Mercurial > hg > graal-jvmci-8
view src/share/vm/gc_implementation/g1/g1PageBasedVirtualSpace.hpp @ 23287:bd88fd590f4e
Restore G1 changes from e13c65f874e5 after merge
author | Gilles Duboscq <gilles.m.duboscq@oracle.com> |
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date | Fri, 08 Jan 2016 15:46:55 +0100 |
parents | 33e421924c67 |
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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. // For systems that only commits of memory in a given size (always greater than // page size) the base address is required to be aligned to that page size. // The actual size requested need not be aligned to that page size, but the size // of the reservation passed may be rounded up to this page size. Any fragment // (less than the page size) of the actual size at the tail of the request will // be committed using OS small 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 size of the tail in bytes of the handled space that needs to be committed // using small pages. size_t _tail_size; // The preferred page size used for commit/uncommit 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; // Helper function for committing memory. Commit the given memory range by using // _page_size pages as much as possible and the remainder with small sized pages. void commit_internal(size_t start_page, size_t end_page); // Commit num_pages pages of _page_size size starting from start. All argument // checking has been performed. void commit_preferred_pages(size_t start_page, size_t end_page); // Commit space at the high end of the space that needs to be committed with small // sized pages. void commit_tail(); // Uncommit the given memory range. void uncommit_internal(size_t start_page, size_t end_page); // Pretouch the given memory range. void pretouch_internal(size_t start_page, size_t end_page); // 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(size_t index) const; // Is the given page index the last page? bool is_last_page(size_t index) const { return index == (_committed.size() - 1); } // Is the given page index the first after last page? bool is_after_last_page(size_t index) const; // Is the last page only partially covered by this space? bool is_last_page_partial() const { return !is_ptr_aligned(_high_boundary, _page_size); } // Returns the end address of the given page bounded by the reserved space. char* bounded_end_addr(size_t end_page) const; // Returns true if the entire area is backed by committed memory. bool is_area_committed(size_t start_page, size_t size_in_pages) const; // Returns true if the entire area is not backed by committed memory. bool is_area_uncommitted(size_t start_page, size_t size_in_pages) const; void initialize_with_page_size(ReservedSpace rs, size_t used_size, size_t page_size); 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(size_t start_page, size_t size_in_pages); // Uncommit the given area of pages starting at start being size_in_pages large. void uncommit(size_t start_page, size_t size_in_pages); // Initialize the given reserved space with the given base address and the size // actually used. // Prefer to commit in page_size chunks. G1PageBasedVirtualSpace(ReservedSpace rs, size_t used_size, 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