ladybird/Kernel/TTY/PTYMultiplexer.cpp
2021-07-18 01:53:04 +02:00

63 lines
1.6 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Singleton.h>
#include <Kernel/Debug.h>
#include <Kernel/FileSystem/FileDescription.h>
#include <Kernel/Sections.h>
#include <Kernel/TTY/MasterPTY.h>
#include <Kernel/TTY/PTYMultiplexer.h>
#include <LibC/errno_numbers.h>
namespace Kernel {
static AK::Singleton<PTYMultiplexer> s_the;
PTYMultiplexer& PTYMultiplexer::the()
{
return *s_the;
}
UNMAP_AFTER_INIT PTYMultiplexer::PTYMultiplexer()
: CharacterDevice(5, 2)
{
constexpr unsigned max_pty_pairs = 8;
m_freelist.ensure_capacity(max_pty_pairs);
for (int i = max_pty_pairs; i > 0; --i)
m_freelist.unchecked_append(i - 1);
}
UNMAP_AFTER_INIT PTYMultiplexer::~PTYMultiplexer()
{
}
KResultOr<NonnullRefPtr<FileDescription>> PTYMultiplexer::open(int options)
{
MutexLocker locker(m_lock);
if (m_freelist.is_empty())
return EBUSY;
auto master_index = m_freelist.take_last();
auto master = try_create<MasterPTY>(master_index);
if (!master)
return ENOMEM;
dbgln_if(PTMX_DEBUG, "PTYMultiplexer::open: Vending master {}", master->index());
auto description = FileDescription::create(*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)
{
MutexLocker locker(m_lock);
m_freelist.append(index);
dbgln_if(PTMX_DEBUG, "PTYMultiplexer: {} added to freelist", index);
}
}