1 /*
   2  * Copyright (c) 2014, 2015, 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/shared/gcId.hpp"
  27 #include "runtime/safepoint.hpp"
  28 #include "runtime/thread.inline.hpp"
  29 #include "runtime/threadLocalStorage.hpp"
  30 
  31 uint GCId::_next_id = 0;
  32 
  33 NamedThread* currentNamedthread() {
  34   assert(Thread::current()->is_Named_thread(), "This thread must be NamedThread");
  35   return (NamedThread*)Thread::current();
  36 }
  37 
  38 const uint GCId::create() {
  39   return _next_id++;
  40 }
  41 
  42 const uint GCId::peek() {
  43   return _next_id;
  44 }
  45 
  46 const uint GCId::current() {
  47   assert(currentNamedthread()->gc_id() != undefined(), "Using undefined GC id.");
  48   return current_raw();
  49 }
  50 
  51 const uint GCId::current_raw() {
  52   return currentNamedthread()->gc_id();
  53 }
  54 
  55 size_t GCId::print_prefix(char* buf, size_t len) {
  56   if (ThreadLocalStorage::is_initialized() && ThreadLocalStorage::thread()->is_Named_thread()) {
  57     uint gc_id = current_raw();
  58     if (gc_id != undefined()) {
  59       int ret = jio_snprintf(buf, len, "GC(%u) ", gc_id);
  60       assert(ret > 0, "Failed to print prefix. Log buffer too small?");
  61       return (size_t)ret;
  62     }
  63   }
  64   return 0;
  65 }
  66 
  67 GCIdMark::GCIdMark() : _gc_id(GCId::create()) {
  68   currentNamedthread()->set_gc_id(_gc_id);
  69 }
  70 
  71 GCIdMark::GCIdMark(uint gc_id) : _gc_id(gc_id) {
  72   currentNamedthread()->set_gc_id(_gc_id);
  73 }
  74 
  75 GCIdMark::~GCIdMark() {
  76   currentNamedthread()->set_gc_id(GCId::undefined());
  77 }
  78 
  79 GCIdMarkAndRestore::GCIdMarkAndRestore() : _gc_id(GCId::create()) {
  80   _previous_gc_id = GCId::current_raw();
  81   currentNamedthread()->set_gc_id(_gc_id);
  82 }
  83 
  84 GCIdMarkAndRestore::GCIdMarkAndRestore(uint gc_id) : _gc_id(gc_id) {
  85   _previous_gc_id = GCId::current_raw();
  86   currentNamedthread()->set_gc_id(_gc_id);
  87 }
  88 
  89 GCIdMarkAndRestore::~GCIdMarkAndRestore() {
  90   currentNamedthread()->set_gc_id(_previous_gc_id);
  91 }