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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "PTYMultiplexer.h"
#include "MasterPTY.h"
#include <AK/Singleton.h>
#include <Kernel/FileSystem/FileDescription.h>
#include <Kernel/Process.h>
#include <LibC/errno_numbers.h>
//#define PTMX_DEBUG
namespace Kernel {
static const unsigned s_max_pty_pairs = 8;
static AK::Singleton<PTYMultiplexer> s_the;
PTYMultiplexer& PTYMultiplexer::the()
{
return *s_the;
}
PTYMultiplexer::PTYMultiplexer()
: CharacterDevice(5, 2)
{
m_freelist.ensure_capacity(s_max_pty_pairs);
for (int i = s_max_pty_pairs; i > 0; --i)
m_freelist.unchecked_append(i - 1);
}
PTYMultiplexer::~PTYMultiplexer()
{
}
KResultOr<NonnullRefPtr<FileDescription>> PTYMultiplexer::open(int options)
{
LOCKER(m_lock);
if (m_freelist.is_empty())
return EBUSY;
auto master_index = m_freelist.take_last();
auto master = adopt(*new MasterPTY(master_index));
#ifdef PTMX_DEBUG
dbg() << "PTYMultiplexer::open: Vending master " << master->index();
#endif
auto description = FileDescription::create(move(master));
if (!description.is_error()) {
description.value()->set_rw_mode(options);
description.value()->set_file_flags(options);
}
return description;
}
void PTYMultiplexer::notify_master_destroyed(Badge<MasterPTY>, unsigned index)
{
LOCKER(m_lock);
m_freelist.append(index);
#ifdef PTMX_DEBUG
dbg() << "PTYMultiplexer: " << index << " added to freelist";
#endif
}
}
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