jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/g1PageBasedVirtualSpace.hpp@a248d0be1309 (annotated)

src/share/vm/gc_implementation/g1/g1PageBasedVirtualSpace.hpp@a248d0be1309 (annotated)

src/share/vm/gc_implementation/g1/g1PageBasedVirtualSpace.hpp

Mon, 19 Aug 2019 10:11:31 +0200

author: neugens
date: Mon, 19 Aug 2019 10:11:31 +0200
changeset 9861: a248d0be1309
parent 7781: 33e421924c67
permissions: -rw-r--r--

8229401: Fix JFR code cache test failures
8223689: Add JFR Thread Sampling Support
8223690: Add JFR BiasedLock Event Support
8223691: Add JFR G1 Region Type Change Event Support
8223692: Add JFR G1 Heap Summary Event Support
Summary: Backport JFR from JDK11, additional fixes
Reviewed-by: neugens, apetushkov
Contributed-by: denghui.ddh@alibaba-inc.com

 /*
  * 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

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src/share/vm/gc_implementation/g1/g1PageBasedVirtualSpace.hpp@a248d0be1309 (annotated)

src/share/vm/gc_implementation/g1/g1PageBasedVirtualSpace.hpp