--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/memory/heap.hpp Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,161 @@
+/*
+ * Copyright 1997-2006 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+// Blocks
+
+class HeapBlock VALUE_OBJ_CLASS_SPEC {
+ friend class VMStructs;
+
+ public:
+ struct Header {
+ size_t _length; // the length in segments
+ bool _used; // Used bit
+ };
+
+ protected:
+ union {
+ Header _header;
+ int64_t _padding[ (sizeof(Header) + sizeof(int64_t)-1) / sizeof(int64_t) ];
+ // pad to 0 mod 8
+ };
+
+ public:
+ // Initialization
+ void initialize(size_t length) { _header._length = length; set_used(); }
+
+ // Accessors
+ void* allocated_space() const { return (void*)(this + 1); }
+ size_t length() const { return _header._length; }
+
+ // Used/free
+ void set_used() { _header._used = true; }
+ void set_free() { _header._used = false; }
+ bool free() { return !_header._used; }
+};
+
+class FreeBlock: public HeapBlock {
+ friend class VMStructs;
+ protected:
+ FreeBlock* _link;
+
+ public:
+ // Initialization
+ void initialize(size_t length) { HeapBlock::initialize(length); _link= NULL; }
+
+ // Merging
+ void set_length(size_t l) { _header._length = l; }
+
+ // Accessors
+ FreeBlock* link() const { return _link; }
+ void set_link(FreeBlock* link) { _link = link; }
+};
+
+class CodeHeap : public CHeapObj {
+ friend class VMStructs;
+ private:
+ VirtualSpace _memory; // the memory holding the blocks
+ VirtualSpace _segmap; // the memory holding the segment map
+
+ size_t _number_of_committed_segments;
+ size_t _number_of_reserved_segments;
+ size_t _segment_size;
+ int _log2_segment_size;
+
+ size_t _next_segment;
+
+ FreeBlock* _freelist;
+ size_t _free_segments; // No. of segments in freelist
+
+ // Helper functions
+ size_t number_of_segments(size_t size) const { return (size + _segment_size - 1) >> _log2_segment_size; }
+ size_t size(size_t number_of_segments) const { return number_of_segments << _log2_segment_size; }
+
+ size_t segment_for(void* p) const { return ((char*)p - _memory.low()) >> _log2_segment_size; }
+ HeapBlock* block_at(size_t i) const { return (HeapBlock*)(_memory.low() + (i << _log2_segment_size)); }
+
+ void mark_segmap_as_free(size_t beg, size_t end);
+ void mark_segmap_as_used(size_t beg, size_t end);
+
+ // Freelist management helpers
+ FreeBlock* following_block(FreeBlock *b);
+ void insert_after(FreeBlock* a, FreeBlock* b);
+ void merge_right (FreeBlock* a);
+
+ // Toplevel freelist management
+ void add_to_freelist(HeapBlock *b);
+ FreeBlock* search_freelist(size_t length);
+
+ // Iteration helpers
+ void* next_free(HeapBlock* b) const;
+ HeapBlock* first_block() const;
+ HeapBlock* next_block(HeapBlock* b) const;
+ HeapBlock* block_start(void* p) const;
+
+ // to perform additional actions on creation of executable code
+ void on_code_mapping(char* base, size_t size);
+
+ public:
+ CodeHeap();
+
+ // Heap extents
+ bool reserve(size_t reserved_size, size_t committed_size, size_t segment_size);
+ void release(); // releases all allocated memory
+ bool expand_by(size_t size); // expands commited memory by size
+ void shrink_by(size_t size); // shrinks commited memory by size
+ void clear(); // clears all heap contents
+
+ // Memory allocation
+ void* allocate (size_t size); // allocates a block of size or returns NULL
+ void deallocate(void* p); // deallocates a block
+
+ // Attributes
+ void* begin() const { return _memory.low (); }
+ void* end() const { return _memory.high(); }
+ bool contains(void* p) const { return begin() <= p && p < end(); }
+ void* find_start(void* p) const; // returns the block containing p or NULL
+ size_t alignment_unit() const; // alignment of any block
+ size_t alignment_offset() const; // offset of first byte of any block, within the enclosing alignment unit
+ static size_t header_size(); // returns the header size for each heap block
+
+ // Returns reserved area high and low addresses
+ char *low_boundary() const { return _memory.low_boundary (); }
+ char *high_boundary() const { return _memory.high_boundary(); }
+
+ // Iteration
+
+ // returns the first block or NULL
+ void* first() const { return next_free(first_block()); }
+ // returns the next block given a block p or NULL
+ void* next(void* p) const { return next_free(next_block(block_start(p))); }
+
+ // Statistics
+ size_t capacity() const;
+ size_t max_capacity() const;
+ size_t allocated_capacity() const;
+ size_t unallocated_capacity() const { return max_capacity() - allocated_capacity(); }
+
+ // Debugging
+ void verify();
+ void print() PRODUCT_RETURN;
+};