1 /*
2 ******************************************************************************
3 *
4 * Copyright (C) 1997-2010, International Business Machines
5 * Corporation and others. All Rights Reserved.
6 *
7 ******************************************************************************
8 *
9 * File CMEMORY.H
10 *
11 * Contains stdlib.h/string.h memory functions
12 *
13 * @author Bertrand A. Damiba
14 *
15 * Modification History:
16 *
17 * Date Name Description
18 * 6/20/98 Bertrand Created.
19 * 05/03/99 stephen Changed from functions to macros.
20 *
21 ******************************************************************************
22 */
23
24 #ifndef CMEMORY_H
25 #define CMEMORY_H
26
27 #include <stddef.h>
28 #include <string.h>
29 #include "unicode/utypes.h"
30 #include "unicode/localpointer.h"
31
32 #define uprv_memcpy(dst, src, size) U_STANDARD_CPP_NAMESPACE memcpy(dst, src, size)
33 #define uprv_memmove(dst, src, size) U_STANDARD_CPP_NAMESPACE memmove(dst, src, size)
34 #define uprv_memset(buffer, mark, size) U_STANDARD_CPP_NAMESPACE memset(buffer, mark, size)
35 #define uprv_memcmp(buffer1, buffer2, size) U_STANDARD_CPP_NAMESPACE memcmp(buffer1, buffer2,size)
36
37 U_CAPI void * U_EXPORT2
38 uprv_malloc(size_t s);
39
40 U_CAPI void * U_EXPORT2
41 uprv_realloc(void *mem, size_t size);
42
43 U_CAPI void U_EXPORT2
44 uprv_free(void *mem);
45
46 /**
47 * This should align the memory properly on any machine.
48 * This is very useful for the safeClone functions.
49 */
50 typedef union {
51 long t1;
52 double t2;
53 void *t3;
54 } UAlignedMemory;
55
56 /**
57 * Get the least significant bits of a pointer (a memory address).
58 * For example, with a mask of 3, the macro gets the 2 least significant bits,
59 * which will be 0 if the pointer is 32-bit (4-byte) aligned.
60 *
61 * ptrdiff_t is the most appropriate integer type to cast to.
62 * size_t should work too, since on most (or all?) platforms it has the same
63 * width as ptrdiff_t.
64 */
65 #define U_POINTER_MASK_LSB(ptr, mask) (((ptrdiff_t)(char *)(ptr)) & (mask))
66
67 /**
68 * Get the amount of bytes that a pointer is off by from
69 * the previous UAlignedMemory-aligned pointer.
70 */
71 #define U_ALIGNMENT_OFFSET(ptr) U_POINTER_MASK_LSB(ptr, sizeof(UAlignedMemory) - 1)
72
73 /**
74 * Get the amount of bytes to add to a pointer
75 * in order to get the next UAlignedMemory-aligned address.
76 */
77 #define U_ALIGNMENT_OFFSET_UP(ptr) (sizeof(UAlignedMemory) - U_ALIGNMENT_OFFSET(ptr))
78
79 /**
80 * Indicate whether the ICU allocation functions have been used.
81 * This is used to determine whether ICU is in an initial, unused state.
82 */
83 U_CFUNC UBool
84 cmemory_inUse(void);
85
86 /**
87 * Heap clean up function, called from u_cleanup()
88 * Clears any user heap functions from u_setMemoryFunctions()
89 * Does NOT deallocate any remaining allocated memory.
90 */
91 U_CFUNC UBool
92 cmemory_cleanup(void);
93
94 #ifdef XP_CPLUSPLUS
95
96 U_NAMESPACE_BEGIN
97
98 /**
99 * "Smart pointer" class, deletes memory via uprv_free().
100 * For most methods see the LocalPointerBase base class.
101 * Adds operator[] for array item access.
102 *
103 * @see LocalPointerBase
104 */
105 template<typename T>
106 class LocalMemory : public LocalPointerBase<T> {
107 public:
108 /**
109 * Constructor takes ownership.
110 * @param p simple pointer to an array of T items that is adopted
111 */
112 explicit LocalMemory(T *p=NULL) : LocalPointerBase<T>(p) {}
113 /**
114 * Destructor deletes the memory it owns.
115 */
~LocalMemory()116 ~LocalMemory() {
117 uprv_free(LocalPointerBase<T>::ptr);
118 }
119 /**
120 * Deletes the array it owns,
121 * and adopts (takes ownership of) the one passed in.
122 * @param p simple pointer to an array of T items that is adopted
123 */
adoptInstead(T * p)124 void adoptInstead(T *p) {
125 uprv_free(LocalPointerBase<T>::ptr);
126 LocalPointerBase<T>::ptr=p;
127 }
128 /**
129 * Deletes the array it owns, allocates a new one and reset its bytes to 0.
130 * Returns the new array pointer.
131 * If the allocation fails, then the current array is unchanged and
132 * this method returns NULL.
133 * @param newCapacity must be >0
134 * @return the allocated array pointer, or NULL if the allocation failed
135 */
136 inline T *allocateInsteadAndReset(int32_t newCapacity=1);
137 /**
138 * Deletes the array it owns and allocates a new one, copying length T items.
139 * Returns the new array pointer.
140 * If the allocation fails, then the current array is unchanged and
141 * this method returns NULL.
142 * @param newCapacity must be >0
143 * @param length number of T items to be copied from the old array to the new one;
144 * must be no more than the capacity of the old array,
145 * which the caller must track because the LocalMemory does not track it
146 * @return the allocated array pointer, or NULL if the allocation failed
147 */
148 inline T *allocateInsteadAndCopy(int32_t newCapacity=1, int32_t length=0);
149 /**
150 * Array item access (writable).
151 * No index bounds check.
152 * @param i array index
153 * @return reference to the array item
154 */
155 T &operator[](ptrdiff_t i) const { return LocalPointerBase<T>::ptr[i]; }
156 };
157
158 template<typename T>
allocateInsteadAndReset(int32_t newCapacity)159 inline T *LocalMemory<T>::allocateInsteadAndReset(int32_t newCapacity) {
160 if(newCapacity>0) {
161 T *p=(T *)uprv_malloc(newCapacity*sizeof(T));
162 if(p!=NULL) {
163 uprv_memset(p, 0, newCapacity*sizeof(T));
164 uprv_free(LocalPointerBase<T>::ptr);
165 LocalPointerBase<T>::ptr=p;
166 }
167 return p;
168 } else {
169 return NULL;
170 }
171 }
172
173
174 template<typename T>
allocateInsteadAndCopy(int32_t newCapacity,int32_t length)175 inline T *LocalMemory<T>::allocateInsteadAndCopy(int32_t newCapacity, int32_t length) {
176 if(newCapacity>0) {
177 T *p=(T *)uprv_malloc(newCapacity*sizeof(T));
178 if(p!=NULL) {
179 if(length>0) {
180 if(length>newCapacity) {
181 length=newCapacity;
182 }
183 uprv_memcpy(p, LocalPointerBase<T>::ptr, length*sizeof(T));
184 }
185 uprv_free(LocalPointerBase<T>::ptr);
186 LocalPointerBase<T>::ptr=p;
187 }
188 return p;
189 } else {
190 return NULL;
191 }
192 }
193
194 /**
195 * Simple array/buffer management class using uprv_malloc() and uprv_free().
196 * Provides an internal array with fixed capacity. Can alias another array
197 * or allocate one.
198 *
199 * The array address is properly aligned for type T. It might not be properly
200 * aligned for types larger than T (or larger than the largest subtype of T).
201 *
202 * Unlike LocalMemory and LocalArray, this class never adopts
203 * (takes ownership of) another array.
204 */
205 template<typename T, int32_t stackCapacity>
206 class MaybeStackArray {
207 public:
208 /**
209 * Default constructor initializes with internal T[stackCapacity] buffer.
210 */
MaybeStackArray()211 MaybeStackArray() : ptr(stackArray), capacity(stackCapacity), needToRelease(FALSE) {}
212 /**
213 * Destructor deletes the array (if owned).
214 */
~MaybeStackArray()215 ~MaybeStackArray() { releaseArray(); }
216 /**
217 * Returns the array capacity (number of T items).
218 * @return array capacity
219 */
getCapacity()220 int32_t getCapacity() const { return capacity; }
221 /**
222 * Access without ownership change.
223 * @return the array pointer
224 */
getAlias()225 T *getAlias() const { return ptr; }
226 /**
227 * Returns the array limit. Simple convenience method.
228 * @return getAlias()+getCapacity()
229 */
getArrayLimit()230 T *getArrayLimit() const { return getAlias()+capacity; }
231 /**
232 * Access without ownership change. Same as getAlias().
233 * A class instance can be used directly in expressions that take a T *.
234 * @return the array pointer
235 */
236 operator T *() const { return ptr; }
237 /**
238 * Array item access (writable).
239 * No index bounds check.
240 * @param i array index
241 * @return reference to the array item
242 */
243 T &operator[](ptrdiff_t i) { return ptr[i]; }
244 /**
245 * Deletes the array (if owned) and aliases another one, no transfer of ownership.
246 * If the arguments are illegal, then the current array is unchanged.
247 * @param otherArray must not be NULL
248 * @param otherCapacity must be >0
249 */
aliasInstead(T * otherArray,int32_t otherCapacity)250 void aliasInstead(T *otherArray, int32_t otherCapacity) {
251 if(otherArray!=NULL && otherCapacity>0) {
252 releaseArray();
253 ptr=otherArray;
254 capacity=otherCapacity;
255 needToRelease=FALSE;
256 }
257 };
258 /**
259 * Deletes the array (if owned) and allocates a new one, copying length T items.
260 * Returns the new array pointer.
261 * If the allocation fails, then the current array is unchanged and
262 * this method returns NULL.
263 * @param newCapacity can be less than or greater than the current capacity;
264 * must be >0
265 * @param length number of T items to be copied from the old array to the new one
266 * @return the allocated array pointer, or NULL if the allocation failed
267 */
268 inline T *resize(int32_t newCapacity, int32_t length=0);
269 /**
270 * Gives up ownership of the array if owned, or else clones it,
271 * copying length T items; resets itself to the internal stack array.
272 * Returns NULL if the allocation failed.
273 * @param length number of T items to copy when cloning,
274 * and capacity of the clone when cloning
275 * @param resultCapacity will be set to the returned array's capacity (output-only)
276 * @return the array pointer;
277 * caller becomes responsible for deleting the array
278 * @draft ICU 4.4
279 */
280 inline T *orphanOrClone(int32_t length, int32_t &resultCapacity);
281 private:
282 T *ptr;
283 int32_t capacity;
284 UBool needToRelease;
285 T stackArray[stackCapacity];
releaseArray()286 void releaseArray() {
287 if(needToRelease) {
288 uprv_free(ptr);
289 }
290 }
291 /* No comparison operators with other MaybeStackArray's. */
292 bool operator==(const MaybeStackArray & /*other*/) {return FALSE;};
293 bool operator!=(const MaybeStackArray & /*other*/) {return TRUE;};
294 /* No ownership transfer: No copy constructor, no assignment operator. */
MaybeStackArray(const MaybeStackArray &)295 MaybeStackArray(const MaybeStackArray & /*other*/) {};
296 void operator=(const MaybeStackArray & /*other*/) {};
297
298 // No heap allocation. Use only on the stack.
299 // (Declaring these functions private triggers a cascade of problems:
300 // MSVC insists on exporting an instantiation of MaybeStackArray, which
301 // requires that all functions be defined.
302 // An empty implementation of new() is rejected, it must return a value.
303 // Returning NULL is rejected by gcc for operator new.
304 // The expedient thing is just not to override operator new.
305 // While relatively pointless, heap allocated instances will function.
306 // static void * U_EXPORT2 operator new(size_t size);
307 // static void * U_EXPORT2 operator new[](size_t size);
308 #if U_HAVE_PLACEMENT_NEW
309 // static void * U_EXPORT2 operator new(size_t, void *ptr);
310 #endif
311 };
312
313 template<typename T, int32_t stackCapacity>
resize(int32_t newCapacity,int32_t length)314 inline T *MaybeStackArray<T, stackCapacity>::resize(int32_t newCapacity, int32_t length) {
315 if(newCapacity>0) {
316 T *p=(T *)uprv_malloc(newCapacity*sizeof(T));
317 if(p!=NULL) {
318 if(length>0) {
319 if(length>capacity) {
320 length=capacity;
321 }
322 if(length>newCapacity) {
323 length=newCapacity;
324 }
325 uprv_memcpy(p, ptr, length*sizeof(T));
326 }
327 releaseArray();
328 ptr=p;
329 capacity=newCapacity;
330 needToRelease=TRUE;
331 }
332 return p;
333 } else {
334 return NULL;
335 }
336 }
337
338 template<typename T, int32_t stackCapacity>
orphanOrClone(int32_t length,int32_t & resultCapacity)339 inline T *MaybeStackArray<T, stackCapacity>::orphanOrClone(int32_t length, int32_t &resultCapacity) {
340 T *p;
341 if(needToRelease) {
342 p=ptr;
343 } else if(length<=0) {
344 return NULL;
345 } else {
346 if(length>capacity) {
347 length=capacity;
348 }
349 p=(T *)uprv_malloc(length*sizeof(T));
350 if(p==NULL) {
351 return NULL;
352 }
353 uprv_memcpy(p, ptr, length*sizeof(T));
354 }
355 resultCapacity=length;
356 ptr=stackArray;
357 capacity=stackCapacity;
358 needToRelease=FALSE;
359 return p;
360 }
361
362 /**
363 * Variant of MaybeStackArray that allocates a header struct and an array
364 * in one contiguous memory block, using uprv_malloc() and uprv_free().
365 * Provides internal memory with fixed array capacity. Can alias another memory
366 * block or allocate one.
367 * The stackCapacity is the number of T items in the internal memory,
368 * not counting the H header.
369 * Unlike LocalMemory and LocalArray, this class never adopts
370 * (takes ownership of) another memory block.
371 */
372 template<typename H, typename T, int32_t stackCapacity>
373 class MaybeStackHeaderAndArray {
374 public:
375 /**
376 * Default constructor initializes with internal H+T[stackCapacity] buffer.
377 */
MaybeStackHeaderAndArray()378 MaybeStackHeaderAndArray() : ptr(&stackHeader), capacity(stackCapacity), needToRelease(FALSE) {}
379 /**
380 * Destructor deletes the memory (if owned).
381 */
~MaybeStackHeaderAndArray()382 ~MaybeStackHeaderAndArray() { releaseMemory(); }
383 /**
384 * Returns the array capacity (number of T items).
385 * @return array capacity
386 */
getCapacity()387 int32_t getCapacity() const { return capacity; }
388 /**
389 * Access without ownership change.
390 * @return the header pointer
391 */
getAlias()392 H *getAlias() const { return ptr; }
393 /**
394 * Returns the array start.
395 * @return array start, same address as getAlias()+1
396 */
getArrayStart()397 T *getArrayStart() const { return reinterpret_cast<T *>(getAlias()+1); }
398 /**
399 * Returns the array limit.
400 * @return array limit
401 */
getArrayLimit()402 T *getArrayLimit() const { return getArrayStart()+capacity; }
403 /**
404 * Access without ownership change. Same as getAlias().
405 * A class instance can be used directly in expressions that take a T *.
406 * @return the header pointer
407 */
408 operator H *() const { return ptr; }
409 /**
410 * Array item access (writable).
411 * No index bounds check.
412 * @param i array index
413 * @return reference to the array item
414 */
415 T &operator[](ptrdiff_t i) { return getArrayStart()[i]; }
416 /**
417 * Deletes the memory block (if owned) and aliases another one, no transfer of ownership.
418 * If the arguments are illegal, then the current memory is unchanged.
419 * @param otherArray must not be NULL
420 * @param otherCapacity must be >0
421 */
aliasInstead(H * otherMemory,int32_t otherCapacity)422 void aliasInstead(H *otherMemory, int32_t otherCapacity) {
423 if(otherMemory!=NULL && otherCapacity>0) {
424 releaseMemory();
425 ptr=otherMemory;
426 capacity=otherCapacity;
427 needToRelease=FALSE;
428 }
429 };
430 /**
431 * Deletes the memory block (if owned) and allocates a new one,
432 * copying the header and length T array items.
433 * Returns the new header pointer.
434 * If the allocation fails, then the current memory is unchanged and
435 * this method returns NULL.
436 * @param newCapacity can be less than or greater than the current capacity;
437 * must be >0
438 * @param length number of T items to be copied from the old array to the new one
439 * @return the allocated pointer, or NULL if the allocation failed
440 */
441 inline H *resize(int32_t newCapacity, int32_t length=0);
442 /**
443 * Gives up ownership of the memory if owned, or else clones it,
444 * copying the header and length T array items; resets itself to the internal memory.
445 * Returns NULL if the allocation failed.
446 * @param length number of T items to copy when cloning,
447 * and array capacity of the clone when cloning
448 * @param resultCapacity will be set to the returned array's capacity (output-only)
449 * @return the header pointer;
450 * caller becomes responsible for deleting the array
451 * @draft ICU 4.4
452 */
453 inline H *orphanOrClone(int32_t length, int32_t &resultCapacity);
454 private:
455 H *ptr;
456 int32_t capacity;
457 UBool needToRelease;
458 // stackHeader must precede stackArray immediately.
459 H stackHeader;
460 T stackArray[stackCapacity];
releaseMemory()461 void releaseMemory() {
462 if(needToRelease) {
463 uprv_free(ptr);
464 }
465 }
466 /* No comparison operators with other MaybeStackHeaderAndArray's. */
467 bool operator==(const MaybeStackHeaderAndArray & /*other*/) {return FALSE;};
468 bool operator!=(const MaybeStackHeaderAndArray & /*other*/) {return TRUE;};
469 /* No ownership transfer: No copy constructor, no assignment operator. */
MaybeStackHeaderAndArray(const MaybeStackHeaderAndArray &)470 MaybeStackHeaderAndArray(const MaybeStackHeaderAndArray & /*other*/) {};
471 void operator=(const MaybeStackHeaderAndArray & /*other*/) {};
472
473 // No heap allocation. Use only on the stack.
474 // (Declaring these functions private triggers a cascade of problems;
475 // see the MaybeStackArray class for details.)
476 // static void * U_EXPORT2 operator new(size_t size);
477 // static void * U_EXPORT2 operator new[](size_t size);
478 #if U_HAVE_PLACEMENT_NEW
479 // static void * U_EXPORT2 operator new(size_t, void *ptr);
480 #endif
481 };
482
483 template<typename H, typename T, int32_t stackCapacity>
resize(int32_t newCapacity,int32_t length)484 inline H *MaybeStackHeaderAndArray<H, T, stackCapacity>::resize(int32_t newCapacity,
485 int32_t length) {
486 if(newCapacity>=0) {
487 H *p=(H *)uprv_malloc(sizeof(H)+newCapacity*sizeof(T));
488 if(p!=NULL) {
489 if(length<0) {
490 length=0;
491 } else if(length>0) {
492 if(length>capacity) {
493 length=capacity;
494 }
495 if(length>newCapacity) {
496 length=newCapacity;
497 }
498 }
499 uprv_memcpy(p, ptr, sizeof(H)+length*sizeof(T));
500 releaseMemory();
501 ptr=p;
502 capacity=newCapacity;
503 needToRelease=TRUE;
504 }
505 return p;
506 } else {
507 return NULL;
508 }
509 }
510
511 template<typename H, typename T, int32_t stackCapacity>
orphanOrClone(int32_t length,int32_t & resultCapacity)512 inline H *MaybeStackHeaderAndArray<H, T, stackCapacity>::orphanOrClone(int32_t length,
513 int32_t &resultCapacity) {
514 H *p;
515 if(needToRelease) {
516 p=ptr;
517 } else {
518 if(length<0) {
519 length=0;
520 } else if(length>capacity) {
521 length=capacity;
522 }
523 p=(H *)uprv_malloc(sizeof(H)+length*sizeof(T));
524 if(p==NULL) {
525 return NULL;
526 }
527 uprv_memcpy(p, ptr, sizeof(H)+length*sizeof(T));
528 }
529 resultCapacity=length;
530 ptr=&stackHeader;
531 capacity=stackCapacity;
532 needToRelease=FALSE;
533 return p;
534 }
535
536 U_NAMESPACE_END
537
538 #endif /* XP_CPLUSPLUS */
539 #endif /* CMEMORY_H */
540