virtualspace.hpp revision 13370:731370f39fcd 
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24
25#ifndef SHARE_VM_RUNTIME_VIRTUALSPACE_HPP
26#define SHARE_VM_RUNTIME_VIRTUALSPACE_HPP
27
28#include "memory/allocation.hpp"
29
30// ReservedSpace is a data structure for reserving a contiguous address range.
31
32class ReservedSpace VALUE_OBJ_CLASS_SPEC {
33  friend class VMStructs;
34 protected:
35  char*  _base;
36  size_t _size;
37  size_t _noaccess_prefix;
38  size_t _alignment;
39  bool   _special;
40 private:
41  bool   _executable;
42
43  // ReservedSpace
44  ReservedSpace(char* base, size_t size, size_t alignment, bool special,
45                bool executable);
46 protected:
47  void initialize(size_t size, size_t alignment, bool large,
48                  char* requested_address,
49                  bool executable);
50
51 public:
52  // Constructor
53  ReservedSpace();
54  // Initialize the reserved space with the given size. If preferred_page_size
55  // is set, use this as minimum page size/alignment. This may waste some space
56  // if the given size is not aligned to that value, as the reservation will be
57  // aligned up to the final alignment in this case.
58  ReservedSpace(size_t size, size_t preferred_page_size = 0);
59  ReservedSpace(size_t size, size_t alignment, bool large,
60                char* requested_address = NULL);
61  ReservedSpace(size_t size, size_t alignment, bool large, bool executable);
62
63  // Accessors
64  char*  base()            const { return _base;      }
65  size_t size()            const { return _size;      }
66  char*  end()             const { return _base + _size; }
67  size_t alignment()       const { return _alignment; }
68  bool   special()         const { return _special;   }
69  bool   executable()      const { return _executable;   }
70  size_t noaccess_prefix() const { return _noaccess_prefix;   }
71  bool is_reserved()       const { return _base != NULL; }
72  void release();
73
74  // Splitting
75  ReservedSpace first_part(size_t partition_size, size_t alignment,
76                           bool split = false, bool realloc = true);
77  ReservedSpace last_part (size_t partition_size, size_t alignment);
78
79  // These simply call the above using the default alignment.
80  inline ReservedSpace first_part(size_t partition_size,
81                                  bool split = false, bool realloc = true);
82  inline ReservedSpace last_part (size_t partition_size);
83
84  // Alignment
85  static size_t page_align_size_up(size_t size);
86  static size_t page_align_size_down(size_t size);
87  static size_t allocation_align_size_up(size_t size);
88  static size_t allocation_align_size_down(size_t size);
89  bool contains(const void* p) const {
90    return (base() <= ((char*)p)) && (((char*)p) < (base() + size()));
91  }
92};
93
94ReservedSpace
95ReservedSpace::first_part(size_t partition_size, bool split, bool realloc)
96{
97  return first_part(partition_size, alignment(), split, realloc);
98}
99
100ReservedSpace ReservedSpace::last_part(size_t partition_size)
101{
102  return last_part(partition_size, alignment());
103}
104
105// Class encapsulating behavior specific of memory space reserved for Java heap.
106class ReservedHeapSpace : public ReservedSpace {
107 private:
108  void try_reserve_heap(size_t size, size_t alignment, bool large,
109                        char *requested_address);
110  void try_reserve_range(char *highest_start, char *lowest_start,
111                         size_t attach_point_alignment, char *aligned_HBMA,
112                         char *upper_bound, size_t size, size_t alignment, bool large);
113  void initialize_compressed_heap(const size_t size, size_t alignment, bool large);
114  // Create protection page at the beginning of the space.
115  void establish_noaccess_prefix();
116 public:
117  // Constructor. Tries to find a heap that is good for compressed oops.
118  ReservedHeapSpace(size_t size, size_t forced_base_alignment, bool large);
119  // Returns the base to be used for compression, i.e. so that null can be
120  // encoded safely and implicit null checks can work.
121  char *compressed_oop_base() { return _base - _noaccess_prefix; }
122};
123
124// Class encapsulating behavior specific memory space for Code
125class ReservedCodeSpace : public ReservedSpace {
126 public:
127  // Constructor
128  ReservedCodeSpace(size_t r_size, size_t rs_align, bool large);
129};
130
131// VirtualSpace is data structure for committing a previously reserved address range in smaller chunks.
132
133class VirtualSpace VALUE_OBJ_CLASS_SPEC {
134  friend class VMStructs;
135 private:
136  // Reserved area
137  char* _low_boundary;
138  char* _high_boundary;
139
140  // Committed area
141  char* _low;
142  char* _high;
143
144  // The entire space has been committed and pinned in memory, no
145  // os::commit_memory() or os::uncommit_memory().
146  bool _special;
147
148  // Need to know if commit should be executable.
149  bool   _executable;
150
151  // MPSS Support
152  // Each virtualspace region has a lower, middle, and upper region.
153  // Each region has an end boundary and a high pointer which is the
154  // high water mark for the last allocated byte.
155  // The lower and upper unaligned to LargePageSizeInBytes uses default page.
156  // size.  The middle region uses large page size.
157  char* _lower_high;
158  char* _middle_high;
159  char* _upper_high;
160
161  char* _lower_high_boundary;
162  char* _middle_high_boundary;
163  char* _upper_high_boundary;
164
165  size_t _lower_alignment;
166  size_t _middle_alignment;
167  size_t _upper_alignment;
168
169  // MPSS Accessors
170  char* lower_high() const { return _lower_high; }
171  char* middle_high() const { return _middle_high; }
172  char* upper_high() const { return _upper_high; }
173
174  char* lower_high_boundary() const { return _lower_high_boundary; }
175  char* middle_high_boundary() const { return _middle_high_boundary; }
176  char* upper_high_boundary() const { return _upper_high_boundary; }
177
178  size_t lower_alignment() const { return _lower_alignment; }
179  size_t middle_alignment() const { return _middle_alignment; }
180  size_t upper_alignment() const { return _upper_alignment; }
181
182 public:
183  // Committed area
184  char* low()  const { return _low; }
185  char* high() const { return _high; }
186
187  // Reserved area
188  char* low_boundary()  const { return _low_boundary; }
189  char* high_boundary() const { return _high_boundary; }
190
191#if INCLUDE_AOT
192  // Set boundaries for code section in AOT library.
193  void set_low_boundary(char *p)  { _low_boundary = p; }
194  void set_high_boundary(char *p) { _high_boundary = p; }
195  void set_low(char *p)           { _low = p; }
196  void set_high(char *p)          { _high = p; }
197#endif
198
199  bool special() const { return _special; }
200
201 public:
202  // Initialization
203  VirtualSpace();
204  bool initialize_with_granularity(ReservedSpace rs, size_t committed_byte_size, size_t max_commit_ganularity);
205  bool initialize(ReservedSpace rs, size_t committed_byte_size);
206
207  // Destruction
208  ~VirtualSpace();
209
210  // Reserved memory
211  size_t reserved_size() const;
212  // Actually committed OS memory
213  size_t actual_committed_size() const;
214  // Memory used/expanded in this virtual space
215  size_t committed_size() const;
216  // Memory left to use/expand in this virtual space
217  size_t uncommitted_size() const;
218
219  bool   contains(const void* p) const;
220
221  // Operations
222  // returns true on success, false otherwise
223  bool expand_by(size_t bytes, bool pre_touch = false);
224  void shrink_by(size_t bytes);
225  void release();
226
227  void check_for_contiguity() PRODUCT_RETURN;
228
229  // Debugging
230  void print_on(outputStream* out) PRODUCT_RETURN;
231  void print();
232};
233
234#endif // SHARE_VM_RUNTIME_VIRTUALSPACE_HPP
235