jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/parallelScavenge/psYoungGen.cpp@af8f16ac392c (annotated)

src/share/vm/gc_implementation/parallelScavenge/psYoungGen.cpp@af8f16ac392c (annotated)

src/share/vm/gc_implementation/parallelScavenge/psYoungGen.cpp

Thu, 09 Apr 2015 15:59:26 +0200

author: mlarsson
date: Thu, 09 Apr 2015 15:59:26 +0200
changeset 7687: af8f16ac392c
parent 6680: 78bbf4d43a14
child 6876: 710a3c8b516e
permissions: -rw-r--r--

8066771: Refactor VM GC operations caused by allocation failure
Reviewed-by: brutisso, jmasa

 /*
  * Copyright (c) 2001, 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/parallelScavenge/parallelScavengeHeap.hpp"
 #include "gc_implementation/parallelScavenge/psMarkSweepDecorator.hpp"
 #include "gc_implementation/parallelScavenge/psScavenge.hpp"
 #include "gc_implementation/parallelScavenge/psYoungGen.hpp"
 #include "gc_implementation/shared/gcUtil.hpp"
 #include "gc_implementation/shared/mutableNUMASpace.hpp"
 #include "gc_implementation/shared/spaceDecorator.hpp"
 #include "oops/oop.inline.hpp"
 #include "runtime/java.hpp"
 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
 PSYoungGen::PSYoungGen(size_t        initial_size,
                        size_t        min_size,
                        size_t        max_size) :
   _init_gen_size(initial_size),
   _min_gen_size(min_size),
   _max_gen_size(max_size)
 {}
 void PSYoungGen::initialize_virtual_space(ReservedSpace rs, size_t alignment) {
   assert(_init_gen_size != 0, "Should have a finite size");
   _virtual_space = new PSVirtualSpace(rs, alignment);
   if (!virtual_space()->expand_by(_init_gen_size)) {
     vm_exit_during_initialization("Could not reserve enough space for "
                                   "object heap");
   }
 }
 void PSYoungGen::initialize(ReservedSpace rs, size_t alignment) {
   initialize_virtual_space(rs, alignment);
   initialize_work();
 }
 void PSYoungGen::initialize_work() {
   _reserved = MemRegion((HeapWord*)virtual_space()->low_boundary(),
                         (HeapWord*)virtual_space()->high_boundary());
   MemRegion cmr((HeapWord*)virtual_space()->low(),
                 (HeapWord*)virtual_space()->high());
   Universe::heap()->barrier_set()->resize_covered_region(cmr);
   if (ZapUnusedHeapArea) {
     // Mangle newly committed space immediately because it
     // can be done here more simply that after the new
     // spaces have been computed.
     SpaceMangler::mangle_region(cmr);
   }
   if (UseNUMA) {
     _eden_space = new MutableNUMASpace(virtual_space()->alignment());
   } else {
     _eden_space = new MutableSpace(virtual_space()->alignment());
   }
   _from_space = new MutableSpace(virtual_space()->alignment());
   _to_space   = new MutableSpace(virtual_space()->alignment());
   if (_eden_space == NULL || _from_space == NULL || _to_space == NULL) {
     vm_exit_during_initialization("Could not allocate a young gen space");
   }
   // Allocate the mark sweep views of spaces
   _eden_mark_sweep =
       new PSMarkSweepDecorator(_eden_space, NULL, MarkSweepDeadRatio);
   _from_mark_sweep =
       new PSMarkSweepDecorator(_from_space, NULL, MarkSweepDeadRatio);
   _to_mark_sweep =
       new PSMarkSweepDecorator(_to_space, NULL, MarkSweepDeadRatio);
   if (_eden_mark_sweep == NULL ||
       _from_mark_sweep == NULL ||
       _to_mark_sweep == NULL) {
     vm_exit_during_initialization("Could not complete allocation"
                                   " of the young generation");
   }
   // Generation Counters - generation 0, 3 subspaces
   _gen_counters = new PSGenerationCounters("new", 0, 3, _virtual_space);
   // Compute maximum space sizes for performance counters
   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
   size_t alignment = heap->space_alignment();
   size_t size = virtual_space()->reserved_size();
   size_t max_survivor_size;
   size_t max_eden_size;
   if (UseAdaptiveSizePolicy) {
     max_survivor_size = size / MinSurvivorRatio;
     // round the survivor space size down to the nearest alignment
     // and make sure its size is greater than 0.
     max_survivor_size = align_size_down(max_survivor_size, alignment);
     max_survivor_size = MAX2(max_survivor_size, alignment);
     // set the maximum size of eden to be the size of the young gen
     // less two times the minimum survivor size. The minimum survivor
     // size for UseAdaptiveSizePolicy is one alignment.
     max_eden_size = size - 2 * alignment;
   } else {
     max_survivor_size = size / InitialSurvivorRatio;
     // round the survivor space size down to the nearest alignment
     // and make sure its size is greater than 0.
     max_survivor_size = align_size_down(max_survivor_size, alignment);
     max_survivor_size = MAX2(max_survivor_size, alignment);
     // set the maximum size of eden to be the size of the young gen
     // less two times the survivor size when the generation is 100%
     // committed. The minimum survivor size for -UseAdaptiveSizePolicy
     // is dependent on the committed portion (current capacity) of the
     // generation - the less space committed, the smaller the survivor
     // space, possibly as small as an alignment. However, we are interested
     // in the case where the young generation is 100% committed, as this
     // is the point where eden reachs its maximum size. At this point,
     // the size of a survivor space is max_survivor_size.
     max_eden_size = size - 2 * max_survivor_size;
   }
   _eden_counters = new SpaceCounters("eden", 0, max_eden_size, _eden_space,
                                      _gen_counters);
   _from_counters = new SpaceCounters("s0", 1, max_survivor_size, _from_space,
                                      _gen_counters);
   _to_counters = new SpaceCounters("s1", 2, max_survivor_size, _to_space,
                                    _gen_counters);
   compute_initial_space_boundaries();
 }
 void PSYoungGen::compute_initial_space_boundaries() {
   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
   // Compute sizes
   size_t alignment = heap->space_alignment();
   size_t size = virtual_space()->committed_size();
   assert(size >= 3 * alignment, "Young space is not large enough for eden + 2 survivors");
   size_t survivor_size = size / InitialSurvivorRatio;
   survivor_size = align_size_down(survivor_size, alignment);
   // ... but never less than an alignment
   survivor_size = MAX2(survivor_size, alignment);
   // Young generation is eden + 2 survivor spaces
   size_t eden_size = size - (2 * survivor_size);
   // Now go ahead and set 'em.
   set_space_boundaries(eden_size, survivor_size);
   space_invariants();
   if (UsePerfData) {
     _eden_counters->update_capacity();
     _from_counters->update_capacity();
     _to_counters->update_capacity();
   }
 }
 void PSYoungGen::set_space_boundaries(size_t eden_size, size_t survivor_size) {
   assert(eden_size < virtual_space()->committed_size(), "just checking");
   assert(eden_size > 0  && survivor_size > 0, "just checking");
   // Initial layout is Eden, to, from. After swapping survivor spaces,
   // that leaves us with Eden, from, to, which is step one in our two
   // step resize-with-live-data procedure.
   char *eden_start = virtual_space()->low();
   char *to_start   = eden_start + eden_size;
   char *from_start = to_start   + survivor_size;
   char *from_end   = from_start + survivor_size;
   assert(from_end == virtual_space()->high(), "just checking");
   assert(is_object_aligned((intptr_t)eden_start), "checking alignment");
   assert(is_object_aligned((intptr_t)to_start),   "checking alignment");
   assert(is_object_aligned((intptr_t)from_start), "checking alignment");
   MemRegion eden_mr((HeapWord*)eden_start, (HeapWord*)to_start);
   MemRegion to_mr  ((HeapWord*)to_start, (HeapWord*)from_start);
   MemRegion from_mr((HeapWord*)from_start, (HeapWord*)from_end);
   eden_space()->initialize(eden_mr, true, ZapUnusedHeapArea);
     to_space()->initialize(to_mr  , true, ZapUnusedHeapArea);
   from_space()->initialize(from_mr, true, ZapUnusedHeapArea);
 }
 #ifndef PRODUCT
 void PSYoungGen::space_invariants() {
   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
   const size_t alignment = heap->space_alignment();
   // Currently, our eden size cannot shrink to zero
   guarantee(eden_space()->capacity_in_bytes() >= alignment, "eden too small");
   guarantee(from_space()->capacity_in_bytes() >= alignment, "from too small");
   guarantee(to_space()->capacity_in_bytes() >= alignment, "to too small");
   // Relationship of spaces to each other
   char* eden_start = (char*)eden_space()->bottom();
   char* eden_end   = (char*)eden_space()->end();
   char* from_start = (char*)from_space()->bottom();
   char* from_end   = (char*)from_space()->end();
   char* to_start   = (char*)to_space()->bottom();
   char* to_end     = (char*)to_space()->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_space()->capacity_in_bytes() +
      to_space()->capacity_in_bytes() +
      from_space()->capacity_in_bytes()), "Committed size is inconsistent");
   assert(virtual_space()->committed_size() <= virtual_space()->reserved_size(),
     "Space invariant");
   char* eden_top = (char*)eden_space()->top();
   char* from_top = (char*)from_space()->top();
   char* to_top = (char*)to_space()->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");
   virtual_space()->verify();
 }
 #endif
 void PSYoungGen::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_in_bytes(), capacity_in_bytes(),
         _max_gen_size, min_gen_size());
     }
   }
 }
 bool PSYoungGen::resize_generation(size_t eden_size, size_t survivor_size) {
   const size_t alignment = virtual_space()->alignment();
   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_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_size()),
                              min_gen_size());
   assert(desired_size <= max_size(), "just checking");
   if (desired_size > orig_size) {
     // Grow the generation
     size_t change = desired_size - orig_size;
     assert(change % alignment == 0, "just checking");
     HeapWord* prev_high = (HeapWord*) virtual_space()->high();
     if (!virtual_space()->expand_by(change)) {
       return false; // Error if we fail to resize!
     }
     if (ZapUnusedHeapArea) {
       // Mangle newly committed space immediately because it
       // can be done here more simply that after the new
       // spaces have been computed.
       HeapWord* new_high = (HeapWord*) virtual_space()->high();
       MemRegion mangle_region(prev_high, new_high);
       SpaceMangler::mangle_region(mangle_region);
     }
     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 == gen_size_limit()) {
         gclog_or_tty->print_cr("PSYoung generation size at maximum: "
           SIZE_FORMAT "K", orig_size/K);
       } else if (orig_size == min_gen_size()) {
         gclog_or_tty->print_cr("PSYoung generation size at minium: "
           SIZE_FORMAT "K", orig_size/K);
       }
     }
   }
   if (size_changed) {
     post_resize();
     if (Verbose && PrintGC) {
       size_t current_size  = virtual_space()->committed_size();
       gclog_or_tty->print_cr("PSYoung 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_size(), "Sanity");
   return true;
 }
 #ifndef PRODUCT
 // In the numa case eden is not mangled so a survivor space
 // moving into a region previously occupied by a survivor
 // may find an unmangled region.  Also in the PS case eden
 // to-space and from-space may not touch (i.e., there may be
 // gaps between them due to movement while resizing the
 // spaces).  Those gaps must be mangled.
 void PSYoungGen::mangle_survivors(MutableSpace* s1,
                                   MemRegion s1MR,
                                   MutableSpace* s2,
                                   MemRegion s2MR) {
   // Check eden and gap between eden and from-space, in deciding
   // what to mangle in from-space.  Check the gap between from-space
   // and to-space when deciding what to mangle.
   //
   //      +--------+   +----+    +---+
   //      | eden   |   |s1  |    |s2 |
   //      +--------+   +----+    +---+
   //                 +-------+ +-----+
   //                 |s1MR   | |s2MR |
   //                 +-------+ +-----+
   // All of survivor-space is properly mangled so find the
   // upper bound on the mangling for any portion above current s1.
   HeapWord* delta_end = MIN2(s1->bottom(), s1MR.end());
   MemRegion delta1_left;
   if (s1MR.start() < delta_end) {
     delta1_left = MemRegion(s1MR.start(), delta_end);
     s1->mangle_region(delta1_left);
   }
   // Find any portion to the right of the current s1.
   HeapWord* delta_start = MAX2(s1->end(), s1MR.start());
   MemRegion delta1_right;
   if (delta_start < s1MR.end()) {
     delta1_right = MemRegion(delta_start, s1MR.end());
     s1->mangle_region(delta1_right);
   }
   // Similarly for the second survivor space except that
   // any of the new region that overlaps with the current
   // region of the first survivor space has already been
   // mangled.
   delta_end = MIN2(s2->bottom(), s2MR.end());
   delta_start = MAX2(s2MR.start(), s1->end());
   MemRegion delta2_left;
   if (s2MR.start() < delta_end) {
     delta2_left = MemRegion(s2MR.start(), delta_end);
     s2->mangle_region(delta2_left);
   }
   delta_start = MAX2(s2->end(), s2MR.start());
   MemRegion delta2_right;
   if (delta_start < s2MR.end()) {
     s2->mangle_region(delta2_right);
   }
   if (TraceZapUnusedHeapArea) {
     // s1
     gclog_or_tty->print_cr("Current region: [" PTR_FORMAT ", " PTR_FORMAT ") "
       "New region: [" PTR_FORMAT ", " PTR_FORMAT ")",
       s1->bottom(), s1->end(), s1MR.start(), s1MR.end());
     gclog_or_tty->print_cr("    Mangle before: [" PTR_FORMAT ", "
       PTR_FORMAT ")  Mangle after: [" PTR_FORMAT ", " PTR_FORMAT ")",
       delta1_left.start(), delta1_left.end(), delta1_right.start(),
       delta1_right.end());
     // s2
     gclog_or_tty->print_cr("Current region: [" PTR_FORMAT ", " PTR_FORMAT ") "
       "New region: [" PTR_FORMAT ", " PTR_FORMAT ")",
       s2->bottom(), s2->end(), s2MR.start(), s2MR.end());
     gclog_or_tty->print_cr("    Mangle before: [" PTR_FORMAT ", "
       PTR_FORMAT ")  Mangle after: [" PTR_FORMAT ", " PTR_FORMAT ")",
       delta2_left.start(), delta2_left.end(), delta2_right.start(),
       delta2_right.end());
   }
 }
 #endif // NOT PRODUCT
 void PSYoungGen::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");
   // We require eden and to space to be empty
   if ((!eden_space()->is_empty()) || (!to_space()->is_empty())) {
     return;
   }
   if (PrintAdaptiveSizePolicy && Verbose) {
     gclog_or_tty->print_cr("PSYoungGen::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,
                   eden_space()->bottom(),
                   eden_space()->end(),
                   pointer_delta(eden_space()->end(),
                                 eden_space()->bottom(),
                                 sizeof(char)));
     gclog_or_tty->print_cr("    from: [" PTR_FORMAT ".." PTR_FORMAT ") "
                   SIZE_FORMAT,
                   from_space()->bottom(),
                   from_space()->end(),
                   pointer_delta(from_space()->end(),
                                 from_space()->bottom(),
                                 sizeof(char)));
     gclog_or_tty->print_cr("      to: [" PTR_FORMAT ".." PTR_FORMAT ") "
                   SIZE_FORMAT,
                   to_space()->bottom(),
                   to_space()->end(),
                   pointer_delta(  to_space()->end(),
                                   to_space()->bottom(),
                                   sizeof(char)));
   }
   // There's nothing to do if the new sizes are the same as the current
   if (requested_survivor_size == to_space()->capacity_in_bytes() &&
       requested_survivor_size == from_space()->capacity_in_bytes() &&
       requested_eden_size == eden_space()->capacity_in_bytes()) {
     if (PrintAdaptiveSizePolicy && Verbose) {
       gclog_or_tty->print_cr("    capacities are the right sizes, returning");
     }
     return;
   }
   char* eden_start = (char*)eden_space()->bottom();
   char* eden_end   = (char*)eden_space()->end();
   char* from_start = (char*)from_space()->bottom();
   char* from_end   = (char*)from_space()->end();
   char* to_start   = (char*)to_space()->bottom();
   char* to_end     = (char*)to_space()->end();
   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
   const size_t alignment = heap->space_alignment();
   const bool maintain_minimum =
     (requested_eden_size + 2 * requested_survivor_size) <= min_gen_size();
   bool eden_from_to_order = from_start < to_start;
   // Check whether from space is below to space
   if (eden_from_to_order) {
     // Eden, from, to
     eden_from_to_order = true;
     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_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_space()->end()) {
       assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
       // Calculate the minimum offset possible for from_end
       size_t from_size = pointer_delta(from_space()->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_space()->end(), "from_end moved to the right");
       // Now update to_start with the new from_end
       to_start = MAX2(from_end, to_start);
     }
     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,
                     eden_start,
                     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,
                     from_start,
                     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,
                     to_start,
                     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:");
     }
     // To space gets priority over eden resizing. Note that we position
     // to space as if we were able to resize from space, even though from
     // space is not modified.
     // Giving eden priority was tried and gave poorer performance.
     to_end   = (char*)pointer_delta(virtual_space()->high(),
                                     (char*)requested_survivor_size,
                                     sizeof(char));
     to_end   = MIN2(to_end, from_start);
     to_start = (char*)pointer_delta(to_end, (char*)requested_survivor_size,
                                     sizeof(char));
     // if the space sizes are to be increased by several times then
     // 'to_start' will point beyond the young generation. In this case
     // 'to_start' should be adjusted.
     to_start = MAX2(to_start, eden_start + alignment);
     // Compute how big eden can be, then adjust end.
     // See  comments above on calculating eden_end.
     size_t eden_size;
     if (maintain_minimum) {
       eden_size = pointer_delta(to_start, eden_start, sizeof(char));
     } else {
       eden_size = MIN2(requested_eden_size,
                        pointer_delta(to_start, eden_start, sizeof(char)));
     }
     eden_end = eden_start + eden_size;
     assert(eden_end >= eden_start, "addition overflowed");
     // Could choose to not let eden shrink
     // to_start = MAX2(to_start, eden_end);
     // Don't let eden shrink down to 0 or less.
     eden_end = MAX2(eden_end, eden_start + alignment);
     to_start = MAX2(to_start, eden_end);
     if (PrintAdaptiveSizePolicy && Verbose) {
       gclog_or_tty->print_cr("    [eden_start .. eden_end): "
                     "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
                     eden_start,
                     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,
                     to_start,
                     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,
                     from_start,
                     from_end,
                     pointer_delta(from_end, from_start, sizeof(char)));
     }
   }
   guarantee((HeapWord*)from_start <= from_space()->bottom(),
             "from start moved to the right");
   guarantee((HeapWord*)from_end >= from_space()->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_space()->top();
   // For PrintAdaptiveSizePolicy block  below
   size_t old_from = from_space()->capacity_in_bytes();
   size_t old_to   = to_space()->capacity_in_bytes();
   if (ZapUnusedHeapArea) {
     // NUMA is a special case because a numa space is not mangled
     // in order to not prematurely bind its address to memory to
     // the wrong memory (i.e., don't want the GC thread to first
     // touch the memory).  The survivor spaces are not numa
     // spaces and are mangled.
     if (UseNUMA) {
       if (eden_from_to_order) {
         mangle_survivors(from_space(), fromMR, to_space(), toMR);
       } else {
         mangle_survivors(to_space(), toMR, from_space(), fromMR);
       }
     }
     // If not mangling the spaces, do some checking to verify that
     // the spaces are already mangled.
     // The spaces should be correctly mangled at this point so
     // do some checking here. Note that they are not being mangled
     // in the calls to initialize().
     // Must check mangling before the spaces are reshaped.  Otherwise,
     // the bottom or end of one space may have moved into an area
     // covered by another space and a failure of the check may
     // not correctly indicate which space is not properly mangled.
     HeapWord* limit = (HeapWord*) virtual_space()->high();
     eden_space()->check_mangled_unused_area(limit);
     from_space()->check_mangled_unused_area(limit);
       to_space()->check_mangled_unused_area(limit);
   }
   // When an existing space is being initialized, it is not
   // mangled because the space has been previously mangled.
   eden_space()->initialize(edenMR,
                            SpaceDecorator::Clear,
                            SpaceDecorator::DontMangle);
     to_space()->initialize(toMR,
                            SpaceDecorator::Clear,
                            SpaceDecorator::DontMangle);
   from_space()->initialize(fromMR,
                            SpaceDecorator::DontClear,
                            SpaceDecorator::DontMangle);
   assert(from_space()->top() == old_from_top, "from top changed!");
   if (PrintAdaptiveSizePolicy) {
     ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
     assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
     gclog_or_tty->print("AdaptiveSizePolicy::survivor space sizes: "
                   "collection: %d "
                   "(" SIZE_FORMAT ", " SIZE_FORMAT ") -> "
                   "(" SIZE_FORMAT ", " SIZE_FORMAT ") ",
                   heap->total_collections(),
                   old_from, old_to,
                   from_space()->capacity_in_bytes(),
                   to_space()->capacity_in_bytes());
     gclog_or_tty->cr();
   }
 }
 void PSYoungGen::swap_spaces() {
   MutableSpace* s    = from_space();
   _from_space        = to_space();
   _to_space          = s;
   // Now update the decorators.
   PSMarkSweepDecorator* md = from_mark_sweep();
   _from_mark_sweep           = to_mark_sweep();
   _to_mark_sweep             = md;
   assert(from_mark_sweep()->space() == from_space(), "Sanity");
   assert(to_mark_sweep()->space() == to_space(), "Sanity");
 }
 size_t PSYoungGen::capacity_in_bytes() const {
   return eden_space()->capacity_in_bytes()
        + from_space()->capacity_in_bytes();  // to_space() is only used during scavenge
 }
 size_t PSYoungGen::used_in_bytes() const {
   return eden_space()->used_in_bytes()
        + from_space()->used_in_bytes();      // to_space() is only used during scavenge
 }
 size_t PSYoungGen::free_in_bytes() const {
   return eden_space()->free_in_bytes()
        + from_space()->free_in_bytes();      // to_space() is only used during scavenge
 }
 size_t PSYoungGen::capacity_in_words() const {
   return eden_space()->capacity_in_words()
        + from_space()->capacity_in_words();  // to_space() is only used during scavenge
 }
 size_t PSYoungGen::used_in_words() const {
   return eden_space()->used_in_words()
        + from_space()->used_in_words();      // to_space() is only used during scavenge
 }
 size_t PSYoungGen::free_in_words() const {
   return eden_space()->free_in_words()
        + from_space()->free_in_words();      // to_space() is only used during scavenge
 }
 void PSYoungGen::object_iterate(ObjectClosure* blk) {
   eden_space()->object_iterate(blk);
   from_space()->object_iterate(blk);
   to_space()->object_iterate(blk);
 }
 void PSYoungGen::precompact() {
   eden_mark_sweep()->precompact();
   from_mark_sweep()->precompact();
   to_mark_sweep()->precompact();
 }
 void PSYoungGen::adjust_pointers() {
   eden_mark_sweep()->adjust_pointers();
   from_mark_sweep()->adjust_pointers();
   to_mark_sweep()->adjust_pointers();
 }
 void PSYoungGen::compact() {
   eden_mark_sweep()->compact(ZapUnusedHeapArea);
   from_mark_sweep()->compact(ZapUnusedHeapArea);
   // Mark sweep stores preserved markOops in to space, don't disturb!
   to_mark_sweep()->compact(false);
 }
 void PSYoungGen::print() const { print_on(tty); }
 void PSYoungGen::print_on(outputStream* st) const {
   st->print(" %-15s", "PSYoungGen");
   if (PrintGCDetails && Verbose) {
     st->print(" total " SIZE_FORMAT ", used " SIZE_FORMAT,
                capacity_in_bytes(), used_in_bytes());
   } else {
     st->print(" total " SIZE_FORMAT "K, used " SIZE_FORMAT "K",
                capacity_in_bytes()/K, used_in_bytes()/K);
   }
   virtual_space()->print_space_boundaries_on(st);
   st->print("  eden"); eden_space()->print_on(st);
   st->print("  from"); from_space()->print_on(st);
   st->print("  to  "); to_space()->print_on(st);
 }
 // Note that a space is not printed before the [NAME:
 void PSYoungGen::print_used_change(size_t prev_used) const {
   gclog_or_tty->print("[%s:", name());
   gclog_or_tty->print(" "  SIZE_FORMAT "K"
                       "->" SIZE_FORMAT "K"
                       "("  SIZE_FORMAT "K)",
                       prev_used / K, used_in_bytes() / K,
                       capacity_in_bytes() / K);
   gclog_or_tty->print("]");
 }
 size_t PSYoungGen::available_for_expansion() {
   ShouldNotReachHere();
   return 0;
 }
 size_t PSYoungGen::available_for_contraction() {
   ShouldNotReachHere();
   return 0;
 }
 size_t PSYoungGen::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 PSYoungGen::available_to_live() {
   size_t delta_in_survivor = 0;
   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
   const size_t space_alignment = heap->space_alignment();
   const size_t gen_alignment = heap->generation_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;
 }
 // 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 PSYoungGen::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, virtual_space()->alignment());
 }
 void PSYoungGen::reset_after_change() {
   ShouldNotReachHere();
 }
 void PSYoungGen::reset_survivors_after_shrink() {
   _reserved = MemRegion((HeapWord*)virtual_space()->low_boundary(),
                         (HeapWord*)virtual_space()->high_boundary());
   PSScavenge::reference_processor()->set_span(_reserved);
   MutableSpace* space_shrinking = NULL;
   if (from_space()->end() > to_space()->end()) {
     space_shrinking = from_space();
   } else {
     space_shrinking = to_space();
   }
   HeapWord* new_end = (HeapWord*)virtual_space()->high();
   assert(new_end >= space_shrinking->bottom(), "Shrink was too large");
   // Was there a shrink of the survivor space?
   if (new_end < space_shrinking->end()) {
     MemRegion mr(space_shrinking->bottom(), new_end);
     space_shrinking->initialize(mr,
                                 SpaceDecorator::DontClear,
                                 SpaceDecorator::Mangle);
   }
 }
 // This method currently does not expect to expand into eden (i.e.,
 // the virtual space boundaries is expected to be consistent
 // with the eden boundaries..
 void PSYoungGen::post_resize() {
   assert_locked_or_safepoint(Heap_lock);
   assert((eden_space()->bottom() < to_space()->bottom()) &&
          (eden_space()->bottom() < from_space()->bottom()),
          "Eden is assumed to be below the survivor spaces");
   MemRegion cmr((HeapWord*)virtual_space()->low(),
                 (HeapWord*)virtual_space()->high());
   Universe::heap()->barrier_set()->resize_covered_region(cmr);
   space_invariants();
 }
 void PSYoungGen::update_counters() {
   if (UsePerfData) {
     _eden_counters->update_all();
     _from_counters->update_all();
     _to_counters->update_all();
     _gen_counters->update_all();
   }
 }
 void PSYoungGen::verify() {
   eden_space()->verify();
   from_space()->verify();
   to_space()->verify();
 }
 #ifndef PRODUCT
 void PSYoungGen::record_spaces_top() {
   assert(ZapUnusedHeapArea, "Not mangling unused space");
   eden_space()->set_top_for_allocations();
   from_space()->set_top_for_allocations();
   to_space()->set_top_for_allocations();
 }
 #endif

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/parallelScavenge/psYoungGen.cpp@af8f16ac392c (annotated)

src/share/vm/gc_implementation/parallelScavenge/psYoungGen.cpp