1 /*
   2  * Copyright (c) 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 "runtime/threadLocalStorage.hpp"
  27 #include <windows.h>
  28 
  29 static DWORD _thread_key;
  30 static bool _initialized = false;
  31 
  32 
  33 void ThreadLocalStorage::init() {
  34   assert(!_initialized, "initializing TLS more than once!");
  35   _thread_key = TlsAlloc();
  36   // If this assert fails we will get a recursive assertion failure
  37   // and not see the actual error message or get a hs_err file
  38   assert(_thread_key != TLS_OUT_OF_INDEXES, "TlsAlloc failed: out of indices");
  39   _initialized = true;
  40 }
  41 
  42 bool ThreadLocalStorage::is_initialized() {
  43   return _initialized;
  44 }
  45 
  46 Thread* ThreadLocalStorage::thread() {
  47   // If this assert fails we will get a recursive assertion failure
  48   // and not see the actual error message or get a hs_err file.
  49   // Which most likely indicates we have taken an error path early in
  50   // the initialization process, which is using Thread::current without
  51   // checking TLS is initialized - see java.cpp vm_exit
  52   assert(_initialized, "TLS not initialized yet!");
  53   Thread* current = (Thread*) TlsGetValue(_thread_key);
  54   assert(current != 0 || GetLastError() == ERROR_SUCCESS,
  55          "TlsGetValue failed with error code: %lu", GetLastError());
  56   return current;
  57 }
  58 
  59 void ThreadLocalStorage::set_thread(Thread* current) {
  60   assert(_initialized, "TLS not initialized yet!");
  61   BOOL res = TlsSetValue(_thread_key, current);
  62   assert(res, "TlsSetValue failed with error code: %lu", GetLastError());
  63 }