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1 : /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2 : /*
3 : * This file is part of the LibreOffice project.
4 : *
5 : * This Source Code Form is subject to the terms of the Mozilla Public
6 : * License, v. 2.0. If a copy of the MPL was not distributed with this
7 : * file, You can obtain one at http://mozilla.org/MPL/2.0/.
8 : *
9 : * This file incorporates work covered by the following license notice:
10 : *
11 : * Licensed to the Apache Software Foundation (ASF) under one or more
12 : * contributor license agreements. See the NOTICE file distributed
13 : * with this work for additional information regarding copyright
14 : * ownership. The ASF licenses this file to you under the Apache
15 : * License, Version 2.0 (the "License"); you may not use this file
16 : * except in compliance with the License. You may obtain a copy of
17 : * the License at http://www.apache.org/licenses/LICENSE-2.0 .
18 : */
19 :
20 : #include <threadhelp/transactionmanager.hxx>
21 :
22 : #include <macros/generic.hxx>
23 :
24 : #include <com/sun/star/lang/DisposedException.hpp>
25 :
26 : namespace framework{
27 :
28 : /*-************************************************************************************************************
29 : @short standard ctor
30 : @descr Initialize instance with right start values for correct working.
31 : *//*-*************************************************************************************************************/
32 0 : TransactionManager::TransactionManager()
33 : : m_eWorkingMode ( E_INIT )
34 0 : , m_nTransactionCount ( 0 )
35 : {
36 0 : m_aBarrier.open();
37 0 : }
38 :
39 : /*-************************************************************************************************************
40 : @short standard dtor
41 : *//*-*************************************************************************************************************/
42 0 : TransactionManager::~TransactionManager()
43 : {
44 0 : }
45 :
46 : /*-****************************************************************************************************
47 : @interface ITransactionManager
48 : @short set new working mode
49 : @descr These implementation knows for states of working: E_INIT, E_WORK, E_CLOSING, E_CLOSE
50 : You can step during this ones only from the left to the right side and start at left side again!
51 : (This is necessary e.g. for refcounted objects!)
52 : This call will block till all current existing transactions was finished.
53 : Following results can occur:
54 : E_INIT : All requests on this implementation are refused.
55 : It's your decision to react in a right way.
56 :
57 : E_WORK : The object can work now. The full functionality is available.
58 :
59 : E_BEFORECLOSE : The object start the closing mechanism ... but sometimes
60 : e.g. the dispose() method need to call some private methods.
61 : These some special methods should use E_SOFTEXCEPTIONS or ignore
62 : E_INCLOSE as returned reason for E_NOEXCEPTIONS to detect this special case!
63 :
64 : E_CLOSE : Object is already dead! All further requests will be refused.
65 : It's your decision to react in a right way.
66 : @param "eMode", is the new mode - but we don't accept setting mode in wrong order!
67 : @onerror We do nothing.
68 : *//*-*****************************************************************************************************/
69 0 : void TransactionManager::setWorkingMode( EWorkingMode eMode )
70 : {
71 : // Safe member access.
72 0 : ::osl::ClearableMutexGuard aAccessGuard( m_aAccessLock );
73 0 : bool bWaitFor = false;
74 : // Change working mode first!
75 0 : if (
76 0 : ( m_eWorkingMode == E_INIT && eMode == E_WORK ) ||
77 0 : ( m_eWorkingMode == E_WORK && eMode == E_BEFORECLOSE ) ||
78 0 : ( m_eWorkingMode == E_BEFORECLOSE && eMode == E_CLOSE ) ||
79 0 : ( m_eWorkingMode == E_CLOSE && eMode == E_INIT )
80 : )
81 : {
82 0 : m_eWorkingMode = eMode;
83 0 : if( m_eWorkingMode == E_BEFORECLOSE || m_eWorkingMode == E_CLOSE )
84 : {
85 0 : bWaitFor = true;
86 : }
87 : }
88 :
89 : // Wait for current existing transactions then!
90 : // (Only necessary for changing to E_BEFORECLOSE or E_CLOSE! ...
91 : // otherwise; if you wait at setting E_WORK another thrad could finish a acquire-call during our unlock() and wait() call
92 : // ... and we will wait forever here!!!)
93 : // Don't forget to release access mutex before.
94 0 : aAccessGuard.clear();
95 0 : if( bWaitFor )
96 : {
97 0 : m_aBarrier.wait();
98 0 : }
99 0 : }
100 :
101 : /*-****************************************************************************************************
102 : @interface ITransactionManager
103 : @short get current working mode
104 : @descr If you stand in your close() or init() method ... but don't know
105 : if you called more then ones(!) ... you can use this function to get
106 : right information.
107 : e.g: You have a method init() which is used to change working mode from
108 : E_INIT to E_WORK and should be used to initialize some member too ...
109 : What should you do:
110 :
111 : void init( sal_Int32 nValue )
112 : {
113 : // Reject this call if our transaction manager say: "Object already initialized!"
114 : // Otherwise initialize your member.
115 : if( m_aTransactionManager.getWorkingMode() == E_INIT )
116 : {
117 : // Object is uninitialized ...
118 : // Make member access threadsafe!
119 : Guard aGuard( m_aMutex );
120 :
121 : // Check working mode again .. because another instance could be faster.
122 : // (It's possible to set this guard at first of this method too!)
123 : if( m_aTransactionManager.getWorkingMode() == E_INIT )
124 : {
125 : m_aMember = nValue;
126 :
127 : // Object is initialized now ... set working mode to E_WORK!
128 : m_aTransactionManager.setWorkingMode( E_WORK );
129 : }
130 : }
131 : }
132 :
133 : @seealso method setWorkingMode()
134 : @return Current set mode.
135 :
136 : @onerror No error should occur.
137 : *//*-*****************************************************************************************************/
138 0 : EWorkingMode TransactionManager::getWorkingMode() const
139 : {
140 : // Synchronize access to internal member!
141 0 : ::osl::MutexGuard aAccessLock( m_aAccessLock );
142 0 : return m_eWorkingMode;
143 : }
144 :
145 : /*-****************************************************************************************************
146 : @interface ITransactionManager
147 : @short start new transaction
148 : @descr A guard should use this method to start a new transaction. He should looks for rejected
149 : calls to by using parameter eMode and eReason.
150 : If call was not rejected your transaction will be non breakable during releasing your transaction
151 : guard! BUT ... your code isn't threadsafe then! It's a transaction manager only ....
152 :
153 : @seealso method unregisterTransaction()
154 :
155 : @param "eMode" ,used to enable/disable throwing exceptions automatically for rejected calls
156 : @param "eReason" ,reason for rejected calls if eMode=E_NOEXCEPTIONS
157 : *//*-*****************************************************************************************************/
158 0 : void TransactionManager::registerTransaction( EExceptionMode eMode, ERejectReason& eReason ) throw( css::uno::RuntimeException, css::lang::DisposedException )
159 : {
160 : // Look for rejected calls first.
161 : // If call was refused we throw some exceptions or do nothing!
162 : // It depends from given parameter eMode.
163 0 : if( isCallRejected( eReason ) )
164 : {
165 0 : impl_throwExceptions( eMode, eReason );
166 : }
167 :
168 : // BUT if no exception was thrown ... (may be eMode = E_SOFTEXCEPTIONS!)
169 : // we must register this transaction too!
170 : // Don't use "else" or a new scope here!!!
171 :
172 : // Safe access to internal member.
173 0 : ::osl::MutexGuard aAccessGuard( m_aAccessLock );
174 :
175 : // Register this new transaction.
176 : // If it is the first one .. close gate to disable changing of working mode.
177 0 : ++m_nTransactionCount;
178 0 : if( m_nTransactionCount == 1 )
179 : {
180 0 : m_aBarrier.close();
181 0 : }
182 0 : }
183 :
184 : /*-****************************************************************************************************
185 : @interface ITransactionManager
186 : @short finish transaction
187 : @descr A guard should call this method to release current transaction.
188 :
189 : @seealso method registerTransaction()
190 : *//*-*****************************************************************************************************/
191 0 : void TransactionManager::unregisterTransaction() throw( css::uno::RuntimeException, css::lang::DisposedException )
192 : {
193 : // This call could not rejected!
194 : // Safe access to internal member.
195 0 : ::osl::MutexGuard aAccessGuard( m_aAccessLock );
196 :
197 : // Deregister this transaction.
198 : // If it was the last one ... open gate to enable changing of working mode!
199 : // (see setWorkingMode())
200 :
201 0 : --m_nTransactionCount;
202 0 : if( m_nTransactionCount == 0 )
203 : {
204 0 : m_aBarrier.open();
205 0 : }
206 0 : }
207 :
208 : /*-****************************************************************************************************
209 : @interface ITransactionManager
210 : @short look for rejected calls
211 : @descr Sometimes user need a possibility to get information about rejected calls
212 : without starting a transaction!
213 : @param "eReason" returns reason of a rejected call
214 : @return true if call was rejected, false otherwise
215 :
216 : @onerror We return false.
217 : *//*-*****************************************************************************************************/
218 0 : bool TransactionManager::isCallRejected( ERejectReason& eReason ) const
219 : {
220 : // This call must safe access to internal member only.
221 : // Set "possible reason" for return and check reject-state then!
222 : // User should look for return value first - reason then ...
223 0 : ::osl::MutexGuard aAccessGuard( m_aAccessLock );
224 0 : switch( m_eWorkingMode )
225 : {
226 0 : case E_INIT : eReason = E_UNINITIALIZED;
227 0 : break;
228 0 : case E_WORK : eReason = E_NOREASON;
229 0 : break;
230 0 : case E_BEFORECLOSE : eReason = E_INCLOSE;
231 0 : break;
232 0 : case E_CLOSE : eReason = E_CLOSED;
233 0 : break;
234 : }
235 0 : return( eReason!=E_NOREASON );
236 : }
237 :
238 : /*-****************************************************************************************************
239 : @short throw any exceptions for rejected calls
240 : @descr If a user wishes to use our automatic exception mode we use this impl-method.
241 : We check all combinations of eReason and eExceptionMode and throw correct exception with some
242 : descriptions for the recipient.
243 :
244 : @seealso method registerTransaction()
245 : @seealso enum ERejectReason
246 : @seealso enum EExceptionMode
247 :
248 : @param "eReason" , reason for rejected call
249 : @param "eMode" , exception mode - set by user
250 : *//*-*****************************************************************************************************/
251 0 : void TransactionManager::impl_throwExceptions( EExceptionMode eMode, ERejectReason eReason ) const throw( css::uno::RuntimeException, css::lang::DisposedException )
252 : {
253 0 : if( eMode != E_NOEXCEPTIONS )
254 : {
255 0 : switch( eReason )
256 : {
257 0 : case E_UNINITIALIZED : if( eMode == E_HARDEXCEPTIONS )
258 : {
259 : // Help programmer to find out, why this exception is thrown!
260 : SAL_WARN( "fwk", "TransactionManager...: Owner instance not correctly initialized yet. Call was rejected! Normally it's an algorithm error ... wrong use of class!" );
261 : //ATTENTION: temp. disabled - till all bad code positions are detected and changed! */
262 : // throw css::uno::RuntimeException( "TransactionManager...\nOwner instance not right initialized yet. Call was rejected! Normaly it's an algorithm error ... wrong usin of class!\n", css::uno::Reference< css::uno::XInterface >() );
263 : }
264 0 : break;
265 0 : case E_INCLOSE : if( eMode == E_HARDEXCEPTIONS )
266 : {
267 : // Help programmer to find out, why this exception is thrown!
268 : SAL_WARN( "fwk", "TransactionManager...: Owner instance stand in close method. Call was rejected!" );
269 0 : throw css::lang::DisposedException( "TransactionManager...\nOwner instance stand in close method. Call was rejected!\n", css::uno::Reference< css::uno::XInterface >() );
270 : }
271 0 : break;
272 : case E_CLOSED : {
273 : // Help programmer to find out, why this exception is thrown!
274 : SAL_WARN( "fwk", "TransactionManager...: Owner instance already closed. Call was rejected!" );
275 0 : throw css::lang::DisposedException( "TransactionManager...\nOwner instance already closed. Call was rejected!\n", css::uno::Reference< css::uno::XInterface >() );
276 : }
277 : case E_NOREASON : {
278 : // Help programmer to find out
279 : SAL_WARN( "fwk", "TransactionManager...: Impossible case E_NOREASON!" );
280 : }
281 0 : break;
282 0 : default: break; // nothing to do
283 : }
284 : }
285 0 : }
286 :
287 : } // namespace framework
288 :
289 : /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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