1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466
|
// -*- c++ -*-
//*****************************************************************************
/** @file countedref.h
*
* This file defines reusable classes supporting reference counted interpreter
* objects and initiates the @c blackbox operations for high-level types
* 'reference' and 'shared'.
*
* @note This works was supported by the "Industrial Algebra" project.
*
* @author Alexander Dreyer
* @date 2012-08-15
*
* @par Copyright:
* (c) 2012 by The Singular Team, see LICENSE file
**/
//*****************************************************************************
#ifndef SINGULAR_COUNTEDREF_H_
#define SINGULAR_COUNTEDREF_H_
#include "omalloc/omalloc.h"
#include "kernel/structs.h"
#include "Singular/subexpr.h"
#include "Singular/idrec.h"
#include "Singular/ipid.h"
/** @class CountedRefPtr
* This class implements a smart pointer which handles pointer-style access
* to a reference-counted structure and destructing the latter after use.
*
* The template arguments, include the pointer type @c PtrType, and two
* integral (bool) properties: use @c Nondestructive to disallow destruction
* and @c NeverNull to assume, that @c PtrType cannot be @c NULL.
* Finally, @c CountType allows you to select a typ to represent the internal reference count.
*
* @note The class of @c PtrType must have an accessible integral attribute @c ref.
* For convenience use @c RefCounter as public base.
* In addition you must overload @c void CountedRefPtr_kill(PtrType) accordingly.
**/
template <class PtrType, bool Nondestructive = false, bool NeverNull = false,
class CountType = short>
class CountedRefPtr {
typedef CountedRefPtr self;
public:
//{ @name Name template arguments
typedef PtrType ptr_type;
typedef CountType count_type;
enum { nondestructive = Nondestructive, never_null = NeverNull };
//}
/// Default constructor @note: exisis only if @c NeverNull is false
CountedRefPtr(): m_ptr(NULL) {}
/// Convert from pointer
CountedRefPtr(ptr_type ptr): m_ptr(ptr) { reclaim(); }
/// Convert from compatible smart pointer
template <bool Never>
CountedRefPtr(const CountedRefPtr<ptr_type, !nondestructive, Never, count_type>& rhs):
m_ptr(rhs.m_ptr) { reclaim(); }
/// Construct refernce copy
CountedRefPtr(const self& rhs):
m_ptr(rhs.m_ptr) { reclaim(); }
/// Unlink one reference
~CountedRefPtr() { release(); }
//{ @name Replace data behind reference
self& operator=(const self& rhs) { return operator=(rhs.m_ptr); }
self& operator=(ptr_type ptr) {
release();
m_ptr = ptr;
reclaim();
return *this;
}
//}
/// Checking equality
bool operator==(const self& rhs) const { return m_ptr == rhs.m_ptr; }
//{ @name Pointer-style interface
bool operator==(ptr_type ptr) const { return m_ptr == ptr; }
operator bool() const { return NeverNull || m_ptr; }
operator const ptr_type() const { return m_ptr; }
operator ptr_type() { return m_ptr; }
const ptr_type operator->() const { return *this; }
ptr_type operator->() { return *this; }
//}
/// @name Reference count interface
//@{
count_type count() const { return (*this? m_ptr->ref: 0); }
void reclaim() { if (*this) ++m_ptr->ref; }
void release() {
if (*this && (--m_ptr->ref <= 0) && !nondestructive)
CountedRefPtr_kill(m_ptr);
}
//@}
private:
/// Store actual pointer
ptr_type m_ptr;
};
/** @class RefCounter
* This class implements implements a refernce counter which we can use
* as a public base of objects managed by @CountedRefPtr.
**/
class RefCounter {
public:
/// Name numerical type for enumbering
typedef short count_type;
/// Allow our smart pointer to access internals
template <class, bool, bool, class> friend class CountedRefPtr;
/// Any Constructor resets the counter
RefCounter(...): ref(0) {}
/// Destructor
~RefCounter() { assume(ref == 0); }
private:
/// Number of references
count_type ref; // naming consistent with other classes
};
template <class PtrType>
class CountedRefWeakPtr;
template <class PtrType>
class CountedRefIndirectPtr:
public RefCounter {
public:
friend class CountedRefWeakPtr<PtrType>;
~CountedRefIndirectPtr() { }
private:
CountedRefIndirectPtr(PtrType ptr): m_ptr(ptr) { }
CountedRefIndirectPtr& operator=(PtrType ptr) { m_ptr = ptr; return *this; }
PtrType m_ptr;
};
template <class PtrType>
inline void CountedRefPtr_kill(CountedRefIndirectPtr<PtrType>* pval) { delete pval; }
template <class PtrType>
class CountedRefWeakPtr {
typedef CountedRefWeakPtr self;
public:
/// @name Name template arguments
//@{ Name template arguments
typedef PtrType ptr_type;
typedef CountedRefPtr<CountedRefIndirectPtr<ptr_type>*> ptrptr_type;
//@}
/// Construct unassigned weak reference
CountedRefWeakPtr(): m_indirect(NULL) { }
/// Convert from pointer
CountedRefWeakPtr(ptr_type ptr): m_indirect(new CountedRefIndirectPtr<ptr_type>(ptr)) { }
/// Construct copy
CountedRefWeakPtr(const self& rhs): m_indirect(rhs.m_indirect) { }
/// Unlink one reference (handled by CountedRefPtr)
~CountedRefWeakPtr() { }
/// Mark weak reference as invalid
void invalidate() { *this = NULL; }
/// Test whether reference was never used
bool unassigned() const { return !m_indirect; }
/// Pointer-style interface
//@{
operator bool() const { return operator->(); }
self& operator=(const self& rhs) {
m_indirect = rhs.m_indirect;
return *this;
}
self& operator=(ptr_type ptr) {
if (!m_indirect)
m_indirect = new CountedRefIndirectPtr<ptr_type>(ptr);
else
m_indirect->m_ptr = ptr;
return *this;
}
bool operator==(ptr_type ptr) const {
return m_indirect &&(m_indirect->m_ptr == ptr);
}
bool operator!=(ptr_type rhs) const { return !operator==(rhs); }
const ptr_type operator->() const { return (m_indirect? m_indirect->m_ptr: NULL); }
ptr_type operator->() { return (m_indirect? m_indirect->m_ptr:NULL); }
//@}
private:
ptrptr_type m_indirect;
};
/** @class LeftvHelper
* This class implements some recurrent code sniplets to be used with
* @c leftv and @c idhdl.implements a refernce counter which we can use
**/
class LeftvHelper {
public:
static leftv idify(leftv head, idhdl* root) {
idhdl handle = newid(head, root);
leftv res = (leftv)omAlloc0(sizeof(*res));
res->data =(void*) handle;
res->rtyp = IDHDL;
return res;
}
static idhdl newid(leftv head, idhdl* root) {
static unsigned int counter = 0;
char* name = (char*) omAlloc0(512);
sprintf(name, " :%u:%p:_shared_: ", ++counter, head->data);
if ((*root) == NULL )
enterid(name, 0, head->rtyp, root, TRUE, FALSE);
else
*root = (*root)->set(name, 0, head->rtyp, TRUE);
IDDATA(*root) = (char*) head->data;
return *root;
}
static void clearid(idhdl handle, idhdl* root) {
IDDATA(handle)=NULL;
IDTYP(handle)=NONE;
killhdl2(handle, root, NULL);
}
template <class Type>
static Type* cpy(Type* result, Type* data) {
return (Type*)memcpy(result, data, sizeof(Type));
}
template <class Type>
static Type* cpy(Type* data) {
return cpy((Type*)omAlloc0(sizeof(Type)), data);
}
template <class Type>
static Type* recursivecpy(Type* data) {
if (data == NULL) return data;
Type* result = cpy(data);
result->next = recursivecpy(data->next);
return result;
}
template <class Type>
static Type* shallowcpy(Type* result, Type* data) {
cpy(result, data)->e = recursivecpy(data->e);
return result;
}
template <class Type>
static Type* shallowcpy(Type* data) {
return shallowcpy((Type*) omAlloc0(sizeof(Type)), data);
}
template <class Type>
static void recursivekill(Type* current) {
if(current == NULL) return;
recursivekill(current->next);
omFree(current);
}
static leftv allocate() { return (leftv)omAlloc0(sizeof(sleftv)); }
};
/** @class LeftvShallow
* Ths class wraps @c leftv by taking into acount memory allocation, destruction
* as well as shallowly copying of a given @c leftv, i.e. we just copy auxiliary
* information (like subexpressions), but not the actual data.
*
* @note This is useful to avoid invalidating @c leftv while operating on th
**/
class LeftvShallow:
public LeftvHelper {
typedef LeftvShallow self;
public:
/// Just allocate (all-zero) @c leftv
LeftvShallow(): m_data(allocate()) { }
/// Shallow copy the input data
LeftvShallow(leftv data): m_data(shallowcpy(data)) { }
/// Construct (shallow) copy of @c *this
LeftvShallow(const self& rhs): m_data(shallowcpy(rhs.m_data)) { }
/// Destruct
~LeftvShallow() {
recursivekill(m_data->e);
omFree(m_data);
}
/// Assign shallow copy of the input
self& operator=(leftv rhs) {
recursivekill(m_data->e);
shallowcpy(m_data, rhs);
return *this;
}
/// Assign (shallow) copy of @c *this
self& operator=(const self& rhs) { return (*this) = rhs.m_data; }
/// @name Pointer-style access
//@{
/*const*/ leftv operator->() const { return m_data; }
/*^ warning: 'const' type qualifier on return type has no effect!!! */
leftv operator->() { return m_data; }
//@]
protected:
/// The actual data pointer
leftv m_data;
};
/** @class LeftvDeep
* This class wraps @c leftv by taking into acount memory allocation, destruction
* as well as deeply copying of a given @c leftv, i.e. we also take over
* ownership of the @c leftv data.
*
* We have two variants:
+ LeftvDeep(leftv): treats referenced identifiers as "the data"
+ LeftvDeep(leftv, copy_tag): takes care of a full copy of identifier's data
*
* @note It invalidats @c leftv on input.
**/
class LeftvDeep:
public LeftvHelper {
typedef LeftvDeep self;
/// @name Do not permit copying (avoid inconsistence)
//@{
self& operator=(const self&);
LeftvDeep(const self&);
//@}
public:
/// Allocate all-zero object by default
LeftvDeep(): m_data(allocate()) {}
/// Store a deep copy of the data
/// @ note Occupies the provided @c leftv and invalidates the latter
LeftvDeep(leftv data): m_data(cpy(data)) {
data->e = NULL; // occupy subexpression
if(!isid()) m_data->data=data->CopyD();
}
/// Construct even deeper copy:
/// Skip identifier (if any) and take care of the data on our own
struct copy_tag {};
LeftvDeep(leftv data, copy_tag): m_data(allocate()) { m_data->Copy(data); }
/// Really clear data
~LeftvDeep() { m_data->CleanUp(); }
/// @name Access via shallow copy to avoid invalidating the stored handle
//@{
operator LeftvShallow() { return m_data; }
LeftvShallow operator*() {return *this; }
//@}
/// Determine whether we point to the same data
bool like(const self& rhs) const { return m_data->data == rhs.m_data->data; }
/// Reassign a new deep copy by occupieing another @c leftv
/// @note clears @c *this in the first
self& operator=(leftv rhs) {
if(isid()) {
m_data->e = rhs->e;
rhs->e = NULL;
IDTYP((idhdl)m_data->data) = rhs->Typ();
IDDATA((idhdl)m_data->data) = (char*) rhs->CopyD();
}
else {
m_data->CleanUp();
m_data->Copy(rhs);
}
return *this;
}
/// Check a given context for our identifier
BOOLEAN brokenid(idhdl context) const {
assume(isid());
return (context == NULL) ||
((context != (idhdl) m_data->data) && brokenid(IDNEXT(context)));
}
/// Put a shallow copy to given @c leftv
BOOLEAN put(leftv result) {
leftv next = result->next;
result->next = NULL;
result->CleanUp();
shallowcpy(result, m_data);
result->next = next;
/// @note @c attrib should read the attributes of the identifier
if (isid()) {
result->attribute = ((idhdl)m_data->data)->attribute;
result->flag = ((idhdl)m_data->data)->flag;
}
return FALSE;
}
/// Get additional data (e.g. subexpression data) from likewise instances
BOOLEAN retrieve(leftv res) {
if (res->data == m_data->data) {
if(m_data->e != res->e) recursivekill(m_data->e);
cpy(m_data, res);
res->Init();
return TRUE;
}
return FALSE;
}
/// Check for being an identifier
BOOLEAN isid() const { return m_data->rtyp==IDHDL;}
/// Test whether we reference to ring-dependent data
BOOLEAN ringed() { return m_data->RingDependend(); }
/// Check whether (all-zero) initialized data was never assigned.
BOOLEAN unassigned() const { return m_data->Typ()==0; }
/// Wrap data by identifier, if not done yet
leftv idify(idhdl* root) {
leftv res = (isid()? m_data: LeftvHelper::idify(m_data, root));
++(((idhdl)res->data)->ref);
return res;
}
/// Erase identifier handles by @c *this
/// @note Assumes that we reference an identifier and that we own the latter.
/// This is useful to clear the result of a subsequent call of @c idify.
void clearid(idhdl* root) {
assume(isid());
if (--((idhdl)m_data->data)->ref <= 0) // clear only if we own
LeftvHelper::clearid((idhdl)m_data->data, root);
}
private:
/// Store the actual data
leftv m_data;
};
/// Initialize @c blackbox types 'reference' and 'shared', or both
void countedref_reference_load();
void countedref_shared_load();
inline void
countedref_init()
{
countedref_reference_load();
countedref_shared_load();
}
#endif /*SINGULAR_COUNTEDREF_H_ */
|