duke@435: /*
stefank@2314:  * Copyright (c) 2003, 2010, 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/parallelScavenge/asPSYoungGen.hpp"
stefank@2314: #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
stefank@2314: #include "gc_implementation/parallelScavenge/psMarkSweepDecorator.hpp"
stefank@2314: #include "gc_implementation/parallelScavenge/psScavenge.hpp"
stefank@2314: #include "gc_implementation/parallelScavenge/psYoungGen.hpp"
stefank@2314: #include "gc_implementation/shared/gcUtil.hpp"
stefank@2314: #include "gc_implementation/shared/spaceDecorator.hpp"
stefank@2314: #include "oops/oop.inline.hpp"
stefank@2314: #include "runtime/java.hpp"
duke@435: 
duke@435: ASPSYoungGen::ASPSYoungGen(size_t init_byte_size,
duke@435:                            size_t minimum_byte_size,
duke@435:                            size_t byte_size_limit) :
duke@435:   PSYoungGen(init_byte_size, minimum_byte_size, byte_size_limit),
duke@435:   _gen_size_limit(byte_size_limit) {
duke@435: }
duke@435: 
duke@435: 
duke@435: ASPSYoungGen::ASPSYoungGen(PSVirtualSpace* vs,
duke@435:                            size_t init_byte_size,
duke@435:                            size_t minimum_byte_size,
duke@435:                            size_t byte_size_limit) :
duke@435:   //PSYoungGen(init_byte_size, minimum_byte_size, byte_size_limit),
duke@435:   PSYoungGen(vs->committed_size(), minimum_byte_size, byte_size_limit),
duke@435:   _gen_size_limit(byte_size_limit) {
duke@435: 
duke@435:   assert(vs->committed_size() == init_byte_size, "Cannot replace with");
duke@435: 
duke@435:   _virtual_space = vs;
duke@435: }
duke@435: 
duke@435: void ASPSYoungGen::initialize_virtual_space(ReservedSpace rs,
duke@435:                                             size_t alignment) {
duke@435:   assert(_init_gen_size != 0, "Should have a finite size");
duke@435:   _virtual_space = new PSVirtualSpaceHighToLow(rs, alignment);
duke@435:   if (!_virtual_space->expand_by(_init_gen_size)) {
duke@435:     vm_exit_during_initialization("Could not reserve enough space for "
duke@435:                                   "object heap");
duke@435:   }
duke@435: }
duke@435: 
duke@435: void ASPSYoungGen::initialize(ReservedSpace rs, size_t alignment) {
duke@435:   initialize_virtual_space(rs, alignment);
duke@435:   initialize_work();
duke@435: }
duke@435: 
duke@435: size_t ASPSYoungGen::available_for_expansion() {
duke@435: 
duke@435:   size_t current_committed_size = virtual_space()->committed_size();
duke@435:   assert((gen_size_limit() >= current_committed_size),
duke@435:     "generation size limit is wrong");
duke@435:   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
duke@435:   size_t result =  gen_size_limit() - current_committed_size;
duke@435:   size_t result_aligned = align_size_down(result, heap->young_gen_alignment());
duke@435:   return result_aligned;
duke@435: }
duke@435: 
duke@435: // Return the number of bytes the young gen is willing give up.
duke@435: //
duke@435: // Future implementations could check the survivors and if to_space is in the
duke@435: // right place (below from_space), take a chunk from to_space.
duke@435: size_t ASPSYoungGen::available_for_contraction() {
duke@435: 
duke@435:   size_t uncommitted_bytes = virtual_space()->uncommitted_size();
duke@435:   if (uncommitted_bytes != 0) {
duke@435:     return uncommitted_bytes;
duke@435:   }
duke@435: 
duke@435:   if (eden_space()->is_empty()) {
duke@435:     // Respect the minimum size for eden and for the young gen as a whole.
duke@435:     ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
jmasa@448:     const size_t eden_alignment = heap->intra_heap_alignment();
duke@435:     const size_t gen_alignment = heap->young_gen_alignment();
duke@435: 
duke@435:     assert(eden_space()->capacity_in_bytes() >= eden_alignment,
duke@435:       "Alignment is wrong");
duke@435:     size_t eden_avail = eden_space()->capacity_in_bytes() - eden_alignment;
duke@435:     eden_avail = align_size_down(eden_avail, gen_alignment);
duke@435: 
duke@435:     assert(virtual_space()->committed_size() >= min_gen_size(),
duke@435:       "minimum gen size is wrong");
duke@435:     size_t gen_avail = virtual_space()->committed_size() - min_gen_size();
duke@435:     assert(virtual_space()->is_aligned(gen_avail), "not aligned");
duke@435: 
duke@435:     const size_t max_contraction = MIN2(eden_avail, gen_avail);
duke@435:     // See comment for ASPSOldGen::available_for_contraction()
duke@435:     // for reasons the "increment" fraction is used.
duke@435:     PSAdaptiveSizePolicy* policy = heap->size_policy();
duke@435:     size_t result = policy->eden_increment_aligned_down(max_contraction);
duke@435:     size_t result_aligned = align_size_down(result, gen_alignment);
duke@435:     if (PrintAdaptiveSizePolicy && Verbose) {
duke@435:       gclog_or_tty->print_cr("ASPSYoungGen::available_for_contraction: %d K",
duke@435:         result_aligned/K);
duke@435:       gclog_or_tty->print_cr("  max_contraction %d K", max_contraction/K);
duke@435:       gclog_or_tty->print_cr("  eden_avail %d K", eden_avail/K);
duke@435:       gclog_or_tty->print_cr("  gen_avail %d K", gen_avail/K);
duke@435:     }
duke@435:     return result_aligned;
duke@435: 
duke@435:   }
duke@435: 
duke@435:   return 0;
duke@435: }
duke@435: 
duke@435: // The current implementation only considers to the end of eden.
duke@435: // If to_space is below from_space, to_space is not considered.
duke@435: // to_space can be.
duke@435: size_t ASPSYoungGen::available_to_live() {
duke@435:   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
jmasa@448:   const size_t alignment = heap->intra_heap_alignment();
duke@435: 
duke@435:   // Include any space that is committed but is not in eden.
duke@435:   size_t available = pointer_delta(eden_space()->bottom(),
duke@435:                                    virtual_space()->low(),
duke@435:                                    sizeof(char));
duke@435: 
duke@435:   const size_t eden_capacity = eden_space()->capacity_in_bytes();
duke@435:   if (eden_space()->is_empty() && eden_capacity > alignment) {
duke@435:     available += eden_capacity - alignment;
duke@435:   }
duke@435:   return available;
duke@435: }
duke@435: 
duke@435: // Similar to PSYoungGen::resize_generation() but
duke@435: //  allows sum of eden_size and 2 * survivor_size to exceed _max_gen_size
duke@435: //  expands at the low end of the virtual space
duke@435: //  moves the boundary between the generations in order to expand
duke@435: //  some additional diagnostics
duke@435: // If no additional changes are required, this can be deleted
duke@435: // and the changes factored back into PSYoungGen::resize_generation().
duke@435: bool ASPSYoungGen::resize_generation(size_t eden_size, size_t survivor_size) {
duke@435:   const size_t alignment = virtual_space()->alignment();
duke@435:   size_t orig_size = virtual_space()->committed_size();
duke@435:   bool size_changed = false;
duke@435: 
duke@435:   // There used to be a guarantee here that
duke@435:   //   (eden_size + 2*survivor_size)  <= _max_gen_size
duke@435:   // This requirement is enforced by the calculation of desired_size
duke@435:   // below.  It may not be true on entry since the size of the
duke@435:   // eden_size is no bounded by the generation size.
duke@435: 
duke@435:   assert(max_size() == reserved().byte_size(), "max gen size problem?");
duke@435:   assert(min_gen_size() <= orig_size && orig_size <= max_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, gen_size_limit()),
duke@435:                              min_gen_size());
duke@435:   assert(desired_size <= gen_size_limit(), "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;
jmasa@698:     HeapWord* prev_low = (HeapWord*) virtual_space()->low();
duke@435:     if (!virtual_space()->expand_by(change)) {
duke@435:       return false;
duke@435:     }
jmasa@698:     if (ZapUnusedHeapArea) {
jmasa@698:       // Mangle newly committed space immediately because it
jmasa@698:       // can be done here more simply that after the new
jmasa@698:       // spaces have been computed.
jmasa@698:       HeapWord* new_low = (HeapWord*) virtual_space()->low();
jmasa@698:       assert(new_low < prev_low, "Did not grow");
jmasa@698: 
jmasa@698:       MemRegion mangle_region(new_low, prev_low);
jmasa@698:       SpaceMangler::mangle_region(mangle_region);
jmasa@698:     }
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: 
duke@435:     // How much is available for shrinking.
duke@435:     size_t available_bytes = limit_gen_shrink(desired_change);
duke@435:     size_t change = MIN2(desired_change, available_bytes);
duke@435:     virtual_space()->shrink_by(change);
duke@435:     size_changed = true;
duke@435:   } else {
duke@435:     if (Verbose && PrintGC) {
duke@435:       if (orig_size == gen_size_limit()) {
duke@435:         gclog_or_tty->print_cr("ASPSYoung 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("ASPSYoung 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:     reset_after_change();
duke@435:     if (Verbose && PrintGC) {
duke@435:       size_t current_size  = virtual_space()->committed_size();
duke@435:       gclog_or_tty->print_cr("ASPSYoung 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_size(), "Sanity");
duke@435: 
duke@435:   return true;
duke@435: }
duke@435: 
duke@435: // Similar to PSYoungGen::resize_spaces() but
duke@435: //  eden always starts at the low end of the committed virtual space
duke@435: //  current implementation does not allow holes between the spaces
duke@435: //  _young_generation_boundary has to be reset because it changes.
duke@435: //  so additional verification
jmasa@698: 
duke@435: void ASPSYoungGen::resize_spaces(size_t requested_eden_size,
duke@435:                                  size_t requested_survivor_size) {
jmasa@698:   assert(UseAdaptiveSizePolicy, "sanity check");
duke@435:   assert(requested_eden_size > 0 && requested_survivor_size > 0,
duke@435:          "just checking");
duke@435: 
duke@435:   space_invariants();
duke@435: 
duke@435:   // We require eden and to space to be empty
duke@435:   if ((!eden_space()->is_empty()) || (!to_space()->is_empty())) {
duke@435:     return;
duke@435:   }
duke@435: 
duke@435:   if (PrintAdaptiveSizePolicy && Verbose) {
duke@435:     gclog_or_tty->print_cr("PSYoungGen::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,
duke@435:                   eden_space()->bottom(),
duke@435:                   eden_space()->end(),
duke@435:                   pointer_delta(eden_space()->end(),
duke@435:                                 eden_space()->bottom(),
duke@435:                                 sizeof(char)));
duke@435:     gclog_or_tty->print_cr("    from: [" PTR_FORMAT ".." PTR_FORMAT ") "
duke@435:                   SIZE_FORMAT,
duke@435:                   from_space()->bottom(),
duke@435:                   from_space()->end(),
duke@435:                   pointer_delta(from_space()->end(),
duke@435:                                 from_space()->bottom(),
duke@435:                                 sizeof(char)));
duke@435:     gclog_or_tty->print_cr("      to: [" PTR_FORMAT ".." PTR_FORMAT ") "
duke@435:                   SIZE_FORMAT,
duke@435:                   to_space()->bottom(),
duke@435:                   to_space()->end(),
duke@435:                   pointer_delta(  to_space()->end(),
duke@435:                                   to_space()->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_space()->capacity_in_bytes() &&
duke@435:       requested_survivor_size == from_space()->capacity_in_bytes() &&
duke@435:       requested_eden_size == eden_space()->capacity_in_bytes()) {
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*)virtual_space()->low();
duke@435:   char* eden_end   = (char*)eden_space()->end();
duke@435:   char* from_start = (char*)from_space()->bottom();
duke@435:   char* from_end   = (char*)from_space()->end();
duke@435:   char* to_start   = (char*)to_space()->bottom();
duke@435:   char* to_end     = (char*)to_space()->end();
duke@435: 
duke@435:   assert(eden_start < from_start, "Cannot push into from_space");
duke@435: 
duke@435:   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
jmasa@448:   const size_t alignment = heap->intra_heap_alignment();
jmasa@698:   const bool maintain_minimum =
jmasa@698:     (requested_eden_size + 2 * requested_survivor_size) <= min_gen_size();
duke@435: 
jmasa@698:   bool eden_from_to_order = from_start < to_start;
duke@435:   // Check whether from space is below to space
jmasa@698:   if (eden_from_to_order) {
duke@435:     // Eden, from, to
jmasa@698: 
duke@435:     if (PrintAdaptiveSizePolicy && Verbose) {
duke@435:       gclog_or_tty->print_cr("  Eden, from, to:");
duke@435:     }
duke@435: 
duke@435:     // Set eden
jmasa@698:     // "requested_eden_size" is a goal for the size of eden
jmasa@698:     // and may not be attainable.  "eden_size" below is
jmasa@698:     // calculated based on the location of from-space and
jmasa@698:     // the goal for the size of eden.  from-space is
jmasa@698:     // fixed in place because it contains live data.
jmasa@698:     // The calculation is done this way to avoid 32bit
jmasa@698:     // overflow (i.e., eden_start + requested_eden_size
jmasa@698:     // may too large for representation in 32bits).
jmasa@698:     size_t eden_size;
jmasa@698:     if (maintain_minimum) {
jmasa@698:       // Only make eden larger than the requested size if
jmasa@698:       // the minimum size of the generation has to be maintained.
jmasa@698:       // This could be done in general but policy at a higher
jmasa@698:       // level is determining a requested size for eden and that
jmasa@698:       // should be honored unless there is a fundamental reason.
jmasa@698:       eden_size = pointer_delta(from_start,
jmasa@698:                                 eden_start,
jmasa@698:                                 sizeof(char));
jmasa@698:     } else {
jmasa@698:       eden_size = MIN2(requested_eden_size,
jmasa@698:                        pointer_delta(from_start, eden_start, sizeof(char)));
jmasa@698:     }
jmasa@698: 
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,
duke@435:                                     (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_space()->end()) {
duke@435:       assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
duke@435: 
duke@435:       // Calculate the minimum offset possible for from_end
duke@435:       size_t from_size =
duke@435:         pointer_delta(from_space()->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_space()->end(),
duke@435:         "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:     }
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,
duke@435:                     eden_start,
duke@435:                     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,
duke@435:                     from_start,
duke@435:                     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,
duke@435:                     to_start,
duke@435:                     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:     // To space gets priority over eden resizing. Note that we position
duke@435:     // to space as if we were able to resize from space, even though from
duke@435:     // space is not modified.
duke@435:     // Giving eden priority was tried and gave poorer performance.
duke@435:     to_end   = (char*)pointer_delta(virtual_space()->high(),
duke@435:                                     (char*)requested_survivor_size,
duke@435:                                     sizeof(char));
duke@435:     to_end   = MIN2(to_end, from_start);
duke@435:     to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size,
duke@435:                                     sizeof(char));
duke@435:     // if the space sizes are to be increased by several times then
duke@435:     // 'to_start' will point beyond the young generation. In this case
duke@435:     // 'to_start' should be adjusted.
duke@435:     to_start = MAX2(to_start, eden_start + alignment);
duke@435: 
duke@435:     // Compute how big eden can be, then adjust end.
jmasa@698:     // See  comments above on calculating eden_end.
jmasa@698:     size_t eden_size;
jmasa@698:     if (maintain_minimum) {
jmasa@698:       eden_size = pointer_delta(to_start, eden_start, sizeof(char));
jmasa@698:     } else {
jmasa@698:       eden_size = MIN2(requested_eden_size,
jmasa@698:                        pointer_delta(to_start, eden_start, sizeof(char)));
jmasa@698:     }
duke@435:     eden_end = eden_start + eden_size;
jcoomes@1844:     assert(eden_end >= eden_start, "addition overflowed");
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:     to_start = MAX2(to_start, eden_end);
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,
duke@435:                     eden_start,
duke@435:                     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,
duke@435:                     to_start,
duke@435:                     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,
duke@435:                     from_start,
duke@435:                     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_space()->bottom(),
duke@435:             "from start moved to the right");
duke@435:   guarantee((HeapWord*)from_end >= from_space()->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:   DEBUG_ONLY(HeapWord* old_from_top = from_space()->top();)
duke@435: 
duke@435:   // For PrintAdaptiveSizePolicy block  below
duke@435:   size_t old_from = from_space()->capacity_in_bytes();
duke@435:   size_t old_to   = to_space()->capacity_in_bytes();
duke@435: 
jmasa@698:   if (ZapUnusedHeapArea) {
jmasa@698:     // NUMA is a special case because a numa space is not mangled
jmasa@698:     // in order to not prematurely bind its address to memory to
jmasa@698:     // the wrong memory (i.e., don't want the GC thread to first
jmasa@698:     // touch the memory).  The survivor spaces are not numa
jmasa@698:     // spaces and are mangled.
jmasa@698:     if (UseNUMA) {
jmasa@698:       if (eden_from_to_order) {
jmasa@698:         mangle_survivors(from_space(), fromMR, to_space(), toMR);
jmasa@698:       } else {
jmasa@698:         mangle_survivors(to_space(), toMR, from_space(), fromMR);
jmasa@698:       }
jmasa@698:     }
jmasa@698: 
jmasa@698:     // If not mangling the spaces, do some checking to verify that
jmasa@698:     // the spaces are already mangled.
jmasa@698:     // The spaces should be correctly mangled at this point so
jmasa@698:     // do some checking here. Note that they are not being mangled
jmasa@698:     // in the calls to initialize().
jmasa@698:     // Must check mangling before the spaces are reshaped.  Otherwise,
jmasa@698:     // the bottom or end of one space may have moved into an area
jmasa@698:     // covered by another space and a failure of the check may
jmasa@698:     // not correctly indicate which space is not properly mangled.
jmasa@698: 
jmasa@698:     HeapWord* limit = (HeapWord*) virtual_space()->high();
jmasa@698:     eden_space()->check_mangled_unused_area(limit);
jmasa@698:     from_space()->check_mangled_unused_area(limit);
jmasa@698:       to_space()->check_mangled_unused_area(limit);
jmasa@698:   }
jmasa@698:   // When an existing space is being initialized, it is not
jmasa@698:   // mangled because the space has been previously mangled.
jmasa@698:   eden_space()->initialize(edenMR,
jmasa@698:                            SpaceDecorator::Clear,
jmasa@698:                            SpaceDecorator::DontMangle);
jmasa@698:     to_space()->initialize(toMR,
jmasa@698:                            SpaceDecorator::Clear,
jmasa@698:                            SpaceDecorator::DontMangle);
jmasa@698:   from_space()->initialize(fromMR,
jmasa@698:                            SpaceDecorator::DontClear,
jmasa@698:                            SpaceDecorator::DontMangle);
jmasa@698: 
duke@435:   PSScavenge::set_young_generation_boundary(eden_space()->bottom());
duke@435: 
duke@435:   assert(from_space()->top() == old_from_top, "from top changed!");
duke@435: 
duke@435:   if (PrintAdaptiveSizePolicy) {
duke@435:     ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
duke@435:     assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "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:                   heap->total_collections(),
duke@435:                   old_from, old_to,
duke@435:                   from_space()->capacity_in_bytes(),
duke@435:                   to_space()->capacity_in_bytes());
duke@435:     gclog_or_tty->cr();
duke@435:   }
duke@435:   space_invariants();
duke@435: }
duke@435: void ASPSYoungGen::reset_after_change() {
duke@435:   assert_locked_or_safepoint(Heap_lock);
duke@435: 
duke@435:   _reserved = MemRegion((HeapWord*)virtual_space()->low_boundary(),
duke@435:                         (HeapWord*)virtual_space()->high_boundary());
duke@435:   PSScavenge::reference_processor()->set_span(_reserved);
duke@435: 
duke@435:   HeapWord* new_eden_bottom = (HeapWord*)virtual_space()->low();
duke@435:   HeapWord* eden_bottom = eden_space()->bottom();
duke@435:   if (new_eden_bottom != eden_bottom) {
duke@435:     MemRegion eden_mr(new_eden_bottom, eden_space()->end());
jmasa@698:     eden_space()->initialize(eden_mr,
jmasa@698:                              SpaceDecorator::Clear,
jmasa@698:                              SpaceDecorator::Mangle);
duke@435:     PSScavenge::set_young_generation_boundary(eden_space()->bottom());
duke@435:   }
duke@435:   MemRegion cmr((HeapWord*)virtual_space()->low(),
duke@435:                 (HeapWord*)virtual_space()->high());
duke@435:   Universe::heap()->barrier_set()->resize_covered_region(cmr);
duke@435: 
duke@435:   space_invariants();
duke@435: }