Mercurial > hg > graal-jvmci-8
view src/share/vm/runtime/threadCritical.hpp @ 6725:da91efe96a93
6964458: Reimplement class meta-data storage to use native memory
Summary: Remove PermGen, allocate meta-data in metaspace linked to class loaders, rewrite GC walking, rewrite and rename metadata to be C++ classes
Reviewed-by: jmasa, stefank, never, coleenp, kvn, brutisso, mgerdin, dholmes, jrose, twisti, roland
Contributed-by: jmasa <jon.masamitsu@oracle.com>, stefank <stefan.karlsson@oracle.com>, mgerdin <mikael.gerdin@oracle.com>, never <tom.rodriguez@oracle.com>
author | coleenp |
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date | Sat, 01 Sep 2012 13:25:18 -0400 |
parents | f95d63e2154a |
children |
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/* * 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