jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/parallelScavenge/asPSYoungGen.cpp@f90c822e73f8 (annotated)

src/share/vm/gc_implementation/parallelScavenge/asPSYoungGen.cpp@f90c822e73f8 (annotated)

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

Wed, 27 Apr 2016 01:25:04 +0800

author: aoqi
date: Wed, 27 Apr 2016 01:25:04 +0800
changeset 0: f90c822e73f8
child 6876: 710a3c8b516e
permissions: -rw-r--r--

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http://hg.openjdk.java.net/jdk8u/jdk8u/hotspot/
changeset: 6782:28b50d07f6f8
tag: jdk8u25-b17

 /*
  * Copyright (c) 2003, 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/asPSYoungGen.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/spaceDecorator.hpp"
 #include "oops/oop.inline.hpp"
 #include "runtime/java.hpp"
 ASPSYoungGen::ASPSYoungGen(size_t init_byte_size,
                            size_t minimum_byte_size,
                            size_t byte_size_limit) :
   PSYoungGen(init_byte_size, minimum_byte_size, byte_size_limit),
   _gen_size_limit(byte_size_limit) {
 }
 ASPSYoungGen::ASPSYoungGen(PSVirtualSpace* vs,
                            size_t init_byte_size,
                            size_t minimum_byte_size,
                            size_t byte_size_limit) :
   //PSYoungGen(init_byte_size, minimum_byte_size, byte_size_limit),
   PSYoungGen(vs->committed_size(), minimum_byte_size, byte_size_limit),
   _gen_size_limit(byte_size_limit) {
   assert(vs->committed_size() == init_byte_size, "Cannot replace with");
   _virtual_space = vs;
 }
 void ASPSYoungGen::initialize_virtual_space(ReservedSpace rs,
                                             size_t alignment) {
   assert(_init_gen_size != 0, "Should have a finite size");
   _virtual_space = new PSVirtualSpaceHighToLow(rs, alignment);
   if (!_virtual_space->expand_by(_init_gen_size)) {
     vm_exit_during_initialization("Could not reserve enough space for "
                                   "object heap");
   }
 }
 void ASPSYoungGen::initialize(ReservedSpace rs, size_t alignment) {
   initialize_virtual_space(rs, alignment);
   initialize_work();
 }
 size_t ASPSYoungGen::available_for_expansion() {
   size_t current_committed_size = virtual_space()->committed_size();
   assert((gen_size_limit() >= current_committed_size),
     "generation size limit is wrong");
   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
   size_t result =  gen_size_limit() - current_committed_size;
   size_t result_aligned = align_size_down(result, heap->generation_alignment());
   return result_aligned;
 }
 // Return the number of bytes the young gen is willing give up.
 //
 // Future implementations could check the survivors and if to_space is in the
 // right place (below from_space), take a chunk from to_space.
 size_t ASPSYoungGen::available_for_contraction() {
   size_t uncommitted_bytes = virtual_space()->uncommitted_size();
   if (uncommitted_bytes != 0) {
     return uncommitted_bytes;
   }
   if (eden_space()->is_empty()) {
     // Respect the minimum size for eden and for the young gen as a whole.
     ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
     const size_t eden_alignment = heap->space_alignment();
     const size_t gen_alignment = heap->generation_alignment();
     assert(eden_space()->capacity_in_bytes() >= eden_alignment,
       "Alignment is wrong");
     size_t eden_avail = eden_space()->capacity_in_bytes() - eden_alignment;
     eden_avail = align_size_down(eden_avail, gen_alignment);
     assert(virtual_space()->committed_size() >= min_gen_size(),
       "minimum gen size is wrong");
     size_t gen_avail = virtual_space()->committed_size() - min_gen_size();
     assert(virtual_space()->is_aligned(gen_avail), "not aligned");
     const size_t max_contraction = MIN2(eden_avail, gen_avail);
     // See comment for ASPSOldGen::available_for_contraction()
     // for reasons the "increment" fraction is used.
     PSAdaptiveSizePolicy* policy = heap->size_policy();
     size_t result = policy->eden_increment_aligned_down(max_contraction);
     size_t result_aligned = align_size_down(result, gen_alignment);
     if (PrintAdaptiveSizePolicy && Verbose) {
       gclog_or_tty->print_cr("ASPSYoungGen::available_for_contraction: " SIZE_FORMAT " K",
         result_aligned/K);
       gclog_or_tty->print_cr("  max_contraction " SIZE_FORMAT " K", max_contraction/K);
       gclog_or_tty->print_cr("  eden_avail " SIZE_FORMAT " K", eden_avail/K);
       gclog_or_tty->print_cr("  gen_avail " SIZE_FORMAT " K", gen_avail/K);
     }
     return result_aligned;
   }
   return 0;
 }
 // The current implementation only considers to the end of eden.
 // If to_space is below from_space, to_space is not considered.
 // to_space can be.
 size_t ASPSYoungGen::available_to_live() {
   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
   const size_t alignment = heap->space_alignment();
   // Include any space that is committed but is not in eden.
   size_t available = pointer_delta(eden_space()->bottom(),
                                    virtual_space()->low(),
                                    sizeof(char));
   const size_t eden_capacity = eden_space()->capacity_in_bytes();
   if (eden_space()->is_empty() && eden_capacity > alignment) {
     available += eden_capacity - alignment;
   }
   return available;
 }
 // Similar to PSYoungGen::resize_generation() but
 //  allows sum of eden_size and 2 * survivor_size to exceed _max_gen_size
 //  expands at the low end of the virtual space
 //  moves the boundary between the generations in order to expand
 //  some additional diagnostics
 // If no additional changes are required, this can be deleted
 // and the changes factored back into PSYoungGen::resize_generation().
 bool ASPSYoungGen::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 a guarantee here that
   //   (eden_size + 2*survivor_size)  <= _max_gen_size
   // This requirement is enforced by the calculation of desired_size
   // below.  It may not be true on entry since the size of the
   // eden_size is no bounded by the generation size.
   assert(max_size() == reserved().byte_size(), "max gen size problem?");
   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, gen_size_limit()),
                              min_gen_size());
   assert(desired_size <= gen_size_limit(), "just checking");
   if (desired_size > orig_size) {
     // Grow the generation
     size_t change = desired_size - orig_size;
     HeapWord* prev_low = (HeapWord*) virtual_space()->low();
     if (!virtual_space()->expand_by(change)) {
       return false;
     }
     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_low = (HeapWord*) virtual_space()->low();
       assert(new_low < prev_low, "Did not grow");
       MemRegion mangle_region(new_low, prev_low);
       SpaceMangler::mangle_region(mangle_region);
     }
     size_changed = true;
   } else if (desired_size < orig_size) {
     size_t desired_change = orig_size - desired_size;
     // How much is available for shrinking.
     size_t available_bytes = limit_gen_shrink(desired_change);
     size_t change = MIN2(desired_change, available_bytes);
     virtual_space()->shrink_by(change);
     size_changed = true;
   } else {
     if (Verbose && PrintGC) {
       if (orig_size == gen_size_limit()) {
         gclog_or_tty->print_cr("ASPSYoung generation size at maximum: "
           SIZE_FORMAT "K", orig_size/K);
       } else if (orig_size == min_gen_size()) {
         gclog_or_tty->print_cr("ASPSYoung generation size at minium: "
           SIZE_FORMAT "K", orig_size/K);
       }
     }
   }
   if (size_changed) {
     reset_after_change();
     if (Verbose && PrintGC) {
       size_t current_size  = virtual_space()->committed_size();
       gclog_or_tty->print_cr("ASPSYoung 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;
 }
 // Similar to PSYoungGen::resize_spaces() but
 //  eden always starts at the low end of the committed virtual space
 //  current implementation does not allow holes between the spaces
 //  _young_generation_boundary has to be reset because it changes.
 //  so additional verification
 void ASPSYoungGen::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");
   space_invariants();
   // 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,
                   p2i(eden_space()->bottom()),
                   p2i(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,
                   p2i(from_space()->bottom()),
                   p2i(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,
                   p2i(to_space()->bottom()),
                   p2i(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*)virtual_space()->low();
   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();
   assert(eden_start < from_start, "Cannot push into from_space");
   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
     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,
                     p2i(eden_start),
                     p2i(eden_end),
                     pointer_delta(eden_end, eden_start, sizeof(char)));
       gclog_or_tty->print_cr("    [from_start .. from_end): "
                     "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
                     p2i(from_start),
                     p2i(from_end),
                     pointer_delta(from_end, from_start, sizeof(char)));
       gclog_or_tty->print_cr("    [  to_start ..   to_end): "
                     "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
                     p2i(to_start),
                     p2i(to_end),
                     pointer_delta(  to_end,   to_start, sizeof(char)));
     }
   } else {
     // Eden, to, from
     if (PrintAdaptiveSizePolicy && Verbose) {
       gclog_or_tty->print_cr("  Eden, to, from:");
     }
     // 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");
     // 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,
                     p2i(eden_start),
                     p2i(eden_end),
                     pointer_delta(eden_end, eden_start, sizeof(char)));
       gclog_or_tty->print_cr("    [  to_start ..   to_end): "
                     "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
                     p2i(to_start),
                     p2i(to_end),
                     pointer_delta(  to_end,   to_start, sizeof(char)));
       gclog_or_tty->print_cr("    [from_start .. from_end): "
                     "[" PTR_FORMAT " .. " PTR_FORMAT ") " SIZE_FORMAT,
                     p2i(from_start),
                     p2i(from_end),
                     pointer_delta(from_end, from_start, sizeof(char)));
     }
   }
   guarantee((HeapWord*)from_start <= from_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"!
   DEBUG_ONLY(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);
   PSScavenge::set_young_generation_boundary(eden_space()->bottom());
   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();
   }
   space_invariants();
 }
 void ASPSYoungGen::reset_after_change() {
   assert_locked_or_safepoint(Heap_lock);
   _reserved = MemRegion((HeapWord*)virtual_space()->low_boundary(),
                         (HeapWord*)virtual_space()->high_boundary());
   PSScavenge::reference_processor()->set_span(_reserved);
   HeapWord* new_eden_bottom = (HeapWord*)virtual_space()->low();
   HeapWord* eden_bottom = eden_space()->bottom();
   if (new_eden_bottom != eden_bottom) {
     MemRegion eden_mr(new_eden_bottom, eden_space()->end());
     eden_space()->initialize(eden_mr,
                              SpaceDecorator::Clear,
                              SpaceDecorator::Mangle);
     PSScavenge::set_young_generation_boundary(eden_space()->bottom());
   }
   MemRegion cmr((HeapWord*)virtual_space()->low(),
                 (HeapWord*)virtual_space()->high());
   Universe::heap()->barrier_set()->resize_covered_region(cmr);
   space_invariants();
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/parallelScavenge/asPSYoungGen.cpp@f90c822e73f8 (annotated)

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