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view src/share/vm/gc_implementation/g1/g1PageBasedVirtualSpace.hpp @ 21167:ab451b6de9f8
Interop: introduce separate global language scope
author | Matthias Grimmer <grimmer@ssw.jku.at> |
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date | Thu, 30 Apr 2015 17:27:53 +0200 |
parents | ae52ee069062 |
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/* * Copyright (c) 2014, 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_GC_IMPLEMENTATION_G1_G1PAGEBASEDVIRTUALSPACE_HPP #define SHARE_VM_GC_IMPLEMENTATION_G1_G1PAGEBASEDVIRTUALSPACE_HPP #include "memory/allocation.hpp" #include "memory/memRegion.hpp" #include "runtime/virtualspace.hpp" #include "utilities/bitMap.hpp" // Virtual space management helper for a virtual space with an OS page allocation // granularity. // (De-)Allocation requests are always OS page aligned by passing a page index // and multiples of pages. // The implementation gives an error when trying to commit or uncommit pages that // have already been committed or uncommitted. class G1PageBasedVirtualSpace VALUE_OBJ_CLASS_SPEC { friend class VMStructs; private: // Reserved area addresses. char* _low_boundary; char* _high_boundary; // The commit/uncommit granularity in bytes. size_t _page_size; // Bitmap used for verification of commit/uncommit operations. BitMap _committed; // Bitmap used to keep track of which pages are dirty or not for _special // spaces. This is needed because for those spaces the underlying memory // will only be zero filled the first time it is committed. Calls to commit // will use this bitmap and return whether or not the memory is zero filled. BitMap _dirty; // Indicates that the entire space has been committed and pinned in memory, // os::commit_memory() or os::uncommit_memory() have no function. bool _special; // Indicates whether the committed space should be executable. bool _executable; // Returns the index of the page which contains the given address. uintptr_t addr_to_page_index(char* addr) const; // Returns the address of the given page index. char* page_start(uintptr_t index); // Returns the byte size of the given number of pages. size_t byte_size_for_pages(size_t num); // Returns true if the entire area is backed by committed memory. bool is_area_committed(uintptr_t start, size_t size_in_pages) const; // Returns true if the entire area is not backed by committed memory. bool is_area_uncommitted(uintptr_t start, size_t size_in_pages) const; public: // Commit the given area of pages starting at start being size_in_pages large. // Returns true if the given area is zero filled upon completion. bool commit(uintptr_t start, size_t size_in_pages); // Uncommit the given area of pages starting at start being size_in_pages large. void uncommit(uintptr_t start, size_t size_in_pages); // Initialization G1PageBasedVirtualSpace(); bool initialize_with_granularity(ReservedSpace rs, size_t page_size); // Destruction ~G1PageBasedVirtualSpace(); // Amount of reserved memory. size_t reserved_size() const; // Memory used in this virtual space. size_t committed_size() const; // Memory left to use/expand in this virtual space. size_t uncommitted_size() const; bool contains(const void* p) const; MemRegion reserved() { MemRegion x((HeapWord*)_low_boundary, reserved_size() / HeapWordSize); return x; } void release(); void check_for_contiguity() PRODUCT_RETURN; // Debugging void print_on(outputStream* out) PRODUCT_RETURN; void print(); }; #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1PAGEBASEDVIRTUALSPACE_HPP