jdk8-mips64-public/hotspot: src/share/vm/memory/tenuredGeneration.cpp@f90c822e73f8 (annotated)

src/share/vm/memory/tenuredGeneration.cpp@f90c822e73f8 (annotated)

src/share/vm/memory/tenuredGeneration.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) 2001, 2013, 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/shared/collectorCounters.hpp"
 #include "gc_implementation/shared/parGCAllocBuffer.hpp"
 #include "memory/allocation.inline.hpp"
 #include "memory/blockOffsetTable.inline.hpp"
 #include "memory/generation.inline.hpp"
 #include "memory/generationSpec.hpp"
 #include "memory/space.hpp"
 #include "memory/tenuredGeneration.hpp"
 #include "oops/oop.inline.hpp"
 #include "runtime/java.hpp"
 #include "utilities/macros.hpp"
 TenuredGeneration::TenuredGeneration(ReservedSpace rs,
                                      size_t initial_byte_size, int level,
                                      GenRemSet* remset) :
   OneContigSpaceCardGeneration(rs, initial_byte_size,
                                level, remset, NULL)
 {
   HeapWord* bottom = (HeapWord*) _virtual_space.low();
   HeapWord* end    = (HeapWord*) _virtual_space.high();
   _the_space  = new TenuredSpace(_bts, MemRegion(bottom, end));
   _the_space->reset_saved_mark();
   _shrink_factor = 0;
   _capacity_at_prologue = 0;
   _gc_stats = new GCStats();
   // initialize performance counters
   const char* gen_name = "old";
   // Generation Counters -- generation 1, 1 subspace
   _gen_counters = new GenerationCounters(gen_name, 1, 1, &_virtual_space);
   _gc_counters = new CollectorCounters("MSC", 1);
   _space_counters = new CSpaceCounters(gen_name, 0,
                                        _virtual_space.reserved_size(),
                                        _the_space, _gen_counters);
 #if INCLUDE_ALL_GCS
   if (UseParNewGC) {
     typedef ParGCAllocBufferWithBOT* ParGCAllocBufferWithBOTPtr;
     _alloc_buffers = NEW_C_HEAP_ARRAY(ParGCAllocBufferWithBOTPtr,
                                       ParallelGCThreads, mtGC);
     if (_alloc_buffers == NULL)
       vm_exit_during_initialization("Could not allocate alloc_buffers");
     for (uint i = 0; i < ParallelGCThreads; i++) {
       _alloc_buffers[i] =
         new ParGCAllocBufferWithBOT(OldPLABSize, _bts);
       if (_alloc_buffers[i] == NULL)
         vm_exit_during_initialization("Could not allocate alloc_buffers");
     }
   } else {
     _alloc_buffers = NULL;
   }
 #endif // INCLUDE_ALL_GCS
 }
 const char* TenuredGeneration::name() const {
   return "tenured generation";
 }
 void TenuredGeneration::gc_prologue(bool full) {
   _capacity_at_prologue = capacity();
   _used_at_prologue = used();
   if (VerifyBeforeGC) {
     verify_alloc_buffers_clean();
   }
 }
 void TenuredGeneration::gc_epilogue(bool full) {
   if (VerifyAfterGC) {
     verify_alloc_buffers_clean();
   }
   OneContigSpaceCardGeneration::gc_epilogue(full);
 }
 bool TenuredGeneration::should_collect(bool  full,
                                        size_t size,
                                        bool   is_tlab) {
   // This should be one big conditional or (||), but I want to be able to tell
   // why it returns what it returns (without re-evaluating the conditionals
   // in case they aren't idempotent), so I'm doing it this way.
   // DeMorgan says it's okay.
   bool result = false;
   if (!result && full) {
     result = true;
     if (PrintGC && Verbose) {
       gclog_or_tty->print_cr("TenuredGeneration::should_collect: because"
                     " full");
     }
   }
   if (!result && should_allocate(size, is_tlab)) {
     result = true;
     if (PrintGC && Verbose) {
       gclog_or_tty->print_cr("TenuredGeneration::should_collect: because"
                     " should_allocate(" SIZE_FORMAT ")",
                     size);
     }
   }
   // If we don't have very much free space.
   // XXX: 10000 should be a percentage of the capacity!!!
   if (!result && free() < 10000) {
     result = true;
     if (PrintGC && Verbose) {
       gclog_or_tty->print_cr("TenuredGeneration::should_collect: because"
                     " free(): " SIZE_FORMAT,
                     free());
     }
   }
   // If we had to expand to accomodate promotions from younger generations
   if (!result && _capacity_at_prologue < capacity()) {
     result = true;
     if (PrintGC && Verbose) {
       gclog_or_tty->print_cr("TenuredGeneration::should_collect: because"
                     "_capacity_at_prologue: " SIZE_FORMAT " < capacity(): " SIZE_FORMAT,
                     _capacity_at_prologue, capacity());
     }
   }
   return result;
 }
 void TenuredGeneration::collect(bool   full,
                                 bool   clear_all_soft_refs,
                                 size_t size,
                                 bool   is_tlab) {
   retire_alloc_buffers_before_full_gc();
   OneContigSpaceCardGeneration::collect(full, clear_all_soft_refs,
                                         size, is_tlab);
 }
 void TenuredGeneration::compute_new_size() {
   assert_locked_or_safepoint(Heap_lock);
   // Compute some numbers about the state of the heap.
   const size_t used_after_gc = used();
   const size_t capacity_after_gc = capacity();
   CardGeneration::compute_new_size();
   assert(used() == used_after_gc && used_after_gc <= capacity(),
          err_msg("used: " SIZE_FORMAT " used_after_gc: " SIZE_FORMAT
          " capacity: " SIZE_FORMAT, used(), used_after_gc, capacity()));
 }
 void TenuredGeneration::update_gc_stats(int current_level,
                                         bool full) {
   // If the next lower level(s) has been collected, gather any statistics
   // that are of interest at this point.
   if (!full && (current_level + 1) == level()) {
     // Calculate size of data promoted from the younger generations
     // before doing the collection.
     size_t used_before_gc = used();
     // If the younger gen collections were skipped, then the
     // number of promoted bytes will be 0 and adding it to the
     // average will incorrectly lessen the average.  It is, however,
     // also possible that no promotion was needed.
     if (used_before_gc >= _used_at_prologue) {
       size_t promoted_in_bytes = used_before_gc - _used_at_prologue;
       gc_stats()->avg_promoted()->sample(promoted_in_bytes);
     }
   }
 }
 void TenuredGeneration::update_counters() {
   if (UsePerfData) {
     _space_counters->update_all();
     _gen_counters->update_all();
   }
 }
 #if INCLUDE_ALL_GCS
 oop TenuredGeneration::par_promote(int thread_num,
                                    oop old, markOop m, size_t word_sz) {
   ParGCAllocBufferWithBOT* buf = _alloc_buffers[thread_num];
   HeapWord* obj_ptr = buf->allocate(word_sz);
   bool is_lab = true;
   if (obj_ptr == NULL) {
 #ifndef PRODUCT
     if (Universe::heap()->promotion_should_fail()) {
       return NULL;
     }
 #endif  // #ifndef PRODUCT
     // Slow path:
     if (word_sz * 100 < ParallelGCBufferWastePct * buf->word_sz()) {
       // Is small enough; abandon this buffer and start a new one.
       size_t buf_size = buf->word_sz();
       HeapWord* buf_space =
         TenuredGeneration::par_allocate(buf_size, false);
       if (buf_space == NULL) {
         buf_space = expand_and_allocate(buf_size, false, true /* parallel*/);
       }
       if (buf_space != NULL) {
         buf->retire(false, false);
         buf->set_buf(buf_space);
         obj_ptr = buf->allocate(word_sz);
         assert(obj_ptr != NULL, "Buffer was definitely big enough...");
       }
     };
     // Otherwise, buffer allocation failed; try allocating object
     // individually.
     if (obj_ptr == NULL) {
       obj_ptr = TenuredGeneration::par_allocate(word_sz, false);
       if (obj_ptr == NULL) {
         obj_ptr = expand_and_allocate(word_sz, false, true /* parallel */);
       }
     }
     if (obj_ptr == NULL) return NULL;
   }
   assert(obj_ptr != NULL, "program logic");
   Copy::aligned_disjoint_words((HeapWord*)old, obj_ptr, word_sz);
   oop obj = oop(obj_ptr);
   // Restore the mark word copied above.
   obj->set_mark(m);
   return obj;
 }
 void TenuredGeneration::par_promote_alloc_undo(int thread_num,
                                                HeapWord* obj,
                                                size_t word_sz) {
   ParGCAllocBufferWithBOT* buf = _alloc_buffers[thread_num];
   if (buf->contains(obj)) {
     guarantee(buf->contains(obj + word_sz - 1),
               "should contain whole object");
     buf->undo_allocation(obj, word_sz);
   } else {
     CollectedHeap::fill_with_object(obj, word_sz);
   }
 }
 void TenuredGeneration::par_promote_alloc_done(int thread_num) {
   ParGCAllocBufferWithBOT* buf = _alloc_buffers[thread_num];
   buf->retire(true, ParallelGCRetainPLAB);
 }
 void TenuredGeneration::retire_alloc_buffers_before_full_gc() {
   if (UseParNewGC) {
     for (uint i = 0; i < ParallelGCThreads; i++) {
       _alloc_buffers[i]->retire(true /*end_of_gc*/, false /*retain*/);
     }
   }
 }
 // Verify that any retained parallel allocation buffers do not
 // intersect with dirty cards.
 void TenuredGeneration::verify_alloc_buffers_clean() {
   if (UseParNewGC) {
     for (uint i = 0; i < ParallelGCThreads; i++) {
       _rs->verify_aligned_region_empty(_alloc_buffers[i]->range());
     }
   }
 }
 #else  // INCLUDE_ALL_GCS
 void TenuredGeneration::retire_alloc_buffers_before_full_gc() {}
 void TenuredGeneration::verify_alloc_buffers_clean() {}
 #endif // INCLUDE_ALL_GCS
 bool TenuredGeneration::promotion_attempt_is_safe(size_t max_promotion_in_bytes) const {
   size_t available = max_contiguous_available();
   size_t av_promo  = (size_t)gc_stats()->avg_promoted()->padded_average();
   bool   res = (available >= av_promo) || (available >= max_promotion_in_bytes);
   if (PrintGC && Verbose) {
     gclog_or_tty->print_cr(
       "Tenured: promo attempt is%s safe: available("SIZE_FORMAT") %s av_promo("SIZE_FORMAT"),"
       "max_promo("SIZE_FORMAT")",
       res? "":" not", available, res? ">=":"<",
       av_promo, max_promotion_in_bytes);
   }
   return res;
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/memory/tenuredGeneration.cpp@f90c822e73f8 (annotated)

src/share/vm/memory/tenuredGeneration.cpp