1 /************************************************************** 2 * 3 * Licensed to the Apache Software Foundation (ASF) under one 4 * or more contributor license agreements. See the NOTICE file 5 * distributed with this work for additional information 6 * regarding copyright ownership. The ASF licenses this file 7 * to you under the Apache License, Version 2.0 (the 8 * "License"); you may not use this file except in compliance 9 * with the License. You may obtain a copy of the License at 10 * 11 * http://www.apache.org/licenses/LICENSE-2.0 12 * 13 * Unless required by applicable law or agreed to in writing, 14 * software distributed under the License is distributed on an 15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16 * KIND, either express or implied. See the License for the 17 * specific language governing permissions and limitations 18 * under the License. 19 * 20 *************************************************************/ 21 22 23 24 #ifndef __FRAMEWORK_THREADHELP_READGUARD_HXX_ 25 #define __FRAMEWORK_THREADHELP_READGUARD_HXX_ 26 27 //_________________________________________________________________________________________________________________ 28 // my own includes 29 //_________________________________________________________________________________________________________________ 30 31 #include <threadhelp/inoncopyable.h> 32 #include <threadhelp/irwlock.h> 33 34 //#ifndef __FRAMEWORK_THREADHELP_THREADHELPBASE_HXX_ 35 //#include <threadhelp/threadhelpbase.hxx> 36 //#endif 37 38 //_________________________________________________________________________________________________________________ 39 // interface includes 40 //_________________________________________________________________________________________________________________ 41 42 //_________________________________________________________________________________________________________________ 43 // other includes 44 //_________________________________________________________________________________________________________________ 45 #include <sal/types.h> 46 47 //_________________________________________________________________________________________________________________ 48 // namespace 49 //_________________________________________________________________________________________________________________ 50 51 namespace framework{ 52 53 //_________________________________________________________________________________________________________________ 54 // const 55 //_________________________________________________________________________________________________________________ 56 57 //_________________________________________________________________________________________________________________ 58 // declarations 59 //_________________________________________________________________________________________________________________ 60 61 /*-************************************************************************************************************//** 62 @short implement a guard to set read locks 63 @descr This guard should be used to set a lock for reading object internal member. 64 Nobody can control it but don't use member after successfully locking for writing! 65 We never need a own mutex to safe our internal member access - because 66 a guard is used as function-local member only. There exists no multithreaded access to it really ... 67 68 @attention a) To prevent us against wrong using, the default ctor, copy ctor and the =operator are marked private! 69 b) Use interface "IRWLock" of set LockHelper only - because we must support a finer granularity of locking. 70 Interface "IMutex" should be used by easier guard implementations ... like "ResetableGuard"! 71 72 @implements - 73 @base INonCopyable 74 75 @devstatus ready to use 76 *//*-*************************************************************************************************************/ 77 class ReadGuard : private INonCopyable 78 { 79 //------------------------------------------------------------------------------------------------------------- 80 // public methods 81 //------------------------------------------------------------------------------------------------------------- 82 public: 83 84 /*-****************************************************************************************************//** 85 @short ctor 86 @descr These ctors initialize the guard with a reference to used lock member of object to protect. 87 Null isn't allowed as value! 88 89 @seealso - 90 91 @param "pLock" ,reference to used lock member of object to protect 92 @param "rLock" ,reference to used lock member of object to protect 93 @return - 94 95 @onerror - 96 *//*-*****************************************************************************************************/ 97 inline ReadGuard( IRWLock* pLock ) 98 : m_pLock ( pLock ) 99 , m_bLocked ( sal_False ) 100 { 101 lock(); 102 } 103 104 //********************************************************************************************************* 105 inline ReadGuard( IRWLock& rLock ) 106 : m_pLock ( &rLock ) 107 , m_bLocked ( sal_False ) 108 { 109 lock(); 110 } 111 112 /*-****************************************************************************************************//** 113 @short dtor 114 @descr We unlock the used lock member automatically if user forgets it. 115 116 @seealso - 117 118 @param - 119 @return - 120 121 @onerror - 122 *//*-*****************************************************************************************************/ 123 inline ~ReadGuard() 124 { 125 unlock(); 126 } 127 128 /*-****************************************************************************************************//** 129 @short set read lock 130 @descr Call this method to set the read lock. The call will block till all current threads are synchronized! 131 132 @seealso method unlock() 133 134 @param - 135 @return - 136 137 @onerror - 138 *//*-*****************************************************************************************************/ 139 inline void lock() 140 { 141 if( m_bLocked == sal_False ) 142 { 143 m_pLock->acquireReadAccess(); 144 m_bLocked = sal_True; 145 } 146 } 147 148 /*-****************************************************************************************************//** 149 @short unset read lock 150 @descr Call this method to unlock the rw-lock temp.! 151 Normaly we do it at dtor automatically for you ... 152 153 @seealso method lock() 154 155 @param - 156 @return - 157 158 @onerror - 159 *//*-*****************************************************************************************************/ 160 inline void unlock() 161 { 162 if( m_bLocked == sal_True ) 163 { 164 m_pLock->releaseReadAccess(); 165 m_bLocked = sal_False; 166 } 167 } 168 169 //------------------------------------------------------------------------------------------------------------- 170 // private methods 171 //------------------------------------------------------------------------------------------------------------- 172 private: 173 174 /*-****************************************************************************************************//** 175 @short disable using of these functions! 176 @descr It's not allowed to use this methods. Different problems can occur otherwise. 177 Thats why we disable it by make it private. 178 179 @seealso other ctor 180 181 @param - 182 @return - 183 184 @onerror - 185 *//*-*****************************************************************************************************/ 186 ReadGuard(); 187 188 //------------------------------------------------------------------------------------------------------------- 189 // private member 190 //------------------------------------------------------------------------------------------------------------- 191 private: 192 193 IRWLock* m_pLock ; /// reference to lock-member of protected object 194 sal_Bool m_bLocked ; /// protection against multiple lock calls without unlock! 195 196 }; // class ReadGuard 197 198 } // namespace framework 199 200 #endif // #ifndef __FRAMEWORK_THREADHELP_READGUARD_HXX_ 201