63 lines
1.6 KiB
C++
63 lines
1.6 KiB
C++
/*
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* Copyright (c) 2012 Jonas 'Sortie' Termansen.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*
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* refcount.cpp
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* A class that implements reference counting.
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*/
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#include <assert.h>
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#include <sortix/kernel/kernel.h>
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#include <sortix/kernel/kthread.h>
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#include <sortix/kernel/refcount.h>
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namespace Sortix {
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Refcountable::Refcountable()
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{
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reflock = KTHREAD_MUTEX_INITIALIZER;
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refcount = 0;
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being_deleted = false;
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}
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Refcountable::~Refcountable()
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{
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// It's OK to be deleted if our refcount is 1, it won't mess with any
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// other owners that might need us.
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assert(refcount <= 1);
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}
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void Refcountable::Refer_Renamed()
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{
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ScopedLock lock(&reflock);
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refcount++;
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}
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void Refcountable::Unref_Renamed()
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{
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assert(!being_deleted);
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kthread_mutex_lock(&reflock);
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assert(refcount);
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bool deleteme = !refcount || !--refcount;
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kthread_mutex_unlock(&reflock);
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if ( deleteme )
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{
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being_deleted = true;
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delete this;
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}
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}
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} // namespace Sortix
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