Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 #ifndef SHARE_VM_RUNTIME_THREADCRITICAL_HPP

 #define SHARE_VM_RUNTIME_THREADCRITICAL_HPP

 #include "memory/allocation.hpp"

 // ThreadCritical is used to protect short non-blocking critical sections.

 // This class must use no vm facilities that require initialization.

 // It is used very early in the vm's initialization, in allocation

 // code and other areas. ThreadCritical regions are reentrant.

 //

 // Due to race conditions during vm exit, some of the os level

 // synchronization primitives may not be deallocated at exit. It

 // is a good plan to implement the platform dependent sections of

 // code with resources that are recoverable during process

 // cleanup by the os. Calling the initialize method before use

 // is also problematic, it is best to use preinitialized primitives

 // if possible. As an example:

 //

 // mutex_t  mp  =  DEFAULTMUTEX;

 //

 // Also note that this class is declared as a StackObj to enforce

 // block structured short locks. It cannot be declared a ResourceObj

 // or CHeapObj, due to initialization issues.

 class ThreadCritical : public StackObj {

  friend class os;

  private:

   static void initialize();

   static void release();

  public:

   ThreadCritical();

   ~ThreadCritical();

 };

 #endif // SHARE_VM_RUNTIME_THREADCRITICAL_HPP