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comparison src/share/vm/memory/filemap.hpp @ 20375:6e0cb14ce59b

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8046070: Class Data Sharing clean up and refactoring Summary: Cleaned up CDS to be more configurable, maintainable and extensible Reviewed-by: dholmes, coleenp, acorn, mchung
author iklam
date Thu, 21 Aug 2014 13:57:51 -0700
parents 85c1ca43713f
children 8cb56c8cb30d
comparison
equal deleted inserted replaced
20374:999824269b71 20375:6e0cb14ce59b
35 // read-write space from CompactingPermGenGen 35 // read-write space from CompactingPermGenGen
36 // read-only space from CompactingPermGenGen 36 // read-only space from CompactingPermGenGen
37 // misc data (block offset table, string table, symbols, dictionary, etc.) 37 // misc data (block offset table, string table, symbols, dictionary, etc.)
38 // tag(666) 38 // tag(666)
39 39
40 static const int JVM_SHARED_JARS_MAX = 128;
41 static const int JVM_SPACENAME_MAX = 128;
42 static const int JVM_IDENT_MAX = 256; 40 static const int JVM_IDENT_MAX = 256;
43 static const int JVM_ARCH_MAX = 12;
44
45 41
46 class Metaspace; 42 class Metaspace;
43
44 class SharedClassPathEntry VALUE_OBJ_CLASS_SPEC {
45 public:
46 const char *_name;
47 time_t _timestamp; // jar timestamp, 0 if is directory
48 long _filesize; // jar file size, -1 if is directory
49 bool is_dir() {
50 return _filesize == -1;
51 }
52 };
47 53
48 class FileMapInfo : public CHeapObj<mtInternal> { 54 class FileMapInfo : public CHeapObj<mtInternal> {
49 private: 55 private:
56 friend class ManifestStream;
50 enum { 57 enum {
51 _invalid_version = -1, 58 _invalid_version = -1,
52 _current_version = 1 59 _current_version = 2
53 }; 60 };
54 61
55 bool _file_open; 62 bool _file_open;
56 int _fd; 63 int _fd;
57 long _file_offset; 64 long _file_offset;
58 65
66 private:
67 static SharedClassPathEntry* _classpath_entry_table;
68 static int _classpath_entry_table_size;
69 static size_t _classpath_entry_size;
70 static bool _validating_classpath_entry_table;
71
59 // FileMapHeader describes the shared space data in the file to be 72 // FileMapHeader describes the shared space data in the file to be
60 // mapped. This structure gets written to a file. It is not a class, so 73 // mapped. This structure gets written to a file. It is not a class, so
61 // that the compilers don't add any compiler-private data to it. 74 // that the compilers don't add any compiler-private data to it.
62 75
63 struct FileMapHeader { 76 public:
77 struct FileMapHeaderBase : public CHeapObj<mtClass> {
78 virtual bool validate() = 0;
79 virtual void populate(FileMapInfo* info, size_t alignment) = 0;
80 };
81 struct FileMapHeader : FileMapHeaderBase {
82 // Use data() and data_size() to memcopy to/from the FileMapHeader. We need to
83 // avoid read/writing the C++ vtable pointer.
84 static size_t data_size();
85 char* data() {
86 return ((char*)this) + sizeof(FileMapHeaderBase);
87 }
88
64 int _magic; // identify file type. 89 int _magic; // identify file type.
65 int _version; // (from enum, above.) 90 int _version; // (from enum, above.)
66 size_t _alignment; // how shared archive should be aligned 91 size_t _alignment; // how shared archive should be aligned
67 int _obj_alignment; // value of ObjectAlignmentInBytes 92 int _obj_alignment; // value of ObjectAlignmentInBytes
68 93
76 } _space[MetaspaceShared::n_regions]; 101 } _space[MetaspaceShared::n_regions];
77 102
78 // The following fields are all sanity checks for whether this archive 103 // The following fields are all sanity checks for whether this archive
79 // will function correctly with this JVM and the bootclasspath it's 104 // will function correctly with this JVM and the bootclasspath it's
80 // invoked with. 105 // invoked with.
81 char _arch[JVM_ARCH_MAX]; // architecture
82 char _jvm_ident[JVM_IDENT_MAX]; // identifier for jvm 106 char _jvm_ident[JVM_IDENT_MAX]; // identifier for jvm
83 int _num_jars; // Number of jars in bootclasspath 107
84 108 // The _paths_misc_info is a variable-size structure that records "miscellaneous"
85 // Per jar file data: timestamp, size. 109 // information during dumping. It is generated and validated by the
86 110 // SharedPathsMiscInfo class. See SharedPathsMiscInfo.hpp and sharedClassUtil.hpp for
87 struct { 111 // detailed description.
88 time_t _timestamp; // jar timestamp. 112 //
89 long _filesize; // jar file size. 113 // The _paths_misc_info data is stored as a byte array in the archive file header,
90 } _jar[JVM_SHARED_JARS_MAX]; 114 // immediately after the _header field. This information is used only when
91 } _header; 115 // checking the validity of the archive and is deallocated after the archive is loaded.
116 //
117 // Note that the _paths_misc_info does NOT include information for JAR files
118 // that existed during dump time. Their information is stored in _classpath_entry_table.
119 int _paths_misc_info_size;
120
121 // The following is a table of all the class path entries that were used
122 // during dumping. At run time, we require these files to exist and have the same
123 // size/modification time, or else the archive will refuse to load.
124 //
125 // All of these entries must be JAR files. The dumping process would fail if a non-empty
126 // directory was specified in the classpaths. If an empty directory was specified
127 // it is checked by the _paths_misc_info as described above.
128 //
129 // FIXME -- if JAR files in the tail of the list were specified but not used during dumping,
130 // they should be removed from this table, to save space and to avoid spurious
131 // loading failures during runtime.
132 int _classpath_entry_table_size;
133 size_t _classpath_entry_size;
134 SharedClassPathEntry* _classpath_entry_table;
135
136 virtual bool validate();
137 virtual void populate(FileMapInfo* info, size_t alignment);
138 };
139
140 FileMapHeader * _header;
141
92 const char* _full_path; 142 const char* _full_path;
143 char* _paths_misc_info;
93 144
94 static FileMapInfo* _current_info; 145 static FileMapInfo* _current_info;
95 146
96 bool init_from_file(int fd); 147 bool init_from_file(int fd);
97 void align_file_position(); 148 void align_file_position();
149 bool validate_header_impl();
98 150
99 public: 151 public:
100 FileMapInfo() { 152 FileMapInfo();
101 _file_offset = 0; 153 ~FileMapInfo();
102 _file_open = false;
103 _header._version = _invalid_version;
104 }
105 154
106 static int current_version() { return _current_version; } 155 static int current_version() { return _current_version; }
107 void populate_header(size_t alignment); 156 void populate_header(size_t alignment);
108 bool validate(); 157 bool validate_header();
109 void invalidate(); 158 void invalidate();
110 int version() { return _header._version; } 159 int version() { return _header->_version; }
111 size_t alignment() { return _header._alignment; } 160 size_t alignment() { return _header->_alignment; }
112 size_t space_capacity(int i) { return _header._space[i]._capacity; } 161 size_t space_capacity(int i) { return _header->_space[i]._capacity; }
113 char* region_base(int i) { return _header._space[i]._base; } 162 char* region_base(int i) { return _header->_space[i]._base; }
114 struct FileMapHeader* header() { return &_header; } 163 struct FileMapHeader* header() { return _header; }
115
116 static void set_current_info(FileMapInfo* info) {
117 CDS_ONLY(_current_info = info;)
118 }
119 164
120 static FileMapInfo* current_info() { 165 static FileMapInfo* current_info() {
121 CDS_ONLY(return _current_info;) 166 CDS_ONLY(return _current_info;)
122 NOT_CDS(return NULL;) 167 NOT_CDS(return NULL;)
123 } 168 }
144 // Remap the shared readonly space to shared readwrite, private. 189 // Remap the shared readonly space to shared readwrite, private.
145 bool remap_shared_readonly_as_readwrite(); 190 bool remap_shared_readonly_as_readwrite();
146 191
147 // Errors. 192 // Errors.
148 static void fail_stop(const char *msg, ...); 193 static void fail_stop(const char *msg, ...);
149 void fail_continue(const char *msg, ...); 194 static void fail_continue(const char *msg, ...);
150 195
151 // Return true if given address is in the mapped shared space. 196 // Return true if given address is in the mapped shared space.
152 bool is_in_shared_space(const void* p) NOT_CDS_RETURN_(false); 197 bool is_in_shared_space(const void* p) NOT_CDS_RETURN_(false);
153 void print_shared_spaces() NOT_CDS_RETURN; 198 void print_shared_spaces() NOT_CDS_RETURN;
154 199
158 os::vm_allocation_granularity()); 203 os::vm_allocation_granularity());
159 } 204 }
160 205
161 // Stop CDS sharing and unmap CDS regions. 206 // Stop CDS sharing and unmap CDS regions.
162 static void stop_sharing_and_unmap(const char* msg); 207 static void stop_sharing_and_unmap(const char* msg);
208
209 static void allocate_classpath_entry_table();
210 bool validate_classpath_entry_table();
211
212 static SharedClassPathEntry* shared_classpath(int index) {
213 char* p = (char*)_classpath_entry_table;
214 p += _classpath_entry_size * index;
215 return (SharedClassPathEntry*)p;
216 }
217 static const char* shared_classpath_name(int index) {
218 return shared_classpath(index)->_name;
219 }
220
221 static int get_number_of_share_classpaths() {
222 return _classpath_entry_table_size;
223 }
163 }; 224 };
164 225
165 #endif // SHARE_VM_MEMORY_FILEMAP_HPP 226 #endif // SHARE_VM_MEMORY_FILEMAP_HPP