aoqi@0: /*
aoqi@0:  * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  *
aoqi@0:  */
aoqi@0: 
aoqi@0: #include "precompiled.hpp"
aoqi@0: #include "gc_implementation/shared/collectorCounters.hpp"
aoqi@0: #include "gc_implementation/shared/parGCAllocBuffer.hpp"
aoqi@0: #include "memory/allocation.inline.hpp"
aoqi@0: #include "memory/blockOffsetTable.inline.hpp"
aoqi@0: #include "memory/generation.inline.hpp"
aoqi@0: #include "memory/generationSpec.hpp"
aoqi@0: #include "memory/space.hpp"
aoqi@0: #include "memory/tenuredGeneration.hpp"
aoqi@0: #include "oops/oop.inline.hpp"
aoqi@0: #include "runtime/java.hpp"
aoqi@0: #include "utilities/macros.hpp"
aoqi@0: 
aoqi@0: TenuredGeneration::TenuredGeneration(ReservedSpace rs,
aoqi@0:                                      size_t initial_byte_size, int level,
aoqi@0:                                      GenRemSet* remset) :
aoqi@0:   OneContigSpaceCardGeneration(rs, initial_byte_size,
aoqi@0:                                level, remset, NULL)
aoqi@0: {
aoqi@0:   HeapWord* bottom = (HeapWord*) _virtual_space.low();
aoqi@0:   HeapWord* end    = (HeapWord*) _virtual_space.high();
aoqi@0:   _the_space  = new TenuredSpace(_bts, MemRegion(bottom, end));
aoqi@0:   _the_space->reset_saved_mark();
aoqi@0:   _shrink_factor = 0;
aoqi@0:   _capacity_at_prologue = 0;
aoqi@0: 
aoqi@0:   _gc_stats = new GCStats();
aoqi@0: 
aoqi@0:   // initialize performance counters
aoqi@0: 
aoqi@0:   const char* gen_name = "old";
aoqi@0: 
aoqi@0:   // Generation Counters -- generation 1, 1 subspace
aoqi@0:   _gen_counters = new GenerationCounters(gen_name, 1, 1, &_virtual_space);
aoqi@0: 
aoqi@0:   _gc_counters = new CollectorCounters("MSC", 1);
aoqi@0: 
aoqi@0:   _space_counters = new CSpaceCounters(gen_name, 0,
aoqi@0:                                        _virtual_space.reserved_size(),
aoqi@0:                                        _the_space, _gen_counters);
aoqi@0: #if INCLUDE_ALL_GCS
aoqi@0:   if (UseParNewGC) {
aoqi@0:     typedef ParGCAllocBufferWithBOT* ParGCAllocBufferWithBOTPtr;
aoqi@0:     _alloc_buffers = NEW_C_HEAP_ARRAY(ParGCAllocBufferWithBOTPtr,
aoqi@0:                                       ParallelGCThreads, mtGC);
aoqi@0:     if (_alloc_buffers == NULL)
aoqi@0:       vm_exit_during_initialization("Could not allocate alloc_buffers");
aoqi@0:     for (uint i = 0; i < ParallelGCThreads; i++) {
aoqi@0:       _alloc_buffers[i] =
aoqi@0:         new ParGCAllocBufferWithBOT(OldPLABSize, _bts);
aoqi@0:       if (_alloc_buffers[i] == NULL)
aoqi@0:         vm_exit_during_initialization("Could not allocate alloc_buffers");
aoqi@0:     }
aoqi@0:   } else {
aoqi@0:     _alloc_buffers = NULL;
aoqi@0:   }
aoqi@0: #endif // INCLUDE_ALL_GCS
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: const char* TenuredGeneration::name() const {
aoqi@0:   return "tenured generation";
aoqi@0: }
aoqi@0: 
aoqi@0: void TenuredGeneration::gc_prologue(bool full) {
aoqi@0:   _capacity_at_prologue = capacity();
aoqi@0:   _used_at_prologue = used();
aoqi@0:   if (VerifyBeforeGC) {
aoqi@0:     verify_alloc_buffers_clean();
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: void TenuredGeneration::gc_epilogue(bool full) {
aoqi@0:   if (VerifyAfterGC) {
aoqi@0:     verify_alloc_buffers_clean();
aoqi@0:   }
aoqi@0:   OneContigSpaceCardGeneration::gc_epilogue(full);
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: bool TenuredGeneration::should_collect(bool  full,
aoqi@0:                                        size_t size,
aoqi@0:                                        bool   is_tlab) {
aoqi@0:   // This should be one big conditional or (||), but I want to be able to tell
aoqi@0:   // why it returns what it returns (without re-evaluating the conditionals
aoqi@0:   // in case they aren't idempotent), so I'm doing it this way.
aoqi@0:   // DeMorgan says it's okay.
aoqi@0:   bool result = false;
aoqi@0:   if (!result && full) {
aoqi@0:     result = true;
aoqi@0:     if (PrintGC && Verbose) {
aoqi@0:       gclog_or_tty->print_cr("TenuredGeneration::should_collect: because"
aoqi@0:                     " full");
aoqi@0:     }
aoqi@0:   }
aoqi@0:   if (!result && should_allocate(size, is_tlab)) {
aoqi@0:     result = true;
aoqi@0:     if (PrintGC && Verbose) {
aoqi@0:       gclog_or_tty->print_cr("TenuredGeneration::should_collect: because"
aoqi@0:                     " should_allocate(" SIZE_FORMAT ")",
aoqi@0:                     size);
aoqi@0:     }
aoqi@0:   }
aoqi@0:   // If we don't have very much free space.
aoqi@0:   // XXX: 10000 should be a percentage of the capacity!!!
aoqi@0:   if (!result && free() < 10000) {
aoqi@0:     result = true;
aoqi@0:     if (PrintGC && Verbose) {
aoqi@0:       gclog_or_tty->print_cr("TenuredGeneration::should_collect: because"
aoqi@0:                     " free(): " SIZE_FORMAT,
aoqi@0:                     free());
aoqi@0:     }
aoqi@0:   }
aoqi@0:   // If we had to expand to accomodate promotions from younger generations
aoqi@0:   if (!result && _capacity_at_prologue < capacity()) {
aoqi@0:     result = true;
aoqi@0:     if (PrintGC && Verbose) {
aoqi@0:       gclog_or_tty->print_cr("TenuredGeneration::should_collect: because"
aoqi@0:                     "_capacity_at_prologue: " SIZE_FORMAT " < capacity(): " SIZE_FORMAT,
aoqi@0:                     _capacity_at_prologue, capacity());
aoqi@0:     }
aoqi@0:   }
aoqi@0:   return result;
aoqi@0: }
aoqi@0: 
aoqi@0: void TenuredGeneration::collect(bool   full,
aoqi@0:                                 bool   clear_all_soft_refs,
aoqi@0:                                 size_t size,
aoqi@0:                                 bool   is_tlab) {
aoqi@0:   retire_alloc_buffers_before_full_gc();
aoqi@0:   OneContigSpaceCardGeneration::collect(full, clear_all_soft_refs,
aoqi@0:                                         size, is_tlab);
aoqi@0: }
aoqi@0: 
aoqi@0: void TenuredGeneration::compute_new_size() {
aoqi@0:   assert_locked_or_safepoint(Heap_lock);
aoqi@0: 
aoqi@0:   // Compute some numbers about the state of the heap.
aoqi@0:   const size_t used_after_gc = used();
aoqi@0:   const size_t capacity_after_gc = capacity();
aoqi@0: 
aoqi@0:   CardGeneration::compute_new_size();
aoqi@0: 
aoqi@0:   assert(used() == used_after_gc && used_after_gc <= capacity(),
aoqi@0:          err_msg("used: " SIZE_FORMAT " used_after_gc: " SIZE_FORMAT
aoqi@0:          " capacity: " SIZE_FORMAT, used(), used_after_gc, capacity()));
aoqi@0: }
aoqi@0: void TenuredGeneration::update_gc_stats(int current_level,
aoqi@0:                                         bool full) {
aoqi@0:   // If the next lower level(s) has been collected, gather any statistics
aoqi@0:   // that are of interest at this point.
aoqi@0:   if (!full && (current_level + 1) == level()) {
aoqi@0:     // Calculate size of data promoted from the younger generations
aoqi@0:     // before doing the collection.
aoqi@0:     size_t used_before_gc = used();
aoqi@0: 
aoqi@0:     // If the younger gen collections were skipped, then the
aoqi@0:     // number of promoted bytes will be 0 and adding it to the
aoqi@0:     // average will incorrectly lessen the average.  It is, however,
aoqi@0:     // also possible that no promotion was needed.
aoqi@0:     if (used_before_gc >= _used_at_prologue) {
aoqi@0:       size_t promoted_in_bytes = used_before_gc - _used_at_prologue;
aoqi@0:       gc_stats()->avg_promoted()->sample(promoted_in_bytes);
aoqi@0:     }
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: void TenuredGeneration::update_counters() {
aoqi@0:   if (UsePerfData) {
aoqi@0:     _space_counters->update_all();
aoqi@0:     _gen_counters->update_all();
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: #if INCLUDE_ALL_GCS
aoqi@0: oop TenuredGeneration::par_promote(int thread_num,
aoqi@0:                                    oop old, markOop m, size_t word_sz) {
aoqi@0: 
aoqi@0:   ParGCAllocBufferWithBOT* buf = _alloc_buffers[thread_num];
aoqi@0:   HeapWord* obj_ptr = buf->allocate(word_sz);
aoqi@0:   bool is_lab = true;
aoqi@0:   if (obj_ptr == NULL) {
aoqi@0: #ifndef PRODUCT
aoqi@0:     if (Universe::heap()->promotion_should_fail()) {
aoqi@0:       return NULL;
aoqi@0:     }
aoqi@0: #endif  // #ifndef PRODUCT
aoqi@0: 
aoqi@0:     // Slow path:
aoqi@0:     if (word_sz * 100 < ParallelGCBufferWastePct * buf->word_sz()) {
aoqi@0:       // Is small enough; abandon this buffer and start a new one.
aoqi@0:       size_t buf_size = buf->word_sz();
aoqi@0:       HeapWord* buf_space =
aoqi@0:         TenuredGeneration::par_allocate(buf_size, false);
aoqi@0:       if (buf_space == NULL) {
aoqi@0:         buf_space = expand_and_allocate(buf_size, false, true /* parallel*/);
aoqi@0:       }
aoqi@0:       if (buf_space != NULL) {
aoqi@0:         buf->retire(false, false);
aoqi@0:         buf->set_buf(buf_space);
aoqi@0:         obj_ptr = buf->allocate(word_sz);
aoqi@0:         assert(obj_ptr != NULL, "Buffer was definitely big enough...");
aoqi@0:       }
aoqi@0:     };
aoqi@0:     // Otherwise, buffer allocation failed; try allocating object
aoqi@0:     // individually.
aoqi@0:     if (obj_ptr == NULL) {
aoqi@0:       obj_ptr = TenuredGeneration::par_allocate(word_sz, false);
aoqi@0:       if (obj_ptr == NULL) {
aoqi@0:         obj_ptr = expand_and_allocate(word_sz, false, true /* parallel */);
aoqi@0:       }
aoqi@0:     }
aoqi@0:     if (obj_ptr == NULL) return NULL;
aoqi@0:   }
aoqi@0:   assert(obj_ptr != NULL, "program logic");
aoqi@0:   Copy::aligned_disjoint_words((HeapWord*)old, obj_ptr, word_sz);
aoqi@0:   oop obj = oop(obj_ptr);
aoqi@0:   // Restore the mark word copied above.
aoqi@0:   obj->set_mark(m);
aoqi@0:   return obj;
aoqi@0: }
aoqi@0: 
aoqi@0: void TenuredGeneration::par_promote_alloc_undo(int thread_num,
aoqi@0:                                                HeapWord* obj,
aoqi@0:                                                size_t word_sz) {
aoqi@0:   ParGCAllocBufferWithBOT* buf = _alloc_buffers[thread_num];
aoqi@0:   if (buf->contains(obj)) {
aoqi@0:     guarantee(buf->contains(obj + word_sz - 1),
aoqi@0:               "should contain whole object");
aoqi@0:     buf->undo_allocation(obj, word_sz);
aoqi@0:   } else {
aoqi@0:     CollectedHeap::fill_with_object(obj, word_sz);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: void TenuredGeneration::par_promote_alloc_done(int thread_num) {
aoqi@0:   ParGCAllocBufferWithBOT* buf = _alloc_buffers[thread_num];
aoqi@0:   buf->retire(true, ParallelGCRetainPLAB);
aoqi@0: }
aoqi@0: 
aoqi@0: void TenuredGeneration::retire_alloc_buffers_before_full_gc() {
aoqi@0:   if (UseParNewGC) {
aoqi@0:     for (uint i = 0; i < ParallelGCThreads; i++) {
aoqi@0:       _alloc_buffers[i]->retire(true /*end_of_gc*/, false /*retain*/);
aoqi@0:     }
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: // Verify that any retained parallel allocation buffers do not
aoqi@0: // intersect with dirty cards.
aoqi@0: void TenuredGeneration::verify_alloc_buffers_clean() {
aoqi@0:   if (UseParNewGC) {
aoqi@0:     for (uint i = 0; i < ParallelGCThreads; i++) {
aoqi@0:       _rs->verify_aligned_region_empty(_alloc_buffers[i]->range());
aoqi@0:     }
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: #else  // INCLUDE_ALL_GCS
aoqi@0: void TenuredGeneration::retire_alloc_buffers_before_full_gc() {}
aoqi@0: void TenuredGeneration::verify_alloc_buffers_clean() {}
aoqi@0: #endif // INCLUDE_ALL_GCS
aoqi@0: 
aoqi@0: bool TenuredGeneration::promotion_attempt_is_safe(size_t max_promotion_in_bytes) const {
aoqi@0:   size_t available = max_contiguous_available();
aoqi@0:   size_t av_promo  = (size_t)gc_stats()->avg_promoted()->padded_average();
aoqi@0:   bool   res = (available >= av_promo) || (available >= max_promotion_in_bytes);
aoqi@0:   if (PrintGC && Verbose) {
aoqi@0:     gclog_or_tty->print_cr(
aoqi@0:       "Tenured: promo attempt is%s safe: available("SIZE_FORMAT") %s av_promo("SIZE_FORMAT"),"
aoqi@0:       "max_promo("SIZE_FORMAT")",
aoqi@0:       res? "":" not", available, res? ">=":"<",
aoqi@0:       av_promo, max_promotion_in_bytes);
aoqi@0:   }
aoqi@0:   return res;
aoqi@0: }