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. 18class GrSingleOwner { 19public: 20 GrSingleOwner() : fOwner(kIllegalThreadID), fReentranceCount(0) {} 21 22 struct AutoEnforce { 23 AutoEnforce(GrSingleOwner* so) : fSO(so) { fSO->enter(); } 24 ~AutoEnforce() { fSO->exit(); } 25 26 GrSingleOwner* fSO; 27 }; 28 29private: 30 void enter() { 31 SkAutoMutexAcquire lock(fMutex); 32 SkThreadID self = SkGetThreadID(); 33 SkASSERT(fOwner == self || fOwner == kIllegalThreadID); 34 fReentranceCount++; 35 fOwner = self; 36 } 37 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 52class GrSingleOwner {}; // Provide a dummy implementation so we can pass pointers to constructors 53#endif 54 55#endif 56