so again make sure
duke@435:     // the to-space and eden don't overlap.
duke@435:     to_start = MAX2(eden_end, to_start);
duke@435: 
duke@435:     // from-space
duke@435:     size_t from_used = from()->used();
duke@435:     if (requested_survivor_size > from_used) {
duke@435:       if (from_start + requested_survivor_size >= from_start) {
duke@435:         from_end = from_start + requested_survivor_size;
duke@435:       }
duke@435:       if (from_end > virtual_space()->high()) {
duke@435:         from_end = virtual_space()->high();
duke@435:       }
duke@435:     }
duke@435: 
duke@435:     assert(to_start >= eden_end, "to-space should be above eden");
duke@435:     if (PrintAdaptiveSizePolicy && Verbose) {
duke@435:       gclog_or_tty->print_cr("    [eden_start .. eden_end): "
duke@435:                     "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
drchase@6680:                     p2i(eden_start),
drchase@6680:                     p2i(eden_end),
duke@435:                     pointer_delta(eden_end, eden_start, sizeof(char)));
duke@435:       gclog_or_tty->print_cr("    [  to_start ..   to_end): "
duke@435:                     "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
drchase@6680:                     p2i(to_start),
drchase@6680:                     p2i(to_end),
duke@435:                     pointer_delta(  to_end,   to_start, sizeof(char)));
duke@435:       gclog_or_tty->print_cr("    [from_start .. from_end): "
duke@435:                     "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
drchase@6680:                     p2i(from_start),
drchase@6680:                     p2i(from_end),
duke@435:                     pointer_delta(from_end, from_start, sizeof(char)));
duke@435:     }
duke@435:   }
duke@435: 
duke@435: 
duke@435:   guarantee((HeapWord*)from_start <= from()->bottom(),
duke@435:             "from start moved to the right");
duke@435:   guarantee((HeapWord*)from_end >= from()->top(),
duke@435:             "from end moved into live data");
duke@435:   assert(is_object_aligned((intptr_t)eden_start), "checking alignment");
duke@435:   assert(is_object_aligned((intptr_t)from_start), "checking alignment");
duke@435:   assert(is_object_aligned((intptr_t)to_start), "checking alignment");
duke@435: 
duke@435:   MemRegion edenMR((HeapWord*)eden_start, (HeapWord*)eden_end);
duke@435:   MemRegion toMR  ((HeapWord*)to_start,   (HeapWord*)to_end);
duke@435:   MemRegion fromMR((HeapWord*)from_start, (HeapWord*)from_end);
duke@435: 
duke@435:   // Let's make sure the call to initialize doesn't reset "top"!
duke@435:   HeapWord* old_from_top = from()->top();
duke@435: 
duke@435:   // For PrintAdaptiveSizePolicy block  below
duke@435:   size_t old_from = from()->capacity();
duke@435:   size_t old_to   = to()->capacity();
duke@435: 
jmasa@698:   // If not clearing the spaces, do some checking to verify that
jmasa@698:   // the spaces are already mangled.
jmasa@698: 
jmasa@698:   // Must check mangling before the spaces are reshaped.  Otherwise,
jmasa@698:   // the bottom or end of one space may have moved into another
jmasa@698:   // a failure of the check may not correctly indicate which space
jmasa@698:   // is not properly mangled.
jmasa@698:   if (ZapUnusedHeapArea) {
jmasa@698:     HeapWord* limit = (HeapWord*) virtual_space()->high();
jmasa@698:     eden()->check_mangled_unused_area(limit);
jmasa@698:     from()->check_mangled_unused_area(limit);
jmasa@698:       to()->check_mangled_unused_area(limit);
jmasa@698:   }
jmasa@698: 
duke@435:   // The call to initialize NULL's the next compaction space
jmasa@698:   eden()->initialize(edenMR,
jmasa@698:                      SpaceDecorator::Clear,
jmasa@698:                      SpaceDecorator::DontMangle);
duke@435:   eden()->set_next_compaction_space(from());
jmasa@698:     to()->initialize(toMR  ,
jmasa@698:                      SpaceDecorator::Clear,
jmasa@698:                      SpaceDecorator::DontMangle);
jmasa@698:   from()->initialize(fromMR,
jmasa@698:                      SpaceDecorator::DontClear,
jmasa@698:                      SpaceDecorator::DontMangle);
duke@435: 
duke@435:   assert(from()->top() == old_from_top, "from top changed!");
duke@435: 
duke@435:   if (PrintAdaptiveSizePolicy) {
duke@435:     GenCollectedHeap* gch = GenCollectedHeap::heap();
duke@435:     assert(gch->kind() == CollectedHeap::GenCollectedHeap, "Sanity");
duke@435: 
duke@435:     gclog_or_tty->print("AdaptiveSizePolicy::survivor space sizes: "
duke@435:                   "collection: %d "
duke@435:                   "(" SIZE_FORMAT ", " SIZE_FORMAT ") -> "
duke@435:                   "(" SIZE_FORMAT ", " SIZE_FORMAT ") ",
duke@435:                   gch->total_collections(),
duke@435:                   old_from, old_to,
duke@435:                   from()->capacity(),
duke@435:                   to()->capacity());
duke@435:     gclog_or_tty->cr();
duke@435:   }
duke@435: }
duke@435: 
duke@435: void ASParNewGeneration::compute_new_size() {
duke@435:   GenCollectedHeap* gch = GenCollectedHeap::heap();
duke@435:   assert(gch->kind() == CollectedHeap::GenCollectedHeap,
duke@435:     "not a CMS generational heap");
duke@435: 
duke@435: 
duke@435:   CMSAdaptiveSizePolicy* size_policy =
duke@435:     (CMSAdaptiveSizePolicy*)gch->gen_policy()->size_policy();
duke@435:   assert(size_policy->is_gc_cms_adaptive_size_policy(),
duke@435:     "Wrong type of size policy");
duke@435: 
duke@435:   size_t survived = from()->used();
duke@435:   if (!survivor_overflow()) {
duke@435:     // Keep running averages on how much survived
duke@435:     size_policy->avg_survived()->sample(survived);
duke@435:   } else {
duke@435:     size_t promoted =
duke@435:       (size_t) next_gen()->gc_stats()->avg_promoted()->last_sample();
duke@435:     assert(promoted < gch->capacity(), "Conversion problem?");
duke@435:     size_t survived_guess = survived + promoted;
duke@435:     size_policy->avg_survived()->sample(survived_guess);
duke@435:   }
duke@435: 
duke@435:   size_t survivor_limit = max_survivor_size();
duke@435:   _tenuring_threshold =
duke@435:     size_policy->compute_survivor_space_size_and_threshold(
duke@435:                                                      _survivor_overflow,
duke@435:                                                      _tenuring_threshold,
duke@435:                                                      survivor_limit);
duke@435:   size_policy->avg_young_live()->sample(used());
duke@435:   size_policy->avg_eden_live()->sample(eden()->used());
duke@435: 
tamao@5192:   size_policy->compute_eden_space_size(eden()->capacity(), max_gen_size());
duke@435: 
duke@435:   resize(size_policy->calculated_eden_size_in_bytes(),
duke@435:          size_policy->calculated_survivor_size_in_bytes());
duke@435: 
duke@435:   if (UsePerfData) {
duke@435:     CMSGCAdaptivePolicyCounters* counters =
duke@435:       (CMSGCAdaptivePolicyCounters*) gch->collector_policy()->counters();
duke@435:     assert(counters->kind() ==
duke@435:            GCPolicyCounters::CMSGCAdaptivePolicyCountersKind,
duke@435:       "Wrong kind of counters");
duke@435:     counters->update_tenuring_threshold(_tenuring_threshold);
duke@435:     counters->update_survivor_overflowed(_survivor_overflow);
duke@435:     counters->update_young_capacity(capacity());
duke@435:   }
duke@435: }
duke@435: 
duke@435: 
duke@435: #ifndef PRODUCT
duke@435: // Changes from PSYoungGen version
duke@435: //      value of "alignment"
duke@435: void ASParNewGeneration::space_invariants() {
duke@435:   const size_t alignment = os::vm_page_size();
duke@435: 
duke@435:   // Currently, our eden size cannot shrink to zero
duke@435:   guarantee(eden()->capacity() >= alignment, "eden too small");
duke@435:   guarantee(from()->capacity() >= alignment, "from too small");
duke@435:   guarantee(to()->capacity() >= alignment, "to too small");
duke@435: 
duke@435:   // Relationship of spaces to each other
duke@435:   char* eden_start = (char*)eden()->bottom();
duke@435:   char* eden_end   = (char*)eden()->end();
duke@435:   char* from_start = (char*)from()->bottom();
duke@435:   char* from_end   = (char*)from()->end();
duke@435:   char* to_start   = (char*)to()->bottom();
duke@435:   char* to_end     = (char*)to()->end();
duke@435: 
duke@435:   guarantee(eden_start >= virtual_space()->low(), "eden bottom");
duke@435:   guarantee(eden_start < eden_end, "eden space consistency");
duke@435:   guarantee(from_start < from_end, "from space consistency");
duke@435:   guarantee(to_start < to_end, "to space consistency");
duke@435: 
duke@435:   // Check whether from space is below to space
duke@435:   if (from_start < to_start) {
duke@435:     // Eden, from, to
duke@435:     guarantee(eden_end <= from_start, "eden/from boundary");
duke@435:     guarantee(from_end <= to_start,   "from/to boundary");
duke@435:     guarantee(to_end <= virtual_space()->high(), "to end");
duke@435:   } else {
duke@435:     // Eden, to, from
duke@435:     guarantee(eden_end <= to_start, "eden/to boundary");
duke@435:     guarantee(to_end <= from_start, "to/from boundary");
duke@435:     guarantee(from_end <= virtual_space()->high(), "from end");
duke@435:   }
duke@435: 
duke@435:   // More checks that the virtual space is consistent with the spaces
duke@435:   assert(virtual_space()->committed_size() >=
duke@435:     (eden()->capacity() +
duke@435:      to()->capacity() +
duke@435:      from()->capacity()), "Committed size is inconsistent");
duke@435:   assert(virtual_space()->committed_size() <= virtual_space()->reserved_size(),
duke@435:     "Space invariant");
duke@435:   char* eden_top = (char*)eden()->top();
duke@435:   char* from_top = (char*)from()->top();
duke@435:   char* to_top = (char*)to()->top();
duke@435:   assert(eden_top <= virtual_space()->high(), "eden top");
duke@435:   assert(from_top <= virtual_space()->high(), "from top");
duke@435:   assert(to_top <= virtual_space()->high(), "to top");
duke@435: }
duke@435: #endif