1// AutoLocker.h 2// 3// Copyright (c) 2004, Ingo Weinhold (bonefish@cs.tu-berlin.de) 4// 5// Permission is hereby granted, free of charge, to any person obtaining a 6// copy of this software and associated documentation files (the "Software"), 7// to deal in the Software without restriction, including without limitation 8// the rights to use, copy, modify, merge, publish, distribute, sublicense, 9// and/or sell copies of the Software, and to permit persons to whom the 10// Software is furnished to do so, subject to the following conditions: 11// 12// The above copyright notice and this permission notice shall be included in 13// all copies or substantial portions of the Software. 14// 15// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 21// DEALINGS IN THE SOFTWARE. 22// 23// Except as contained in this notice, the name of a copyright holder shall 24// not be used in advertising or otherwise to promote the sale, use or other 25// dealings in this Software without prior written authorization of the 26// copyright holder. 27 28#ifndef AUTO_LOCKER_H 29#define AUTO_LOCKER_H 30 31#include <SupportDefs.h> 32 33// locking 34 35// AutoLockerStandardLocking 36template<typename Lockable> 37class AutoLockerStandardLocking { 38public: 39 inline bool Lock(Lockable *lockable) 40 { 41 return lockable->Lock(); 42 } 43 44 inline void Unlock(Lockable *lockable) 45 { 46 lockable->Unlock(); 47 } 48}; 49 50// AutoLockerReadLocking 51template<typename Lockable> 52class AutoLockerReadLocking { 53public: 54 inline bool Lock(Lockable *lockable) 55 { 56 return lockable->ReadLock(); 57 } 58 59 inline void Unlock(Lockable *lockable) 60 { 61 lockable->ReadUnlock(); 62 } 63}; 64 65// AutoLockerWriteLocking 66template<typename Lockable> 67class AutoLockerWriteLocking { 68public: 69 inline bool Lock(Lockable *lockable) 70 { 71 return lockable->WriteLock(); 72 } 73 74 inline void Unlock(Lockable *lockable) 75 { 76 lockable->WriteUnlock(); 77 } 78}; 79 80// AutoLocker 81template<typename Lockable, 82 typename Locking = AutoLockerStandardLocking<Lockable> > 83class AutoLocker { 84private: 85 typedef AutoLocker<Lockable, Locking> ThisClass; 86public: 87 inline AutoLocker(Lockable *lockable, bool alreadyLocked = false) 88 : fLockable(lockable), 89 fLocked(fLockable && alreadyLocked) 90 { 91 if (!fLocked) 92 _Lock(); 93 } 94 95 inline AutoLocker(Lockable &lockable, bool alreadyLocked = false) 96 : fLockable(&lockable), 97 fLocked(fLockable && alreadyLocked) 98 { 99 if (!fLocked) 100 _Lock(); 101 } 102 103 inline ~AutoLocker() 104 { 105 Unlock(); 106 } 107 108 inline void SetTo(Lockable *lockable, bool alreadyLocked) 109 { 110 Unlock(); 111 fLockable = lockable; 112 fLocked = alreadyLocked; 113 if (!fLocked) 114 _Lock(); 115 } 116 117 inline void SetTo(Lockable &lockable, bool alreadyLocked) 118 { 119 SetTo(&lockable, alreadyLocked); 120 } 121 122 inline void Unset() 123 { 124 Unlock(); 125 } 126 127 inline AutoLocker<Lockable, Locking> &operator=(Lockable *lockable) 128 { 129 SetTo(lockable); 130 return *this; 131 } 132 133 inline AutoLocker<Lockable, Locking> &operator=(Lockable &lockable) 134 { 135 SetTo(&lockable); 136 return *this; 137 } 138 139 inline bool IsLocked() const { return fLocked; } 140 141 inline void Unlock() 142 { 143 if (fLockable && fLocked) { 144 fLocking.Unlock(fLockable); 145 fLocked = false; 146 } 147 } 148 149 inline operator bool() const { return fLocked; } 150 151private: 152 inline void _Lock() 153 { 154 if (fLockable) 155 fLocked = fLocking.Lock(fLockable); 156 } 157 158private: 159 Lockable *fLockable; 160 bool fLocked; 161 Locking fLocking; 162}; 163 164#endif // AUTO_LOCKER_H 165