OpenWalnut
1.2.5
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00001 //--------------------------------------------------------------------------- 00002 // 00003 // Project: OpenWalnut ( http://www.openwalnut.org ) 00004 // 00005 // Copyright 2009 OpenWalnut Community, BSV@Uni-Leipzig and CNCF@MPI-CBS 00006 // For more information see http://www.openwalnut.org/copying 00007 // 00008 // This file is part of OpenWalnut. 00009 // 00010 // OpenWalnut is free software: you can redistribute it and/or modify 00011 // it under the terms of the GNU Lesser General Public License as published by 00012 // the Free Software Foundation, either version 3 of the License, or 00013 // (at your option) any later version. 00014 // 00015 // OpenWalnut is distributed in the hope that it will be useful, 00016 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00017 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00018 // GNU Lesser General Public License for more details. 00019 // 00020 // You should have received a copy of the GNU Lesser General Public License 00021 // along with OpenWalnut. If not, see <http://www.gnu.org/licenses/>. 00022 // 00023 //--------------------------------------------------------------------------- 00024 00025 #ifndef WCONDITIONSET_H 00026 #define WCONDITIONSET_H 00027 00028 #include <map> 00029 #include <utility> 00030 00031 #include <boost/shared_ptr.hpp> 00032 #include <boost/thread.hpp> 00033 00034 #include "WCondition.h" 00035 #include "WExportCommon.h" 00036 00037 /** 00038 * Class allowing multiple conditions to be used for one waiting cycle. Since wait() can not be used for waiting on multiple 00039 * conditions, this class can encapsulate multiple conditions and offer a wait() command to wait for one of them to change its 00040 * state. Please not that this class can also be used as condition. 00041 */ 00042 class OWCOMMON_EXPORT WConditionSet: public WCondition 00043 { 00044 friend class WConditionSetTest; 00045 public: 00046 00047 /** 00048 * Default constructor. 00049 */ 00050 WConditionSet(); 00051 00052 /** 00053 * Destructor. 00054 */ 00055 virtual ~WConditionSet(); 00056 00057 /** 00058 * Adds another condition to the set of conditions to wait for. Note that, whenever someone is waiting for this WConditionSet, 00059 * the newly added one is also directly included into the wait() call. 00060 * 00061 * \param condition the condition to add. 00062 */ 00063 virtual void add( boost::shared_ptr< WCondition > condition ); 00064 00065 /** 00066 * Removes the specified condition. As add() this immediately takes effect on running wait() calls. 00067 * 00068 * \param condition the condition to remove 00069 */ 00070 virtual void remove( boost::shared_ptr< WCondition > condition ); 00071 00072 /** 00073 * Wait for the condition. Sets the calling thread asleep. If the condition set is resetable, this will return immediately 00074 * when a condition in the set fired in the past and there has been no reset() call until now. 00075 */ 00076 virtual void wait() const; 00077 00078 /** 00079 * Resets the internal fire state. This does nothing if !isResetable(). 00080 */ 00081 virtual void reset() const; 00082 00083 /** 00084 * Sets the resetable flag. This causes the condition set to act like a WConditionOneShot. There are several implications to 00085 * this you should consider when using the condition set as a resetable. If one condition in the condition set fires, a 00086 * subsequent call to wait() will immediately return until a reset() call has been done. If you share one condition set among 00087 * several threads, you should consider, that one thread can reset the condition set before the other thread had a chance to 00088 * call wait() which causes the other thread to wait until the next condition in the set fires. 00089 * 00090 * \param resetable true if the fire state should be delayed and can be reseted. 00091 * \param autoReset true if the state should be reset whenever a wait call is called and continues.This is especially useful if a 00092 * condition set is used only by one thread, so there is no need to call reset() explicitly. 00093 */ 00094 void setResetable( bool resetable = true, bool autoReset = true ); 00095 00096 /** 00097 * Returns whether the condition set acts like a one shot condition. 00098 * 00099 * \return true if the fire state is delayed and can be reseted. 00100 */ 00101 bool isResetable(); 00102 00103 protected: 00104 00105 /** 00106 * Flag denoting whether the condition set should act like a one shot condition. 00107 */ 00108 bool m_resetable; 00109 00110 /** 00111 * Flag which shows whether the wait() call should reset the state m_fired when it returns. 00112 */ 00113 bool m_autoReset; 00114 00115 /** 00116 * We need to keep track of the connections a condition has made since boost::function objects do not provide a == operator and can therefore 00117 * not easily be removed from a signals by signal.desconnect( functor ). 00118 */ 00119 typedef std::map< boost::shared_ptr< WCondition >, boost::signals2::connection > ConditionConnectionMap; 00120 00121 /** 00122 * Set of conditions to be waited for. 00123 */ 00124 ConditionConnectionMap m_conditionSet; 00125 00126 /** 00127 * Each condition has a connection. 00128 */ 00129 typedef std::pair< boost::shared_ptr< WCondition >, boost::signals2::connection > ConditionConnectionPair; 00130 00131 /** 00132 * Lock used for thread-safe writing to the condition set. 00133 */ 00134 boost::shared_mutex m_conditionSetLock; 00135 00136 /** 00137 * Notifier function getting notified whenever a condition got fired. 00138 */ 00139 virtual void conditionFired(); 00140 00141 /** 00142 * Flag denoting whether one condition fired in the past. Just useful when m_resetable is true. 00143 */ 00144 mutable bool m_fired; 00145 00146 /** 00147 * The notifier which gets called by all conditions if they fire 00148 */ 00149 WCondition::t_ConditionNotifierType m_notifier; 00150 00151 private: 00152 }; 00153 00154 #endif // WCONDITIONSET_H 00155