2 * Copyright (C) 2005 The Android Open Source Project
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 #ifndef ANDROID_REF_BASE_H
18 #define ANDROID_REF_BASE_H
20 #include <cutils/atomic.h>
23 #include <sys/types.h>
27 #include <utils/StrongPointer.h>
28 #include <utils/TypeHelpers.h>
30 // ---------------------------------------------------------------------------
34 TextOutput& printWeakPointer(TextOutput& to, const void* val);
36 // ---------------------------------------------------------------------------
38 #define COMPARE_WEAK(_op_) \
39 inline bool operator _op_ (const sp<T>& o) const { \
40 return m_ptr _op_ o.m_ptr; \
42 inline bool operator _op_ (const T* o) const { \
43 return m_ptr _op_ o; \
45 template<typename U> \
46 inline bool operator _op_ (const sp<U>& o) const { \
47 return m_ptr _op_ o.m_ptr; \
49 template<typename U> \
50 inline bool operator _op_ (const U* o) const { \
51 return m_ptr _op_ o; \
54 // ---------------------------------------------------------------------------
56 class ReferenceConverterBase {
58 virtual size_t getReferenceTypeSize() const = 0;
59 virtual void* getReferenceBase(void const*) const = 0;
60 inline virtual ~ReferenceConverterBase() { }
63 // ---------------------------------------------------------------------------
68 void incStrong(const void* id) const;
69 void decStrong(const void* id) const;
71 void forceIncStrong(const void* id) const;
73 //! DEBUGGING ONLY: Get current strong ref count.
74 int32_t getStrongCount() const;
79 RefBase* refBase() const;
81 void incWeak(const void* id);
82 void decWeak(const void* id);
84 // acquires a strong reference if there is already one.
85 bool attemptIncStrong(const void* id);
87 // acquires a weak reference if there is already one.
88 // This is not always safe. see ProcessState.cpp and BpBinder.cpp
90 bool attemptIncWeak(const void* id);
92 //! DEBUGGING ONLY: Get current weak ref count.
93 int32_t getWeakCount() const;
95 //! DEBUGGING ONLY: Print references held on object.
96 void printRefs() const;
98 //! DEBUGGING ONLY: Enable tracking for this object.
99 // enable -- enable/disable tracking
100 // retain -- when tracking is enable, if true, then we save a stack trace
101 // for each reference and dereference; when retain == false, we
102 // match up references and dereferences and keep only the
105 void trackMe(bool enable, bool retain);
108 weakref_type* createWeak(const void* id) const;
110 weakref_type* getWeakRefs() const;
112 //! DEBUGGING ONLY: Print references held on object.
113 inline void printRefs() const { getWeakRefs()->printRefs(); }
115 //! DEBUGGING ONLY: Enable tracking of object.
116 inline void trackMe(bool enable, bool retain)
118 getWeakRefs()->trackMe(enable, retain);
121 typedef RefBase basetype;
127 //! Flags for extendObjectLifetime()
129 OBJECT_LIFETIME_STRONG = 0x0000,
130 OBJECT_LIFETIME_WEAK = 0x0001,
131 OBJECT_LIFETIME_MASK = 0x0001
134 void extendObjectLifetime(int32_t mode);
136 //! Flags for onIncStrongAttempted()
138 FIRST_INC_STRONG = 0x0001
141 virtual void onFirstRef();
142 virtual void onLastStrongRef(const void* id);
143 virtual bool onIncStrongAttempted(uint32_t flags, const void* id);
144 virtual void onLastWeakRef(const void* id);
147 friend class ReferenceMover;
148 static void moveReferences(void* d, void const* s, size_t n,
149 const ReferenceConverterBase& caster);
152 friend class weakref_type;
155 RefBase(const RefBase& o);
156 RefBase& operator=(const RefBase& o);
158 weakref_impl* const mRefs;
161 // ---------------------------------------------------------------------------
167 inline LightRefBase() : mCount(0) { }
168 inline void incStrong(__attribute__((unused)) const void* id) const {
169 android_atomic_inc(&mCount);
171 inline void decStrong(__attribute__((unused)) const void* id) const {
172 if (android_atomic_dec(&mCount) == 1) {
173 delete static_cast<const T*>(this);
176 //! DEBUGGING ONLY: Get current strong ref count.
177 inline int32_t getStrongCount() const {
181 typedef LightRefBase<T> basetype;
184 inline ~LightRefBase() { }
187 friend class ReferenceMover;
188 inline static void moveReferences(void* d, void const* s, size_t n,
189 const ReferenceConverterBase& caster) { }
192 mutable volatile int32_t mCount;
195 // ---------------------------------------------------------------------------
197 template <typename T>
201 typedef typename RefBase::weakref_type weakref_type;
203 inline wp() : m_ptr(0) { }
206 wp(const wp<T>& other);
207 wp(const sp<T>& other);
208 template<typename U> wp(U* other);
209 template<typename U> wp(const sp<U>& other);
210 template<typename U> wp(const wp<U>& other);
216 wp& operator = (T* other);
217 wp& operator = (const wp<T>& other);
218 wp& operator = (const sp<T>& other);
220 template<typename U> wp& operator = (U* other);
221 template<typename U> wp& operator = (const wp<U>& other);
222 template<typename U> wp& operator = (const sp<U>& other);
224 void set_object_and_refs(T* other, weakref_type* refs);
228 sp<T> promote() const;
236 inline weakref_type* get_refs() const { return m_refs; }
238 inline T* unsafe_get() const { return m_ptr; }
249 inline bool operator == (const wp<T>& o) const {
250 return (m_ptr == o.m_ptr) && (m_refs == o.m_refs);
253 inline bool operator == (const wp<U>& o) const {
254 return m_ptr == o.m_ptr;
257 inline bool operator > (const wp<T>& o) const {
258 return (m_ptr == o.m_ptr) ? (m_refs > o.m_refs) : (m_ptr > o.m_ptr);
261 inline bool operator > (const wp<U>& o) const {
262 return (m_ptr == o.m_ptr) ? (m_refs > o.m_refs) : (m_ptr > o.m_ptr);
265 inline bool operator < (const wp<T>& o) const {
266 return (m_ptr == o.m_ptr) ? (m_refs < o.m_refs) : (m_ptr < o.m_ptr);
269 inline bool operator < (const wp<U>& o) const {
270 return (m_ptr == o.m_ptr) ? (m_refs < o.m_refs) : (m_ptr < o.m_ptr);
272 inline bool operator != (const wp<T>& o) const { return m_refs != o.m_refs; }
273 template<typename U> inline bool operator != (const wp<U>& o) const { return !operator == (o); }
274 inline bool operator <= (const wp<T>& o) const { return !operator > (o); }
275 template<typename U> inline bool operator <= (const wp<U>& o) const { return !operator > (o); }
276 inline bool operator >= (const wp<T>& o) const { return !operator < (o); }
277 template<typename U> inline bool operator >= (const wp<U>& o) const { return !operator < (o); }
280 template<typename Y> friend class sp;
281 template<typename Y> friend class wp;
284 weakref_type* m_refs;
287 template <typename T>
288 TextOutput& operator<<(TextOutput& to, const wp<T>& val);
292 // ---------------------------------------------------------------------------
293 // No user serviceable parts below here.
299 if (other) m_refs = other->createWeak(this);
303 wp<T>::wp(const wp<T>& other)
304 : m_ptr(other.m_ptr), m_refs(other.m_refs)
306 if (m_ptr) m_refs->incWeak(this);
310 wp<T>::wp(const sp<T>& other)
314 m_refs = m_ptr->createWeak(this);
318 template<typename T> template<typename U>
322 if (other) m_refs = other->createWeak(this);
325 template<typename T> template<typename U>
326 wp<T>::wp(const wp<U>& other)
330 m_refs = other.m_refs;
331 m_refs->incWeak(this);
335 template<typename T> template<typename U>
336 wp<T>::wp(const sp<U>& other)
340 m_refs = m_ptr->createWeak(this);
347 if (m_ptr) m_refs->decWeak(this);
351 wp<T>& wp<T>::operator = (T* other)
353 weakref_type* newRefs =
354 other ? other->createWeak(this) : 0;
355 if (m_ptr) m_refs->decWeak(this);
362 wp<T>& wp<T>::operator = (const wp<T>& other)
364 weakref_type* otherRefs(other.m_refs);
365 T* otherPtr(other.m_ptr);
366 if (otherPtr) otherRefs->incWeak(this);
367 if (m_ptr) m_refs->decWeak(this);
374 wp<T>& wp<T>::operator = (const sp<T>& other)
376 weakref_type* newRefs =
377 other != NULL ? other->createWeak(this) : 0;
378 T* otherPtr(other.m_ptr);
379 if (m_ptr) m_refs->decWeak(this);
385 template<typename T> template<typename U>
386 wp<T>& wp<T>::operator = (U* other)
388 weakref_type* newRefs =
389 other ? other->createWeak(this) : 0;
390 if (m_ptr) m_refs->decWeak(this);
396 template<typename T> template<typename U>
397 wp<T>& wp<T>::operator = (const wp<U>& other)
399 weakref_type* otherRefs(other.m_refs);
400 U* otherPtr(other.m_ptr);
401 if (otherPtr) otherRefs->incWeak(this);
402 if (m_ptr) m_refs->decWeak(this);
408 template<typename T> template<typename U>
409 wp<T>& wp<T>::operator = (const sp<U>& other)
411 weakref_type* newRefs =
412 other != NULL ? other->createWeak(this) : 0;
413 U* otherPtr(other.m_ptr);
414 if (m_ptr) m_refs->decWeak(this);
421 void wp<T>::set_object_and_refs(T* other, weakref_type* refs)
423 if (other) refs->incWeak(this);
424 if (m_ptr) m_refs->decWeak(this);
430 sp<T> wp<T>::promote() const
433 if (m_ptr && m_refs->attemptIncStrong(&result)) {
434 result.set_pointer(m_ptr);
443 m_refs->decWeak(this);
448 template <typename T>
449 inline TextOutput& operator<<(TextOutput& to, const wp<T>& val)
451 return printWeakPointer(to, val.unsafe_get());
454 // ---------------------------------------------------------------------------
456 // this class just serves as a namespace so TYPE::moveReferences can stay
459 class ReferenceMover {
460 // StrongReferenceCast and WeakReferenceCast do the impedance matching
461 // between the generic (void*) implementation in Refbase and the strongly typed
462 // template specializations below.
464 template <typename TYPE>
465 struct StrongReferenceCast : public ReferenceConverterBase {
466 virtual size_t getReferenceTypeSize() const { return sizeof( sp<TYPE> ); }
467 virtual void* getReferenceBase(void const* p) const {
468 sp<TYPE> const* sptr(reinterpret_cast<sp<TYPE> const*>(p));
469 return static_cast<typename TYPE::basetype *>(sptr->get());
473 template <typename TYPE>
474 struct WeakReferenceCast : public ReferenceConverterBase {
475 virtual size_t getReferenceTypeSize() const { return sizeof( wp<TYPE> ); }
476 virtual void* getReferenceBase(void const* p) const {
477 wp<TYPE> const* sptr(reinterpret_cast<wp<TYPE> const*>(p));
478 return static_cast<typename TYPE::basetype *>(sptr->unsafe_get());
483 template<typename TYPE> static inline
484 void move_references(sp<TYPE>* d, sp<TYPE> const* s, size_t n) {
485 memmove(d, s, n*sizeof(sp<TYPE>));
486 StrongReferenceCast<TYPE> caster;
487 TYPE::moveReferences(d, s, n, caster);
489 template<typename TYPE> static inline
490 void move_references(wp<TYPE>* d, wp<TYPE> const* s, size_t n) {
491 memmove(d, s, n*sizeof(wp<TYPE>));
492 WeakReferenceCast<TYPE> caster;
493 TYPE::moveReferences(d, s, n, caster);
497 // specialization for moving sp<> and wp<> types.
498 // these are used by the [Sorted|Keyed]Vector<> implementations
499 // sp<> and wp<> need to be handled specially, because they do not
500 // have trivial copy operation in the general case (see RefBase.cpp
501 // when DEBUG ops are enabled), but can be implemented very
502 // efficiently in most cases.
504 template<typename TYPE> inline
505 void move_forward_type(sp<TYPE>* d, sp<TYPE> const* s, size_t n) {
506 ReferenceMover::move_references(d, s, n);
509 template<typename TYPE> inline
510 void move_backward_type(sp<TYPE>* d, sp<TYPE> const* s, size_t n) {
511 ReferenceMover::move_references(d, s, n);
514 template<typename TYPE> inline
515 void move_forward_type(wp<TYPE>* d, wp<TYPE> const* s, size_t n) {
516 ReferenceMover::move_references(d, s, n);
519 template<typename TYPE> inline
520 void move_backward_type(wp<TYPE>* d, wp<TYPE> const* s, size_t n) {
521 ReferenceMover::move_references(d, s, n);
525 }; // namespace android
527 // ---------------------------------------------------------------------------
529 #endif // ANDROID_REF_BASE_H