64 lines
1016 B
C++
64 lines
1016 B
C++
/*
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* \brief Kernel lock
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* \author Martin Stein
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* \author Stefan Kalkowski
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* \date 2012-11-30
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*/
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/*
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* Copyright (C) 2012-2015 Genode Labs GmbH
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*
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* This file is part of the Genode OS framework, which is distributed
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* under the terms of the GNU General Public License version 2.
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*/
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#ifndef _KERNEL__LOCK_H_
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#define _KERNEL__LOCK_H_
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/* Genode includes */
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#include <base/lock_guard.h>
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#include <cpu/atomic.h>
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#include <cpu/memory_barrier.h>
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namespace Kernel
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{
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/**
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* Lock that enables synchronization inside the kernel
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*/
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class Lock;
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Lock & data_lock();
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}
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class Kernel::Lock
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{
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private:
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int volatile _locked;
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public:
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Lock() : _locked(0) { }
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/**
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* Request the lock
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*/
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void lock() { while (!Genode::cmpxchg(&_locked, 0, 1)); }
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/**
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* Free the lock
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*/
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void unlock()
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{
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Genode::memory_barrier();
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_locked = 0;
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}
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/**
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* Provide guard semantic for this type of lock
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*/
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typedef Genode::Lock_guard<Kernel::Lock> Guard;
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};
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#endif /* _KERNEL__LOCK_H_ */
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