Thu, 07 Sep 2017 09:17:43 -0400
8072428: Enable UseLoopCounter ergonomically if on-stack-replacement is enabled
Summary: Set UseLoopCounter ergonomically if on-stack-replacement is enabled. Print warning.
Reviewed-by: kvn
duke@435 | 1 | /* |
stefank@2314 | 2 | * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. |
duke@435 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
duke@435 | 4 | * |
duke@435 | 5 | * This code is free software; you can redistribute it and/or modify it |
duke@435 | 6 | * under the terms of the GNU General Public License version 2 only, as |
duke@435 | 7 | * published by the Free Software Foundation. |
duke@435 | 8 | * |
duke@435 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
duke@435 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
duke@435 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
duke@435 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
duke@435 | 13 | * accompanied this code). |
duke@435 | 14 | * |
duke@435 | 15 | * You should have received a copy of the GNU General Public License version |
duke@435 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
duke@435 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
duke@435 | 18 | * |
trims@1907 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
trims@1907 | 20 | * or visit www.oracle.com if you need additional information or have any |
trims@1907 | 21 | * questions. |
duke@435 | 22 | * |
duke@435 | 23 | */ |
duke@435 | 24 | |
stefank@2314 | 25 | #ifndef SHARE_VM_RUNTIME_THREADCRITICAL_HPP |
stefank@2314 | 26 | #define SHARE_VM_RUNTIME_THREADCRITICAL_HPP |
stefank@2314 | 27 | |
stefank@2314 | 28 | #include "memory/allocation.hpp" |
stefank@2314 | 29 | |
duke@435 | 30 | // ThreadCritical is used to protect short non-blocking critical sections. |
duke@435 | 31 | // This class must use no vm facilities that require initialization. |
duke@435 | 32 | // It is used very early in the vm's initialization, in allocation |
duke@435 | 33 | // code and other areas. ThreadCritical regions are reentrant. |
duke@435 | 34 | // |
duke@435 | 35 | // Due to race conditions during vm exit, some of the os level |
duke@435 | 36 | // synchronization primitives may not be deallocated at exit. It |
twisti@1040 | 37 | // is a good plan to implement the platform dependent sections of |
duke@435 | 38 | // code with resources that are recoverable during process |
duke@435 | 39 | // cleanup by the os. Calling the initialize method before use |
duke@435 | 40 | // is also problematic, it is best to use preinitialized primitives |
duke@435 | 41 | // if possible. As an example: |
duke@435 | 42 | // |
duke@435 | 43 | // mutex_t mp = DEFAULTMUTEX; |
duke@435 | 44 | // |
duke@435 | 45 | // Also note that this class is declared as a StackObj to enforce |
duke@435 | 46 | // block structured short locks. It cannot be declared a ResourceObj |
duke@435 | 47 | // or CHeapObj, due to initialization issues. |
duke@435 | 48 | |
duke@435 | 49 | class ThreadCritical : public StackObj { |
duke@435 | 50 | friend class os; |
duke@435 | 51 | private: |
duke@435 | 52 | static void initialize(); |
duke@435 | 53 | static void release(); |
duke@435 | 54 | |
duke@435 | 55 | public: |
duke@435 | 56 | ThreadCritical(); |
duke@435 | 57 | ~ThreadCritical(); |
duke@435 | 58 | }; |
stefank@2314 | 59 | |
stefank@2314 | 60 | #endif // SHARE_VM_RUNTIME_THREADCRITICAL_HPP |