jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/g1StringDedup.cpp@595c0f60d50d (annotated)

src/share/vm/gc_implementation/g1/g1StringDedup.cpp@595c0f60d50d (annotated)

src/share/vm/gc_implementation/g1/g1StringDedup.cpp

Tue, 18 Mar 2014 19:07:22 +0100

author: pliden
date: Tue, 18 Mar 2014 19:07:22 +0100
changeset 6413: 595c0f60d50d
child 6690: 1772223a25a2
permissions: -rw-r--r--

8029075: String deduplication in G1
Summary: Implementation of JEP 192, http://openjdk.java.net/jeps/192
Reviewed-by: brutisso, tschatzl, coleenp

 /*
  * Copyright (c) 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 "classfile/javaClasses.hpp"
 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
 #include "gc_implementation/g1/g1GCPhaseTimes.hpp"
 #include "gc_implementation/g1/g1StringDedup.hpp"
 #include "gc_implementation/g1/g1StringDedupQueue.hpp"
 #include "gc_implementation/g1/g1StringDedupStat.hpp"
 #include "gc_implementation/g1/g1StringDedupTable.hpp"
 #include "gc_implementation/g1/g1StringDedupThread.hpp"
 bool G1StringDedup::_enabled = false;
 void G1StringDedup::initialize() {
   assert(UseG1GC, "String deduplication only available with G1");
   if (UseStringDeduplication) {
     _enabled = true;
     G1StringDedupQueue::create();
     G1StringDedupTable::create();
     G1StringDedupThread::create();
   }
 }
 bool G1StringDedup::is_candidate_from_mark(oop obj) {
   if (java_lang_String::is_instance(obj)) {
     bool from_young = G1CollectedHeap::heap()->heap_region_containing_raw(obj)->is_young();
     if (from_young && obj->age() < StringDeduplicationAgeThreshold) {
       // Candidate found. String is being evacuated from young to old but has not
       // reached the deduplication age threshold, i.e. has not previously been a
       // candidate during its life in the young generation.
       return true;
     }
   }
   // Not a candidate
   return false;
 }
 void G1StringDedup::enqueue_from_mark(oop java_string) {
   assert(is_enabled(), "String deduplication not enabled");
   if (is_candidate_from_mark(java_string)) {
     G1StringDedupQueue::push(0 /* worker_id */, java_string);
   }
 }
 bool G1StringDedup::is_candidate_from_evacuation(bool from_young, bool to_young, oop obj) {
   if (from_young && java_lang_String::is_instance(obj)) {
     if (to_young && obj->age() == StringDeduplicationAgeThreshold) {
       // Candidate found. String is being evacuated from young to young and just
       // reached the deduplication age threshold.
       return true;
     }
     if (!to_young && obj->age() < StringDeduplicationAgeThreshold) {
       // Candidate found. String is being evacuated from young to old but has not
       // reached the deduplication age threshold, i.e. has not previously been a
       // candidate during its life in the young generation.
       return true;
     }
   }
   // Not a candidate
   return false;
 }
 void G1StringDedup::enqueue_from_evacuation(bool from_young, bool to_young, uint worker_id, oop java_string) {
   assert(is_enabled(), "String deduplication not enabled");
   if (is_candidate_from_evacuation(from_young, to_young, java_string)) {
     G1StringDedupQueue::push(worker_id, java_string);
   }
 }
 void G1StringDedup::deduplicate(oop java_string) {
   assert(is_enabled(), "String deduplication not enabled");
   G1StringDedupStat dummy; // Statistics from this path is never used
   G1StringDedupTable::deduplicate(java_string, dummy);
 }
 void G1StringDedup::oops_do(OopClosure* keep_alive) {
   assert(is_enabled(), "String deduplication not enabled");
   unlink_or_oops_do(NULL, keep_alive);
 }
 void G1StringDedup::unlink(BoolObjectClosure* is_alive) {
   assert(is_enabled(), "String deduplication not enabled");
   // Don't allow a potential resize or rehash during unlink, as the unlink
   // operation itself might remove enough entries to invalidate such a decision.
   unlink_or_oops_do(is_alive, NULL, false /* allow_resize_and_rehash */);
 }
 //
 // Task for parallel unlink_or_oops_do() operation on the deduplication queue
 // and table.
 //
 class G1StringDedupUnlinkOrOopsDoTask : public AbstractGangTask {
 private:
   G1StringDedupUnlinkOrOopsDoClosure _cl;
 public:
   G1StringDedupUnlinkOrOopsDoTask(BoolObjectClosure* is_alive,
                                   OopClosure* keep_alive,
                                   bool allow_resize_and_rehash) :
     AbstractGangTask("G1StringDedupUnlinkOrOopsDoTask"),
     _cl(is_alive, keep_alive, allow_resize_and_rehash) {
   }
   virtual void work(uint worker_id) {
     double queue_fixup_start = os::elapsedTime();
     G1StringDedupQueue::unlink_or_oops_do(&_cl);
     double table_fixup_start = os::elapsedTime();
     G1StringDedupTable::unlink_or_oops_do(&_cl, worker_id);
     double queue_fixup_time_ms = (table_fixup_start - queue_fixup_start) * 1000.0;
     double table_fixup_time_ms = (os::elapsedTime() - table_fixup_start) * 1000.0;
     G1CollectorPolicy* g1p = G1CollectedHeap::heap()->g1_policy();
     g1p->phase_times()->record_string_dedup_queue_fixup_worker_time(worker_id, queue_fixup_time_ms);
     g1p->phase_times()->record_string_dedup_table_fixup_worker_time(worker_id, table_fixup_time_ms);
   }
 };
 void G1StringDedup::unlink_or_oops_do(BoolObjectClosure* is_alive, OopClosure* keep_alive, bool allow_resize_and_rehash) {
   assert(is_enabled(), "String deduplication not enabled");
   G1CollectorPolicy* g1p = G1CollectedHeap::heap()->g1_policy();
   g1p->phase_times()->note_string_dedup_fixup_start();
   double fixup_start = os::elapsedTime();
   G1StringDedupUnlinkOrOopsDoTask task(is_alive, keep_alive, allow_resize_and_rehash);
   if (G1CollectedHeap::use_parallel_gc_threads()) {
     G1CollectedHeap* g1h = G1CollectedHeap::heap();
     g1h->set_par_threads();
     g1h->workers()->run_task(&task);
     g1h->set_par_threads(0);
   } else {
     task.work(0);
   }
   double fixup_time_ms = (os::elapsedTime() - fixup_start) * 1000.0;
   g1p->phase_times()->record_string_dedup_fixup_time(fixup_time_ms);
   g1p->phase_times()->note_string_dedup_fixup_end();
 }
 void G1StringDedup::threads_do(ThreadClosure* tc) {
   assert(is_enabled(), "String deduplication not enabled");
   tc->do_thread(G1StringDedupThread::thread());
 }
 void G1StringDedup::print_worker_threads_on(outputStream* st) {
   assert(is_enabled(), "String deduplication not enabled");
   G1StringDedupThread::thread()->print_on(st);
   st->cr();
 }
 void G1StringDedup::verify() {
   assert(is_enabled(), "String deduplication not enabled");
   G1StringDedupQueue::verify();
   G1StringDedupTable::verify();
 }
 G1StringDedupUnlinkOrOopsDoClosure::G1StringDedupUnlinkOrOopsDoClosure(BoolObjectClosure* is_alive,
                                                                        OopClosure* keep_alive,
                                                                        bool allow_resize_and_rehash) :
   _is_alive(is_alive),
   _keep_alive(keep_alive),
   _resized_table(NULL),
   _rehashed_table(NULL),
   _next_queue(0),
   _next_bucket(0) {
   if (allow_resize_and_rehash) {
     // If both resize and rehash is needed, only do resize. Rehash of
     // the table will eventually happen if the situation persists.
     _resized_table = G1StringDedupTable::prepare_resize();
     if (!is_resizing()) {
       _rehashed_table = G1StringDedupTable::prepare_rehash();
     }
   }
 }
 G1StringDedupUnlinkOrOopsDoClosure::~G1StringDedupUnlinkOrOopsDoClosure() {
   assert(!is_resizing() || !is_rehashing(), "Can not both resize and rehash");
   if (is_resizing()) {
     G1StringDedupTable::finish_resize(_resized_table);
   } else if (is_rehashing()) {
     G1StringDedupTable::finish_rehash(_rehashed_table);
   }
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/g1StringDedup.cpp@595c0f60d50d (annotated)

src/share/vm/gc_implementation/g1/g1StringDedup.cpp