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 "jvm.h"
  27 #include "gc/shared/gcId.hpp"
  28 #include "runtime/safepoint.hpp"
  29 #include "runtime/thread.inline.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   const uint gc_id = currentNamedthread()->gc_id();
  48   assert(gc_id != undefined(), "Using undefined GC id.");
  49   return gc_id;
  50 }
  51 
  52 const uint GCId::current_or_undefined() {
  53   return Thread::current()->is_Named_thread() ? currentNamedthread()->gc_id() : undefined();
  54 }
  55 
  56 size_t GCId::print_prefix(char* buf, size_t len) {
  57   Thread* thread = Thread::current_or_null();
  58   if (thread != NULL) {
  59     uint gc_id = current_or_undefined();
  60     if (gc_id != undefined()) {
  61       int ret = jio_snprintf(buf, len, "GC(%u) ", gc_id);
  62       assert(ret > 0, "Failed to print prefix. Log buffer too small?");
  63       return (size_t)ret;
  64     }
  65   }
  66   return 0;
  67 }
  68 
  69 GCIdMark::GCIdMark() : _gc_id(GCId::create()) {
  70   currentNamedthread()->set_gc_id(_gc_id);
  71 }
  72 
  73 GCIdMark::GCIdMark(uint gc_id) : _gc_id(gc_id) {
  74   currentNamedthread()->set_gc_id(_gc_id);
  75 }
  76 
  77 GCIdMark::~GCIdMark() {
  78   currentNamedthread()->set_gc_id(GCId::undefined());
  79 }
  80 
  81 GCIdMarkAndRestore::GCIdMarkAndRestore() : _gc_id(GCId::create()) {
  82   _previous_gc_id = currentNamedthread()->gc_id();
  83   currentNamedthread()->set_gc_id(_gc_id);
  84 }
  85 
  86 GCIdMarkAndRestore::GCIdMarkAndRestore(uint gc_id) : _gc_id(gc_id) {
  87   _previous_gc_id = currentNamedthread()->gc_id();
  88   currentNamedthread()->set_gc_id(_gc_id);
  89 }
  90 
  91 GCIdMarkAndRestore::~GCIdMarkAndRestore() {
  92   currentNamedthread()->set_gc_id(_previous_gc_id);
  93 }