| /* |
| * Copyright (c) 2001, 2015, 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/serial/genMarkSweep.hpp" |
| #include "gc/serial/tenuredGeneration.inline.hpp" |
| #include "gc/shared/blockOffsetTable.inline.hpp" |
| #include "gc/shared/cardGeneration.inline.hpp" |
| #include "gc/shared/collectorCounters.hpp" |
| #include "gc/shared/gcTimer.hpp" |
| #include "gc/shared/genOopClosures.inline.hpp" |
| #include "gc/shared/generationSpec.hpp" |
| #include "gc/shared/space.hpp" |
| #include "memory/allocation.inline.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "runtime/java.hpp" |
| #include "utilities/macros.hpp" |
| #if INCLUDE_ALL_GCS |
| #include "gc/cms/parOopClosures.hpp" |
| #endif |
| |
| TenuredGeneration::TenuredGeneration(ReservedSpace rs, |
| size_t initial_byte_size, |
| CardTableRS* remset) : |
| CardGeneration(rs, initial_byte_size, remset) |
| { |
| 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"; |
| GenCollectorPolicy* gcp = GenCollectedHeap::heap()->gen_policy(); |
| // Generation Counters -- generation 1, 1 subspace |
| _gen_counters = new GenerationCounters(gen_name, 1, 1, |
| gcp->min_old_size(), gcp->max_old_size(), &_virtual_space); |
| |
| _gc_counters = new CollectorCounters("MSC", 1); |
| |
| _space_counters = new CSpaceCounters(gen_name, 0, |
| _virtual_space.reserved_size(), |
| _the_space, _gen_counters); |
| } |
| |
| void TenuredGeneration::gc_prologue(bool full) { |
| _capacity_at_prologue = capacity(); |
| _used_at_prologue = used(); |
| } |
| |
| 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 accommodate promotions from the young generation |
| 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::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(), |
| "used: " SIZE_FORMAT " used_after_gc: " SIZE_FORMAT |
| " capacity: " SIZE_FORMAT, used(), used_after_gc, capacity()); |
| } |
| |
| void TenuredGeneration::update_gc_stats(Generation* current_generation, |
| bool full) { |
| // If the young generation has been collected, gather any statistics |
| // that are of interest at this point. |
| bool current_is_young = GenCollectedHeap::heap()->is_young_gen(current_generation); |
| if (!full && current_is_young) { |
| // Calculate size of data promoted from the young generation |
| // before doing the collection. |
| size_t used_before_gc = used(); |
| |
| // If the young gen collection was 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(); |
| } |
| } |
| |
| 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; |
| } |
| |
| void TenuredGeneration::collect(bool full, |
| bool clear_all_soft_refs, |
| size_t size, |
| bool is_tlab) { |
| GenCollectedHeap* gch = GenCollectedHeap::heap(); |
| |
| // Temporarily expand the span of our ref processor, so |
| // refs discovery is over the entire heap, not just this generation |
| ReferenceProcessorSpanMutator |
| x(ref_processor(), gch->reserved_region()); |
| |
| STWGCTimer* gc_timer = GenMarkSweep::gc_timer(); |
| gc_timer->register_gc_start(); |
| |
| SerialOldTracer* gc_tracer = GenMarkSweep::gc_tracer(); |
| gc_tracer->report_gc_start(gch->gc_cause(), gc_timer->gc_start()); |
| |
| GenMarkSweep::invoke_at_safepoint(ref_processor(), clear_all_soft_refs); |
| |
| gc_timer->register_gc_end(); |
| |
| gc_tracer->report_gc_end(gc_timer->gc_end(), gc_timer->time_partitions()); |
| } |
| |
| HeapWord* |
| TenuredGeneration::expand_and_allocate(size_t word_size, |
| bool is_tlab, |
| bool parallel) { |
| assert(!is_tlab, "TenuredGeneration does not support TLAB allocation"); |
| if (parallel) { |
| MutexLocker x(ParGCRareEvent_lock); |
| HeapWord* result = NULL; |
| size_t byte_size = word_size * HeapWordSize; |
| while (true) { |
| expand(byte_size, _min_heap_delta_bytes); |
| if (GCExpandToAllocateDelayMillis > 0) { |
| os::sleep(Thread::current(), GCExpandToAllocateDelayMillis, false); |
| } |
| result = _the_space->par_allocate(word_size); |
| if ( result != NULL) { |
| return result; |
| } else { |
| // If there's not enough expansion space available, give up. |
| if (_virtual_space.uncommitted_size() < byte_size) { |
| return NULL; |
| } |
| // else try again |
| } |
| } |
| } else { |
| expand(word_size*HeapWordSize, _min_heap_delta_bytes); |
| return _the_space->allocate(word_size); |
| } |
| } |
| |
| bool TenuredGeneration::expand(size_t bytes, size_t expand_bytes) { |
| GCMutexLocker x(ExpandHeap_lock); |
| return CardGeneration::expand(bytes, expand_bytes); |
| } |
| |
| size_t TenuredGeneration::unsafe_max_alloc_nogc() const { |
| return _the_space->free(); |
| } |
| |
| size_t TenuredGeneration::contiguous_available() const { |
| return _the_space->free() + _virtual_space.uncommitted_size(); |
| } |
| |
| void TenuredGeneration::assert_correct_size_change_locking() { |
| assert_locked_or_safepoint(ExpandHeap_lock); |
| } |
| |
| // Currently nothing to do. |
| void TenuredGeneration::prepare_for_verify() {} |
| |
| void TenuredGeneration::object_iterate(ObjectClosure* blk) { |
| _the_space->object_iterate(blk); |
| } |
| |
| void TenuredGeneration::save_marks() { |
| _the_space->set_saved_mark(); |
| } |
| |
| void TenuredGeneration::reset_saved_marks() { |
| _the_space->reset_saved_mark(); |
| } |
| |
| bool TenuredGeneration::no_allocs_since_save_marks() { |
| return _the_space->saved_mark_at_top(); |
| } |
| |
| #define TenuredGen_SINCE_SAVE_MARKS_ITERATE_DEFN(OopClosureType, nv_suffix) \ |
| \ |
| void TenuredGeneration:: \ |
| oop_since_save_marks_iterate##nv_suffix(OopClosureType* blk) { \ |
| blk->set_generation(this); \ |
| _the_space->oop_since_save_marks_iterate##nv_suffix(blk); \ |
| blk->reset_generation(); \ |
| save_marks(); \ |
| } |
| |
| ALL_SINCE_SAVE_MARKS_CLOSURES(TenuredGen_SINCE_SAVE_MARKS_ITERATE_DEFN) |
| |
| #undef TenuredGen_SINCE_SAVE_MARKS_ITERATE_DEFN |
| |
| void TenuredGeneration::gc_epilogue(bool full) { |
| // update the generation and space performance counters |
| update_counters(); |
| if (ZapUnusedHeapArea) { |
| _the_space->check_mangled_unused_area_complete(); |
| } |
| } |
| |
| void TenuredGeneration::record_spaces_top() { |
| assert(ZapUnusedHeapArea, "Not mangling unused space"); |
| _the_space->set_top_for_allocations(); |
| } |
| |
| void TenuredGeneration::verify() { |
| _the_space->verify(); |
| } |
| |
| void TenuredGeneration::print_on(outputStream* st) const { |
| Generation::print_on(st); |
| st->print(" the"); |
| _the_space->print_on(st); |
| } |