1 /*
   2  * Copyright (c) 2014, 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 "gc_implementation/g1/g1Log.hpp"
  27 #include "gc_implementation/g1/g1StringDedup.hpp"
  28 #include "gc_implementation/g1/g1StringDedupTable.hpp"
  29 #include "gc_implementation/g1/g1StringDedupThread.hpp"
  30 #include "gc_implementation/g1/g1StringDedupQueue.hpp"
  31 
  32 G1StringDedupThread* G1StringDedupThread::_thread = NULL;
  33 
  34 G1StringDedupThread::G1StringDedupThread() :
  35   ConcurrentGCThread() {
  36   set_name("String Deduplication Thread");
  37   create_and_start();
  38 }
  39 
  40 G1StringDedupThread::~G1StringDedupThread() {
  41   ShouldNotReachHere();
  42 }
  43 
  44 void G1StringDedupThread::create() {
  45   assert(G1StringDedup::is_enabled(), "String deduplication not enabled");
  46   assert(_thread == NULL, "One string deduplication thread allowed");
  47   _thread = new G1StringDedupThread();
  48 }
  49 
  50 G1StringDedupThread* G1StringDedupThread::thread() {
  51   assert(G1StringDedup::is_enabled(), "String deduplication not enabled");
  52   assert(_thread != NULL, "String deduplication thread not created");
  53   return _thread;
  54 }
  55 
  56 void G1StringDedupThread::print_on(outputStream* st) const {
  57   st->print("\"%s\" ", name());
  58   Thread::print_on(st);
  59   st->cr();
  60 }
  61 
  62 void G1StringDedupThread::run() {
  63   G1StringDedupStat total_stat;
  64 
  65   initialize_in_thread();
  66   wait_for_universe_init();
  67 
  68   // Main loop
  69   for (;;) {
  70     G1StringDedupStat stat;
  71     oop java_string;
  72 
  73     stat.mark_idle();
  74 
  75     // Wait for the queue to become non-empty
  76     G1StringDedupQueue::wait();
  77 
  78     // Include this thread in safepoints
  79     stsJoin();
  80 
  81     stat.mark_exec();
  82 
  83     // Process the queue
  84     while (G1StringDedupQueue::pop(java_string)) {
  85       G1StringDedupTable::deduplicate(java_string, stat);
  86 
  87       // Safepoint this thread if needed
  88       if (stsShouldYield()) {
  89         stat.mark_block();
  90         stsYield(NULL);
  91         stat.mark_unblock();
  92       }
  93     }
  94 
  95     G1StringDedupTable::trim_entry_cache();
  96 
  97     stat.mark_done();
  98 
  99     // Print statistics
 100     total_stat.add(stat);
 101     print(gclog_or_tty, stat, total_stat);
 102 
 103     // Exclude this thread from safepoints
 104     stsLeave();
 105   }
 106 
 107   ShouldNotReachHere();
 108 }
 109 
 110 void G1StringDedupThread::print(outputStream* st, const G1StringDedupStat& last_stat, const G1StringDedupStat& total_stat) {
 111   if (G1Log::fine() || PrintStringDeduplicationStatistics) {
 112     G1StringDedupStat::print_summary(st, last_stat, total_stat);
 113     if (PrintStringDeduplicationStatistics) {
 114       G1StringDedupStat::print_statistics(st, last_stat, false);
 115       G1StringDedupStat::print_statistics(st, total_stat, true);
 116       G1StringDedupTable::print_statistics(st);
 117       G1StringDedupQueue::print_statistics(st);
 118     }
 119   }
 120 }