xref: /aoo42x/main/framework/inc/threadhelp/irwlock.h (revision 796b7e2a)
1228b4580SAndrew Rist /**************************************************************
2cdf0e10cSrcweir  *
3228b4580SAndrew Rist  * Licensed to the Apache Software Foundation (ASF) under one
4228b4580SAndrew Rist  * or more contributor license agreements.  See the NOTICE file
5228b4580SAndrew Rist  * distributed with this work for additional information
6228b4580SAndrew Rist  * regarding copyright ownership.  The ASF licenses this file
7228b4580SAndrew Rist  * to you under the Apache License, Version 2.0 (the
8228b4580SAndrew Rist  * "License"); you may not use this file except in compliance
9228b4580SAndrew Rist  * with the License.  You may obtain a copy of the License at
10228b4580SAndrew Rist  *
11228b4580SAndrew Rist  *   http://www.apache.org/licenses/LICENSE-2.0
12228b4580SAndrew Rist  *
13228b4580SAndrew Rist  * Unless required by applicable law or agreed to in writing,
14228b4580SAndrew Rist  * software distributed under the License is distributed on an
15228b4580SAndrew Rist  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16228b4580SAndrew Rist  * KIND, either express or implied.  See the License for the
17228b4580SAndrew Rist  * specific language governing permissions and limitations
18228b4580SAndrew Rist  * under the License.
19228b4580SAndrew Rist  *
20228b4580SAndrew Rist  *************************************************************/
21228b4580SAndrew Rist 
22228b4580SAndrew Rist 
23cdf0e10cSrcweir 
24cdf0e10cSrcweir #ifndef __FRAMEWORK_THREADHELP_IRWLOCK_H_
25cdf0e10cSrcweir #define __FRAMEWORK_THREADHELP_IRWLOCK_H_
26cdf0e10cSrcweir 
27cdf0e10cSrcweir //_________________________________________________________________________________________________________________
28cdf0e10cSrcweir //	includes
29cdf0e10cSrcweir //_________________________________________________________________________________________________________________
30cdf0e10cSrcweir 
31cdf0e10cSrcweir //_________________________________________________________________________________________________________________
32cdf0e10cSrcweir //	namespace
33cdf0e10cSrcweir //_________________________________________________________________________________________________________________
34cdf0e10cSrcweir 
35cdf0e10cSrcweir namespace framework{
36cdf0e10cSrcweir 
37cdf0e10cSrcweir //_________________________________________________________________________________________________________________
38cdf0e10cSrcweir //	declarations
39cdf0e10cSrcweir //_________________________________________________________________________________________________________________
40cdf0e10cSrcweir 
41cdf0e10cSrcweir /*-************************************************************************************************************//**
42cdf0e10cSrcweir 	@descr			A guard (specialy a write guard) support different internal working states.
43cdf0e10cSrcweir 					His lock can set for reading or writing/reading! Or he was unlocked by user ...
44cdf0e10cSrcweir *//*-*************************************************************************************************************/
45cdf0e10cSrcweir enum ELockMode
46cdf0e10cSrcweir {
47cdf0e10cSrcweir 	E_NOLOCK	,
48cdf0e10cSrcweir 	E_READLOCK	,
49cdf0e10cSrcweir 	E_WRITELOCK
50cdf0e10cSrcweir };
51cdf0e10cSrcweir 
52cdf0e10cSrcweir /*-************************************************************************************************************//**
53cdf0e10cSrcweir 	@descr			We implement two guards for using an rw-lock. But if you wish to implement
54cdf0e10cSrcweir 					different rw-locks to you will have problems by using with same guard implementation!
55*796b7e2aSmseidel 					That's why we define this "pure virtual base class" ...
56cdf0e10cSrcweir 					All rw-locks must support this base interface for working and all guard must use this one too!
57cdf0e10cSrcweir *//*-*************************************************************************************************************/
58cdf0e10cSrcweir class IRWLock
59cdf0e10cSrcweir {
60cdf0e10cSrcweir 	//-------------------------------------------------------------------------------------------------------------
61cdf0e10cSrcweir 	//	public methods
62cdf0e10cSrcweir 	//-------------------------------------------------------------------------------------------------------------
63cdf0e10cSrcweir 	public:
64cdf0e10cSrcweir 
65cdf0e10cSrcweir 		/*-****************************************************************************************************//**
66cdf0e10cSrcweir 			@descr		These functions must be supported by a derived class!
67cdf0e10cSrcweir 							acquireReadAccess()		-try to register thread as reader
68cdf0e10cSrcweir 							releaseReadAccess()		-unregister thread as reader
69cdf0e10cSrcweir 							acquireWriteAccess()	-try to register thread as writer
70cdf0e10cSrcweir 							releaseWriteAccess()	-unregister thread as writer
71cdf0e10cSrcweir 							downgradeWriteAccess()	-make writer to reader
72cdf0e10cSrcweir 		*//*-*****************************************************************************************************/
73cdf0e10cSrcweir         virtual void acquireReadAccess    () =0;
74cdf0e10cSrcweir         virtual void releaseReadAccess    () =0;
75cdf0e10cSrcweir         virtual void acquireWriteAccess   () =0;
76cdf0e10cSrcweir         virtual void releaseWriteAccess   () =0;
77cdf0e10cSrcweir         virtual void downgradeWriteAccess () =0;
78cdf0e10cSrcweir 
79cdf0e10cSrcweir };		//	class IRWLock
80cdf0e10cSrcweir 
81cdf0e10cSrcweir }		//	namespace framework
82cdf0e10cSrcweir 
83cdf0e10cSrcweir #endif	//	#ifndef __FRAMEWORK_THREADHELP_IRWLOCK_H_
84