1 /*
   2  * Copyright (c) 2011, 2019, 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 #ifndef SHARE_RUNTIME_SERVICETHREAD_HPP
  26 #define SHARE_RUNTIME_SERVICETHREAD_HPP
  27 
  28 #include "runtime/thread.hpp"
  29 
  30 // A hidden from external view JavaThread for JVMTI compiled-method-load
  31 // events, oop storage cleanup, and the maintainance of string, symbol,
  32 // protection domain, and resolved method tables.
  33 
  34 class ServiceThread : public JavaThread {
  35   friend class VMStructs;
  36  private:
  37 
  38   static ServiceThread* _instance;
  39 
  40   static void service_thread_entry(JavaThread* thread, TRAPS);
  41   ServiceThread(ThreadFunction entry_point) : JavaThread(entry_point) {};
  42 
  43  public:
  44   static void initialize();
  45 
  46   // Hide this thread from external view.
  47   bool is_hidden_from_external_view() const      { return true; }
  48 
  49   // Returns true if the passed thread is the service thread.
  50   static bool is_service_thread(Thread* thread);
  51 };
  52 
  53 #endif // SHARE_RUNTIME_SERVICETHREAD_HPP