[5693] | 1 | /* |
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| 2 | * ORXONOX - the hottest 3D action shooter ever to exist |
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| 3 | * > www.orxonox.net < |
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| 4 | * |
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| 5 | * |
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| 6 | * License notice: |
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| 7 | * |
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| 8 | * This program is free software; you can redistribute it and/or |
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| 9 | * modify it under the terms of the GNU General Public License |
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| 10 | * as published by the Free Software Foundation; either version 2 |
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| 11 | * of the License, or (at your option) any later version. |
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| 12 | * |
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| 13 | * This program is distributed in the hope that it will be useful, |
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| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 16 | * GNU General Public License for more details. |
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| 17 | * |
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| 18 | * You should have received a copy of the GNU General Public License |
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| 19 | * along with this program; if not, write to the Free Software |
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| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. |
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| 21 | * |
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| 22 | * Author: |
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| 23 | * Fabian 'x3n' Landau |
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| 24 | * Co-authors: |
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| 25 | * ... |
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| 26 | * |
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| 27 | */ |
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| 28 | |
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| 29 | #ifndef _TclThreadList_H__ |
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| 30 | #define _TclThreadList_H__ |
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| 31 | |
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| 32 | #include "CorePrereqs.h" |
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| 33 | |
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| 34 | #include <list> |
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| 35 | |
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| 36 | #include <boost/thread/condition_variable.hpp> |
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| 37 | #include <boost/thread/shared_mutex.hpp> |
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| 38 | #include <boost/thread/locks.hpp> |
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| 39 | |
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| 40 | namespace orxonox |
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| 41 | { |
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| 42 | template <class T> |
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| 43 | class TclThreadList |
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| 44 | { |
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| 45 | public: |
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| 46 | void push_front(const T& value); |
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| 47 | void push_back(const T& value); |
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| 48 | template <class InputIterator> void insert(typename std::list<T>::iterator position, InputIterator begin, InputIterator end); |
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| 49 | |
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| 50 | void wait_and_pop_front(T* value); |
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| 51 | void wait_and_pop_back(T* value); |
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| 52 | bool try_pop_front(T* value); |
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| 53 | bool try_pop_back(T* value); |
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| 54 | void clear(); |
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| 55 | |
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| 56 | size_t size() const; |
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| 57 | bool empty() const; |
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| 58 | bool is_in(const T& value) const; |
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| 59 | |
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| 60 | /** |
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| 61 | @brief Returns a reference to the list. Don't forget to lock the mutex (see @ref getMutex). |
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| 62 | */ |
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| 63 | inline std::list<T>& getList() |
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| 64 | { return this->list_; } |
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| 65 | |
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| 66 | /** |
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| 67 | @brief Returns a reference to the list. Don't forget to lock the mutex (see @ref getMutex). |
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| 68 | */ |
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| 69 | inline const std::list<T>& getList() const |
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| 70 | { return this->list_; } |
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| 71 | |
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| 72 | /** |
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| 73 | @brief Returns a reference to the mutex which might be useful if you want to iterate through the list (see @ref begin and @ref end). |
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| 74 | */ |
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| 75 | inline boost::shared_mutex& getMutex() const |
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| 76 | { return this->mutex_; } |
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| 77 | |
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| 78 | private: |
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| 79 | std::list<T> list_; ///< A standard list for type T |
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| 80 | mutable boost::shared_mutex mutex_; ///< A mutex to grant exclusive access to the list |
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| 81 | boost::condition_variable_any condition_; ///< A condition variable to wake threads waiting for the mutex to become ready |
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| 82 | }; |
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| 83 | |
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| 84 | /** |
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| 85 | @brief Pushes a new element to the front of the list. A unique_lock is needed. |
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| 86 | */ |
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| 87 | template <class T> |
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| 88 | void TclThreadList<T>::push_front(const T& value) |
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| 89 | { |
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| 90 | boost::unique_lock<boost::shared_mutex> lock(this->mutex_); |
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| 91 | this->list_.push_front(value); |
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| 92 | lock.unlock(); // unlock the mutex... |
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| 93 | this->condition_.notify_all(); // ...then call notify_all to wake threads waiting in wait_and_pop_front/back |
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| 94 | } |
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| 95 | |
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| 96 | /** |
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| 97 | @brief Pushes a new element to the back of the list. A unique_lock is needed. |
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| 98 | */ |
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| 99 | template <class T> |
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| 100 | void TclThreadList<T>::push_back(const T& value) |
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| 101 | { |
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| 102 | boost::unique_lock<boost::shared_mutex> lock(this->mutex_); |
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| 103 | this->list_.push_back(value); |
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| 104 | lock.unlock(); // unlock the mutex... |
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| 105 | this->condition_.notify_all(); // ...then call notify_all to wake threads waiting in wait_and_pop_front/back |
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| 106 | } |
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| 107 | |
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| 108 | /** |
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| 109 | @brief Inserts new elements into the list. A unique_lock is needed. |
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| 110 | */ |
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| 111 | template <class T> |
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| 112 | template <class InputIterator> void TclThreadList<T>::insert(typename std::list<T>::iterator position, InputIterator begin, InputIterator end) |
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| 113 | { |
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| 114 | boost::unique_lock<boost::shared_mutex> lock(this->mutex_); |
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| 115 | this->list_.insert(position, begin, end); |
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| 116 | lock.unlock(); // unlock the mutex... |
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| 117 | this->condition_.notify_all(); // ...then call notify_all to wake threads waiting in wait_and_pop_front/back |
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| 118 | } |
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| 119 | |
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| 120 | /** |
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| 121 | @brief Waits until the list contains at least one element and then pops and returns the front element. |
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| 122 | @param value The front value will be stored in the variable referenced by this pointer. |
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| 123 | */ |
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| 124 | template <class T> |
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| 125 | void TclThreadList<T>::wait_and_pop_front(T* value) |
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| 126 | { |
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| 127 | boost::unique_lock<boost::shared_mutex> lock(this->mutex_); |
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| 128 | |
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| 129 | while (this->list_.empty()) // check if there's an element in the list |
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| 130 | this->condition_.wait(lock); // wait until the condition becomes true (a notification comes from push_front, push_back or insert |
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| 131 | |
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| 132 | *value = this->list_.front(); |
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| 133 | this->list_.pop_front(); |
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| 134 | } |
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| 135 | |
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| 136 | /** |
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| 137 | @brief Waits until the list contains at least one element and then pops and returns the back element. |
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| 138 | @param value The back value will be stored in the variable referenced by this pointer. |
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| 139 | */ |
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| 140 | template <class T> |
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| 141 | void TclThreadList<T>::wait_and_pop_back(T* value) |
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| 142 | { |
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| 143 | boost::unique_lock<boost::shared_mutex> lock(this->mutex_); |
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| 144 | |
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| 145 | while (this->list_.empty()) // check if there's an element in the list |
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| 146 | this->condition_.wait(lock); // wait until the condition becomes true (a notification comes from push_front, push_back or insert |
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| 147 | |
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| 148 | *value = this->list_.back(); |
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| 149 | this->list_.pop_back(); |
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| 150 | } |
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| 151 | |
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| 152 | /** |
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| 153 | @brief Pops and returns the front element if there's at least one element in the list. |
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| 154 | @param value The front value will be stored in the variable referenced by this pointer. |
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| 155 | @return Returns true if there was at least one element in the list (which got poped). If the list was empty, false is returned immediately. |
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| 156 | |
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| 157 | Needs a unique_lock if there's an element to pop. If not, shared_lock is sufficient. |
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| 158 | */ |
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| 159 | template <class T> |
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| 160 | bool TclThreadList<T>::try_pop_front(T* value) |
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| 161 | { |
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| 162 | boost::upgrade_lock<boost::shared_mutex> lock(this->mutex_); // gain shared lock |
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| 163 | |
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| 164 | if (this->list_.empty()) |
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| 165 | { |
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| 166 | // No elements - return immediately |
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| 167 | return false; |
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| 168 | } |
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| 169 | else |
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| 170 | { |
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| 171 | // At least one element - write it into the passed variable and pop it from the list |
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| 172 | boost::upgrade_to_unique_lock<boost::shared_mutex> unique_lock(lock); // upgrade to unique lock to modify the list |
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| 173 | *value = this->list_.front(); |
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| 174 | this->list_.pop_front(); |
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| 175 | } |
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| 176 | return true; |
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| 177 | } |
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| 178 | |
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| 179 | /** |
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| 180 | @brief Pops and returns the back element if there's at least one element in the list. |
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| 181 | @param value The back value will be stored in the variable referenced by this pointer. |
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| 182 | @return Returns true if there was at least one element in the list (which got poped). If the list was empty, false is returned immediately. |
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| 183 | |
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| 184 | Needs a unique_lock if there's an element to pop. If not, shared_lock is sufficient. |
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| 185 | */ |
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| 186 | template <class T> |
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| 187 | bool TclThreadList<T>::try_pop_back(T* value) |
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| 188 | { |
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| 189 | boost::upgrade_lock<boost::shared_mutex> lock(this->mutex_); // gain shared lock |
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| 190 | |
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| 191 | if (this->list_.empty()) |
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| 192 | { |
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| 193 | // No elements - return immediately |
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| 194 | return false; |
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| 195 | } |
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| 196 | else |
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| 197 | { |
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| 198 | // At least one element - write it into the passed variable and pop it from the list |
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| 199 | boost::upgrade_to_unique_lock<boost::shared_mutex> unique_lock(lock); // upgrade to unique lock to modify the list |
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| 200 | *value = this->list_.back(); |
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| 201 | this->list_.pop_back(); |
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| 202 | } |
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| 203 | return true; |
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| 204 | } |
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| 205 | |
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| 206 | /** |
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| 207 | @brief Clears the list. A unique_lock is needed. |
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| 208 | */ |
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| 209 | template <class T> |
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| 210 | void TclThreadList<T>::clear() |
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| 211 | { |
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| 212 | boost::unique_lock<boost::shared_mutex> lock(this->mutex_); |
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| 213 | this->list_.clear(); |
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| 214 | } |
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| 215 | |
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| 216 | /** |
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| 217 | @brief Returns the size of the list. A shared_lock is needed. |
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| 218 | |
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| 219 | Warning: Don't change the list based on the result of size(). Use an atomic function instead. Other threads may change the list |
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| 220 | beween your call to size() and your further actions, so be careful and use this function only if you really want nothing else than |
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| 221 | just the size of the list. |
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| 222 | */ |
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| 223 | template <class T> |
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| 224 | size_t TclThreadList<T>::size() const |
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| 225 | { |
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| 226 | boost::shared_lock<boost::shared_mutex> lock(this->mutex_); |
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| 227 | return this->list_.size(); |
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| 228 | } |
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| 229 | |
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| 230 | /** |
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| 231 | @brief Returns true if the list is empty, false otherwise. A shared_lock is needed. |
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| 232 | |
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| 233 | Warning: Don't change the list based on the result of empty(). Use an atomic function instead. Other threads may change the list |
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| 234 | beween your call to empty() and your further actions, so be careful and use this function only if you really want nothing else than |
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| 235 | just if the list is empty or not. |
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| 236 | */ |
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| 237 | template <class T> |
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| 238 | bool TclThreadList<T>::empty() const |
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| 239 | { |
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| 240 | boost::shared_lock<boost::shared_mutex> lock(this->mutex_); |
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| 241 | return this->list_.empty(); |
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| 242 | } |
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| 243 | |
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| 244 | /** |
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| 245 | @brief Returns true if a given element is in the list, false otherwise. A shared_lock is needed. |
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| 246 | |
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| 247 | Warning: The result of this function might be wrong just one instruction after the call. Use this function just to get information |
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| 248 | about a temporary snapshot and don't change the list based on the result of this function. |
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| 249 | */ |
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| 250 | template <class T> |
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| 251 | bool TclThreadList<T>::is_in(const T& value) const |
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| 252 | { |
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| 253 | boost::shared_lock<boost::shared_mutex> lock(this->mutex_); |
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| 254 | |
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| 255 | for (typename std::list<T>::const_iterator it = this->list_.begin(); it != this->list_.end(); ++it) |
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| 256 | if (*it == value) |
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| 257 | return true; |
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| 258 | |
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| 259 | return false; |
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| 260 | } |
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| 261 | } |
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| 262 | |
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| 263 | #endif /* _TclThreadList_H__ */ |
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