tschatzl@7051: /*
tschatzl@7051:  * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
tschatzl@7051:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
tschatzl@7051:  *
tschatzl@7051:  * This code is free software; you can redistribute it and/or modify it
tschatzl@7051:  * under the terms of the GNU General Public License version 2 only, as
tschatzl@7051:  * published by the Free Software Foundation.
tschatzl@7051:  *
tschatzl@7051:  * This code is distributed in the hope that it will be useful, but WITHOUT
tschatzl@7051:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
tschatzl@7051:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
tschatzl@7051:  * version 2 for more details (a copy is included in the LICENSE file that
tschatzl@7051:  * accompanied this code).
tschatzl@7051:  *
tschatzl@7051:  * You should have received a copy of the GNU General Public License version
tschatzl@7051:  * 2 along with this work; if not, write to the Free Software Foundation,
tschatzl@7051:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
tschatzl@7051:  *
tschatzl@7051:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
tschatzl@7051:  * or visit www.oracle.com if you need additional information or have any
tschatzl@7051:  * questions.
tschatzl@7051:  *
tschatzl@7051:  */
tschatzl@7051: 
tschatzl@7051: #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1PAGEBASEDVIRTUALSPACE_HPP
tschatzl@7051: #define SHARE_VM_GC_IMPLEMENTATION_G1_G1PAGEBASEDVIRTUALSPACE_HPP
tschatzl@7051: 
tschatzl@7051: #include "memory/allocation.hpp"
tschatzl@7051: #include "memory/memRegion.hpp"
tschatzl@7051: #include "runtime/virtualspace.hpp"
tschatzl@7051: #include "utilities/bitMap.hpp"
tschatzl@7051: 
tschatzl@7051: // Virtual space management helper for a virtual space with an OS page allocation
tschatzl@7051: // granularity.
tschatzl@7051: // (De-)Allocation requests are always OS page aligned by passing a page index
tschatzl@7051: // and multiples of pages.
tschatzl@7781: // For systems that only commits of memory in a given size (always greater than
tschatzl@7781: // page size) the base address is required to be aligned to that page size.
tschatzl@7781: // The actual size requested need not be aligned to that page size, but the size
tschatzl@7781: // of the reservation passed may be rounded up to this page size. Any fragment
tschatzl@7781: // (less than the page size) of the actual size at the tail of the request will
tschatzl@7781: // be committed using OS small pages.
tschatzl@7051: // The implementation gives an error when trying to commit or uncommit pages that
tschatzl@7051: // have already been committed or uncommitted.
tschatzl@7051: class G1PageBasedVirtualSpace VALUE_OBJ_CLASS_SPEC {
tschatzl@7051:   friend class VMStructs;
tschatzl@7051:  private:
tschatzl@7051:   // Reserved area addresses.
tschatzl@7051:   char* _low_boundary;
tschatzl@7051:   char* _high_boundary;
tschatzl@7051: 
tschatzl@7781:   // The size of the tail in bytes of the handled space that needs to be committed
tschatzl@7781:   // using small pages.
tschatzl@7781:   size_t _tail_size;
tschatzl@7781: 
tschatzl@7781:   // The preferred page size used for commit/uncommit in bytes.
tschatzl@7051:   size_t _page_size;
tschatzl@7051: 
tschatzl@7051:   // Bitmap used for verification of commit/uncommit operations.
tschatzl@7051:   BitMap _committed;
tschatzl@7051: 
sjohanss@7509:   // Bitmap used to keep track of which pages are dirty or not for _special
sjohanss@7509:   // spaces. This is needed because for those spaces the underlying memory
sjohanss@7509:   // will only be zero filled the first time it is committed. Calls to commit
sjohanss@7509:   // will use this bitmap and return whether or not the memory is zero filled.
sjohanss@7509:   BitMap _dirty;
sjohanss@7509: 
tschatzl@7051:   // Indicates that the entire space has been committed and pinned in memory,
tschatzl@7051:   // os::commit_memory() or os::uncommit_memory() have no function.
tschatzl@7051:   bool _special;
tschatzl@7051: 
tschatzl@7051:   // Indicates whether the committed space should be executable.
tschatzl@7051:   bool _executable;
tschatzl@7051: 
tschatzl@7781:   // Helper function for committing memory. Commit the given memory range by using
tschatzl@7781:   // _page_size pages as much as possible and the remainder with small sized pages.
tschatzl@7781:   void commit_internal(size_t start_page, size_t end_page);
tschatzl@7781:   // Commit num_pages pages of _page_size size starting from start. All argument
tschatzl@7781:   // checking has been performed.
tschatzl@7781:   void commit_preferred_pages(size_t start_page, size_t end_page);
tschatzl@7781:   // Commit space at the high end of the space that needs to be committed with small
tschatzl@7781:   // sized pages.
tschatzl@7781:   void commit_tail();
tschatzl@7781: 
tschatzl@7781:   // Uncommit the given memory range.
tschatzl@7781:   void uncommit_internal(size_t start_page, size_t end_page);
tschatzl@7781: 
tschatzl@7781:   // Pretouch the given memory range.
tschatzl@7781:   void pretouch_internal(size_t start_page, size_t end_page);
tschatzl@7781: 
tschatzl@7051:   // Returns the index of the page which contains the given address.
tschatzl@7051:   uintptr_t  addr_to_page_index(char* addr) const;
tschatzl@7051:   // Returns the address of the given page index.
tschatzl@7781:   char*  page_start(size_t index) const;
tschatzl@7781: 
tschatzl@7781:   // Is the given page index the last page?
tschatzl@7781:   bool is_last_page(size_t index) const { return index == (_committed.size() - 1); }
tschatzl@7781:   // Is the given page index the first after last page?
tschatzl@7781:   bool is_after_last_page(size_t index) const;
tschatzl@7781:   // Is the last page only partially covered by this space?
tschatzl@7781:   bool is_last_page_partial() const { return !is_ptr_aligned(_high_boundary, _page_size); }
tschatzl@7781:   // Returns the end address of the given page bounded by the reserved space.
tschatzl@7781:   char* bounded_end_addr(size_t end_page) const;
tschatzl@7051: 
tschatzl@7051:   // Returns true if the entire area is backed by committed memory.
tschatzl@7781:   bool is_area_committed(size_t start_page, size_t size_in_pages) const;
tschatzl@7051:   // Returns true if the entire area is not backed by committed memory.
tschatzl@7781:   bool is_area_uncommitted(size_t start_page, size_t size_in_pages) const;
tschatzl@7051: 
tschatzl@7781:   void initialize_with_page_size(ReservedSpace rs, size_t used_size, size_t page_size);
tschatzl@7051:  public:
tschatzl@7051: 
tschatzl@7051:   // Commit the given area of pages starting at start being size_in_pages large.
sjohanss@7509:   // Returns true if the given area is zero filled upon completion.
tschatzl@7781:   bool commit(size_t start_page, size_t size_in_pages);
tschatzl@7051: 
tschatzl@7051:   // Uncommit the given area of pages starting at start being size_in_pages large.
tschatzl@7781:   void uncommit(size_t start_page, size_t size_in_pages);
tschatzl@7051: 
tschatzl@7781:   // Initialize the given reserved space with the given base address and the size
tschatzl@7781:   // actually used.
tschatzl@7781:   // Prefer to commit in page_size chunks.
tschatzl@7781:   G1PageBasedVirtualSpace(ReservedSpace rs, size_t used_size, size_t page_size);
tschatzl@7051: 
tschatzl@7051:   // Destruction
tschatzl@7051:   ~G1PageBasedVirtualSpace();
tschatzl@7051: 
tschatzl@7051:   // Amount of reserved memory.
tschatzl@7051:   size_t reserved_size() const;
tschatzl@7051:   // Memory used in this virtual space.
tschatzl@7051:   size_t committed_size() const;
tschatzl@7051:   // Memory left to use/expand in this virtual space.
tschatzl@7051:   size_t uncommitted_size() const;
tschatzl@7051: 
tschatzl@7051:   bool contains(const void* p) const;
tschatzl@7051: 
tschatzl@7051:   MemRegion reserved() {
tschatzl@7051:     MemRegion x((HeapWord*)_low_boundary, reserved_size() / HeapWordSize);
tschatzl@7051:     return x;
tschatzl@7051:   }
tschatzl@7051: 
tschatzl@7051:   void release();
tschatzl@7051: 
tschatzl@7051:   void check_for_contiguity() PRODUCT_RETURN;
tschatzl@7051: 
tschatzl@7051:   // Debugging
tschatzl@7051:   void print_on(outputStream* out) PRODUCT_RETURN;
tschatzl@7051:   void print();
tschatzl@7051: };
tschatzl@7051: 
tschatzl@7051: #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1PAGEBASEDVIRTUALSPACE_HPP