jdk8-mips64-public/hotspot: src/share/vm/memory/freeList.hpp@f90c822e73f8 (annotated)

src/share/vm/memory/freeList.hpp@f90c822e73f8 (annotated)

src/share/vm/memory/freeList.hpp

Wed, 27 Apr 2016 01:25:04 +0800

author: aoqi
date: Wed, 27 Apr 2016 01:25:04 +0800
changeset 0: f90c822e73f8
child 6876: 710a3c8b516e
permissions: -rw-r--r--

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http://hg.openjdk.java.net/jdk8u/jdk8u/hotspot/
changeset: 6782:28b50d07f6f8
tag: jdk8u25-b17

 /*
  * Copyright (c) 2001, 2013, 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_MEMORY_FREELIST_HPP
 #define SHARE_VM_MEMORY_FREELIST_HPP
 #include "gc_implementation/shared/allocationStats.hpp"
 class CompactibleFreeListSpace;
 // A class for maintaining a free list of Chunk's.  The FreeList
 // maintains a the structure of the list (head, tail, etc.) plus
 // statistics for allocations from the list.  The links between items
 // are not part of FreeList.  The statistics are
 // used to make decisions about coalescing Chunk's when they
 // are swept during collection.
 //
 // See the corresponding .cpp file for a description of the specifics
 // for that implementation.
 class Mutex;
 template <class Chunk_t>
 class FreeList VALUE_OBJ_CLASS_SPEC {
   friend class CompactibleFreeListSpace;
   friend class VMStructs;
  private:
   Chunk_t*      _head;          // Head of list of free chunks
   Chunk_t*      _tail;          // Tail of list of free chunks
   size_t        _size;          // Size in Heap words of each chunk
   ssize_t       _count;         // Number of entries in list
  protected:
 #ifdef ASSERT
   Mutex*        _protecting_lock;
 #endif
   // Asserts false if the protecting lock (if any) is not held.
   void assert_proper_lock_protection_work() const PRODUCT_RETURN;
   void assert_proper_lock_protection() const {
 #ifdef ASSERT
     if (_protecting_lock != NULL)
       assert_proper_lock_protection_work();
 #endif
   }
   void increment_count()    {
     _count++;
   }
   void decrement_count() {
     _count--;
     assert(_count >= 0, "Count should not be negative");
   }
  public:
   // Constructor
   // Construct a list without any entries.
   FreeList();
   // Do initialization
   void initialize();
   // Reset the head, tail, and count of a free list.
   void reset();
   // Declare the current free list to be protected by the given lock.
 #ifdef ASSERT
   Mutex* protecting_lock() const { return _protecting_lock; }
   void set_protecting_lock(Mutex* v) {
     _protecting_lock = v;
   }
 #endif
   // Accessors.
   Chunk_t* head() const {
     assert_proper_lock_protection();
     return _head;
   }
   void set_head(Chunk_t* v) {
     assert_proper_lock_protection();
     _head = v;
     assert(!_head || _head->size() == _size, "bad chunk size");
   }
   // Set the head of the list and set the prev field of non-null
   // values to NULL.
   void link_head(Chunk_t* v);
   Chunk_t* tail() const {
     assert_proper_lock_protection();
     return _tail;
   }
   void set_tail(Chunk_t* v) {
     assert_proper_lock_protection();
     _tail = v;
     assert(!_tail || _tail->size() == _size, "bad chunk size");
   }
   // Set the tail of the list and set the next field of non-null
   // values to NULL.
   void link_tail(Chunk_t* v) {
     assert_proper_lock_protection();
     set_tail(v);
     if (v != NULL) {
       v->clear_next();
     }
   }
   // No locking checks in read-accessors: lock-free reads (only) are benign.
   // Readers are expected to have the lock if they are doing work that
   // requires atomicity guarantees in sections of code.
   size_t size() const {
     return _size;
   }
   void set_size(size_t v) {
     assert_proper_lock_protection();
     _size = v;
   }
   ssize_t count() const { return _count; }
   void set_count(ssize_t v) { _count = v;}
   size_t get_better_size() { return size(); }
   size_t returned_bytes() const { ShouldNotReachHere(); return 0; }
   void set_returned_bytes(size_t v) {}
   void increment_returned_bytes_by(size_t v) {}
   // Unlink head of list and return it.  Returns NULL if
   // the list is empty.
   Chunk_t* get_chunk_at_head();
   // Remove the first "n" or "count", whichever is smaller, chunks from the
   // list, setting "fl", which is required to be empty, to point to them.
   void getFirstNChunksFromList(size_t n, FreeList<Chunk_t>* fl);
   // Unlink this chunk from it's free list
   void remove_chunk(Chunk_t* fc);
   // Add this chunk to this free list.
   void return_chunk_at_head(Chunk_t* fc);
   void return_chunk_at_tail(Chunk_t* fc);
   // Similar to returnChunk* but also records some diagnostic
   // information.
   void return_chunk_at_head(Chunk_t* fc, bool record_return);
   void return_chunk_at_tail(Chunk_t* fc, bool record_return);
   // Prepend "fl" (whose size is required to be the same as that of "this")
   // to the front of "this" list.
   void prepend(FreeList<Chunk_t>* fl);
   // Verify that the chunk is in the list.
   // found.  Return NULL if "fc" is not found.
   bool verify_chunk_in_free_list(Chunk_t* fc) const;
   // Printing support
   static void print_labels_on(outputStream* st, const char* c);
   void print_on(outputStream* st, const char* c = NULL) const;
 };
 #endif // SHARE_VM_MEMORY_FREELIST_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/memory/freeList.hpp@f90c822e73f8 (annotated)

src/share/vm/memory/freeList.hpp