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_IRWLOCK_H_ 25 #define __FRAMEWORK_THREADHELP_IRWLOCK_H_ 26 27 //_________________________________________________________________________________________________________________ 28 // includes 29 //_________________________________________________________________________________________________________________ 30 31 //_________________________________________________________________________________________________________________ 32 // namespace 33 //_________________________________________________________________________________________________________________ 34 35 namespace framework{ 36 37 //_________________________________________________________________________________________________________________ 38 // declarations 39 //_________________________________________________________________________________________________________________ 40 41 /*-************************************************************************************************************//** 42 @descr A guard (specialy a write guard) support different internal working states. 43 His lock can set for reading or writing/reading! Or he was unlocked by user ... 44 *//*-*************************************************************************************************************/ 45 enum ELockMode 46 { 47 E_NOLOCK , 48 E_READLOCK , 49 E_WRITELOCK 50 }; 51 52 /*-************************************************************************************************************//** 53 @descr We implement two guards for using an rw-lock. But if you wish to implement 54 different rw-locks to you will have problems by using with same guard implementation! 55 That's why we define this "pure virtual base class" ... 56 All rw-locks must support this base interface for working and all guard must use this one too! 57 *//*-*************************************************************************************************************/ 58 class IRWLock 59 { 60 //------------------------------------------------------------------------------------------------------------- 61 // public methods 62 //------------------------------------------------------------------------------------------------------------- 63 public: 64 65 /*-****************************************************************************************************//** 66 @descr These functions must be supported by a derived class! 67 acquireReadAccess() -try to register thread as reader 68 releaseReadAccess() -unregister thread as reader 69 acquireWriteAccess() -try to register thread as writer 70 releaseWriteAccess() -unregister thread as writer 71 downgradeWriteAccess() -make writer to reader 72 *//*-*****************************************************************************************************/ 73 virtual void acquireReadAccess () =0; 74 virtual void releaseReadAccess () =0; 75 virtual void acquireWriteAccess () =0; 76 virtual void releaseWriteAccess () =0; 77 virtual void downgradeWriteAccess () =0; 78 79 }; // class IRWLock 80 81 } // namespace framework 82 83 #endif // #ifndef __FRAMEWORK_THREADHELP_IRWLOCK_H_ 84