serenity/Kernel/Devices/TTY/SlavePTY.cpp
Liav A. 16244c490a Kernel: Allocate all device major numbers within one known header file
We used to allocate major numbers quite randomly, with no common place
to look them up if needed.
This commit is changing that by placing all major number allocations
under a new C++ namespace, in the API/MajorNumberAllocation.h file.

We also add the foundations of what is needed before we can publish this
information (allocated numbers for block and char devices) to userspace.
2024-07-06 21:42:32 +02:00

115 lines
2.9 KiB
C++

/*
* Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/Singleton.h>
#include <Kernel/API/MajorNumberAllocation.h>
#include <Kernel/Debug.h>
#include <Kernel/Devices/TTY/MasterPTY.h>
#include <Kernel/Devices/TTY/SlavePTY.h>
#include <Kernel/Tasks/Process.h>
namespace Kernel {
static Singleton<SpinlockProtected<SlavePTY::List, LockRank::None>> s_all_instances;
SpinlockProtected<SlavePTY::List, LockRank::None>& SlavePTY::all_instances()
{
return s_all_instances;
}
bool SlavePTY::unref() const
{
bool did_hit_zero = SlavePTY::all_instances().with([&](auto&) {
if (deref_base())
return false;
m_list_node.remove();
const_cast<SlavePTY&>(*this).revoke_weak_ptrs();
return true;
});
if (did_hit_zero) {
const_cast<SlavePTY&>(*this).will_be_destroyed();
delete this;
}
return did_hit_zero;
}
SlavePTY::SlavePTY(NonnullRefPtr<MasterPTY> master, UserID uid, GroupID gid, unsigned index)
: TTY(MajorAllocation::CharacterDeviceFamily::SlavePTY, index)
, m_master(move(master))
, m_index(index)
, m_uid(uid)
, m_gid(gid)
{
set_size(80, 25);
SlavePTY::all_instances().with([&](auto& list) { list.append(*this); });
}
SlavePTY::~SlavePTY()
{
dbgln_if(SLAVEPTY_DEBUG, "~SlavePTY({})", m_index);
}
ErrorOr<NonnullOwnPtr<KString>> SlavePTY::pseudo_name() const
{
return KString::formatted("pts:{}", m_index);
}
void SlavePTY::echo(u8 ch)
{
if (should_echo_input()) {
auto buffer = UserOrKernelBuffer::for_kernel_buffer(&ch);
[[maybe_unused]] auto result = m_master->on_slave_write(buffer, 1);
}
}
void SlavePTY::on_master_write(UserOrKernelBuffer const& buffer, size_t size)
{
auto result = buffer.read_buffered<128>(size, [&](ReadonlyBytes data) {
for (auto const& byte : data)
emit(byte, false);
return data.size();
});
if (!result.is_error())
evaluate_block_conditions();
}
ErrorOr<size_t> SlavePTY::on_tty_write(UserOrKernelBuffer const& data, size_t size)
{
m_time_of_last_write = kgettimeofday();
return m_master->on_slave_write(data, size);
}
bool SlavePTY::can_write(OpenFileDescription const&, u64) const
{
return m_master->can_write_from_slave();
}
bool SlavePTY::can_read(OpenFileDescription const& description, u64 offset) const
{
if (m_master->is_closed())
return true;
return TTY::can_read(description, offset);
}
ErrorOr<size_t> SlavePTY::read(OpenFileDescription& description, u64 offset, UserOrKernelBuffer& buffer, size_t size)
{
if (m_master->is_closed())
return 0;
return TTY::read(description, offset, buffer, size);
}
ErrorOr<void> SlavePTY::close()
{
m_master->notify_slave_closed({});
return {};
}
FileBlockerSet& SlavePTY::blocker_set()
{
return m_master->blocker_set();
}
}