98 lines
3.0 KiB
C++
98 lines
3.0 KiB
C++
/*! \file pispinlock.h
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* \ingroup Thread
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* \~\brief
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* \~english Fast and full-load lock
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* \~russian Быстрая блокировка с полной нагрузкой
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*/
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/*
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PIP - Platform Independent Primitives
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PISpinlock
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Ivan Pelipenko peri4ko@yandex.ru
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef PISPINLOCK_H
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#define PISPINLOCK_H
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#include "piinit.h"
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#include <atomic>
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class PIP_EXPORT PISpinlock {
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public:
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NO_COPY_CLASS(PISpinlock);
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//! \~english Constructs unlocked spinlock
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//! \~russian Создает незаблокированный спинлок
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explicit PISpinlock() { flag.clear(); }
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//! \~english Destroy spinlock
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//! \~russian Деструктор спинлока
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~PISpinlock() {}
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//! \~english Lock spinlock
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//! \~russian Блокирует спинлок
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//! \~\details
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//! \~english
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//! If spinlock is unlocked it set to locked state and returns immediate.
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//! If spinlock is already locked function blocks until spinlock will be unlocked
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//! \~russian
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//! Если спинлок свободен, то блокирует его и возвращает управление немедленно.
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//! Если спинлок заблокирован, то ожидает разблокировки, затем блокирует и возвращает управление
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void lock() {
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while (flag.test_and_set(std::memory_order_acquire))
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;
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}
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//! \~english Unlock spinlock
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//! \~russian Разблокирует спинлок
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//! \~\details
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//! \~english
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//! In any case this function returns immediate
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//! \~russian
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//! В любом случае возвращает управление немедленно
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void unlock() { flag.clear(std::memory_order_release); }
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private:
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std::atomic_flag flag;
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};
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class PIP_EXPORT PISpinlockLocker {
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public:
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NO_COPY_CLASS(PISpinlockLocker);
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//! \~english Constructs and lock "s" if "condition" is \c true
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//! \~russianСоздает и блокирует спинлок "m" если "condition" \c true
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PISpinlockLocker(PISpinlock & s, bool condition = true): spinlock(s), cond(condition) {
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if (cond) spinlock.lock();
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}
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//! \~english Unlock "s" if "condition" was \c true
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//! \~russian Разблокирует спинлок "m" если "condition" был \c true
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~PISpinlockLocker() {
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if (cond) spinlock.unlock();
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}
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private:
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PISpinlock & spinlock;
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bool cond;
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};
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#endif // PISPINLOCK_H
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