1 |
schoenebeck |
2581 |
/* |
2 |
|
|
* Copyright (c) 2014 Christian Schoenebeck |
3 |
|
|
* |
4 |
|
|
* http://www.linuxsampler.org |
5 |
|
|
* |
6 |
|
|
* This file is part of LinuxSampler and released under the same terms. |
7 |
|
|
* See README file for details. |
8 |
|
|
*/ |
9 |
|
|
|
10 |
|
|
#ifndef LS_REF_H |
11 |
|
|
#define LS_REF_H |
12 |
|
|
|
13 |
|
|
#include <set> |
14 |
|
|
#include <stdio.h> |
15 |
|
|
|
16 |
|
|
// You may enable this while developing or at least when you encounter any kind |
17 |
|
|
// of crashes or other misbehaviors in conjunction with Ref class guarded code. |
18 |
|
|
// Enabling the following macro will add a bunch of sanity checks for easing |
19 |
|
|
// debugging of such issues, however it comes with the cost that everything will |
20 |
|
|
// be much slower. |
21 |
|
|
#define LS_REF_ASSERT_MODE 1 |
22 |
|
|
|
23 |
|
|
#if LS_REF_ASSERT_MODE |
24 |
|
|
# warning LS_REF_ASSERT_MODE is enabled which will decrease runtime efficiency! |
25 |
|
|
#endif |
26 |
|
|
|
27 |
|
|
// Enable this for VERY verbose debug messages for debbugging deep issues with |
28 |
|
|
// Ref class. |
29 |
|
|
#define LS_REF_VERBOSE_DEBUG_MSG 0 |
30 |
|
|
|
31 |
|
|
#if LS_REF_ASSERT_MODE |
32 |
|
|
# include <assert.h> |
33 |
|
|
#endif |
34 |
|
|
|
35 |
|
|
namespace LinuxSampler { |
36 |
|
|
|
37 |
|
|
//TODO: make reference count increment/decrement thread safe |
38 |
|
|
|
39 |
|
|
template<typename T, typename T_BASE> class Ref; |
40 |
|
|
|
41 |
|
|
extern std::set<void*> _allRefPtrs; |
42 |
|
|
|
43 |
|
|
/** |
44 |
|
|
* Exists just for implementation detail purpose, you cannot use it |
45 |
|
|
* directly. Use its derived template class Ref instead. |
46 |
|
|
* |
47 |
|
|
* @see Ref |
48 |
|
|
*/ |
49 |
|
|
template<typename T_BASE> |
50 |
|
|
class RefBase { |
51 |
|
|
public: |
52 |
|
|
template<typename T_BASE1> |
53 |
|
|
class _RefCounter { |
54 |
|
|
public: |
55 |
|
|
_RefCounter(T_BASE1* p, int refs) : |
56 |
|
|
references(refs), ptr(p) |
57 |
|
|
{ |
58 |
|
|
#if LS_REF_VERBOSE_DEBUG_MSG |
59 |
|
|
printf("Ref 0x%lx: new counter (refs=%d)\n", (long long)ptr, references); |
60 |
|
|
#endif |
61 |
|
|
#if LS_REF_ASSERT_MODE |
62 |
|
|
assert(p); |
63 |
|
|
assert(refs > 0); |
64 |
|
|
assert(!_allRefPtrs.count(p)); |
65 |
|
|
_allRefPtrs.insert(p); |
66 |
|
|
#endif |
67 |
|
|
} |
68 |
|
|
|
69 |
|
|
virtual ~_RefCounter() { |
70 |
|
|
#if LS_REF_VERBOSE_DEBUG_MSG |
71 |
|
|
printf("Ref 0x%lx: counter destructor (refs=%d)\n", (long long)ptr, references); |
72 |
|
|
#endif |
73 |
|
|
fflush(stdout); |
74 |
|
|
} |
75 |
|
|
|
76 |
|
|
void retain() { |
77 |
|
|
references++; |
78 |
|
|
#if LS_REF_VERBOSE_DEBUG_MSG |
79 |
|
|
printf("Ref 0x%lx: retain (refs=%d)\n", (long long)ptr, references); |
80 |
|
|
#endif |
81 |
|
|
} |
82 |
|
|
|
83 |
|
|
void release() { |
84 |
|
|
if (!references) return; |
85 |
|
|
references--; |
86 |
|
|
#if LS_REF_VERBOSE_DEBUG_MSG |
87 |
|
|
printf("Ref 0x%lx: release (refs=%d)\n", (long long)ptr, references); |
88 |
|
|
#endif |
89 |
|
|
if (!references) deletePtr(); |
90 |
|
|
} |
91 |
|
|
//protected: |
92 |
|
|
void deletePtr() { |
93 |
|
|
#if LS_REF_VERBOSE_DEBUG_MSG |
94 |
|
|
printf("RefCounter 0x%lx: deletePtr() (refs=%d)\n", (long long)ptr, references); |
95 |
|
|
#endif |
96 |
|
|
#if LS_REF_ASSERT_MODE |
97 |
|
|
assert(!references); |
98 |
|
|
_allRefPtrs.erase(ptr); |
99 |
|
|
#endif |
100 |
|
|
delete ptr; |
101 |
|
|
delete this; |
102 |
|
|
} |
103 |
|
|
|
104 |
|
|
int references; |
105 |
|
|
T_BASE1* ptr; |
106 |
|
|
//friend class ... todo |
107 |
|
|
}; |
108 |
|
|
typedef _RefCounter<T_BASE> RefCounter; |
109 |
|
|
|
110 |
|
|
virtual ~RefBase() { |
111 |
|
|
if (refCounter) refCounter->release(); |
112 |
|
|
refCounter = NULL; |
113 |
|
|
} |
114 |
|
|
|
115 |
|
|
//protected: |
116 |
|
|
RefCounter* refCounter; |
117 |
|
|
//friend class Ref<T_BASE, T_BASE>; |
118 |
|
|
|
119 |
|
|
protected: |
120 |
|
|
RefBase() : refCounter(NULL) { |
121 |
|
|
#if LS_REF_VERBOSE_DEBUG_MSG |
122 |
|
|
printf("(RefBase empty ctor)\n"); |
123 |
|
|
#endif |
124 |
|
|
} |
125 |
|
|
/* |
126 |
|
|
RefBase(RefCounter* rc) { |
127 |
|
|
refCounter = rc; |
128 |
|
|
} |
129 |
|
|
|
130 |
|
|
RefBase(const RefBase& r) { |
131 |
|
|
refCounter = r.refCounter; |
132 |
|
|
if (refCounter) refCounter->retain(); |
133 |
|
|
} |
134 |
|
|
*/ |
135 |
|
|
}; |
136 |
|
|
|
137 |
|
|
/** |
138 |
|
|
* Replicates a std::shared_ptr template class, to avoid a build requirement |
139 |
|
|
* of having a C++11 compliant compiler (std::shared_ptr was not part of the |
140 |
|
|
* C++03 standard). |
141 |
|
|
* |
142 |
|
|
* In contrast to the STL implementation though this implementation here |
143 |
|
|
* also supports copying references of derived, different types (in a type |
144 |
|
|
* safe manner). You can achieve that by providing a second template |
145 |
|
|
* argument (which is optional), for declaring a common subtype. For example |
146 |
|
|
* the following code would not compile: |
147 |
|
|
* @code |
148 |
|
|
* void example(UILabel* pLabel) { |
149 |
|
|
* Ref<UILabel> lbl = pLabel; |
150 |
|
|
* Ref<UIWidget> w = lbl; // compile error, incompatible Ref types |
151 |
|
|
* w->resize(16,300); |
152 |
|
|
* } |
153 |
|
|
* @endcode |
154 |
|
|
* Whereas the following would work: |
155 |
|
|
* @code |
156 |
|
|
* void example(UILabel* pLabel) { |
157 |
|
|
* Ref<UILabel,UIWidget> lbl = pLabel; |
158 |
|
|
* Ref<UIWidget> w = lbl; // works (assuming that UILabel is a subclass of UIWidget) |
159 |
|
|
* w->resize(16,300); |
160 |
|
|
* } |
161 |
|
|
* @endcode |
162 |
|
|
* Like the STL's std::shared_ptr, this class also emulates raw pointer |
163 |
|
|
* access and operators. With one addition: if used in the derived common |
164 |
|
|
* subtype manner as shown above, access to the actual data and boolean |
165 |
|
|
* operator will also check whether the underlying pointer (of the common |
166 |
|
|
* subclass) can actually be casted safely to the objects main type (first |
167 |
|
|
* template argument of this class). For example: |
168 |
|
|
* @code |
169 |
|
|
* void example(UILabel* pLabel) { // assuming pLabel is not NULL ... |
170 |
|
|
* Ref<UILabel,UIWidget> lbl = pLabel; |
171 |
|
|
* Ref<UIDialog,UIWidget> dlg = lbl; |
172 |
|
|
* bool b1 = lbl; // will be true (assuming pLabel was not NULL) |
173 |
|
|
* bool b2 = dlg; // will be false (assuming that UIDialog is not derived from UILabel) |
174 |
|
|
* lbl->setText("foo"); // works |
175 |
|
|
* dlg->showModal(); // would crash with -> operator providing a NULL pointer |
176 |
|
|
* } |
177 |
|
|
* @endcode |
178 |
|
|
* Like with std::shared_ptr you must be @b very cautious that you |
179 |
|
|
* initialize only one Ref class object directly with the same raw pointer. |
180 |
|
|
* If you forget this fundamental rule somewhere, your code will crash! |
181 |
|
|
* @code |
182 |
|
|
* UIWidget* ptr = new UIWidget(); |
183 |
|
|
* Ref<UIWidget> w1 = ptr; |
184 |
|
|
* Ref<UIWidget> w2 = w1; // this is OK, copy from a Ref object |
185 |
|
|
* Ref<UIWidget> w3 = ptr; // illegal! 2nd direct init from same raw pointer. This will crash! |
186 |
|
|
* @endcode |
187 |
|
|
* It would be possible to write an implementation of the Ref class that |
188 |
|
|
* could handle the case above as well without crashing, however it would be |
189 |
|
|
* too slow for practice. Because it would require a global lookup table |
190 |
|
|
* maintaining all memory pointers which are currently already guarded by |
191 |
|
|
* this class. Plus it would need an expensive synchronization to prevent |
192 |
|
|
* concurrent access on that global lookup table. |
193 |
|
|
*/ |
194 |
|
|
template<typename T, typename T_BASE = T> |
195 |
|
|
class Ref : public RefBase<T_BASE> { |
196 |
|
|
public: |
197 |
|
|
typedef RefBase<T_BASE> RefBaseT; |
198 |
|
|
typedef typename RefBase<T_BASE>::RefCounter RefCounter; |
199 |
|
|
|
200 |
|
|
Ref() : RefBaseT() { |
201 |
|
|
#if LS_REF_VERBOSE_DEBUG_MSG |
202 |
|
|
printf("Ref empty ctor Ref:0x%lx\n", (long long)this); |
203 |
|
|
#endif |
204 |
|
|
} |
205 |
|
|
|
206 |
|
|
Ref(const T_BASE* p) : RefBaseT() { |
207 |
|
|
#if LS_REF_VERBOSE_DEBUG_MSG |
208 |
|
|
printf("Ref base ptr ctor Ref:0x%lx <- p:0x%lx\n", (long long)this, (long long)p); |
209 |
|
|
#endif |
210 |
|
|
RefBaseT::refCounter = p ? new RefCounter((T_BASE*)p, 1) : NULL; |
211 |
|
|
} |
212 |
|
|
|
213 |
|
|
Ref(const T* p) : RefBaseT() { |
214 |
|
|
#if LS_REF_VERBOSE_DEBUG_MSG |
215 |
|
|
printf("Ref main ptr ctor Ref:0x%lx <- p:0x%lx\n", (long long)this, (long long)p); |
216 |
|
|
#endif |
217 |
|
|
RefBaseT::refCounter = p ? new RefCounter((T*)p, 1) : NULL; |
218 |
|
|
} |
219 |
|
|
|
220 |
|
|
Ref(const RefBaseT& r) : RefBaseT() { |
221 |
|
|
#if LS_REF_VERBOSE_DEBUG_MSG |
222 |
|
|
printf("Ref base ref ctor Ref:0x%lx <- Ref:0x%lx\n", (long long)this, (long long)&r); |
223 |
|
|
#endif |
224 |
|
|
RefBaseT::refCounter = r.refCounter; |
225 |
|
|
if (RefBaseT::refCounter) |
226 |
|
|
RefBaseT::refCounter->retain(); |
227 |
|
|
} |
228 |
|
|
|
229 |
|
|
Ref(const Ref& r) : RefBaseT() { |
230 |
|
|
#if LS_REF_VERBOSE_DEBUG_MSG |
231 |
|
|
printf("Ref main ref ctor Ref:0x%lx <- Ref:0x%lx\n", (long long)this, (long long)&r); |
232 |
|
|
#endif |
233 |
|
|
RefBaseT::refCounter = r.refCounter; |
234 |
|
|
if (RefBaseT::refCounter) |
235 |
|
|
RefBaseT::refCounter->retain(); |
236 |
|
|
} |
237 |
|
|
|
238 |
|
|
inline T* operator->() { |
239 |
|
|
return dynamic_cast<T*>( RefBaseT::refCounter->ptr ); |
240 |
|
|
} |
241 |
|
|
|
242 |
|
|
inline const T* operator->() const { |
243 |
|
|
return dynamic_cast<const T*>( RefBaseT::refCounter->ptr ); |
244 |
|
|
} |
245 |
|
|
|
246 |
|
|
inline T& operator*() { |
247 |
|
|
return *dynamic_cast<T*>( RefBaseT::refCounter->ptr ); |
248 |
|
|
} |
249 |
|
|
|
250 |
|
|
inline const T& operator*() const { |
251 |
|
|
return *dynamic_cast<const T*>( RefBaseT::refCounter->ptr ); |
252 |
|
|
} |
253 |
|
|
|
254 |
|
|
inline bool operator==(const RefBaseT& other) const { |
255 |
|
|
return RefBaseT::refCounter == other.refCounter; |
256 |
|
|
} |
257 |
|
|
|
258 |
|
|
inline bool operator!=(const RefBaseT& other) const { |
259 |
|
|
return RefBaseT::refCounter != other.refCounter; |
260 |
|
|
} |
261 |
|
|
|
262 |
|
|
inline operator bool() const { |
263 |
|
|
return RefBaseT::refCounter && RefBaseT::refCounter->ptr && |
264 |
|
|
dynamic_cast<const T*>( RefBaseT::refCounter->ptr ); |
265 |
|
|
} |
266 |
|
|
|
267 |
|
|
inline bool operator!() const { |
268 |
|
|
return !( RefBaseT::refCounter && RefBaseT::refCounter->ptr && |
269 |
|
|
dynamic_cast<const T*>( RefBaseT::refCounter->ptr ) ); |
270 |
|
|
} |
271 |
|
|
|
272 |
|
|
/* |
273 |
|
|
inline operator RefBaseT&() { |
274 |
|
|
return *this; |
275 |
|
|
} |
276 |
|
|
|
277 |
|
|
inline operator const RefBaseT&() const { |
278 |
|
|
return *this; |
279 |
|
|
} |
280 |
|
|
*/ |
281 |
|
|
inline bool isEquivalent(const RefBaseT& other) const { |
282 |
|
|
if (static_cast<const RefBaseT*>(this) == &other) |
283 |
|
|
return true; |
284 |
|
|
return (RefBaseT::refCounter == other.refCounter); |
285 |
|
|
} |
286 |
|
|
|
287 |
|
|
inline bool isEquivalent(const T_BASE* const other) const { |
288 |
|
|
if (!other) return !RefBaseT::refCounter; |
289 |
|
|
if (!RefBaseT::refCounter) return false; |
290 |
|
|
return other == RefBaseT::refCounter->ptr; |
291 |
|
|
} |
292 |
|
|
|
293 |
|
|
Ref<T,T_BASE>& operator=(const RefBaseT& other) { |
294 |
|
|
#if LS_REF_VERBOSE_DEBUG_MSG |
295 |
|
|
printf("Ref base ref assignment Ref:0x%lx <- Ref:0x%lx\n", (long long)this, (long long)&other); |
296 |
|
|
#endif |
297 |
|
|
if (isEquivalent(other)) { |
298 |
|
|
#if LS_REF_VERBOSE_DEBUG_MSG |
299 |
|
|
printf("Ref 0x%lx WRN: equivalent ref assignment ignored.\n", (long long)this); |
300 |
|
|
#endif |
301 |
|
|
return *this; |
302 |
|
|
} |
303 |
|
|
if (RefBaseT::refCounter) { |
304 |
|
|
RefBaseT::refCounter->release(); |
305 |
|
|
RefBaseT::refCounter = NULL; |
306 |
|
|
} |
307 |
|
|
RefBaseT::refCounter = other.refCounter; |
308 |
|
|
if (RefBaseT::refCounter) |
309 |
|
|
RefBaseT::refCounter->retain(); |
310 |
|
|
return *this; |
311 |
|
|
} |
312 |
|
|
|
313 |
|
|
Ref<T,T_BASE>& operator=(const Ref<T,T_BASE>& other) { |
314 |
|
|
#if LS_REF_VERBOSE_DEBUG_MSG |
315 |
|
|
printf("Ref main ref assignment Ref:0x%lx <- Ref:0x%lx\n", (long long)this, (long long)&other); |
316 |
|
|
#endif |
317 |
|
|
if (isEquivalent(other)) { |
318 |
|
|
#if LS_REF_VERBOSE_DEBUG_MSG |
319 |
|
|
printf("Ref 0x%lx WRN: equivalent ref assignment ignored.\n", (long long)this); |
320 |
|
|
#endif |
321 |
|
|
return *this; |
322 |
|
|
} |
323 |
|
|
if (RefBaseT::refCounter) { |
324 |
|
|
RefBaseT::refCounter->release(); |
325 |
|
|
RefBaseT::refCounter = NULL; |
326 |
|
|
} |
327 |
|
|
RefBaseT::refCounter = other.refCounter; |
328 |
|
|
if (RefBaseT::refCounter) |
329 |
|
|
RefBaseT::refCounter->retain(); |
330 |
|
|
return *this; |
331 |
|
|
} |
332 |
|
|
|
333 |
|
|
Ref<T,T_BASE>& operator=(const T* p) { |
334 |
|
|
#if LS_REF_VERBOSE_DEBUG_MSG |
335 |
|
|
printf("Ref main ptr assignment Ref:0x%lx <- p:0x%lx\n", (long long)this, p); |
336 |
|
|
#endif |
337 |
|
|
if (isEquivalent(p)) { |
338 |
|
|
#if LS_REF_VERBOSE_DEBUG_MSG |
339 |
|
|
printf("Ref 0x%lx WRN: equivalent ptr assignment ignored.\n", (long long)this); |
340 |
|
|
#endif |
341 |
|
|
return *this; |
342 |
|
|
} |
343 |
|
|
if (RefBaseT::refCounter) { |
344 |
|
|
RefBaseT::refCounter->release(); |
345 |
|
|
RefBaseT::refCounter = NULL; |
346 |
|
|
} |
347 |
|
|
RefBaseT::refCounter = p ? new RefCounter((T*)p, 1) : NULL; |
348 |
|
|
#if LS_REF_VERBOSE_DEBUG_MSG |
349 |
|
|
printf("Ref main ptr assignment done\n"); |
350 |
|
|
#endif |
351 |
|
|
return *this; |
352 |
|
|
} |
353 |
|
|
|
354 |
|
|
Ref<T,T_BASE>& operator=(const T_BASE* p) { |
355 |
|
|
#if LS_REF_VERBOSE_DEBUG_MSG |
356 |
|
|
printf("Ref base ptr assignment Ref:0x%lx <- p:0x%lx\n", (long long)this, p); |
357 |
|
|
#endif |
358 |
|
|
if (isEquivalent(p)) { |
359 |
|
|
#if LS_REF_VERBOSE_DEBUG_MSG |
360 |
|
|
printf("Ref 0x%lx WRN: equivalent ptr assignment ignored.\n", (long long)this); |
361 |
|
|
#endif |
362 |
|
|
return *this; |
363 |
|
|
} |
364 |
|
|
if (RefBaseT::refCounter) { |
365 |
|
|
RefBaseT::refCounter->release(); |
366 |
|
|
RefBaseT::refCounter = NULL; |
367 |
|
|
} |
368 |
|
|
RefBaseT::refCounter = p ? new RefCounter((T*)p, 1) : NULL; |
369 |
|
|
return *this; |
370 |
|
|
} |
371 |
|
|
}; |
372 |
|
|
|
373 |
|
|
} // namespace LinuxSampler |
374 |
|
|
|
375 |
|
|
#endif // LS_REF_H |