framework/source/inc/loadenv/actionlockguard.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
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   9  * This file incorporates work covered by the following license notice:
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  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_FRAMEWORK_SOURCE_INC_LOADENV_ACTIONLOCKGUARD_HXX
  21 #define INCLUDED_FRAMEWORK_SOURCE_INC_LOADENV_ACTIONLOCKGUARD_HXX
  22
  23 #include <com/sun/star/document/XActionLockable.hpp>
  24 #include <osl/mutex.hxx>
  25
  26 namespace framework{
  27
  28 /** @short  implements a guard, which can use the interface
  29             <type scope="com::sun::star::document">XActionLockable</type>.
  30
  31     @descr  This guard should be used to be sure, that any lock will be
  32             released. Otherwise the locaked document can hinder the office on shutdown!
  33 */
  34 class ActionLockGuard
  35 {
  36
  37     // member
  38
  39     private:
  40         osl::Mutex m_mutex;
  41
  42         /** @short  points to the object, which can be locked from outside. */
  43         css::uno::Reference< css::document::XActionLockable > m_xActionLock;
  44
  45         /** @short  knows if a lock exists on the internal lock object
  46                     forced by this guard instance. */
  47         bool m_bActionLocked;
  48
  49     // interface
  50
  51     public:
  52
  53         /** @short  default ctor to initialize a "non working guard".
  54
  55             @descr  That can be useful in cases, where no resource still exists,
  56                     but will be available next time. Then this guard can be used
  57                     in a mode "use guard for more than one resources".
  58          */
  59         ActionLockGuard()
  60             : m_bActionLocked(false)
  61         {
  62         }
  63
  64         /** @short  initialize new guard instance and lock the given resource immediately.
  65
  66             @param  xLock
  67                     points to the outside resource, which should be locked.
  68          */
  69         ActionLockGuard(const css::uno::Reference< css::document::XActionLockable >& xLock)
  70             : m_bActionLocked(false)
  71         {
  72             setResource(xLock);
  73         }
  74
  75         /** @short  release this guard instance and make sure, that no lock
  76                     will exist afterwards on the internal wrapped resource.
  77          */
  78         virtual ~ActionLockGuard()
  79         {
  80             unlock();
  81         }
  82
  83         /** @short  set a new resource for locking at this guard.
  84
  85             @descr  This call will fail, if an internal resource already exists
  86                     and is currently locked.
  87
  88             @param  xLock
  89                     points to the outside resource, which should be locked.
  90
  91             @return sal_True, if new resource could be set and locked.
  92                     sal_False otherwise.
  93          */
  94         bool setResource(const css::uno::Reference< css::document::XActionLockable >& xLock)
  95         {
  96             osl::MutexGuard g(m_mutex);
  97
  98             if (m_bActionLocked || !xLock.is())
  99                 return false;
 100
 101             m_xActionLock = xLock;
 102             m_xActionLock->addActionLock();
 103             m_bActionLocked = m_xActionLock->isActionLocked();
 104
 105             return true;
 106         }
 107
 108         /** @short  set a new resource for locking at this guard.
 109
 110             @descr  This call will fail, if an internal resource already exists
 111                     and is currently locked.
 112
 113             @param  xLock
 114                     points to the outside resource, which should be locked.
 115
 116             @return sal_True, if new resource could be set and locked.
 117                     sal_False otherwise.
 118          */
 119         void freeResource()
 120         {
 121             // SAFE -> ..........................
 122             osl::ClearableMutexGuard aMutexLock(m_mutex);
 123
 124             css::uno::Reference< css::document::XActionLockable > xLock   = m_xActionLock;
 125             bool                                                  bLocked = m_bActionLocked;
 126
 127             m_xActionLock.clear();
 128             m_bActionLocked = false;
 129
 130             aMutexLock.clear();
 131             // <- SAFE ..........................
 132
 133             if (bLocked && xLock.is())
 134                 xLock->removeActionLock();
 135         }
 136
 137         /** @short  lock the internal wrapped resource, if its not already done. */
 138         void lock()
 139         {
 140             osl::MutexGuard g(m_mutex);
 141             if (!m_bActionLocked && m_xActionLock.is())
 142             {
 143                 m_xActionLock->addActionLock();
 144                 m_bActionLocked = m_xActionLock->isActionLocked();
 145             }
 146         }
 147
 148         /** @short  unlock the internal wrapped resource, if its not already done. */
 149         void unlock()
 150         {
 151             osl::MutexGuard g(m_mutex);
 152             if (m_bActionLocked && m_xActionLock.is())
 153             {
 154                 m_xActionLock->removeActionLock();
 155                 // dont check for any locks here ...
 156                 // May another guard use the same lock object :-(
 157                 m_bActionLocked = false;
 158             }
 159         }
 160 };
 161
 162 } // namespace framework
 163
 164 #endif // INCLUDED_FRAMEWORK_SOURCE_INC_LOADENV_ACTIONLOCKGUARD_HXX
 165
 166 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */