1 /* 2 * Copyright 2016 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 GrSingleOwner_DEFINED 9 #define GrSingleOwner_DEFINED 10 11 #include "SkTypes.h" 12 13 #ifdef SK_DEBUG 14 #include "SkMutex.h" 15 #include "SkThreadID.h" 16 17 // This is a debug tool to verify an object is only being used from one thread at a time. 18 class GrSingleOwner { 19 public: GrSingleOwner()20 GrSingleOwner() : fOwner(kIllegalThreadID), fReentranceCount(0) {} 21 22 struct AutoEnforce { AutoEnforceAutoEnforce23 AutoEnforce(GrSingleOwner* so) : fSO(so) { fSO->enter(); } ~AutoEnforceAutoEnforce24 ~AutoEnforce() { fSO->exit(); } 25 26 GrSingleOwner* fSO; 27 }; 28 29 private: enter()30 void enter() { 31 SkAutoMutexAcquire lock(fMutex); 32 SkThreadID self = SkGetThreadID(); 33 SkASSERT(fOwner == self || fOwner == kIllegalThreadID); 34 fReentranceCount++; 35 fOwner = self; 36 } 37 exit()38 void exit() { 39 SkAutoMutexAcquire lock(fMutex); 40 SkASSERT(fOwner == SkGetThreadID()); 41 fReentranceCount--; 42 if (fReentranceCount == 0) { 43 fOwner = kIllegalThreadID; 44 } 45 } 46 47 SkMutex fMutex; 48 SkThreadID fOwner; // guarded by fMutex 49 int fReentranceCount; // guarded by fMutex 50 }; 51 #else 52 class GrSingleOwner {}; // Provide a dummy implementation so we can pass pointers to constructors 53 #endif 54 55 #endif 56