2 * Copyright 2001-2006 Internet2
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4 * Licensed under the Apache License, Version 2.0 (the "License");
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5 * you may not use this file except in compliance with the License.
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6 * You may obtain a copy of the License at
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8 * http://www.apache.org/licenses/LICENSE-2.0
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10 * Unless required by applicable law or agreed to in writing, software
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11 * distributed under the License is distributed on an "AS IS" BASIS,
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12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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13 * See the License for the specific language governing permissions and
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14 * limitations under the License.
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20 * Locking abstraction
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23 #ifndef __xmltooling_lockable_h__
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24 #define __xmltooling_lockable_h__
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26 #include <xmltooling/base.h>
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28 namespace xmltooling {
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31 * Abstract mixin interface for interfaces that support locking
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33 struct XMLTOOL_API Lockable
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35 virtual ~Lockable() {}
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38 * Lock the associated object for exclusive access.
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40 * @return a pointer to the object being locked
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42 virtual Lockable* lock()=0;
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45 * Unlock the associated object from exclusive access.
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47 virtual void unlock()=0;
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51 * RAII wrapper for lockable objects to ensure lock release
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53 class XMLTOOL_API Locker
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55 MAKE_NONCOPYABLE(Locker);
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58 * Optionally locks an object and stores it for later release.
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60 * @param lockee pointer to an object to hold, and optionally lock
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61 * @param lock true iff object is not yet locked
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63 Locker(Lockable* lockee=NULL, bool lock=true) {
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65 m_lockee=lockee->lock();
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71 * Optionally locks an object and stores it for later release.
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72 * If an object is already held, it is unlocked and detached.
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74 * @param lockee pointer to an object to hold, and optionally lock
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75 * @param lock true iff object is not yet locked
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77 void assign(Lockable* lockee=NULL, bool lock=true) {
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82 m_lockee=lockee->lock();
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88 * Destructor releases lock on held pointer, if any.
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101 #endif /* __xmltooling_lockable_h__ */
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