13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_GC_G1_G1PAGEBASEDVIRTUALSPACE_HPP
26 #define SHARE_VM_GC_G1_G1PAGEBASEDVIRTUALSPACE_HPP
27
28 #include "memory/allocation.hpp"
29 #include "memory/memRegion.hpp"
30 #include "memory/virtualspace.hpp"
31 #include "utilities/bitMap.hpp"
32
33 // Virtual space management helper for a virtual space with an OS page allocation
34 // granularity.
35 // (De-)Allocation requests are always OS page aligned by passing a page index
36 // and multiples of pages.
37 // For systems that only commits of memory in a given size (always greater than
38 // page size) the base address is required to be aligned to that page size.
39 // The actual size requested need not be aligned to that page size, but the size
40 // of the reservation passed may be rounded up to this page size. Any fragment
41 // (less than the page size) of the actual size at the tail of the request will
42 // be committed using OS small pages.
43 // The implementation gives an error when trying to commit or uncommit pages that
44 // have already been committed or uncommitted.
45 class G1PageBasedVirtualSpace VALUE_OBJ_CLASS_SPEC {
46 friend class VMStructs;
47 private:
48 // Reserved area addresses.
49 char* _low_boundary;
50 char* _high_boundary;
51
52 // The size of the tail in bytes of the handled space that needs to be committed
99 bool is_after_last_page(size_t index) const;
100 // Is the last page only partially covered by this space?
101 bool is_last_page_partial() const { return !is_ptr_aligned(_high_boundary, _page_size); }
102 // Returns the end address of the given page bounded by the reserved space.
103 char* bounded_end_addr(size_t end_page) const;
104
105 // Returns true if the entire area is backed by committed memory.
106 bool is_area_committed(size_t start_page, size_t size_in_pages) const;
107 // Returns true if the entire area is not backed by committed memory.
108 bool is_area_uncommitted(size_t start_page, size_t size_in_pages) const;
109
110 void initialize_with_page_size(ReservedSpace rs, size_t used_size, size_t page_size);
111 public:
112
113 // Commit the given area of pages starting at start being size_in_pages large.
114 // Returns true if the given area is zero filled upon completion.
115 bool commit(size_t start_page, size_t size_in_pages);
116
117 // Uncommit the given area of pages starting at start being size_in_pages large.
118 void uncommit(size_t start_page, size_t size_in_pages);
119
120 // Initialize the given reserved space with the given base address and the size
121 // actually used.
122 // Prefer to commit in page_size chunks.
123 G1PageBasedVirtualSpace(ReservedSpace rs, size_t used_size, size_t page_size);
124
125 // Destruction
126 ~G1PageBasedVirtualSpace();
127
128 // Amount of reserved memory.
129 size_t reserved_size() const;
130 // Memory used in this virtual space.
131 size_t committed_size() const;
132 // Memory left to use/expand in this virtual space.
133 size_t uncommitted_size() const;
134
135 bool contains(const void* p) const;
136
137 MemRegion reserved() {
138 MemRegion x((HeapWord*)_low_boundary, reserved_size() / HeapWordSize);
|
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_GC_G1_G1PAGEBASEDVIRTUALSPACE_HPP
26 #define SHARE_VM_GC_G1_G1PAGEBASEDVIRTUALSPACE_HPP
27
28 #include "memory/allocation.hpp"
29 #include "memory/memRegion.hpp"
30 #include "memory/virtualspace.hpp"
31 #include "utilities/bitMap.hpp"
32
33 class WorkGang;
34
35 // Virtual space management helper for a virtual space with an OS page allocation
36 // granularity.
37 // (De-)Allocation requests are always OS page aligned by passing a page index
38 // and multiples of pages.
39 // For systems that only commits of memory in a given size (always greater than
40 // page size) the base address is required to be aligned to that page size.
41 // The actual size requested need not be aligned to that page size, but the size
42 // of the reservation passed may be rounded up to this page size. Any fragment
43 // (less than the page size) of the actual size at the tail of the request will
44 // be committed using OS small pages.
45 // The implementation gives an error when trying to commit or uncommit pages that
46 // have already been committed or uncommitted.
47 class G1PageBasedVirtualSpace VALUE_OBJ_CLASS_SPEC {
48 friend class VMStructs;
49 private:
50 // Reserved area addresses.
51 char* _low_boundary;
52 char* _high_boundary;
53
54 // The size of the tail in bytes of the handled space that needs to be committed
101 bool is_after_last_page(size_t index) const;
102 // Is the last page only partially covered by this space?
103 bool is_last_page_partial() const { return !is_ptr_aligned(_high_boundary, _page_size); }
104 // Returns the end address of the given page bounded by the reserved space.
105 char* bounded_end_addr(size_t end_page) const;
106
107 // Returns true if the entire area is backed by committed memory.
108 bool is_area_committed(size_t start_page, size_t size_in_pages) const;
109 // Returns true if the entire area is not backed by committed memory.
110 bool is_area_uncommitted(size_t start_page, size_t size_in_pages) const;
111
112 void initialize_with_page_size(ReservedSpace rs, size_t used_size, size_t page_size);
113 public:
114
115 // Commit the given area of pages starting at start being size_in_pages large.
116 // Returns true if the given area is zero filled upon completion.
117 bool commit(size_t start_page, size_t size_in_pages);
118
119 // Uncommit the given area of pages starting at start being size_in_pages large.
120 void uncommit(size_t start_page, size_t size_in_pages);
121
122 void pretouch(size_t start_page, size_t size_in_pages, WorkGang* pretouch_gang = NULL);
123
124 // Initialize the given reserved space with the given base address and the size
125 // actually used.
126 // Prefer to commit in page_size chunks.
127 G1PageBasedVirtualSpace(ReservedSpace rs, size_t used_size, size_t page_size);
128
129 // Destruction
130 ~G1PageBasedVirtualSpace();
131
132 // Amount of reserved memory.
133 size_t reserved_size() const;
134 // Memory used in this virtual space.
135 size_t committed_size() const;
136 // Memory left to use/expand in this virtual space.
137 size_t uncommitted_size() const;
138
139 bool contains(const void* p) const;
140
141 MemRegion reserved() {
142 MemRegion x((HeapWord*)_low_boundary, reserved_size() / HeapWordSize);
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