1 /*
   2  * Copyright (c) 2014, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/stringTable.hpp"
  27 #include "gc/g1/g1StringDedup.hpp"
  28 #include "gc/g1/g1StringDedupQueue.hpp"
  29 #include "gc/g1/g1StringDedupTable.hpp"
  30 #include "gc/g1/g1StringDedupThread.hpp"

  31 #include "gc/shared/suspendibleThreadSet.hpp"
  32 #include "logging/log.hpp"
  33 #include "oops/access.inline.hpp"
  34 #include "oops/oop.inline.hpp"
  35 #include "runtime/atomic.hpp"
  36 
  37 G1StringDedupThread* G1StringDedupThread::_thread = NULL;
  38 
  39 G1StringDedupThread::G1StringDedupThread() :
  40   ConcurrentGCThread() {
  41   set_name("G1 StrDedup");
  42   create_and_start();
  43 }
  44 
  45 G1StringDedupThread::~G1StringDedupThread() {
  46   ShouldNotReachHere();
  47 }
  48 
  49 void G1StringDedupThread::create() {
  50   assert(G1StringDedup::is_enabled(), "String deduplication not enabled");
  51   assert(_thread == NULL, "One string deduplication thread allowed");
  52   _thread = new G1StringDedupThread();
  53 }
  54 
  55 G1StringDedupThread* G1StringDedupThread::thread() {
  56   assert(G1StringDedup::is_enabled(), "String deduplication not enabled");
  57   assert(_thread != NULL, "String deduplication thread not created");
  58   return _thread;
  59 }
  60 
  61 class G1StringDedupSharedClosure: public OopClosure {
  62  private:
  63   G1StringDedupStat& _stat;
  64 
  65  public:
  66   G1StringDedupSharedClosure(G1StringDedupStat& stat) : _stat(stat) {}
  67 
  68   virtual void do_oop(oop* p) { ShouldNotReachHere(); }
  69   virtual void do_oop(narrowOop* p) {
  70     oop java_string = RawAccess<>::oop_load(p);
  71     G1StringDedupTable::deduplicate(java_string, _stat);
  72   }
  73 };
  74 
  75 // The CDS archive does not include the string dedupication table. Only the string
  76 // table is saved in the archive. The shared strings from CDS archive need to be
  77 // added to the string dedupication table before deduplication occurs. That is
  78 // done in the begining of the G1StringDedupThread (see G1StringDedupThread::run()
  79 // below).
  80 void G1StringDedupThread::deduplicate_shared_strings(G1StringDedupStat& stat) {
  81   G1StringDedupSharedClosure sharedStringDedup(stat);
  82   StringTable::shared_oops_do(&sharedStringDedup);
  83 }
  84 
  85 void G1StringDedupThread::run_service() {
  86   G1StringDedupStat total_stat;
  87 
  88   deduplicate_shared_strings(total_stat);
  89 
  90   // Main loop
  91   for (;;) {
  92     G1StringDedupStat stat;
  93 
  94     stat.mark_idle();
  95 
  96     // Wait for the queue to become non-empty
  97     G1StringDedupQueue::wait();
  98     if (should_terminate()) {
  99       break;
 100     }
 101 
 102     {
 103       // Include thread in safepoints
 104       SuspendibleThreadSetJoiner sts_join;
 105 
 106       stat.mark_exec();
 107       print_start(stat);
 108 
 109       // Process the queue
 110       for (;;) {
 111         oop java_string = G1StringDedupQueue::pop();
 112         if (java_string == NULL) {
 113           break;
 114         }
 115 
 116         G1StringDedupTable::deduplicate(java_string, stat);
 117 
 118         // Safepoint this thread if needed
 119         if (sts_join.should_yield()) {
 120           stat.mark_block();
 121           sts_join.yield();
 122           stat.mark_unblock();
 123         }
 124       }
 125 
 126       stat.mark_done();
 127 
 128       total_stat.add(stat);
 129       print_end(stat, total_stat);
 130     }
 131 
 132     G1StringDedupTable::clean_entry_cache();
 133   }
 134 }
 135 
 136 void G1StringDedupThread::stop_service() {
 137   G1StringDedupQueue::cancel_wait();
 138 }
 139 
 140 void G1StringDedupThread::print_start(const G1StringDedupStat& last_stat) {
 141   G1StringDedupStat::print_start(last_stat);
 142 }
 143 
 144 void G1StringDedupThread::print_end(const G1StringDedupStat& last_stat, const G1StringDedupStat& total_stat) {
 145   G1StringDedupStat::print_end(last_stat, total_stat);
 146   if (log_is_enabled(Debug, gc, stringdedup)) {
 147     G1StringDedupStat::print_statistics(last_stat, false);
 148     G1StringDedupStat::print_statistics(total_stat, true);
 149     G1StringDedupTable::print_statistics();
 150     G1StringDedupQueue::print_statistics();

 151   }
 152 }

   1 /*
   2  * Copyright (c) 2014, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/stringTable.hpp"
  27 #include "gc/shared/stringdedup/stringDedup.hpp"
  28 #include "gc/shared/stringdedup/stringDedupQueue.hpp"
  29 #include "gc/shared/stringdedup/stringDedupQueue.inline.hpp"
  30 #include "gc/shared/stringdedup/stringDedupTable.hpp"
  31 #include "gc/shared/stringdedup/stringDedupThread.hpp"
  32 #include "gc/shared/suspendibleThreadSet.hpp"
  33 #include "logging/log.hpp"
  34 #include "oops/access.inline.hpp"
  35 #include "oops/oop.inline.hpp"
  36 #include "runtime/atomic.hpp"
  37 
  38 StringDedupThread* StringDedupThread::_thread = NULL;
  39 
  40 StringDedupThread::StringDedupThread() :
  41   ConcurrentGCThread() {
  42   set_name("StrDedup");
  43   create_and_start();
  44 }
  45 
  46 StringDedupThread::~StringDedupThread() {
  47   ShouldNotReachHere();
  48 }
  49 
  50 StringDedupThread* StringDedupThread::thread() {







  51   assert(_thread != NULL, "String deduplication thread not created");
  52   return _thread;
  53 }
  54 
  55 class StringDedupSharedClosure: public OopClosure {
  56  private:
  57   StringDedupStat* _stat;
  58 
  59  public:
  60   StringDedupSharedClosure(StringDedupStat* stat) : _stat(stat) {}
  61 
  62   virtual void do_oop(oop* p) { ShouldNotReachHere(); }
  63   virtual void do_oop(narrowOop* p) {
  64     oop java_string = RawAccess<>::oop_load(p);
  65     StringDedupTable::deduplicate(java_string, _stat);
  66   }
  67 };
  68 
  69 // The CDS archive does not include the string dedupication table. Only the string
  70 // table is saved in the archive. The shared strings from CDS archive need to be
  71 // added to the string dedupication table before deduplication occurs. That is
  72 // done in the begining of the StringDedupThread (see StringDedupThread::do_deduplication()).
  73 void StringDedupThread::deduplicate_shared_strings(StringDedupStat* stat) {
  74   StringDedupSharedClosure sharedStringDedup(stat);

  75   StringTable::shared_oops_do(&sharedStringDedup);
  76 }
  77 
  78 void StringDedupThread::stop_service() {
  79   StringDedupQueue::cancel_wait();















































  80 }
  81 
  82 void StringDedupThread::print_start(const StringDedupStat* last_stat) {
  83   StringDedupStat::print_start(last_stat);
  84 }
  85 
  86 void StringDedupThread::print_end(const StringDedupStat* last_stat, const StringDedupStat* total_stat) {
  87   StringDedupStat::print_end(last_stat, total_stat);




  88   if (log_is_enabled(Debug, gc, stringdedup)) {
  89     last_stat->print_statistics(false);
  90     total_stat->print_statistics(true);
  91 
  92     StringDedupTable::print_statistics();
  93     StringDedupQueue::print_statistics();
  94   }
  95 }