1 /* 2 * Copyright 2015 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #ifndef GrNonAtomicRef_DEFINED 9 #define GrNonAtomicRef_DEFINED 10 11 #include "include/core/SkRefCnt.h" 12 #include "include/private/SkNoncopyable.h" 13 #include "include/private/SkTArray.h" 14 15 /** 16 * A simple non-atomic ref used in the GrBackendApi when we don't want to pay for the overhead of a 17 * threadsafe ref counted object 18 */ 19 template<typename TSubclass> class GrNonAtomicRef : public SkNoncopyable { 20 public: GrNonAtomicRef()21 GrNonAtomicRef() : fRefCnt(1) {} 22 23 #ifdef SK_DEBUG ~GrNonAtomicRef()24 ~GrNonAtomicRef() { 25 // fRefCnt can be one when a subclass is created statically 26 SkASSERT((0 == fRefCnt || 1 == fRefCnt)); 27 // Set to invalid values. 28 fRefCnt = -10; 29 } 30 #endif 31 unique()32 bool unique() const { return 1 == fRefCnt; } 33 34 // We allow this getter because this type is not thread-safe, meaning only one thread should 35 // have ownership and be manipulating the ref count or querying this. refCnt()36 int refCnt() const { return fRefCnt; } 37 ref()38 void ref() const { 39 // Once the ref cnt reaches zero it should never be ref'ed again. 40 SkASSERT(fRefCnt > 0); 41 ++fRefCnt; 42 } 43 unref()44 void unref() const { 45 SkASSERT(fRefCnt > 0); 46 --fRefCnt; 47 if (0 == fRefCnt) { 48 GrTDeleteNonAtomicRef(static_cast<const TSubclass*>(this)); 49 return; 50 } 51 } 52 53 private: 54 mutable int32_t fRefCnt; 55 56 using INHERITED = SkNoncopyable; 57 }; 58 GrTDeleteNonAtomicRef(const T * ref)59template<typename T> inline void GrTDeleteNonAtomicRef(const T* ref) { 60 delete ref; 61 } 62 63 #endif 64