jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/parallelScavenge/psOldGen.cpp@1fdb98a17101 (annotated)

src/share/vm/gc_implementation/parallelScavenge/psOldGen.cpp@1fdb98a17101 (annotated)

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

Sat, 19 Jul 2008 17:38:22 -0400

author: coleenp
date: Sat, 19 Jul 2008 17:38:22 -0400
changeset 672: 1fdb98a17101
parent 435: a61af66fc99e
child 698: 12eea04c8b06
permissions: -rw-r--r--

6716785: implicit null checks not triggering with CompressedOops
Summary: allocate alignment-sized page(s) below java heap so that memory accesses at heap_base+1page give signal and cause an implicit null check
Reviewed-by: kvn, jmasa, phh, jcoomes

 /*
  * Copyright 2001-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  * CA 95054 USA or visit www.sun.com if you need additional information or
  * have any questions.
  *
  */
 # include "incls/_precompiled.incl"
 # include "incls/_psOldGen.cpp.incl"
 inline const char* PSOldGen::select_name() {
   return UseParallelOldGC ? "ParOldGen" : "PSOldGen";
 }
 PSOldGen::PSOldGen(ReservedSpace rs, size_t alignment,
                    size_t initial_size, size_t min_size, size_t max_size,
                    const char* perf_data_name, int level):
   _name(select_name()), _init_gen_size(initial_size), _min_gen_size(min_size),
   _max_gen_size(max_size)
 {
   initialize(rs, alignment, perf_data_name, level);
 }
 PSOldGen::PSOldGen(size_t initial_size,
                    size_t min_size, size_t max_size,
                    const char* perf_data_name, int level):
   _name(select_name()), _init_gen_size(initial_size), _min_gen_size(min_size),
   _max_gen_size(max_size)
 {}
 void PSOldGen::initialize(ReservedSpace rs, size_t alignment,
                           const char* perf_data_name, int level) {
   initialize_virtual_space(rs, alignment);
   initialize_work(perf_data_name, level);
   // The old gen can grow to gen_size_limit().  _reserve reflects only
   // the current maximum that can be committed.
   assert(_reserved.byte_size() <= gen_size_limit(), "Consistency check");
 }
 void PSOldGen::initialize_virtual_space(ReservedSpace rs, size_t alignment) {
   _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 PSOldGen::initialize_work(const char* perf_data_name, int level) {
   //
   // Basic memory initialization
   //
   MemRegion limit_reserved((HeapWord*)virtual_space()->low_boundary(),
     heap_word_size(_max_gen_size));
   assert(limit_reserved.byte_size() == _max_gen_size,
     "word vs bytes confusion");
   //
   // Object start stuff
   //
   start_array()->initialize(limit_reserved);
   _reserved = MemRegion((HeapWord*)virtual_space()->low_boundary(),
                         (HeapWord*)virtual_space()->high_boundary());
   //
   // Card table stuff
   //
   MemRegion cmr((HeapWord*)virtual_space()->low(),
                 (HeapWord*)virtual_space()->high());
   Universe::heap()->barrier_set()->resize_covered_region(cmr);
   CardTableModRefBS* _ct = (CardTableModRefBS*)Universe::heap()->barrier_set();
   assert (_ct->kind() == BarrierSet::CardTableModRef, "Sanity");
   // Verify that the start and end of this generation is the start of a card.
   // If this wasn't true, a single card could span more than one generation,
   // which would cause problems when we commit/uncommit memory, and when we
   // clear and dirty cards.
   guarantee(_ct->is_card_aligned(_reserved.start()), "generation must be card aligned");
   if (_reserved.end() != Universe::heap()->reserved_region().end()) {
     // Don't check at the very end of the heap as we'll assert that we're probing off
     // the end if we try.
     guarantee(_ct->is_card_aligned(_reserved.end()), "generation must be card aligned");
   }
   //
   // ObjectSpace stuff
   //
   _object_space = new MutableSpace();
   if (_object_space == NULL)
     vm_exit_during_initialization("Could not allocate an old gen space");
   object_space()->initialize(cmr, true);
   _object_mark_sweep = new PSMarkSweepDecorator(_object_space, start_array(), MarkSweepDeadRatio);
   if (_object_mark_sweep == NULL)
     vm_exit_during_initialization("Could not complete allocation of old generation");
   // Update the start_array
   start_array()->set_covered_region(cmr);
   // Generation Counters, generation 'level', 1 subspace
   _gen_counters = new PSGenerationCounters(perf_data_name, level, 1,
                                            virtual_space());
   _space_counters = new SpaceCounters(perf_data_name, 0,
                                       virtual_space()->reserved_size(),
                                       _object_space, _gen_counters);
 }
 // Assume that the generation has been allocated if its
 // reserved size is not 0.
 bool  PSOldGen::is_allocated() {
   return virtual_space()->reserved_size() != 0;
 }
 void PSOldGen::precompact() {
   ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
   assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
   // Reset start array first.
   debug_only(if (!UseParallelOldGC || !VerifyParallelOldWithMarkSweep) {)
   start_array()->reset();
   debug_only(})
   object_mark_sweep()->precompact();
   // Now compact the young gen
   heap->young_gen()->precompact();
 }
 void PSOldGen::adjust_pointers() {
   object_mark_sweep()->adjust_pointers();
 }
 void PSOldGen::compact() {
   object_mark_sweep()->compact(ZapUnusedHeapArea);
 }
 void PSOldGen::move_and_update(ParCompactionManager* cm) {
   PSParallelCompact::move_and_update(cm, PSParallelCompact::old_space_id);
 }
 size_t PSOldGen::contiguous_available() const {
   return object_space()->free_in_bytes() + virtual_space()->uncommitted_size();
 }
 // Allocation. We report all successful allocations to the size policy
 // Note that the perm gen does not use this method, and should not!
 HeapWord* PSOldGen::allocate(size_t word_size, bool is_tlab) {
   assert_locked_or_safepoint(Heap_lock);
   HeapWord* res = allocate_noexpand(word_size, is_tlab);
   if (res == NULL) {
     res = expand_and_allocate(word_size, is_tlab);
   }
   // Allocations in the old generation need to be reported
   if (res != NULL) {
     ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
     heap->size_policy()->tenured_allocation(word_size);
   }
   return res;
 }
 HeapWord* PSOldGen::expand_and_allocate(size_t word_size, bool is_tlab) {
   assert(!is_tlab, "TLAB's are not supported in PSOldGen");
   expand(word_size*HeapWordSize);
   if (GCExpandToAllocateDelayMillis > 0) {
     os::sleep(Thread::current(), GCExpandToAllocateDelayMillis, false);
   }
   return allocate_noexpand(word_size, is_tlab);
 }
 HeapWord* PSOldGen::expand_and_cas_allocate(size_t word_size) {
   expand(word_size*HeapWordSize);
   if (GCExpandToAllocateDelayMillis > 0) {
     os::sleep(Thread::current(), GCExpandToAllocateDelayMillis, false);
   }
   return cas_allocate_noexpand(word_size);
 }
 void PSOldGen::expand(size_t bytes) {
   MutexLocker x(ExpandHeap_lock);
   const size_t alignment = virtual_space()->alignment();
   size_t aligned_bytes  = align_size_up(bytes, alignment);
   size_t aligned_expand_bytes = align_size_up(MinHeapDeltaBytes, alignment);
   bool success = false;
   if (aligned_expand_bytes > aligned_bytes) {
     success = expand_by(aligned_expand_bytes);
   }
   if (!success) {
     success = expand_by(aligned_bytes);
   }
   if (!success) {
     success = expand_to_reserved();
   }
   if (GC_locker::is_active()) {
     if (PrintGC && Verbose) {
       gclog_or_tty->print_cr("Garbage collection disabled, expanded heap instead");
     }
   }
 }
 bool PSOldGen::expand_by(size_t bytes) {
   assert_lock_strong(ExpandHeap_lock);
   assert_locked_or_safepoint(Heap_lock);
   bool result = virtual_space()->expand_by(bytes);
   if (result) {
     post_resize();
     if (UsePerfData) {
       _space_counters->update_capacity();
       _gen_counters->update_all();
     }
   }
   if (result && Verbose && PrintGC) {
     size_t new_mem_size = virtual_space()->committed_size();
     size_t old_mem_size = new_mem_size - bytes;
     gclog_or_tty->print_cr("Expanding %s from " SIZE_FORMAT "K by "
                                        SIZE_FORMAT "K to "
                                        SIZE_FORMAT "K",
                     name(), old_mem_size/K, bytes/K, new_mem_size/K);
   }
   return result;
 }
 bool PSOldGen::expand_to_reserved() {
   assert_lock_strong(ExpandHeap_lock);
   assert_locked_or_safepoint(Heap_lock);
   bool result = true;
   const size_t remaining_bytes = virtual_space()->uncommitted_size();
   if (remaining_bytes > 0) {
     result = expand_by(remaining_bytes);
     DEBUG_ONLY(if (!result) warning("grow to reserve failed"));
   }
   return result;
 }
 void PSOldGen::shrink(size_t bytes) {
   assert_lock_strong(ExpandHeap_lock);
   assert_locked_or_safepoint(Heap_lock);
   size_t size = align_size_down(bytes, virtual_space()->alignment());
   if (size > 0) {
     assert_lock_strong(ExpandHeap_lock);
     virtual_space()->shrink_by(bytes);
     post_resize();
     if (Verbose && PrintGC) {
       size_t new_mem_size = virtual_space()->committed_size();
       size_t old_mem_size = new_mem_size + bytes;
       gclog_or_tty->print_cr("Shrinking %s from " SIZE_FORMAT "K by "
                                          SIZE_FORMAT "K to "
                                          SIZE_FORMAT "K",
                       name(), old_mem_size/K, bytes/K, new_mem_size/K);
     }
   }
 }
 void PSOldGen::resize(size_t desired_free_space) {
   const size_t alignment = virtual_space()->alignment();
   const size_t size_before = virtual_space()->committed_size();
   size_t new_size = used_in_bytes() + desired_free_space;
   if (new_size < used_in_bytes()) {
     // Overflowed the addition.
     new_size = gen_size_limit();
   }
   // Adjust according to our min and max
   new_size = MAX2(MIN2(new_size, gen_size_limit()), min_gen_size());
   assert(gen_size_limit() >= reserved().byte_size(), "max new size problem?");
   new_size = align_size_up(new_size, alignment);
   const size_t current_size = capacity_in_bytes();
   if (PrintAdaptiveSizePolicy && Verbose) {
     gclog_or_tty->print_cr("AdaptiveSizePolicy::old generation size: "
       "desired free: " SIZE_FORMAT " used: " SIZE_FORMAT
       " new size: " SIZE_FORMAT " current size " SIZE_FORMAT
       " gen limits: " SIZE_FORMAT " / " SIZE_FORMAT,
       desired_free_space, used_in_bytes(), new_size, current_size,
       gen_size_limit(), min_gen_size());
   }
   if (new_size == current_size) {
     // No change requested
     return;
   }
   if (new_size > current_size) {
     size_t change_bytes = new_size - current_size;
     expand(change_bytes);
   } else {
     size_t change_bytes = current_size - new_size;
     // shrink doesn't grab this lock, expand does. Is that right?
     MutexLocker x(ExpandHeap_lock);
     shrink(change_bytes);
   }
   if (PrintAdaptiveSizePolicy) {
     ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
     assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
     gclog_or_tty->print_cr("AdaptiveSizePolicy::old generation size: "
                   "collection: %d "
                   "(" SIZE_FORMAT ") -> (" SIZE_FORMAT ") ",
                   heap->total_collections(),
                   size_before, virtual_space()->committed_size());
   }
 }
 // NOTE! We need to be careful about resizing. During a GC, multiple
 // allocators may be active during heap expansion. If we allow the
 // heap resizing to become visible before we have correctly resized
 // all heap related data structures, we may cause program failures.
 void PSOldGen::post_resize() {
   // First construct a memregion representing the new size
   MemRegion new_memregion((HeapWord*)virtual_space()->low(),
     (HeapWord*)virtual_space()->high());
   size_t new_word_size = new_memregion.word_size();
   start_array()->set_covered_region(new_memregion);
   Universe::heap()->barrier_set()->resize_covered_region(new_memregion);
   // Did we expand?
   HeapWord* const virtual_space_high = (HeapWord*) virtual_space()->high();
   if (object_space()->end() < virtual_space_high) {
     // We need to mangle the newly expanded area. The memregion spans
     // end -> new_end, we assume that top -> end is already mangled.
     // This cannot be safely tested for, as allocation may be taking
     // place.
     MemRegion mangle_region(object_space()->end(), virtual_space_high);
     object_space()->mangle_region(mangle_region);
   }
   // ALWAYS do this last!!
   object_space()->set_end(virtual_space_high);
   assert(new_word_size == heap_word_size(object_space()->capacity_in_bytes()),
     "Sanity");
 }
 size_t PSOldGen::gen_size_limit() {
   return _max_gen_size;
 }
 void PSOldGen::reset_after_change() {
   ShouldNotReachHere();
   return;
 }
 size_t PSOldGen::available_for_expansion() {
   ShouldNotReachHere();
   return 0;
 }
 size_t PSOldGen::available_for_contraction() {
   ShouldNotReachHere();
   return 0;
 }
 void PSOldGen::print() const { print_on(tty);}
 void PSOldGen::print_on(outputStream* st) const {
   st->print(" %-15s", name());
   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);
   }
   st->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", " INTPTR_FORMAT ")",
                 virtual_space()->low_boundary(),
                 virtual_space()->high(),
                 virtual_space()->high_boundary());
   st->print("  object"); object_space()->print_on(st);
 }
 void PSOldGen::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("]");
 }
 void PSOldGen::update_counters() {
   if (UsePerfData) {
     _space_counters->update_all();
     _gen_counters->update_all();
   }
 }
 #ifndef PRODUCT
 void PSOldGen::space_invariants() {
   assert(object_space()->end() == (HeapWord*) virtual_space()->high(),
     "Space invariant");
   assert(object_space()->bottom() == (HeapWord*) virtual_space()->low(),
     "Space invariant");
   assert(virtual_space()->low_boundary() <= virtual_space()->low(),
     "Space invariant");
   assert(virtual_space()->high_boundary() >= virtual_space()->high(),
     "Space invariant");
   assert(virtual_space()->low_boundary() == (char*) _reserved.start(),
     "Space invariant");
   assert(virtual_space()->high_boundary() == (char*) _reserved.end(),
     "Space invariant");
   assert(virtual_space()->committed_size() <= virtual_space()->reserved_size(),
     "Space invariant");
 }
 #endif
 void PSOldGen::verify(bool allow_dirty) {
   object_space()->verify(allow_dirty);
 }
 class VerifyObjectStartArrayClosure : public ObjectClosure {
   PSOldGen* _gen;
   ObjectStartArray* _start_array;
  public:
   VerifyObjectStartArrayClosure(PSOldGen* gen, ObjectStartArray* start_array) :
     _gen(gen), _start_array(start_array) { }
   virtual void do_object(oop obj) {
     HeapWord* test_addr = (HeapWord*)obj + 1;
     guarantee(_start_array->object_start(test_addr) == (HeapWord*)obj, "ObjectStartArray cannot find start of object");
     guarantee(_start_array->is_block_allocated((HeapWord*)obj), "ObjectStartArray missing block allocation");
   }
 };
 void PSOldGen::verify_object_start_array() {
   VerifyObjectStartArrayClosure check( this, &_start_array );
   object_iterate(&check);
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/parallelScavenge/psOldGen.cpp@1fdb98a17101 (annotated)

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