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 | #ifndef INCLUDED_OSL_MUTEX_HXX |
21 | #define INCLUDED_OSL_MUTEX_HXX |
22 | |
23 | #ifdef __cplusplus |
24 | |
25 | #include <osl/mutex.h> |
26 | |
27 | |
28 | namespace osl |
29 | { |
30 | /** A mutual exclusion synchronization object |
31 | */ |
32 | class SAL_WARN_UNUSED Mutex { |
33 | |
34 | public: |
35 | /** Create a mutex. |
36 | @return 0 if the mutex could not be created, otherwise a handle to the mutex. |
37 | @see ::osl_createMutex() |
38 | */ |
39 | Mutex() |
40 | { |
41 | mutex = osl_createMutex(); |
42 | } |
43 | |
44 | /** Release the OS-structures and free mutex data-structure. |
45 | @see ::osl_destroyMutex() |
46 | */ |
47 | ~Mutex() |
48 | { |
49 | osl_destroyMutex(mutex); |
50 | } |
51 | |
52 | /** Acquire the mutex, block if already acquired by another thread. |
53 | @return false if system-call fails. |
54 | @see ::osl_acquireMutex() |
55 | */ |
56 | bool acquire() |
57 | { |
58 | return osl_acquireMutex(mutex); |
59 | } |
60 | |
61 | /** Try to acquire the mutex without blocking. |
62 | @return false if it could not be acquired. |
63 | @see ::osl_tryToAcquireMutex() |
64 | */ |
65 | bool tryToAcquire() |
66 | { |
67 | return osl_tryToAcquireMutex(mutex); |
68 | } |
69 | |
70 | /** Release the mutex. |
71 | @return false if system-call fails. |
72 | @see ::osl_releaseMutex() |
73 | */ |
74 | bool release() |
75 | { |
76 | return osl_releaseMutex(mutex); |
77 | } |
78 | |
79 | /** Returns a global static mutex object. |
80 | The global and static mutex object can be used to initialize other |
81 | static objects in a thread safe manner. |
82 | @return the global mutex object |
83 | @see ::osl_getGlobalMutex() |
84 | */ |
85 | static Mutex * getGlobalMutex() |
86 | { |
87 | return (Mutex *)osl_getGlobalMutex(); |
88 | } |
89 | |
90 | private: |
91 | oslMutex mutex; |
92 | |
93 | /** The underlying oslMutex has no reference count. |
94 | |
95 | Since the underlying oslMutex is not a reference counted object, copy |
96 | constructed Mutex may work on an already destructed oslMutex object. |
97 | |
98 | */ |
99 | Mutex(const Mutex&); |
100 | |
101 | /** The underlying oslMutex has no reference count. |
102 | |
103 | When destructed, the Mutex object destroys the undelying oslMutex, |
104 | which might cause severe problems in case it's a temporary object. |
105 | |
106 | */ |
107 | Mutex(oslMutex Mutex); |
108 | |
109 | /** This assignment operator is private for the same reason as |
110 | the copy constructor. |
111 | */ |
112 | Mutex& operator= (const Mutex&); |
113 | |
114 | /** This assignment operator is private for the same reason as |
115 | the constructor taking a oslMutex argument. |
116 | */ |
117 | Mutex& operator= (oslMutex); |
118 | }; |
119 | |
120 | /** A helper class for mutex objects and interfaces. |
121 | */ |
122 | template<class T> |
123 | class Guard |
124 | { |
125 | private: |
126 | Guard( const Guard& ); |
127 | const Guard& operator = ( const Guard& ); |
128 | |
129 | protected: |
130 | T * pT; |
131 | public: |
132 | |
133 | /** Acquires the object specified as parameter. |
134 | */ |
135 | Guard(T * pT_) : pT(pT_) |
136 | { |
137 | pT->acquire(); |
138 | } |
139 | |
140 | /** Acquires the object specified as parameter. |
141 | */ |
142 | Guard(T & t) : pT(&t) |
143 | { |
144 | pT->acquire(); |
145 | } |
146 | |
147 | /** Releases the mutex or interface. */ |
148 | ~Guard() |
149 | { |
150 | pT->release(); |
151 | } |
152 | }; |
153 | |
154 | /** A helper class for mutex objects and interfaces. |
155 | */ |
156 | template<class T> |
157 | class ClearableGuard |
158 | { |
159 | private: |
160 | ClearableGuard( const ClearableGuard& ); |
161 | const ClearableGuard& operator = ( const ClearableGuard& ); |
162 | protected: |
163 | T * pT; |
164 | public: |
165 | |
166 | /** Acquires the object specified as parameter. |
167 | */ |
168 | ClearableGuard(T * pT_) : pT(pT_) |
169 | { |
170 | pT->acquire(); |
171 | } |
172 | |
173 | /** Acquires the object specified as parameter. |
174 | */ |
175 | ClearableGuard(T & t) : pT(&t) |
176 | { |
177 | pT->acquire(); |
178 | } |
179 | |
180 | /** Releases the mutex or interface if not already released by clear(). |
181 | */ |
182 | ~ClearableGuard() |
183 | { |
184 | if (pT) |
185 | pT->release(); |
186 | } |
187 | |
188 | /** Releases the mutex or interface. |
189 | */ |
190 | void clear() |
191 | { |
192 | if(pT) |
193 | { |
194 | pT->release(); |
195 | pT = NULL; |
196 | } |
197 | } |
198 | }; |
199 | |
200 | /** A helper class for mutex objects and interfaces. |
201 | */ |
202 | template< class T > |
203 | class ResettableGuard : public ClearableGuard< T > |
204 | { |
205 | private: |
206 | ResettableGuard(ResettableGuard &); // not defined |
207 | void operator =(ResettableGuard &); // not defined |
208 | |
209 | protected: |
210 | T* pResetT; |
211 | public: |
212 | /** Acquires the object specified as parameter. |
213 | */ |
214 | ResettableGuard( T* pT_ ) : |
215 | ClearableGuard<T>( pT_ ), |
216 | pResetT( pT_ ) |
217 | {} |
218 | |
219 | /** Acquires the object specified as parameter. |
220 | */ |
221 | ResettableGuard( T& rT ) : |
222 | ClearableGuard<T>( rT ), |
223 | pResetT( &rT ) |
224 | {} |
225 | |
226 | /** Re-aquires the mutex or interface. |
227 | */ |
228 | void reset() |
229 | { |
230 | if( pResetT ) |
231 | { |
232 | this->pT = pResetT; |
233 | this->pT->acquire(); |
234 | } |
235 | } |
236 | }; |
237 | |
238 | typedef Guard<Mutex> MutexGuard; |
239 | typedef ClearableGuard<Mutex> ClearableMutexGuard; |
240 | typedef ResettableGuard< Mutex > ResettableMutexGuard; |
241 | } |
242 | |
243 | #endif /* __cplusplus */ |
244 | #endif // INCLUDED_OSL_MUTEX_HXX |
245 | |
246 | /* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |
247 | |