libStatGen Software  1
MemoryMap.cpp
1 /*
2  * Copyright (C) 2010 Regents of the University of Michigan
3  *
4  * This program is free software: you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation, either version 3 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program. If not, see <http://www.gnu.org/licenses/>.
16  */
17 
18 #include <sys/stat.h>
19 #include <sys/types.h>
20 #include <assert.h>
21 #include <errno.h>
22 #include <fcntl.h>
23 #include <iostream>
24 #include <stdio.h>
25 #include <stdexcept>
26 #include <stdlib.h>
27 #include <string>
28 
29 #include "MemoryMap.h"
30 
31 #ifndef _WIN32
32 #include <sys/mman.h>
33 #include <unistd.h>
34 #endif
35 
36 #ifndef MAP_POPULATE
37 #define MAP_POPULATE 0x0000
38 #endif
39 #ifndef MAP_NONBLOCK
40 #define MAP_NONBLOCK 0x0000
41 #endif
42 
43 MemoryMap::MemoryMap()
44 {
45  constructor_clear();
46 #if defined(_WIN32)
47  SYSTEM_INFO sysinfo = {0};
48  ::GetSystemInfo(&sysinfo);
49  DWORD cbView = sysinfo.dwAllocationGranularity;
50 #else
51  page_size = sysconf(_SC_PAGE_SIZE);
52 #endif
53 }
54 
55 MemoryMap::~MemoryMap()
56 {
57  destructor_clear();
58 };
59 
60 void MemoryMap::debug_print()
61 {
62 #if defined(_WIN32)
63  std::cout << "fd = " << file_handle << std::endl;
64 #else
65  std::cout << "fd = " << fd << std::endl;
66 #endif
67  std::cout << "data = 0x" << std::hex << data << std::endl;
68  std::cout << "offset = 0x" << std::hex << offset << std::endl;
69  std::cout << "mapped_length = 0x" << std::hex << mapped_length << std::endl;
70  std::cout << "total_length = 0x" << std::hex << total_length << std::endl;
71  std::cout << "page_size = 0x" << std::hex << page_size << std::endl;
72 };
73 
74 void MemoryMap::constructor_clear()
75 {
76 #if defined(_WIN32)
77  file_handle = NULL;
78  map_handle = NULL;
79 #else
80  fd = -1;
81 #endif
82  data = (void *) NULL;
83  offset = 0;
84  mapped_length = 0;
85  total_length = 0;
86  useMemoryMapFlag = true;
87 };
88 
89 void MemoryMap::destructor_clear()
90 {
91 #if defined(_WIN32)
92  if (data!=NULL)
93  {
94  // free windows mapped object
95  ::UnmapViewOfFile((LPVOID) data);
96  }
97  if (map_handle != NULL)
98  ::CloseHandle(map_handle);
99  if (file_handle != NULL)
100  ::CloseHandle(file_handle);
101 #else
102  if (data!=NULL)
103  {
104  // free unix mapped object
105  munmap(data, mapped_length);
106  }
107  // free unix resources
108  if (fd!=-1)
109  {
110  ::close(fd);
111  }
112 #endif
113 
114  constructor_clear();
115 }
116 
117 
118 bool MemoryMap::allocate()
119 {
120  data = (void *) malloc(mapped_length);
121 
122  if (data == NULL)
123  {
124 #ifdef __WIN32__
125  ::CloseHandle(file_handle);
126 #else
127  ::close(fd);
128 #endif
129  perror("MemoryMap::open");
130  constructor_clear();
131  return true;
132  }
133 
134 #ifdef __WIN32__
135  DWORD resultSize = 0;
136  ReadFile(file_handle, data, mapped_length, &resultSize, NULL);
137 #else
138  size_t resultSize = read(fd, data, mapped_length);
139 #endif
140 
141  if ( resultSize != mapped_length)
142  {
143 #ifdef __WIN32__
144  ::CloseHandle(file_handle);
145 #else
146  ::close(fd);
147 #endif
148  perror("MemoryMap::open");
149  constructor_clear();
150  return true;
151  }
152  return false;
153 }
154 
155 
156 bool MemoryMap::open(const char * file, int flags)
157 {
158  const char * message = "MemoryMap::open - problem opening file %s";
159 #if defined(_WIN32)
160  file_handle = CreateFile(file,
161  (flags==O_RDONLY) ? GENERIC_READ : (GENERIC_READ | GENERIC_WRITE),
162  FILE_SHARE_READ | FILE_SHARE_WRITE, // subsequent opens may either read or write
163  NULL,
164  OPEN_EXISTING,
165  FILE_ATTRIBUTE_NORMAL,
166  NULL);
167 
168  if(file_handle == INVALID_HANDLE_VALUE)
169  {
170  fprintf(stderr, message, file);
171  constructor_clear();
172  return true;
173  }
174 
175  LARGE_INTEGER file_size = {0};
176  ::GetFileSizeEx(file_handle, &file_size);
177  mapped_length = total_length = file_size.QuadPart;
178 
179 #else
180  struct stat buf;
181  fd = ::open(file, flags);
182  if ((fd==-1) || (fstat(fd, &buf) != 0))
183  {
184  fprintf(stderr, message, file);
185  constructor_clear();
186  return true;
187  }
188  mapped_length = total_length = buf.st_size;
189 #endif
190 
191  if(!useMemoryMapFlag)
192  {
193  return allocate();
194  }
195 
196 #if defined(_WIN32)
197  assert(offset == 0);
198 
199  map_handle = CreateFileMapping(file_handle, NULL,
200  (flags==O_RDONLY) ? PAGE_READONLY : PAGE_READWRITE,
201  file_size.HighPart, // upper 32 bits of map size
202  file_size.LowPart, // lower 32 bits of map size
203  NULL);
204 
205  if(map_handle == NULL)
206  {
207  ::CloseHandle(file_handle);
208  fprintf(stderr, message, file);
209  constructor_clear();
210  return true;
211  }
212 
213  data = MapViewOfFile(map_handle,
214  (flags == O_RDONLY) ? FILE_MAP_READ : FILE_MAP_ALL_ACCESS,
215  0, 0, mapped_length);
216 
217  if (data == NULL)
218  {
219  CloseHandle(map_handle);
220  CloseHandle(file_handle);
221 
222  fprintf(stderr, message, file);
223  constructor_clear();
224  return true;
225  }
226 #else
227  data = ::mmap(NULL, mapped_length,
228  (flags == O_RDONLY) ? PROT_READ : PROT_READ | PROT_WRITE,
229  MAP_SHARED, fd, offset);
230 
231  if (data == MAP_FAILED)
232  {
233  ::close(fd);
234  fprintf(stderr, message, file);
235  constructor_clear();
236  return true;
237  }
238 #endif
239  return false;
240 }
241 
242 
243 bool MemoryMap::create(const char *file, size_t size)
244 {
245  if (file==NULL)
246  {
247  data = calloc(size, 1);
248  return(data==NULL);
249  }
250 
251  const char * message = "MemoryMap::create - problem creating file %s";
252 
253 #ifdef __WIN32__
254  file_handle = CreateFile(file,
255  GENERIC_READ | GENERIC_WRITE,
256  FILE_SHARE_READ | FILE_SHARE_WRITE,
257  NULL,
258  CREATE_ALWAYS,
259  FILE_ATTRIBUTE_NORMAL,
260  NULL);
261 
262  if (file_handle == INVALID_HANDLE_VALUE)
263  {
264  fprintf(stderr, message, file);
265  constructor_clear();
266  return true;
267  }
268 
269  SetFilePointer(file_handle, size - 1, NULL, FILE_BEGIN);
270  char dummy = 0;
271  DWORD check = 0;
272  WriteFile(file_handle, &dummy, 1, &check, NULL);
273 
274  if (check != 0)
275  {
276  CloseHandle(file_handle);
277  DeleteFile(file);
278  fprintf(stderr, message, file);
279  constructor_clear();
280  return true;
281  }
282  CloseHandle(file_handle);
283  open(file, O_RDWR);
284 #else
285  fd = ::open(file, O_RDWR|O_CREAT|O_TRUNC, 0666);
286  if(fd == -1)
287  {
288  fprintf(stderr, message, file);
289  constructor_clear();
290  return true;
291  }
292 
293  lseek(fd, (off_t) size - 1, SEEK_SET);
294  char dummy = 0;
295  if(write(fd, &dummy, 1)!=1)
296  {
297  fprintf(stderr, message, file);
298  constructor_clear();
299  return true;
300  }
301 
302  data = ::mmap(NULL, size, PROT_READ|PROT_WRITE,
303  MAP_SHARED, fd, offset);
304 
305  if (data == MAP_FAILED)
306  {
307  ::close(fd);
308  unlink(file);
309  fprintf(stderr, message, file);
310  constructor_clear();
311  return true;
312  }
313  mapped_length = total_length = size;
314 #endif
315  return false;
316 }
317 
318 
319 bool MemoryMap::create(size_t size)
320 {
321  return create(NULL, size);
322 }
323 
324 bool MemoryMap::close()
325 {
326  destructor_clear();
327  return false;
328 }
329 
330 void MemoryMap::test()
331 {
332  int result;
333 
334  result = this->open("test/test_memmap_data.txt");
335  assert(result == 0);
336  assert(data!=NULL);
337  assert(mapped_length == 183); // length of the above file
338  close();
339 
340  // now try non memory mapped (direct slow file I/O)
341  useMemoryMap(false);
342  result = this->open("test/test_memmap_data.txt");
343  assert(result == 0);
344  assert(data!=NULL);
345  assert(mapped_length == 183); // length of the above file
346  close();
347 }
348 
349 int MemoryMap::prefetch()
350 {
351  int sum = 0;
352  size_t i;
353 
354  for (i=0; i<mapped_length; i += page_size) sum += *(i + (char *) data);
355 
356  return sum;
357 }
358 
359 #if defined(TEST)
360 //
361 // compile test using:
362 // g++ -DTEST -o testMemoryMap MemoryMap.cpp Error.o -lz
363 //
364 
365 int main(int argc, const char *argv)
366 {
367  MemoryMap map;
368 
369  map.test();
370 
371 // map.debug_print();
372 
373  exit(0);
374 }
375 #endif
376 
MemoryMap::create
virtual bool create(const char *file, size_t size)
create the memory mapped file on disk
Definition: MemoryMap.cpp:243
MemoryMap::open
virtual bool open(const char *file, int flags=O_RDONLY)
open a previously created mapped vector
Definition: MemoryMap.cpp:156
MemoryMap
There are a pair of related data structures in the operating system, and also a few simple algorithms...
Definition: MemoryMap.h:155