| /* |
| * 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 |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #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 |